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LU-13783 osd-ldiskfs: use alloc_file_pseudo to create fake files
[fs/lustre-release.git] / lustre / osd-ldiskfs / osd_io.c
index 56e5231..1db5db3 100644 (file)
  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2012, 2016, Intel Corporation.
+ * Copyright (c) 2012, 2017, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
- * Lustre is a trademark of Sun Microsystems, Inc.
  *
  * lustre/osd/osd_io.c
  *
  *
  */
 
-/* LUSTRE_VERSION_CODE */
-#include <lustre_ver.h>
+#define DEBUG_SUBSYSTEM        S_OSD
+
 /* prerequisite for linux/xattr.h */
 #include <linux/types.h>
 /* prerequisite for linux/xattr.h */
 #include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/pagevec.h>
 
 /*
  * struct OBD_{ALLOC,FREE}*()
 
 /* ext_depth() */
 #include <ldiskfs/ldiskfs_extents.h>
+#include <ldiskfs/ldiskfs.h>
+
+static inline bool osd_use_page_cache(struct osd_device *d)
+{
+       /* do not use pagecache if write and read caching are disabled */
+       if (d->od_writethrough_cache + d->od_read_cache == 0)
+               return false;
+       /* use pagecache by default */
+       return true;
+}
 
 static int __osd_init_iobuf(struct osd_device *d, struct osd_iobuf *iobuf,
                            int rw, int line, int pages)
@@ -73,7 +85,7 @@ static int __osd_init_iobuf(struct osd_device *d, struct osd_iobuf *iobuf,
        iobuf->dr_error = 0;
        iobuf->dr_dev = d;
        iobuf->dr_frags = 0;
-       iobuf->dr_elapsed = 0;
+       iobuf->dr_elapsed = ktime_set(0, 0);
        /* must be counted before, so assert */
        iobuf->dr_rw = rw;
        iobuf->dr_init_at = line;
@@ -91,12 +103,12 @@ static int __osd_init_iobuf(struct osd_device *d, struct osd_iobuf *iobuf,
                i <<= 1;
 
        CDEBUG(D_OTHER, "realloc %u for %u (%u) pages\n",
-              (unsigned)(pages * sizeof(iobuf->dr_pages[0])), i, pages);
+              (unsigned int)(pages * sizeof(iobuf->dr_pages[0])), i, pages);
        pages = i;
        blocks = pages * (PAGE_SIZE >> osd_sb(d)->s_blocksize_bits);
        iobuf->dr_max_pages = 0;
        CDEBUG(D_OTHER, "realloc %u for %u blocks\n",
-              (unsigned)(blocks * sizeof(iobuf->dr_blocks[0])), blocks);
+              (unsigned int)(blocks * sizeof(iobuf->dr_blocks[0])), blocks);
 
        lu_buf_realloc(&iobuf->dr_bl_buf, blocks * sizeof(iobuf->dr_blocks[0]));
        iobuf->dr_blocks = iobuf->dr_bl_buf.lb_buf;
@@ -108,6 +120,12 @@ static int __osd_init_iobuf(struct osd_device *d, struct osd_iobuf *iobuf,
        if (unlikely(iobuf->dr_pages == NULL))
                return -ENOMEM;
 
+       lu_buf_realloc(&iobuf->dr_lnb_buf,
+                      pages * sizeof(iobuf->dr_lnbs[0]));
+       iobuf->dr_lnbs = iobuf->dr_lnb_buf.lb_buf;
+       if (unlikely(iobuf->dr_lnbs == NULL))
+               return -ENOMEM;
+
        iobuf->dr_max_pages = pages;
 
        return 0;
@@ -115,74 +133,62 @@ static int __osd_init_iobuf(struct osd_device *d, struct osd_iobuf *iobuf,
 #define osd_init_iobuf(dev, iobuf, rw, pages) \
        __osd_init_iobuf(dev, iobuf, rw, __LINE__, pages)
 
-static void osd_iobuf_add_page(struct osd_iobuf *iobuf, struct page *page)
+static void osd_iobuf_add_page(struct osd_iobuf *iobuf,
+                              struct niobuf_local *lnb)
 {
-        LASSERT(iobuf->dr_npages < iobuf->dr_max_pages);
-        iobuf->dr_pages[iobuf->dr_npages++] = page;
+       LASSERT(iobuf->dr_npages < iobuf->dr_max_pages);
+       iobuf->dr_pages[iobuf->dr_npages] = lnb->lnb_page;
+       iobuf->dr_lnbs[iobuf->dr_npages] = lnb;
+       iobuf->dr_npages++;
 }
 
 void osd_fini_iobuf(struct osd_device *d, struct osd_iobuf *iobuf)
 {
-        int rw = iobuf->dr_rw;
-
-        if (iobuf->dr_elapsed_valid) {
-                iobuf->dr_elapsed_valid = 0;
-                LASSERT(iobuf->dr_dev == d);
-                LASSERT(iobuf->dr_frags > 0);
-                lprocfs_oh_tally(&d->od_brw_stats.
-                                 hist[BRW_R_DIO_FRAGS+rw],
-                                 iobuf->dr_frags);
-                lprocfs_oh_tally_log2(&d->od_brw_stats.hist[BRW_R_IO_TIME+rw],
-                                      iobuf->dr_elapsed);
-        }
+       int rw = iobuf->dr_rw;
+
+       if (iobuf->dr_elapsed_valid) {
+               iobuf->dr_elapsed_valid = 0;
+               LASSERT(iobuf->dr_dev == d);
+               LASSERT(iobuf->dr_frags > 0);
+               lprocfs_oh_tally(&d->od_brw_stats.bs_hist[BRW_R_DIO_FRAGS + rw],
+                                iobuf->dr_frags);
+               lprocfs_oh_tally_log2(&d->od_brw_stats.bs_hist[BRW_R_IO_TIME+rw],
+                                     ktime_to_ms(iobuf->dr_elapsed));
+       }
 }
 
-#ifndef REQ_WRITE /* pre-2.6.35 */
-#define __REQ_WRITE BIO_RW
-#endif
-
 #ifdef HAVE_BIO_ENDIO_USES_ONE_ARG
 static void dio_complete_routine(struct bio *bio)
 {
-       int error = bio->bi_error;
+       int error = blk_status_to_errno(bio->bi_status);
 #else
 static void dio_complete_routine(struct bio *bio, int error)
 {
 #endif
        struct osd_iobuf *iobuf = bio->bi_private;
-       int iter;
        struct bio_vec *bvl;
 
-        /* CAVEAT EMPTOR: possibly in IRQ context
-         * DO NOT record procfs stats here!!! */
+       /* CAVEAT EMPTOR: possibly in IRQ context
+        * DO NOT record procfs stats here!!!
+        */
 
        if (unlikely(iobuf == NULL)) {
-               CERROR("***** bio->bi_private is NULL!  This should never "
-                      "happen.  Normally, I would crash here, but instead I "
-                      "will dump the bio contents to the console.  Please "
-                      "report this to <https://jira.hpdd.intel.com/> , along "
-                      "with any interesting messages leading up to this point "
-                      "(like SCSI errors, perhaps).  Because bi_private is "
-                      "NULL, I can't wake up the thread that initiated this "
-                      "IO - you will probably have to reboot this node.\n");
-               CERROR("bi_next: %p, bi_flags: %lx, bi_rw: %lu, bi_vcnt: %d, "
-                      "bi_idx: %d, bi->size: %d, bi_end_io: %p, bi_cnt: %d, "
-                      "bi_private: %p\n", bio->bi_next,
-                       (unsigned long)bio->bi_flags,
-                       bio->bi_rw, bio->bi_vcnt, bio_idx(bio),
-                       bio_sectors(bio) << 9, bio->bi_end_io,
-#ifdef HAVE_BI_CNT
-                       atomic_read(&bio->bi_cnt),
-#else
-                       atomic_read(&bio->__bi_cnt),
-#endif
-                       bio->bi_private);
+               CERROR("***** bio->bi_private is NULL! Dump the bio contents to the console. Please report this to <https://jira.whamcloud.com/>, and probably have to reboot this node.\n");
+               CERROR("bi_next: %p, bi_flags: %lx, " __stringify(bi_opf)
+                      ": %x, bi_vcnt: %d, bi_idx: %d, bi->size: %d, bi_end_io: %p, bi_cnt: %d, bi_private: %p\n",
+                      bio->bi_next, (unsigned long)bio->bi_flags,
+                      (unsigned int)bio->bi_opf, bio->bi_vcnt, bio_idx(bio),
+                      bio_sectors(bio) << 9, bio->bi_end_io,
+                      atomic_read(&bio->__bi_cnt),
+                      bio->bi_private);
                return;
        }
 
        /* the check is outside of the cycle for performance reason -bzzz */
-       if (!test_bit(__REQ_WRITE, &bio->bi_rw)) {
-               bio_for_each_segment_all(bvl, bio, iter) {
+       if (!bio_data_dir(bio)) {
+               DECLARE_BVEC_ITER_ALL(iter_all);
+
+               bio_for_each_segment_all(bvl, bio, iter_all) {
                        if (likely(error == 0))
                                SetPageUptodate(bvl_to_page(bvl));
                        LASSERT(PageLocked(bvl_to_page(bvl)));
@@ -204,7 +210,9 @@ static void dio_complete_routine(struct bio *bio, int error)
         * call to OSD.
         */
        if (atomic_read(&iobuf->dr_numreqs) == 1) {
-               iobuf->dr_elapsed = jiffies - iobuf->dr_start_time;
+               ktime_t now = ktime_get();
+
+               iobuf->dr_elapsed = ktime_sub(now, iobuf->dr_start_time);
                iobuf->dr_elapsed_valid = 1;
        }
        if (atomic_dec_and_test(&iobuf->dr_numreqs))
@@ -214,14 +222,15 @@ static void dio_complete_routine(struct bio *bio, int error)
         * filter_clear_dreq().  It was then possible to exhaust the biovec-256
         * mempool when serious on-disk fragmentation was encountered,
         * deadlocking the OST.  The bios are now released as soon as complete
-        * so the pool cannot be exhausted while IOs are competing. bug 10076 */
+        * so the pool cannot be exhausted while IOs are competing. b=10076
+        */
        bio_put(bio);
 }
 
 static void record_start_io(struct osd_iobuf *iobuf, int size)
 {
-       struct osd_device    *osd = iobuf->dr_dev;
-       struct obd_histogram *h = osd->od_brw_stats.hist;
+       struct osd_device *osd = iobuf->dr_dev;
+       struct obd_histogram *h = osd->od_brw_stats.bs_hist;
 
        iobuf->dr_frags++;
        atomic_inc(&iobuf->dr_numreqs);
@@ -243,11 +252,13 @@ static void record_start_io(struct osd_iobuf *iobuf, int size)
 
 static void osd_submit_bio(int rw, struct bio *bio)
 {
-        LASSERTF(rw == 0 || rw == 1, "%x\n", rw);
-        if (rw == 0)
-                submit_bio(READ, bio);
-        else
-                submit_bio(WRITE, bio);
+       LASSERTF(rw == 0 || rw == 1, "%x\n", rw);
+#ifdef HAVE_SUBMIT_BIO_2ARGS
+       submit_bio(rw ? WRITE : READ, bio);
+#else
+       bio->bi_opf |= rw;
+       submit_bio(bio);
+#endif
 }
 
 static int can_be_merged(struct bio *bio, sector_t sector)
@@ -258,106 +269,350 @@ static int can_be_merged(struct bio *bio, sector_t sector)
        return bio_end_sector(bio) == sector ? 1 : 0;
 }
 
+#if IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY)
+/*
+ * This function will change the data written, thus it should only be
+ * used when checking data integrity feature
+ */
+static void bio_integrity_fault_inject(struct bio *bio)
+{
+       struct bio_vec *bvec;
+       DECLARE_BVEC_ITER_ALL(iter_all);
+       void *kaddr;
+       char *addr;
+
+       bio_for_each_segment_all(bvec, bio, iter_all) {
+               struct page *page = bvec->bv_page;
+
+               kaddr = kmap(page);
+               addr = kaddr;
+               *addr = ~(*addr);
+               kunmap(page);
+               break;
+       }
+}
+
+static int bio_dif_compare(__u16 *expected_guard_buf, void *bio_prot_buf,
+                          unsigned int sectors, int tuple_size)
+{
+       __u16 *expected_guard;
+       __u16 *bio_guard;
+       int i;
+
+       expected_guard = expected_guard_buf;
+       for (i = 0; i < sectors; i++) {
+               bio_guard = (__u16 *)bio_prot_buf;
+               if (*bio_guard != *expected_guard) {
+                       CERROR(
+                              "unexpected guard tags on sector %d expected guard %u, bio guard %u, sectors %u, tuple size %d\n",
+                              i, *expected_guard, *bio_guard, sectors,
+                              tuple_size);
+                       return -EIO;
+               }
+               expected_guard++;
+               bio_prot_buf += tuple_size;
+       }
+       return 0;
+}
+
+static int osd_bio_integrity_compare(struct bio *bio, struct block_device *bdev,
+                                    struct osd_iobuf *iobuf, int index)
+{
+       struct blk_integrity *bi = bdev_get_integrity(bdev);
+       struct bio_integrity_payload *bip = bio->bi_integrity;
+       struct niobuf_local *lnb = NULL;
+       unsigned short sector_size = blk_integrity_interval(bi);
+       void *bio_prot_buf = page_address(bip->bip_vec->bv_page) +
+               bip->bip_vec->bv_offset;
+       struct bio_vec *bv;
+       sector_t sector = bio_start_sector(bio);
+       unsigned int i, sectors, total;
+       DECLARE_BVEC_ITER_ALL(iter_all);
+       __u16 *expected_guard;
+       int rc;
+
+       total = 0;
+       bio_for_each_segment_all(bv, bio, iter_all) {
+               for (i = index; i < iobuf->dr_npages; i++) {
+                       if (iobuf->dr_pages[i] == bv->bv_page) {
+                               lnb = iobuf->dr_lnbs[i];
+                               break;
+                       }
+               }
+               if (!lnb)
+                       continue;
+               expected_guard = lnb->lnb_guards;
+               sectors = bv->bv_len / sector_size;
+               if (lnb->lnb_guard_rpc) {
+                       rc = bio_dif_compare(expected_guard, bio_prot_buf,
+                                            sectors, bi->tuple_size);
+                       if (rc)
+                               return rc;
+               }
+
+               sector += sectors;
+               bio_prot_buf += sectors * bi->tuple_size;
+               total += sectors * bi->tuple_size;
+               LASSERT(total <= bip_size(bio->bi_integrity));
+               index++;
+               lnb = NULL;
+       }
+       return 0;
+}
+
+static int osd_bio_integrity_handle(struct osd_device *osd, struct bio *bio,
+                                   struct osd_iobuf *iobuf,
+                                   int start_page_idx, bool fault_inject,
+                                   bool integrity_enabled)
+{
+       struct super_block *sb = osd_sb(osd);
+       integrity_gen_fn *generate_fn = NULL;
+       integrity_vrfy_fn *verify_fn = NULL;
+       int rc;
+
+       ENTRY;
+
+       if (!integrity_enabled)
+               RETURN(0);
+
+       rc = osd_get_integrity_profile(osd, &generate_fn, &verify_fn);
+       if (rc)
+               RETURN(rc);
+
+       rc = bio_integrity_prep_fn(bio, generate_fn, verify_fn);
+       if (rc)
+               RETURN(rc);
+
+       /* Verify and inject fault only when writing */
+       if (iobuf->dr_rw == 1) {
+               if (unlikely(OBD_FAIL_CHECK(OBD_FAIL_OST_INTEGRITY_CMP))) {
+                       rc = osd_bio_integrity_compare(bio, sb->s_bdev, iobuf,
+                                                      start_page_idx);
+                       if (rc)
+                               RETURN(rc);
+               }
+
+               if (unlikely(fault_inject))
+                       bio_integrity_fault_inject(bio);
+       }
+
+       RETURN(0);
+}
+
+#ifdef HAVE_BIO_INTEGRITY_PREP_FN
+#  ifdef HAVE_BIO_ENDIO_USES_ONE_ARG
+static void dio_integrity_complete_routine(struct bio *bio)
+#  else
+static void dio_integrity_complete_routine(struct bio *bio, int error)
+#  endif
+{
+       struct osd_bio_private *bio_private = bio->bi_private;
+
+       bio->bi_private = bio_private->obp_iobuf;
+       osd_dio_complete_routine(bio, error);
+
+       OBD_FREE_PTR(bio_private);
+}
+#endif /* HAVE_BIO_INTEGRITY_PREP_FN */
+#else  /* !CONFIG_BLK_DEV_INTEGRITY */
+#define osd_bio_integrity_handle(osd, bio, iobuf, start_page_idx, \
+                                fault_inject, integrity_enabled) 0
+#endif /* CONFIG_BLK_DEV_INTEGRITY */
+
+static int osd_bio_init(struct bio *bio, struct osd_iobuf *iobuf,
+                       bool integrity_enabled, int start_page_idx,
+                       struct osd_bio_private **pprivate)
+{
+       ENTRY;
+
+       *pprivate = NULL;
+
+#ifdef HAVE_BIO_INTEGRITY_PREP_FN
+       if (integrity_enabled) {
+               struct osd_bio_private *bio_private = NULL;
+
+               OBD_ALLOC_GFP(bio_private, sizeof(*bio_private), GFP_NOIO);
+               if (bio_private == NULL)
+                       RETURN(-ENOMEM);
+               bio->bi_end_io = dio_integrity_complete_routine;
+               bio->bi_private = bio_private;
+               bio_private->obp_start_page_idx = start_page_idx;
+               bio_private->obp_iobuf = iobuf;
+               *pprivate = bio_private;
+       } else
+#endif
+       {
+               bio->bi_end_io = dio_complete_routine;
+               bio->bi_private = iobuf;
+       }
+
+       RETURN(0);
+}
+
+static void osd_mark_page_io_done(struct osd_iobuf *iobuf,
+                                 struct inode *inode,
+                                 sector_t start_blocks,
+                                 sector_t count)
+{
+       struct niobuf_local *lnb;
+       int blocks_per_page = PAGE_SIZE >> inode->i_blkbits;
+       pgoff_t pg_start, pg_end;
+
+       pg_start = start_blocks / blocks_per_page;
+       if (start_blocks % blocks_per_page)
+               pg_start++;
+       if (count >= blocks_per_page)
+               pg_end = (start_blocks + count -
+                         blocks_per_page) / blocks_per_page;
+       else
+               return; /* nothing to mark */
+       for ( ; pg_start <= pg_end; pg_start++) {
+               lnb = iobuf->dr_lnbs[pg_start];
+               lnb->lnb_flags |= OBD_BRW_DONE;
+       }
+}
+
 static int osd_do_bio(struct osd_device *osd, struct inode *inode,
-                      struct osd_iobuf *iobuf)
+                     struct osd_iobuf *iobuf, sector_t start_blocks,
+                     sector_t count)
 {
-       int            blocks_per_page = PAGE_SIZE >> inode->i_blkbits;
-       struct page  **pages = iobuf->dr_pages;
-       int            npages = iobuf->dr_npages;
-       sector_t      *blocks = iobuf->dr_blocks;
-       int            total_blocks = npages * blocks_per_page;
-       int            sector_bits = inode->i_sb->s_blocksize_bits - 9;
-       unsigned int   blocksize = inode->i_sb->s_blocksize;
-       struct bio    *bio = NULL;
-       struct page   *page;
-       unsigned int   page_offset;
-       sector_t       sector;
-       int            nblocks;
-       int            block_idx;
-       int            page_idx;
-       int            i;
-       int            rc = 0;
-       DECLARE_PLUG(plug);
+       int blocks_per_page = PAGE_SIZE >> inode->i_blkbits;
+       struct page **pages = iobuf->dr_pages;
+       int npages = iobuf->dr_npages;
+       sector_t *blocks = iobuf->dr_blocks;
+       struct super_block *sb = inode->i_sb;
+       int sector_bits = sb->s_blocksize_bits - 9;
+       unsigned int blocksize = sb->s_blocksize;
+       struct block_device *bdev = sb->s_bdev;
+       struct osd_bio_private *bio_private = NULL;
+       struct bio *bio = NULL;
+       int bio_start_page_idx;
+       struct page *page;
+       unsigned int page_offset;
+       sector_t sector;
+       int nblocks;
+       int block_idx, block_idx_end;
+       int page_idx, page_idx_start;
+       int i;
+       int rc = 0;
+       bool fault_inject;
+       bool integrity_enabled;
+       struct blk_plug plug;
+       int blocks_left_page;
+
        ENTRY;
 
-        LASSERT(iobuf->dr_npages == npages);
+       fault_inject = OBD_FAIL_CHECK(OBD_FAIL_OST_INTEGRITY_FAULT);
+       LASSERT(iobuf->dr_npages == npages);
+
+       integrity_enabled = bdev_integrity_enabled(bdev, iobuf->dr_rw);
 
-        osd_brw_stats_update(osd, iobuf);
-        iobuf->dr_start_time = cfs_time_current();
+       osd_brw_stats_update(osd, iobuf);
+       iobuf->dr_start_time = ktime_get();
+
+       if (!count)
+               count = npages * blocks_per_page;
+       block_idx_end = start_blocks + count;
 
        blk_start_plug(&plug);
-        for (page_idx = 0, block_idx = 0;
-             page_idx < npages;
-             page_idx++, block_idx += blocks_per_page) {
-
-                page = pages[page_idx];
-                LASSERT(block_idx + blocks_per_page <= total_blocks);
-
-                for (i = 0, page_offset = 0;
-                     i < blocks_per_page;
-                     i += nblocks, page_offset += blocksize * nblocks) {
-
-                        nblocks = 1;
-
-                        if (blocks[block_idx + i] == 0) {  /* hole */
-                                LASSERTF(iobuf->dr_rw == 0,
-                                         "page_idx %u, block_idx %u, i %u\n",
-                                         page_idx, block_idx, i);
-                                memset(kmap(page) + page_offset, 0, blocksize);
-                                kunmap(page);
-                                continue;
-                        }
-
-                        sector = (sector_t)blocks[block_idx + i] << sector_bits;
-
-                        /* Additional contiguous file blocks? */
-                        while (i + nblocks < blocks_per_page &&
-                               (sector + (nblocks << sector_bits)) ==
-                               ((sector_t)blocks[block_idx + i + nblocks] <<
-                                sector_bits))
-                                nblocks++;
-
-                        if (bio != NULL &&
-                            can_be_merged(bio, sector) &&
-                            bio_add_page(bio, page,
-                                         blocksize * nblocks, page_offset) != 0)
-                                continue;       /* added this frag OK */
+
+       page_idx_start = start_blocks / blocks_per_page;
+       for (page_idx = page_idx_start, block_idx = start_blocks;
+            block_idx < block_idx_end; page_idx++,
+            block_idx += blocks_left_page) {
+               /* For cases where the filesystems blocksize is not the
+                * same as PAGE_SIZE (e.g. ARM with PAGE_SIZE=64KB and
+                * blocksize=4KB), there will be multiple blocks to
+                * read/write per page. Also, the start and end block may
+                * not be aligned to the start and end of the page, so the
+                * first page may skip some blocks at the start ("i != 0",
+                * "blocks_left_page" is reduced), and the last page may
+                * skip some blocks at the end (limited by "count").
+                */
+               page = pages[page_idx];
+               LASSERT(page_idx < iobuf->dr_npages);
+
+               i = block_idx % blocks_per_page;
+               blocks_left_page = blocks_per_page - i;
+               if (block_idx + blocks_left_page > block_idx_end)
+                       blocks_left_page = block_idx_end - block_idx;
+               page_offset = i * blocksize;
+               for (i = 0; i < blocks_left_page;
+                    i += nblocks, page_offset += blocksize * nblocks) {
+                       nblocks = 1;
+
+                       if (blocks[block_idx + i] == 0) {  /* hole */
+                               LASSERTF(iobuf->dr_rw == 0,
+                                        "page_idx %u, block_idx %u, i %u,"
+                                        "start_blocks: %llu, count: %llu, npages: %d\n",
+                                        page_idx, block_idx, i,
+                                        (unsigned long long)start_blocks,
+                                        (unsigned long long)count, npages);
+                               memset(kmap(page) + page_offset, 0, blocksize);
+                               kunmap(page);
+                               continue;
+                       }
+
+                       sector = (sector_t)blocks[block_idx + i] << sector_bits;
+
+                       /* Additional contiguous file blocks? */
+                       while (i + nblocks < blocks_left_page &&
+                              (sector + (nblocks << sector_bits)) ==
+                              ((sector_t)blocks[block_idx + i + nblocks] <<
+                                sector_bits))
+                               nblocks++;
+
+                       if (bio && can_be_merged(bio, sector) &&
+                           bio_add_page(bio, page, blocksize * nblocks,
+                                        page_offset) != 0)
+                               continue;       /* added this frag OK */
 
                        if (bio != NULL) {
-                               struct request_queue *q =
-                                       bdev_get_queue(bio->bi_bdev);
+                               struct request_queue *q = bio_get_queue(bio);
                                unsigned int bi_size = bio_sectors(bio) << 9;
 
                                /* Dang! I have to fragment this I/O */
-                               CDEBUG(D_INODE, "bio++ sz %d vcnt %d(%d) "
-                                      "sectors %d(%d) psg %d(%d) hsg %d(%d)\n",
+                               CDEBUG(D_INODE,
+                                      "bio++ sz %d vcnt %d(%d) sectors %d(%d) psg %d(%d)\n",
                                       bi_size, bio->bi_vcnt, bio->bi_max_vecs,
                                       bio_sectors(bio),
                                       queue_max_sectors(q),
-                                       bio_phys_segments(q, bio),
-                                       queue_max_phys_segments(q),
-                                      0, queue_max_hw_segments(q));
+                                      osd_bio_nr_segs(bio),
+                                      queue_max_segments(q));
+                               rc = osd_bio_integrity_handle(osd, bio,
+                                       iobuf, bio_start_page_idx,
+                                       fault_inject, integrity_enabled);
+                               if (rc) {
+                                       bio_put(bio);
+                                       goto out;
+                               }
+
                                record_start_io(iobuf, bi_size);
                                osd_submit_bio(iobuf->dr_rw, bio);
                        }
 
+                       bio_start_page_idx = page_idx;
                        /* allocate new bio */
                        bio = bio_alloc(GFP_NOIO, min(BIO_MAX_PAGES,
-                                                     (npages - page_idx) *
-                                                     blocks_per_page));
-                        if (bio == NULL) {
-                                CERROR("Can't allocate bio %u*%u = %u pages\n",
-                                       (npages - page_idx), blocks_per_page,
-                                       (npages - page_idx) * blocks_per_page);
-                                rc = -ENOMEM;
-                                goto out;
-                        }
-
-                       bio->bi_bdev = inode->i_sb->s_bdev;
+                                       (block_idx_end - block_idx +
+                                        blocks_left_page - 1)));
+                       if (bio == NULL) {
+                               CERROR("Can't allocate bio %u pages\n",
+                                      block_idx_end - block_idx +
+                                      blocks_left_page - 1);
+                               rc = -ENOMEM;
+                               goto out;
+                       }
+
+                       bio_set_dev(bio, bdev);
                        bio_set_sector(bio, sector);
-                       bio->bi_rw = (iobuf->dr_rw == 0) ? READ : WRITE;
-                       bio->bi_end_io = dio_complete_routine;
-                       bio->bi_private = iobuf;
+                       bio->bi_opf = iobuf->dr_rw ? WRITE : READ;
+                       rc = osd_bio_init(bio, iobuf, integrity_enabled,
+                                         bio_start_page_idx, &bio_private);
+                       if (rc) {
+                               bio_put(bio);
+                               goto out;
+                       }
 
                        rc = bio_add_page(bio, page,
                                          blocksize * nblocks, page_offset);
@@ -366,6 +621,15 @@ static int osd_do_bio(struct osd_device *osd, struct inode *inode,
        }
 
        if (bio != NULL) {
+               rc = osd_bio_integrity_handle(osd, bio, iobuf,
+                                             bio_start_page_idx,
+                                             fault_inject,
+                                             integrity_enabled);
+               if (rc) {
+                       bio_put(bio);
+                       goto out;
+               }
+
                record_start_io(iobuf, bio_sectors(bio) << 9);
                osd_submit_bio(iobuf->dr_rw, bio);
                rc = 0;
@@ -377,31 +641,48 @@ out:
        /* in order to achieve better IO throughput, we don't wait for writes
         * completion here. instead we proceed with transaction commit in
         * parallel and wait for IO completion once transaction is stopped
-        * see osd_trans_stop() for more details -bzzz */
-       if (iobuf->dr_rw == 0) {
+        * see osd_trans_stop() for more details -bzzz
+        */
+       if (iobuf->dr_rw == 0 || fault_inject) {
                wait_event(iobuf->dr_wait,
                           atomic_read(&iobuf->dr_numreqs) == 0);
                osd_fini_iobuf(osd, iobuf);
        }
 
-       if (rc == 0)
+       if (rc == 0) {
                rc = iobuf->dr_error;
+       } else {
+               if (bio_private)
+                       OBD_FREE_PTR(bio_private);
+       }
+
+       /* Write only now */
+       if (rc == 0 && iobuf->dr_rw)
+               osd_mark_page_io_done(iobuf, inode,
+                                     start_blocks, count);
+
        RETURN(rc);
 }
 
 static int osd_map_remote_to_local(loff_t offset, ssize_t len, int *nrpages,
-                                   struct niobuf_local *lnb)
+                                  struct niobuf_local *lnb, int maxlnb)
 {
-        ENTRY;
+       int rc = 0;
+       ENTRY;
 
-        *nrpages = 0;
+       *nrpages = 0;
 
-        while (len > 0) {
+       while (len > 0) {
                int poff = offset & (PAGE_SIZE - 1);
                int plen = PAGE_SIZE - poff;
 
-                if (plen > len)
-                        plen = len;
+               if (*nrpages >= maxlnb) {
+                       rc = -EOVERFLOW;
+                       break;
+               }
+
+               if (plen > len)
+                       plen = len;
                lnb->lnb_file_offset = offset;
                lnb->lnb_page_offset = poff;
                lnb->lnb_len = plen;
@@ -409,34 +690,75 @@ static int osd_map_remote_to_local(loff_t offset, ssize_t len, int *nrpages,
                lnb->lnb_flags = 0;
                lnb->lnb_page = NULL;
                lnb->lnb_rc = 0;
+               lnb->lnb_guard_rpc = 0;
+               lnb->lnb_guard_disk = 0;
+               lnb->lnb_locked = 0;
+
+               LASSERTF(plen <= len, "plen %u, len %lld\n", plen,
+                        (long long) len);
+               offset += plen;
+               len -= plen;
+               lnb++;
+               (*nrpages)++;
+       }
 
-                LASSERTF(plen <= len, "plen %u, len %lld\n", plen,
-                         (long long) len);
-                offset += plen;
-                len -= plen;
-                lnb++;
-                (*nrpages)++;
-        }
-
-        RETURN(0);
+       RETURN(rc);
 }
 
-static struct page *osd_get_page(struct dt_object *dt, loff_t offset,
-                                gfp_t gfp_mask)
+static struct page *osd_get_page(const struct lu_env *env, struct dt_object *dt,
+                                loff_t offset, gfp_t gfp_mask, bool cache)
 {
+       struct osd_thread_info *oti = osd_oti_get(env);
        struct inode *inode = osd_dt_obj(dt)->oo_inode;
        struct osd_device *d = osd_obj2dev(osd_dt_obj(dt));
        struct page *page;
+       int cur;
+
+       LASSERT(inode);
+
+       if (cache) {
+               page = find_or_create_page(inode->i_mapping,
+                                          offset >> PAGE_SHIFT, gfp_mask);
+
+               if (likely(page)) {
+                       LASSERT(!PagePrivate2(page));
+                       wait_on_page_writeback(page);
+               } else {
+                       lprocfs_counter_add(d->od_stats, LPROC_OSD_NO_PAGE, 1);
+               }
+
+               return page;
+       }
 
-        LASSERT(inode);
+       if (inode->i_mapping->nrpages) {
+               /* consult with pagecache, but do not create new pages */
+               /* this is normally used once */
+               page = find_lock_page(inode->i_mapping, offset >> PAGE_SHIFT);
+               if (page) {
+                       wait_on_page_writeback(page);
+                       return page;
+               }
+       }
 
-       page = find_or_create_page(inode->i_mapping, offset >> PAGE_SHIFT,
-                                  gfp_mask);
+       LASSERT(oti->oti_dio_pages);
+       cur = oti->oti_dio_pages_used;
+       page = oti->oti_dio_pages[cur];
+
+       if (unlikely(!page)) {
+               LASSERT(cur < PTLRPC_MAX_BRW_PAGES);
+               page = alloc_page(gfp_mask);
+               if (!page)
+                       return NULL;
+               oti->oti_dio_pages[cur] = page;
+               SetPagePrivate2(page);
+               lock_page(page);
+       }
 
-        if (unlikely(page == NULL))
-                lprocfs_counter_add(d->od_stats, LPROC_OSD_NO_PAGE, 1);
+       ClearPageUptodate(page);
+       page->index = offset >> PAGE_SHIFT;
+       oti->oti_dio_pages_used++;
 
-        return page;
+       return page;
 }
 
 /*
@@ -473,18 +795,38 @@ static struct page *osd_get_page(struct dt_object *dt, loff_t offset,
 static int osd_bufs_put(const struct lu_env *env, struct dt_object *dt,
                        struct niobuf_local *lnb, int npages)
 {
+       struct osd_thread_info *oti = osd_oti_get(env);
+       struct pagevec pvec;
        int i;
 
+       ll_pagevec_init(&pvec, 0);
+
        for (i = 0; i < npages; i++) {
-               if (lnb[i].lnb_page == NULL)
+               struct page *page = lnb[i].lnb_page;
+
+               if (page == NULL)
                        continue;
-               LASSERT(PageLocked(lnb[i].lnb_page));
-               unlock_page(lnb[i].lnb_page);
-               put_page(lnb[i].lnb_page);
-               dt_object_put(env, dt);
+
+               /* if the page isn't cached, then reset uptodate
+                * to prevent reuse
+                */
+               if (PagePrivate2(page)) {
+                       oti->oti_dio_pages_used--;
+               } else {
+                       if (lnb[i].lnb_locked)
+                               unlock_page(page);
+                       if (pagevec_add(&pvec, page) == 0)
+                               pagevec_release(&pvec);
+               }
+
                lnb[i].lnb_page = NULL;
        }
 
+       LASSERTF(oti->oti_dio_pages_used == 0, "%d\n", oti->oti_dio_pages_used);
+
+       /* Release any partial pagevec */
+       pagevec_release(&pvec);
+
        RETURN(0);
 }
 
@@ -514,30 +856,92 @@ static int osd_bufs_put(const struct lu_env *env, struct dt_object *dt,
  */
 static int osd_bufs_get(const struct lu_env *env, struct dt_object *dt,
                        loff_t pos, ssize_t len, struct niobuf_local *lnb,
-                       enum dt_bufs_type rw)
+                       int maxlnb, enum dt_bufs_type rw)
 {
+       struct osd_thread_info *oti = osd_oti_get(env);
        struct osd_object *obj = osd_dt_obj(dt);
-       int npages, i, rc = 0;
+       struct osd_device *osd   = osd_obj2dev(obj);
+       int npages, i, iosize, rc = 0;
+       bool cache, write;
+       loff_t fsize;
        gfp_t gfp_mask;
 
        LASSERT(obj->oo_inode);
 
-       osd_map_remote_to_local(pos, len, &npages, lnb);
+       rc = osd_map_remote_to_local(pos, len, &npages, lnb, maxlnb);
+       if (rc)
+               RETURN(rc);
+
+       write = rw & DT_BUFS_TYPE_WRITE;
+
+       fsize = lnb[npages - 1].lnb_file_offset + lnb[npages - 1].lnb_len;
+       iosize = fsize - lnb[0].lnb_file_offset;
+       fsize = max(fsize, i_size_read(obj->oo_inode));
+
+       cache = rw & DT_BUFS_TYPE_READAHEAD;
+       if (cache)
+               goto bypass_checks;
+
+       cache = osd_use_page_cache(osd);
+       while (cache) {
+               if (write) {
+                       if (!osd->od_writethrough_cache) {
+                               cache = false;
+                               break;
+                       }
+                       if (iosize > osd->od_writethrough_max_iosize) {
+                               cache = false;
+                               break;
+                       }
+               } else {
+                       if (!osd->od_read_cache) {
+                               cache = false;
+                               break;
+                       }
+                       if (iosize > osd->od_readcache_max_iosize) {
+                               cache = false;
+                               break;
+                       }
+               }
+               /* don't use cache on large files */
+               if (osd->od_readcache_max_filesize &&
+                   fsize > osd->od_readcache_max_filesize)
+                       cache = false;
+               break;
+       }
+
+bypass_checks:
+       if (!cache && unlikely(!oti->oti_dio_pages)) {
+               OBD_ALLOC_PTR_ARRAY_LARGE(oti->oti_dio_pages,
+                                         PTLRPC_MAX_BRW_PAGES);
+               if (!oti->oti_dio_pages)
+                       return -ENOMEM;
+       }
 
        /* this could also try less hard for DT_BUFS_TYPE_READAHEAD pages */
        gfp_mask = rw & DT_BUFS_TYPE_LOCAL ? (GFP_NOFS | __GFP_HIGHMEM) :
                                             GFP_HIGHUSER;
        for (i = 0; i < npages; i++, lnb++) {
-               lnb->lnb_page = osd_get_page(dt, lnb->lnb_file_offset,
-                                            gfp_mask);
+               lnb->lnb_page = osd_get_page(env, dt, lnb->lnb_file_offset,
+                                            gfp_mask, cache);
                if (lnb->lnb_page == NULL)
                        GOTO(cleanup, rc = -ENOMEM);
 
-               wait_on_page_writeback(lnb->lnb_page);
-               BUG_ON(PageWriteback(lnb->lnb_page));
+               lnb->lnb_locked = 1;
+               if (cache)
+                       mark_page_accessed(lnb->lnb_page);
+       }
 
-               lu_object_get(&dt->do_lu);
+#if 0
+       /* XXX: this version doesn't invalidate cached pages, but use them */
+       if (!cache && write && obj->oo_inode->i_mapping->nrpages) {
+               /* do not allow data aliasing, invalidate pagecache */
+               /* XXX: can be quite expensive in mixed case */
+               invalidate_mapping_pages(obj->oo_inode->i_mapping,
+                               lnb[0].lnb_file_offset >> PAGE_SHIFT,
+                               lnb[npages - 1].lnb_file_offset >> PAGE_SHIFT);
        }
+#endif
 
        RETURN(i);
 
@@ -546,359 +950,148 @@ cleanup:
                osd_bufs_put(env, dt, lnb - i, i);
        return rc;
 }
+/* Borrow @ext4_chunk_trans_blocks */
+static int osd_chunk_trans_blocks(struct inode *inode, int nrblocks)
+{
+       ldiskfs_group_t groups;
+       int gdpblocks;
+       int idxblocks;
+       int depth;
+       int ret;
 
-#ifndef HAVE_LDISKFS_MAP_BLOCKS
+       depth = ext_depth(inode);
+       idxblocks = depth * 2;
 
-#ifdef HAVE_EXT_PBLOCK /* Name changed to ext4_ext_pblock for kernel 2.6.35 */
-#define ldiskfs_ext_pblock(ex) ext_pblock((ex))
-#endif
+       /*
+        * Now let's see how many group bitmaps and group descriptors need
+        * to account.
+        */
+       groups = idxblocks + 1;
+       gdpblocks = groups;
+       if (groups > LDISKFS_SB(inode->i_sb)->s_groups_count)
+               groups = LDISKFS_SB(inode->i_sb)->s_groups_count;
+       if (gdpblocks > LDISKFS_SB(inode->i_sb)->s_gdb_count)
+               gdpblocks = LDISKFS_SB(inode->i_sb)->s_gdb_count;
 
-struct bpointers {
-       sector_t *blocks;
-       unsigned long start;
-       int num;
-       int init_num;
-       int create;
-};
+       /* bitmaps and block group descriptor blocks */
+       ret = idxblocks + groups + gdpblocks;
 
-static long ldiskfs_ext_find_goal(struct inode *inode,
-                                 struct ldiskfs_ext_path *path,
-                                 unsigned long block, int *aflags)
-{
-       struct ldiskfs_inode_info *ei = LDISKFS_I(inode);
-       unsigned long bg_start;
-       unsigned long colour;
-       int depth;
+       /* Blocks for super block, inode, quota and xattr blocks */
+       ret += LDISKFS_META_TRANS_BLOCKS(inode->i_sb);
 
-       if (path) {
-               struct ldiskfs_extent *ex;
-               depth = path->p_depth;
+       return ret;
+}
 
-               /* try to predict block placement */
-               if ((ex = path[depth].p_ext))
-                       return ldiskfs_ext_pblock(ex) +
-                               (block - le32_to_cpu(ex->ee_block));
+#ifdef HAVE_LDISKFS_JOURNAL_ENSURE_CREDITS
+static int osd_extend_restart_trans(handle_t *handle, int needed,
+                                   struct inode *inode)
+{
+       int rc;
 
-               /* it looks index is empty
-                * try to find starting from index itself */
-               if (path[depth].p_bh)
-                       return path[depth].p_bh->b_blocknr;
-       }
+       rc = ldiskfs_journal_ensure_credits(handle, needed,
+               ldiskfs_trans_default_revoke_credits(inode->i_sb));
+       /* this means journal has been restarted */
+       if (rc > 0)
+               rc = 0;
 
-       /* OK. use inode's group */
-       bg_start = (ei->i_block_group * LDISKFS_BLOCKS_PER_GROUP(inode->i_sb)) +
-               le32_to_cpu(LDISKFS_SB(inode->i_sb)->s_es->s_first_data_block);
-       colour = (current->pid % 16) *
-               (LDISKFS_BLOCKS_PER_GROUP(inode->i_sb) / 16);
-       return bg_start + colour + block;
+       return rc;
 }
-
-static unsigned long new_blocks(handle_t *handle, struct inode *inode,
-                               struct ldiskfs_ext_path *path,
-                               unsigned long block, unsigned long *count,
-                               int *err)
+#else
+static int osd_extend_restart_trans(handle_t *handle, int needed,
+                                   struct inode *inode)
 {
-       struct ldiskfs_allocation_request ar;
-       unsigned long pblock;
-       int aflags;
-
-       /* find neighbour allocated blocks */
-       ar.lleft = block;
-       *err = ldiskfs_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
-       if (*err)
-               return 0;
-       ar.lright = block;
-       *err = ldiskfs_ext_search_right(inode, path, &ar.lright, &ar.pright);
-       if (*err)
+       int rc;
+
+       if (ldiskfs_handle_has_enough_credits(handle, needed))
                return 0;
+       rc = ldiskfs_journal_extend(handle,
+                               needed - handle->h_buffer_credits);
+       if (rc <= 0)
+               return rc;
 
-       /* allocate new block */
-       ar.goal = ldiskfs_ext_find_goal(inode, path, block, &aflags);
-       ar.inode = inode;
-       ar.logical = block;
-       ar.len = *count;
-       ar.flags = LDISKFS_MB_HINT_DATA;
-       pblock = ldiskfs_mb_new_blocks(handle, &ar, err);
-       *count = ar.len;
-       return pblock;
+       return ldiskfs_journal_restart(handle, needed);
 }
+#endif /* HAVE_LDISKFS_JOURNAL_ENSURE_CREDITS */
 
-static int ldiskfs_ext_new_extent_cb(struct inode *inode,
-                                    struct ldiskfs_ext_path *path,
-                                    struct ldiskfs_ext_cache *cex,
-#ifdef HAVE_EXT_PREPARE_CB_EXTENT
-                                    struct ldiskfs_extent *ex,
-#endif
-                                    void *cbdata)
+static int osd_ldiskfs_map_write(struct inode *inode, struct osd_iobuf *iobuf,
+                                struct osd_device *osd, sector_t start_blocks,
+                                sector_t count, loff_t *disk_size,
+                                __u64 user_size)
 {
-       struct bpointers *bp = cbdata;
-       struct ldiskfs_extent nex;
-       unsigned long pblock = 0;
-       unsigned long tgen;
-       int err, i;
-       unsigned long count;
-       handle_t *handle;
-
-#ifdef LDISKFS_EXT_CACHE_EXTENT /* until kernel 2.6.37 */
-       if (cex->ec_type == LDISKFS_EXT_CACHE_EXTENT) {
-#else
-       if ((cex->ec_len != 0) && (cex->ec_start != 0)) {
-#endif
-               err = EXT_CONTINUE;
-               goto map;
-       }
-
-       if (bp->create == 0) {
-               i = 0;
-               if (cex->ec_block < bp->start)
-                       i = bp->start - cex->ec_block;
-               if (i >= cex->ec_len)
-                       CERROR("nothing to do?! i = %d, e_num = %u\n",
-                                       i, cex->ec_len);
-               for (; i < cex->ec_len && bp->num; i++) {
-                       *(bp->blocks) = 0;
-                       bp->blocks++;
-                       bp->num--;
-                       bp->start++;
-               }
+       /* if file has grown, take user_size into account */
+       if (user_size && *disk_size > user_size)
+               *disk_size = user_size;
 
-               return EXT_CONTINUE;
-       }
-
-       tgen = LDISKFS_I(inode)->i_ext_generation;
-       count = ldiskfs_ext_calc_credits_for_insert(inode, path);
-
-       handle = osd_journal_start(inode, LDISKFS_HT_MISC,
-                                  count + LDISKFS_ALLOC_NEEDED + 1);
-       if (IS_ERR(handle)) {
-               return PTR_ERR(handle);
-       }
-
-       if (tgen != LDISKFS_I(inode)->i_ext_generation) {
-               /* the tree has changed. so path can be invalid at moment */
-               ldiskfs_journal_stop(handle);
-               return EXT_REPEAT;
-       }
-
-       /* In 2.6.32 kernel, ldiskfs_ext_walk_space()'s callback func is not
-        * protected by i_data_sem as whole. so we patch it to store
-        * generation to path and now verify the tree hasn't changed */
-       down_write((&LDISKFS_I(inode)->i_data_sem));
-
-       /* validate extent, make sure the extent tree does not changed */
-       if (LDISKFS_I(inode)->i_ext_generation != path[0].p_generation) {
-               /* cex is invalid, try again */
-               up_write(&LDISKFS_I(inode)->i_data_sem);
-               ldiskfs_journal_stop(handle);
-               return EXT_REPEAT;
-       }
-
-       count = cex->ec_len;
-       pblock = new_blocks(handle, inode, path, cex->ec_block, &count, &err);
-       if (!pblock)
-               goto out;
-       BUG_ON(count > cex->ec_len);
-
-       /* insert new extent */
-       nex.ee_block = cpu_to_le32(cex->ec_block);
-       ldiskfs_ext_store_pblock(&nex, pblock);
-       nex.ee_len = cpu_to_le16(count);
-       err = ldiskfs_ext_insert_extent(handle, inode, path, &nex, 0);
-       if (err) {
-               /* free data blocks we just allocated */
-               /* not a good idea to call discard here directly,
-                * but otherwise we'd need to call it every free() */
-               ldiskfs_discard_preallocations(inode);
-#ifdef HAVE_EXT_FREE_BLOCK_WITH_BUFFER_HEAD /* Introduced in 2.6.32-rc7 */
-               ldiskfs_free_blocks(handle, inode, NULL,
-                                   ldiskfs_ext_pblock(&nex),
-                                   le16_to_cpu(nex.ee_len), 0);
-#else
-               ldiskfs_free_blocks(handle, inode, ldiskfs_ext_pblock(&nex),
-                                   le16_to_cpu(nex.ee_len), 0);
-#endif
-               goto out;
+       spin_lock(&inode->i_lock);
+       if (*disk_size > i_size_read(inode)) {
+               i_size_write(inode, *disk_size);
+               LDISKFS_I(inode)->i_disksize = *disk_size;
+               spin_unlock(&inode->i_lock);
+               osd_dirty_inode(inode, I_DIRTY_DATASYNC);
+       } else {
+               spin_unlock(&inode->i_lock);
        }
 
        /*
-        * Putting len of the actual extent we just inserted,
-        * we are asking ldiskfs_ext_walk_space() to continue
-        * scaning after that block
+        * We don't do stats here as in read path because
+        * write is async: we'll do this in osd_put_bufs()
         */
-       cex->ec_len = le16_to_cpu(nex.ee_len);
-       cex->ec_start = ldiskfs_ext_pblock(&nex);
-       BUG_ON(le16_to_cpu(nex.ee_len) == 0);
-       BUG_ON(le32_to_cpu(nex.ee_block) != cex->ec_block);
-
-out:
-       up_write((&LDISKFS_I(inode)->i_data_sem));
-       ldiskfs_journal_stop(handle);
-map:
-       if (err >= 0) {
-               /* map blocks */
-               if (bp->num == 0) {
-                       CERROR("hmm. why do we find this extent?\n");
-                       CERROR("initial space: %lu:%u\n",
-                               bp->start, bp->init_num);
-#ifdef LDISKFS_EXT_CACHE_EXTENT /* until kernel 2.6.37 */
-                       CERROR("current extent: %u/%u/%llu %d\n",
-                               cex->ec_block, cex->ec_len,
-                               (unsigned long long)cex->ec_start,
-                               cex->ec_type);
-#else
-                       CERROR("current extent: %u/%u/%llu\n",
-                               cex->ec_block, cex->ec_len,
-                               (unsigned long long)cex->ec_start);
-#endif
-               }
-               i = 0;
-               if (cex->ec_block < bp->start)
-                       i = bp->start - cex->ec_block;
-               if (i >= cex->ec_len)
-                       CERROR("nothing to do?! i = %d, e_num = %u\n",
-                                       i, cex->ec_len);
-               for (; i < cex->ec_len && bp->num; i++) {
-                       *(bp->blocks) = cex->ec_start + i;
-                       if (pblock != 0) {
-                               /* unmap any possible underlying metadata from
-                                * the block device mapping.  bug 6998. */
-                               unmap_underlying_metadata(inode->i_sb->s_bdev,
-                                                         *(bp->blocks));
-                       }
-                       bp->blocks++;
-                       bp->num--;
-                       bp->start++;
-               }
-       }
-       return err;
+       return osd_do_bio(osd, inode, iobuf, start_blocks, count);
 }
 
-static int osd_ldiskfs_map_nblocks(struct inode *inode, unsigned long index,
-                                  int clen, sector_t *blocks, int create)
+static unsigned int osd_extent_bytes(const struct osd_device *o)
 {
-       int blocks_per_page = PAGE_SIZE >> inode->i_blkbits;
-       struct bpointers bp;
-       int err;
-
-       if (index + clen >= inode->i_sb->s_maxbytes >> PAGE_SHIFT)
-               return -EFBIG;
-
-       bp.blocks = blocks;
-       bp.start = index * blocks_per_page;
-       bp.init_num = bp.num = clen * blocks_per_page;
-       bp.create = create;
+       unsigned int *extent_bytes_ptr =
+                       raw_cpu_ptr(o->od_extent_bytes_percpu);
 
-       CDEBUG(D_OTHER, "blocks %lu-%lu requested for inode %u\n",
-              bp.start, bp.start + bp.num - 1, (unsigned)inode->i_ino);
+       if (likely(*extent_bytes_ptr))
+               return *extent_bytes_ptr;
 
-       err = ldiskfs_ext_walk_space(inode, bp.start, bp.num,
-                                    ldiskfs_ext_new_extent_cb, &bp);
-       ldiskfs_ext_invalidate_cache(inode);
-
-       return err;
-}
+       /* initialize on first access or CPU hotplug */
+       if (!ldiskfs_has_feature_extents(osd_sb(o)))
+               *extent_bytes_ptr = 1 << osd_sb(o)->s_blocksize_bits;
+       else
+               *extent_bytes_ptr = OSD_DEFAULT_EXTENT_BYTES;
 
-static int osd_ldiskfs_map_bm_inode_pages(struct inode *inode,
-                                         struct page **page, int pages,
-                                         sector_t *blocks, int create)
-{
-       int blocks_per_page = PAGE_SIZE >> inode->i_blkbits;
-       pgoff_t bitmap_max_page_index;
-       sector_t *b;
-       int rc = 0, i;
-
-       bitmap_max_page_index = LDISKFS_SB(inode->i_sb)->s_bitmap_maxbytes >>
-                               PAGE_SHIFT;
-       for (i = 0, b = blocks; i < pages; i++, page++) {
-               if ((*page)->index + 1 >= bitmap_max_page_index) {
-                       rc = -EFBIG;
-                       break;
-               }
-               rc = ldiskfs_map_inode_page(inode, *page, b, create);
-               if (rc) {
-                       CERROR("ino %lu, blk %llu create %d: rc %d\n",
-                              inode->i_ino,
-                              (unsigned long long)*b, create, rc);
-                       break;
-               }
-               b += blocks_per_page;
-       }
-       return rc;
+       return *extent_bytes_ptr;
 }
 
-static int osd_ldiskfs_map_ext_inode_pages(struct inode *inode,
-                                          struct page **page,
-                                          int pages, sector_t *blocks,
-                                          int create)
+#define EXTENT_BYTES_DECAY 64
+static void osd_decay_extent_bytes(struct osd_device *osd,
+                                  unsigned int new_bytes)
 {
-       int rc = 0, i = 0, clen = 0;
-       struct page *fp = NULL;
-
-       CDEBUG(D_OTHER, "inode %lu: map %d pages from %lu\n",
-               inode->i_ino, pages, (*page)->index);
-
-       /* pages are sorted already. so, we just have to find
-        * contig. space and process them properly */
-       while (i < pages) {
-               if (fp == NULL) {
-                       /* start new extent */
-                       fp = *page++;
-                       clen = 1;
-                       i++;
-                       continue;
-               } else if (fp->index + clen == (*page)->index) {
-                       /* continue the extent */
-                       page++;
-                       clen++;
-                       i++;
-                       continue;
-               }
-
-               /* process found extent */
-               rc = osd_ldiskfs_map_nblocks(inode, fp->index, clen,
-                                            blocks, create);
-               if (rc)
-                       GOTO(cleanup, rc);
-
-               /* look for next extent */
-               fp = NULL;
-               blocks += clen * (PAGE_SIZE >> inode->i_blkbits);
-       }
+       unsigned int old_bytes;
 
-       if (fp)
-               rc = osd_ldiskfs_map_nblocks(inode, fp->index, clen,
-                                            blocks, create);
+       if (!ldiskfs_has_feature_extents(osd_sb(osd)))
+               return;
 
-cleanup:
-       return rc;
+       old_bytes = osd_extent_bytes(osd);
+       *raw_cpu_ptr(osd->od_extent_bytes_percpu) =
+               (old_bytes * (EXTENT_BYTES_DECAY - 1) +
+                min(new_bytes, OSD_DEFAULT_EXTENT_BYTES) +
+                EXTENT_BYTES_DECAY - 1) / EXTENT_BYTES_DECAY;
 }
 
-static int osd_ldiskfs_map_inode_pages(struct inode *inode, struct page **page,
-                                      int pages, sector_t *blocks,
-                                      int create)
-{
-       int rc;
-
-       if (LDISKFS_I(inode)->i_flags & LDISKFS_EXTENTS_FL) {
-               rc = osd_ldiskfs_map_ext_inode_pages(inode, page, pages,
-                                                    blocks, create);
-               return rc;
-       }
-       rc = osd_ldiskfs_map_bm_inode_pages(inode, page, pages, blocks, create);
-
-       return rc;
-}
-#else
-static int osd_ldiskfs_map_inode_pages(struct inode *inode, struct page **page,
-                                      int pages, sector_t *blocks,
-                                      int create)
+static int osd_ldiskfs_map_inode_pages(struct inode *inode,
+                                      struct osd_iobuf *iobuf,
+                                      struct osd_device *osd,
+                                      int create, __u64 user_size,
+                                      int check_credits,
+                                      struct thandle *thandle)
 {
        int blocks_per_page = PAGE_SIZE >> inode->i_blkbits;
-       int rc = 0, i = 0;
+       int rc = 0, i = 0, mapped_index = 0;
        struct page *fp = NULL;
        int clen = 0;
        pgoff_t max_page_index;
        handle_t *handle = NULL;
+       sector_t start_blocks = 0, count = 0;
+       loff_t disk_size = 0;
+       struct page **page = iobuf->dr_pages;
+       int pages = iobuf->dr_npages;
+       sector_t *blocks = iobuf->dr_blocks;
+       struct niobuf_local *lnb1, *lnb2;
+       loff_t size1, size2;
 
        max_page_index = inode->i_sb->s_maxbytes >> PAGE_SHIFT;
 
@@ -912,11 +1105,18 @@ static int osd_ldiskfs_map_inode_pages(struct inode *inode, struct page **page,
                rc = osd_attach_jinode(inode);
                if (rc)
                        return rc;
+               disk_size = i_size_read(inode);
+               /* if disk_size is already bigger than specified user_size,
+                * ignore user_size
+                */
+               if (disk_size > user_size)
+                       user_size = 0;
        }
        /* pages are sorted already. so, we just have to find
-        * contig. space and process them properly */
+        * contig. space and process them properly
+        */
        while (i < pages) {
-               long blen, total = 0;
+               long blen, total = 0, previous_total = 0;
                struct ldiskfs_map_blocks map = { 0 };
 
                if (fp == NULL) { /* start new extent */
@@ -937,62 +1137,136 @@ static int osd_ldiskfs_map_inode_pages(struct inode *inode, struct page **page,
                map.m_lblk = fp->index * blocks_per_page;
                map.m_len = blen = clen * blocks_per_page;
 cont_map:
+               /**
+                * We might restart transaction for block allocations,
+                * in order to make sure data ordered mode, issue IO, disk
+                * size update and block allocations need be within same
+                * transaction to make sure consistency.
+                */
+               if (handle && check_credits) {
+                       struct osd_thandle *oh;
+
+                       LASSERT(thandle != NULL);
+                       oh = container_of(thandle, struct osd_thandle,
+                                         ot_super);
+                       /*
+                        * only issue IO if restart transaction needed,
+                        * as update disk size need hold inode lock, we
+                        * want to avoid that as much as possible.
+                        */
+                       if (oh->oh_declared_ext <= 0) {
+                               rc = osd_ldiskfs_map_write(inode,
+                                       iobuf, osd, start_blocks,
+                                       count, &disk_size, user_size);
+                               if (rc)
+                                       GOTO(cleanup, rc);
+                               thandle->th_restart_tran = 1;
+                               GOTO(cleanup, rc = -EAGAIN);
+                       }
+
+                       if (OBD_FAIL_CHECK(OBD_FAIL_OST_RESTART_IO))
+                               oh->oh_declared_ext = 0;
+                       else
+                               oh->oh_declared_ext--;
+               }
                rc = ldiskfs_map_blocks(handle, inode, &map, create);
                if (rc >= 0) {
                        int c = 0;
+
                        for (; total < blen && c < map.m_len; c++, total++) {
                                if (rc == 0) {
                                        *(blocks + total) = 0;
                                        total++;
                                        break;
-                               } else {
-                                       *(blocks + total) = map.m_pblk + c;
-                                       /* unmap any possible underlying
-                                        * metadata from the block device
-                                        * mapping.  bug 6998. */
-                                       if ((map.m_flags & LDISKFS_MAP_NEW) &&
-                                           create)
-                                               unmap_underlying_metadata(
-                                                       inode->i_sb->s_bdev,
-                                                       map.m_pblk + c);
                                }
+                               if ((map.m_flags & LDISKFS_MAP_UNWRITTEN) &&
+                                   !create) {
+                                       /* don't try to read allocated, but
+                                        * unwritten blocks, instead fill the
+                                        * patches with zeros in osd_do_bio() */
+                                       *(blocks + total) = 0;
+                                       continue;
+                               }
+                               *(blocks + total) = map.m_pblk + c;
+                               /* unmap any possible underlying
+                                * metadata from the block device
+                                * mapping.  b=6998.
+                                */
+                               if ((map.m_flags & LDISKFS_MAP_NEW) &&
+                                   create)
+                                       clean_bdev_aliases(inode->i_sb->s_bdev,
+                                                          map.m_pblk + c, 1);
                        }
                        rc = 0;
                }
+
+               if (rc == 0 && create) {
+                       count += (total - previous_total);
+                       mapped_index = (count + blocks_per_page -
+                                       1) / blocks_per_page - 1;
+                       lnb1 = iobuf->dr_lnbs[i - clen];
+                       lnb2 = iobuf->dr_lnbs[mapped_index];
+                       size1 = lnb1->lnb_file_offset -
+                               (lnb1->lnb_file_offset % PAGE_SIZE) +
+                               (total << inode->i_blkbits);
+                       size2 = lnb2->lnb_file_offset + lnb2->lnb_len;
+
+                       if (size1 > size2)
+                               size1 = size2;
+                       if (size1 > disk_size)
+                               disk_size = size1;
+               }
+
                if (rc == 0 && total < blen) {
+                       /*
+                        * decay extent blocks if we could not
+                        * allocate extent once.
+                        */
+                       osd_decay_extent_bytes(osd,
+                               (total - previous_total) << inode->i_blkbits);
                        map.m_lblk = fp->index * blocks_per_page + total;
                        map.m_len = blen - total;
+                       previous_total = total;
                        goto cont_map;
                }
                if (rc != 0)
                        GOTO(cleanup, rc);
-
+               /*
+                * decay extent blocks if we could allocate
+                * good large extent.
+                */
+               if (total - previous_total >=
+                   osd_extent_bytes(osd) >> inode->i_blkbits)
+                       osd_decay_extent_bytes(osd,
+                               (total - previous_total) << inode->i_blkbits);
                /* look for next extent */
                fp = NULL;
                blocks += blocks_per_page * clen;
        }
 cleanup:
+       if (rc == 0 && create &&
+           start_blocks < pages * blocks_per_page) {
+               rc = osd_ldiskfs_map_write(inode, iobuf, osd, start_blocks,
+                                          count, &disk_size, user_size);
+               LASSERT(start_blocks + count == pages * blocks_per_page);
+       }
        return rc;
 }
-#endif /* HAVE_LDISKFS_MAP_BLOCKS */
 
 static int osd_write_prep(const struct lu_env *env, struct dt_object *dt,
-                          struct niobuf_local *lnb, int npages)
+                         struct niobuf_local *lnb, int npages)
 {
-        struct osd_thread_info *oti   = osd_oti_get(env);
-        struct osd_iobuf       *iobuf = &oti->oti_iobuf;
-        struct inode           *inode = osd_dt_obj(dt)->oo_inode;
-        struct osd_device      *osd   = osd_obj2dev(osd_dt_obj(dt));
-       ktime_t start;
-       ktime_t end;
+       struct osd_thread_info *oti   = osd_oti_get(env);
+       struct osd_iobuf       *iobuf = &oti->oti_iobuf;
+       struct inode           *inode = osd_dt_obj(dt)->oo_inode;
+       struct osd_device      *osd   = osd_obj2dev(osd_dt_obj(dt));
+       ktime_t start, end;
        s64 timediff;
-        ssize_t                 isize;
-        __s64                   maxidx;
-        int                     rc = 0;
-        int                     i;
-        int                     cache = 0;
+       ssize_t isize;
+       __s64  maxidx;
+       int i, rc = 0;
 
-        LASSERT(inode);
+       LASSERT(inode);
 
        rc = osd_init_iobuf(osd, iobuf, 0, npages);
        if (unlikely(rc != 0))
@@ -1001,18 +1275,9 @@ static int osd_write_prep(const struct lu_env *env, struct dt_object *dt,
        isize = i_size_read(inode);
        maxidx = ((isize + PAGE_SIZE - 1) >> PAGE_SHIFT) - 1;
 
-        if (osd->od_writethrough_cache)
-                cache = 1;
-        if (isize > osd->od_readcache_max_filesize)
-                cache = 0;
-
        start = ktime_get();
        for (i = 0; i < npages; i++) {
 
-               if (cache == 0)
-                       generic_error_remove_page(inode->i_mapping,
-                                                 lnb[i].lnb_page);
-
                /*
                 * till commit the content of the page is undefined
                 * we'll set it uptodate once bulk is done. otherwise
@@ -1024,7 +1289,7 @@ static int osd_write_prep(const struct lu_env *env, struct dt_object *dt,
                        continue;
 
                if (maxidx >= lnb[i].lnb_page->index) {
-                       osd_iobuf_add_page(iobuf, lnb[i].lnb_page);
+                       osd_iobuf_add_page(iobuf, &lnb[i]);
                } else {
                        long off;
                        char *p = kmap(lnb[i].lnb_page);
@@ -1043,22 +1308,22 @@ static int osd_write_prep(const struct lu_env *env, struct dt_object *dt,
        timediff = ktime_us_delta(end, start);
        lprocfs_counter_add(osd->od_stats, LPROC_OSD_GET_PAGE, timediff);
 
-        if (iobuf->dr_npages) {
-               rc = osd_ldiskfs_map_inode_pages(inode, iobuf->dr_pages,
-                                                iobuf->dr_npages,
-                                                iobuf->dr_blocks, 0);
-                if (likely(rc == 0)) {
-                        rc = osd_do_bio(osd, inode, iobuf);
-                        /* do IO stats for preparation reads */
-                        osd_fini_iobuf(osd, iobuf);
-                }
-        }
-        RETURN(rc);
+       if (iobuf->dr_npages) {
+               rc = osd_ldiskfs_map_inode_pages(inode, iobuf, osd, 0,
+                                                0, 0, NULL);
+               if (likely(rc == 0)) {
+                       rc = osd_do_bio(osd, inode, iobuf, 0, 0);
+                       /* do IO stats for preparation reads */
+                       osd_fini_iobuf(osd, iobuf);
+               }
+       }
+       RETURN(rc);
 }
 
 struct osd_fextent {
        sector_t        start;
        sector_t        end;
+       __u32           flags;
        unsigned int    mapped:1;
 };
 
@@ -1070,7 +1335,6 @@ static int osd_is_mapped(struct dt_object *dt, __u64 offset,
        sector_t start;
        struct fiemap_extent_info fei = { 0 };
        struct fiemap_extent fe = { 0 };
-       mm_segment_t saved_fs;
        int rc;
 
        if (block >= cached_extent->start && block < cached_extent->end)
@@ -1086,14 +1350,22 @@ static int osd_is_mapped(struct dt_object *dt, __u64 offset,
        fei.fi_extents_max = 1;
        fei.fi_extents_start = &fe;
 
-       saved_fs = get_fs();
-       set_fs(get_ds());
        rc = inode->i_op->fiemap(inode, &fei, offset, FIEMAP_MAX_OFFSET-offset);
-       set_fs(saved_fs);
        if (rc != 0)
                return 0;
 
        start = fe.fe_logical >> inode->i_blkbits;
+       cached_extent->flags = fe.fe_flags;
+       if (fei.fi_extents_mapped == 0) {
+               /* a special case - no extent found at this offset and forward.
+                * we can consider this as a hole to EOF. it's safe to cache
+                * as other threads can not allocate/punch blocks this thread
+                * is working on (LDLM). */
+               cached_extent->start = block;
+               cached_extent->end = i_size_read(inode) >> inode->i_blkbits;
+               cached_extent->mapped = 0;
+               return 0;
+       }
 
        if (start > block) {
                cached_extent->start = block;
@@ -1109,98 +1381,165 @@ static int osd_is_mapped(struct dt_object *dt, __u64 offset,
        return cached_extent->mapped;
 }
 
+#define MAX_EXTENTS_PER_WRITE 100
 static int osd_declare_write_commit(const struct lu_env *env,
-                                    struct dt_object *dt,
-                                    struct niobuf_local *lnb, int npages,
-                                    struct thandle *handle)
+                                   struct dt_object *dt,
+                                   struct niobuf_local *lnb, int npages,
+                                   struct thandle *handle)
 {
        const struct osd_device *osd = osd_obj2dev(osd_dt_obj(dt));
        struct inode            *inode = osd_dt_obj(dt)->oo_inode;
        struct osd_thandle      *oh;
-       int                     extents = 1;
-       int                     depth;
+       int                     extents = 0, new_meta = 0;
+       int                     depth, new_blocks = 0;
        int                     i;
-       int                     newblocks;
+       int                     dirty_groups = 0;
        int                     rc = 0;
-       int                     flags = 0;
        int                     credits = 0;
        long long               quota_space = 0;
-       struct osd_fextent      extent = { 0 };
+       struct osd_fextent      mapped = { 0 }, extent = { 0 };
+       enum osd_quota_local_flags local_flags = 0;
        enum osd_qid_declare_flags declare_flags = OSD_QID_BLK;
+       unsigned int            extent_bytes;
        ENTRY;
 
-        LASSERT(handle != NULL);
-        oh = container_of0(handle, struct osd_thandle, ot_super);
-        LASSERT(oh->ot_handle == NULL);
+       LASSERT(handle != NULL);
+       oh = container_of(handle, struct osd_thandle, ot_super);
+       LASSERT(oh->ot_handle == NULL);
 
-        newblocks = npages;
+       /*
+        * We track a decaying average extent blocks per filesystem,
+        * for most of time, it will be 1M, with filesystem becoming
+        * heavily-fragmented, it will be reduced to 4K at the worst.
+        */
+       extent_bytes = osd_extent_bytes(osd);
+       LASSERT(extent_bytes >= osd_sb(osd)->s_blocksize);
 
-        /* calculate number of extents (probably better to pass nb) */
+       /* calculate number of extents (probably better to pass nb) */
        for (i = 0; i < npages; i++) {
-               if (i && lnb[i].lnb_file_offset !=
-                   lnb[i - 1].lnb_file_offset + lnb[i - 1].lnb_len)
-                       extents++;
-
-               if (!osd_is_mapped(dt, lnb[i].lnb_file_offset, &extent))
-                       quota_space += PAGE_SIZE;
-
                /* ignore quota for the whole request if any page is from
                 * client cache or written by root.
                 *
-                * XXX once we drop the 1.8 client support, the checking
-                * for whether page is from cache can be simplified as:
-                * !(lnb[i].flags & OBD_BRW_SYNC)
-                *
                 * XXX we could handle this on per-lnb basis as done by
-                * grant. */
+                * grant.
+                */
                if ((lnb[i].lnb_flags & OBD_BRW_NOQUOTA) ||
-                   (lnb[i].lnb_flags & (OBD_BRW_FROM_GRANT | OBD_BRW_SYNC)) ==
-                   OBD_BRW_FROM_GRANT)
+                   (lnb[i].lnb_flags & OBD_BRW_SYS_RESOURCE) ||
+                   !(lnb[i].lnb_flags & OBD_BRW_SYNC))
                        declare_flags |= OSD_QID_FORCE;
+
+               /*
+                * Convert unwritten extent might need split extents, could
+                * not skip it.
+                */
+               if (osd_is_mapped(dt, lnb[i].lnb_file_offset, &mapped) &&
+                   !(mapped.flags & FIEMAP_EXTENT_UNWRITTEN)) {
+                       lnb[i].lnb_flags |= OBD_BRW_MAPPED;
+                       continue;
+               }
+
+               if (lnb[i].lnb_flags & OBD_BRW_DONE) {
+                       lnb[i].lnb_flags |= OBD_BRW_MAPPED;
+                       continue;
+               }
+
+               /* count only unmapped changes */
+               new_blocks++;
+               if (lnb[i].lnb_file_offset != extent.end || extent.end == 0) {
+                       if (extent.end != 0)
+                               extents += (extent.end - extent.start +
+                                           extent_bytes - 1) / extent_bytes;
+                       extent.start = lnb[i].lnb_file_offset;
+                       extent.end = lnb[i].lnb_file_offset + lnb[i].lnb_len;
+               } else {
+                       extent.end += lnb[i].lnb_len;
+               }
+
+               quota_space += PAGE_SIZE;
        }
 
-        /*
-         * each extent can go into new leaf causing a split
-         * 5 is max tree depth: inode + 4 index blocks
-         * with blockmaps, depth is 3 at most
-         */
-        if (LDISKFS_I(inode)->i_flags & LDISKFS_EXTENTS_FL) {
-                /*
-                 * many concurrent threads may grow tree by the time
-                 * our transaction starts. so, consider 2 is a min depth
-                 */
-                depth = ext_depth(inode);
-                depth = max(depth, 1) + 1;
-                newblocks += depth;
-               credits++; /* inode */
-               credits += depth * 2 * extents;
+       credits++; /* inode */
+       /*
+        * overwrite case, no need to modify tree and
+        * allocate blocks.
+        */
+       if (!extent.end)
+               goto out_declare;
+
+       extents += (extent.end - extent.start +
+                   extent_bytes - 1) / extent_bytes;
+       /**
+        * with system space usage growing up, mballoc codes won't
+        * try best to scan block group to align best free extent as
+        * we can. So extent bytes per extent could be decayed to a
+        * very small value, this could make us reserve too many credits.
+        * We could be more optimistic in the credit reservations, even
+        * in a case where the filesystem is nearly full, it is extremely
+        * unlikely that the worst case would ever be hit.
+        */
+       if (extents > MAX_EXTENTS_PER_WRITE)
+               extents = MAX_EXTENTS_PER_WRITE;
+
+       /**
+        * If we add a single extent, then in the worse case, each tree
+        * level index/leaf need to be changed in case of the tree split.
+        * If more extents are inserted, they could cause the whole tree
+        * split more than once, but this is really rare.
+        */
+       if (LDISKFS_I(inode)->i_flags & LDISKFS_EXTENTS_FL) {
+               /*
+                * many concurrent threads may grow tree by the time
+                * our transaction starts. so, consider 2 is a min depth.
+                */
+               depth = ext_depth(inode);
+               depth = min(max(depth, 1) + 1, LDISKFS_MAX_EXTENT_DEPTH);
+               if (extents <= 1) {
+                       credits += depth * 2 * extents;
+                       new_meta = depth;
+               } else {
+                       credits += depth * 3 * extents;
+                       new_meta = depth * 2 * extents;
+               }
        } else {
-               depth = 3;
-               newblocks += depth;
-               credits++; /* inode */
-               credits += depth * extents;
+               /*
+                * With N contiguous data blocks, we need at most
+                * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks,
+                * 2 dindirect blocks, and 1 tindirect block
+                */
+               new_meta = DIV_ROUND_UP(new_blocks,
+                               LDISKFS_ADDR_PER_BLOCK(inode->i_sb)) + 4;
+               credits += new_meta;
        }
+       dirty_groups += (extents + new_meta);
+
+       oh->oh_declared_ext = extents;
 
        /* quota space for metadata blocks */
-       quota_space += depth * extents * LDISKFS_BLOCK_SIZE(osd_sb(osd));
+       quota_space += new_meta * LDISKFS_BLOCK_SIZE(osd_sb(osd));
 
        /* quota space should be reported in 1K blocks */
        quota_space = toqb(quota_space);
 
-        /* each new block can go in different group (bitmap + gd) */
+       /* each new block can go in different group (bitmap + gd) */
 
-        /* we can't dirty more bitmap blocks than exist */
-        if (newblocks > LDISKFS_SB(osd_sb(osd))->s_groups_count)
+       /* we can't dirty more bitmap blocks than exist */
+       if (dirty_groups > LDISKFS_SB(osd_sb(osd))->s_groups_count)
                credits += LDISKFS_SB(osd_sb(osd))->s_groups_count;
-        else
-               credits += newblocks;
+       else
+               credits += dirty_groups;
 
        /* we can't dirty more gd blocks than exist */
-       if (newblocks > LDISKFS_SB(osd_sb(osd))->s_gdb_count)
+       if (dirty_groups > LDISKFS_SB(osd_sb(osd))->s_gdb_count)
                credits += LDISKFS_SB(osd_sb(osd))->s_gdb_count;
        else
-               credits += newblocks;
+               credits += dirty_groups;
+
+       CDEBUG(D_INODE,
+              "%s: inode #%lu extent_bytes %u extents %d credits %d\n",
+              osd_ino2name(inode), inode->i_ino, extent_bytes, extents,
+              credits);
 
+out_declare:
        osd_trans_declare_op(env, oh, OSD_OT_WRITE, credits);
 
        /* make sure the over quota flags were not set */
@@ -1208,48 +1547,50 @@ static int osd_declare_write_commit(const struct lu_env *env,
 
        rc = osd_declare_inode_qid(env, i_uid_read(inode), i_gid_read(inode),
                                   i_projid_read(inode), quota_space, oh,
-                                  osd_dt_obj(dt), &flags, declare_flags);
+                                  osd_dt_obj(dt), &local_flags, declare_flags);
 
        /* we need only to store the overquota flags in the first lnb for
         * now, once we support multiple objects BRW, this code needs be
-        * revised. */
-       if (flags & QUOTA_FL_OVER_USRQUOTA)
+        * revised.
+        */
+       if (local_flags & QUOTA_FL_OVER_USRQUOTA)
                lnb[0].lnb_flags |= OBD_BRW_OVER_USRQUOTA;
-       if (flags & QUOTA_FL_OVER_GRPQUOTA)
+       if (local_flags & QUOTA_FL_OVER_GRPQUOTA)
                lnb[0].lnb_flags |= OBD_BRW_OVER_GRPQUOTA;
-       if (flags & QUOTA_FL_OVER_PRJQUOTA)
+       if (local_flags & QUOTA_FL_OVER_PRJQUOTA)
                lnb[0].lnb_flags |= OBD_BRW_OVER_PRJQUOTA;
 
+       if (rc == 0)
+               rc = osd_trunc_lock(osd_dt_obj(dt), oh, true);
+
        RETURN(rc);
 }
 
 /* Check if a block is allocated or not */
 static int osd_write_commit(const struct lu_env *env, struct dt_object *dt,
-                            struct niobuf_local *lnb, int npages,
-                            struct thandle *thandle)
+                           struct niobuf_local *lnb, int npages,
+                           struct thandle *thandle, __u64 user_size)
 {
-        struct osd_thread_info *oti = osd_oti_get(env);
-        struct osd_iobuf *iobuf = &oti->oti_iobuf;
-        struct inode *inode = osd_dt_obj(dt)->oo_inode;
-        struct osd_device  *osd = osd_obj2dev(osd_dt_obj(dt));
-        loff_t isize;
-        int rc = 0, i;
-       struct osd_fextent extent = { 0 };
+       struct osd_thread_info *oti = osd_oti_get(env);
+       struct osd_iobuf *iobuf = &oti->oti_iobuf;
+       struct inode *inode = osd_dt_obj(dt)->oo_inode;
+       struct osd_device  *osd = osd_obj2dev(osd_dt_obj(dt));
+       int rc = 0, i, check_credits = 0;
 
-        LASSERT(inode);
+       LASSERT(inode);
 
        rc = osd_init_iobuf(osd, iobuf, 1, npages);
        if (unlikely(rc != 0))
                RETURN(rc);
 
-       isize = i_size_read(inode);
-       ll_vfs_dq_init(inode);
+       dquot_initialize(inode);
 
-        for (i = 0; i < npages; i++) {
+       for (i = 0; i < npages; i++) {
                if (lnb[i].lnb_rc == -ENOSPC &&
-                   osd_is_mapped(dt, lnb[i].lnb_file_offset, &extent)) {
+                   (lnb[i].lnb_flags & OBD_BRW_MAPPED)) {
                        /* Allow the write to proceed if overwriting an
-                        * existing block */
+                        * existing block
+                        */
                        lnb[i].lnb_rc = 0;
                }
 
@@ -1262,12 +1603,15 @@ static int osd_write_commit(const struct lu_env *env, struct dt_object *dt,
                        continue;
                }
 
+               if (lnb[i].lnb_flags & OBD_BRW_DONE)
+                       continue;
+
+               if (!(lnb[i].lnb_flags & OBD_BRW_MAPPED))
+                       check_credits = 1;
+
                LASSERT(PageLocked(lnb[i].lnb_page));
                LASSERT(!PageWriteback(lnb[i].lnb_page));
 
-               if (lnb[i].lnb_file_offset + lnb[i].lnb_len > isize)
-                       isize = lnb[i].lnb_file_offset + lnb[i].lnb_len;
-
                /*
                 * Since write and truncate are serialized by oo_sem, even
                 * partial-page truncate should not leave dirty pages in the
@@ -1277,50 +1621,38 @@ static int osd_write_commit(const struct lu_env *env, struct dt_object *dt,
 
                SetPageUptodate(lnb[i].lnb_page);
 
-               osd_iobuf_add_page(iobuf, lnb[i].lnb_page);
-        }
+               osd_iobuf_add_page(iobuf, &lnb[i]);
+       }
 
        osd_trans_exec_op(env, thandle, OSD_OT_WRITE);
 
-        if (OBD_FAIL_CHECK(OBD_FAIL_OST_MAPBLK_ENOSPC)) {
-                rc = -ENOSPC;
-        } else if (iobuf->dr_npages > 0) {
-               rc = osd_ldiskfs_map_inode_pages(inode, iobuf->dr_pages,
-                                                iobuf->dr_npages,
-                                                iobuf->dr_blocks, 1);
-        } else {
-                /* no pages to write, no transno is needed */
-                thandle->th_local = 1;
-        }
-
-       if (likely(rc == 0)) {
-               spin_lock(&inode->i_lock);
-               if (isize > i_size_read(inode)) {
-                       i_size_write(inode, isize);
-                       LDISKFS_I(inode)->i_disksize = isize;
-                       spin_unlock(&inode->i_lock);
-                       ll_dirty_inode(inode, I_DIRTY_DATASYNC);
-               } else {
-                       spin_unlock(&inode->i_lock);
-               }
-
-               rc = osd_do_bio(osd, inode, iobuf);
-               /* we don't do stats here as in read path because
-                * write is async: we'll do this in osd_put_bufs() */
+       if (OBD_FAIL_CHECK(OBD_FAIL_OST_MAPBLK_ENOSPC)) {
+               rc = -ENOSPC;
+       } else if (iobuf->dr_npages > 0) {
+               rc = osd_ldiskfs_map_inode_pages(inode, iobuf, osd,
+                                                1, user_size,
+                                                check_credits,
+                                                thandle);
        } else {
-               osd_fini_iobuf(osd, iobuf);
+               /* no pages to write, no transno is needed */
+               thandle->th_local = 1;
        }
 
+       if (rc != 0 && !thandle->th_restart_tran)
+               osd_fini_iobuf(osd, iobuf);
+
        osd_trans_exec_check(env, thandle, OSD_OT_WRITE);
 
-       if (unlikely(rc != 0)) {
+       if (unlikely(rc != 0 && !thandle->th_restart_tran)) {
                /* if write fails, we should drop pages from the cache */
                for (i = 0; i < npages; i++) {
                        if (lnb[i].lnb_page == NULL)
                                continue;
-                       LASSERT(PageLocked(lnb[i].lnb_page));
-                       generic_error_remove_page(inode->i_mapping,
-                                                 lnb[i].lnb_page);
+                       if (!PagePrivate2(lnb[i].lnb_page)) {
+                               LASSERT(PageLocked(lnb[i].lnb_page));
+                               generic_error_remove_page(inode->i_mapping,
+                                                         lnb[i].lnb_page);
+                       }
                }
        }
 
@@ -1328,18 +1660,18 @@ static int osd_write_commit(const struct lu_env *env, struct dt_object *dt,
 }
 
 static int osd_read_prep(const struct lu_env *env, struct dt_object *dt,
-                         struct niobuf_local *lnb, int npages)
+                        struct niobuf_local *lnb, int npages)
 {
-        struct osd_thread_info *oti = osd_oti_get(env);
-        struct osd_iobuf *iobuf = &oti->oti_iobuf;
-        struct inode *inode = osd_dt_obj(dt)->oo_inode;
-        struct osd_device *osd = osd_obj2dev(osd_dt_obj(dt));
-       int rc = 0, i, cache = 0, cache_hits = 0, cache_misses = 0;
+       struct osd_thread_info *oti = osd_oti_get(env);
+       struct osd_iobuf *iobuf = &oti->oti_iobuf;
+       struct inode *inode = osd_dt_obj(dt)->oo_inode;
+       struct osd_device *osd = osd_obj2dev(osd_dt_obj(dt));
+       int rc = 0, i, cache_hits = 0, cache_misses = 0;
        ktime_t start, end;
        s64 timediff;
        loff_t isize;
 
-        LASSERT(inode);
+       LASSERT(inode);
 
        rc = osd_init_iobuf(osd, iobuf, 0, npages);
        if (unlikely(rc != 0))
@@ -1347,23 +1679,19 @@ static int osd_read_prep(const struct lu_env *env, struct dt_object *dt,
 
        isize = i_size_read(inode);
 
-       if (osd->od_read_cache)
-               cache = 1;
-       if (isize > osd->od_readcache_max_filesize)
-               cache = 0;
-
        start = ktime_get();
        for (i = 0; i < npages; i++) {
 
                if (isize <= lnb[i].lnb_file_offset)
                        /* If there's no more data, abort early.
-                        * lnb->lnb_rc == 0, so it's easy to detect later. */
+                        * lnb->lnb_rc == 0, so it's easy to detect later.
+                        */
                        break;
 
-               if (isize < lnb[i].lnb_file_offset + lnb[i].lnb_len)
-                       lnb[i].lnb_rc = isize - lnb[i].lnb_file_offset;
-               else
-                       lnb[i].lnb_rc = lnb[i].lnb_len;
+               /* instead of looking if we go beyong isize, send complete
+                * pages all the time
+                */
+               lnb[i].lnb_rc = lnb[i].lnb_len;
 
                /* Bypass disk read if fail_loc is set properly */
                if (OBD_FAIL_CHECK(OBD_FAIL_OST_FAKE_RW))
@@ -1371,14 +1699,18 @@ static int osd_read_prep(const struct lu_env *env, struct dt_object *dt,
 
                if (PageUptodate(lnb[i].lnb_page)) {
                        cache_hits++;
+                       unlock_page(lnb[i].lnb_page);
                } else {
                        cache_misses++;
-                       osd_iobuf_add_page(iobuf, lnb[i].lnb_page);
+                       osd_iobuf_add_page(iobuf, &lnb[i]);
                }
-
-               if (cache == 0)
-                       generic_error_remove_page(inode->i_mapping,
-                                                 lnb[i].lnb_page);
+               /* no need to unlock in osd_bufs_put(), the sooner page is
+                * unlocked, the earlier another client can access it.
+                * notice real unlock_page() can be called few lines
+                * below after osd_do_bio(). lnb is a per-thread, so it's
+                * fine to have PG_locked and lnb_locked inconsistent here
+                */
+               lnb[i].lnb_locked = 0;
        }
        end = ktime_get();
        timediff = ktime_us_delta(end, start);
@@ -1394,16 +1726,23 @@ static int osd_read_prep(const struct lu_env *env, struct dt_object *dt,
                lprocfs_counter_add(osd->od_stats, LPROC_OSD_CACHE_ACCESS,
                                    cache_hits + cache_misses);
 
-        if (iobuf->dr_npages) {
-               rc = osd_ldiskfs_map_inode_pages(inode, iobuf->dr_pages,
-                                                iobuf->dr_npages,
-                                                iobuf->dr_blocks, 0);
-                rc = osd_do_bio(osd, inode, iobuf);
+       if (iobuf->dr_npages) {
+               rc = osd_ldiskfs_map_inode_pages(inode, iobuf, osd, 0,
+                                                0, 0, NULL);
+               if (!rc)
+                       rc = osd_do_bio(osd, inode, iobuf, 0, 0);
 
-                /* IO stats will be done in osd_bufs_put() */
-        }
+               /* IO stats will be done in osd_bufs_put() */
 
-        RETURN(rc);
+               /* early release to let others read data during the bulk */
+               for (i = 0; i < iobuf->dr_npages; i++) {
+                       LASSERT(PageLocked(iobuf->dr_pages[i]));
+                       if (!PagePrivate2(iobuf->dr_pages[i]))
+                               unlock_page(iobuf->dr_pages[i]);
+               }
+       }
+
+       RETURN(rc);
 }
 
 /*
@@ -1419,29 +1758,31 @@ static int osd_read_prep(const struct lu_env *env, struct dt_object *dt,
  */
 static int osd_ldiskfs_readlink(struct inode *inode, char *buffer, int buflen)
 {
-        struct ldiskfs_inode_info *ei = LDISKFS_I(inode);
+       struct ldiskfs_inode_info *ei = LDISKFS_I(inode);
 
-        memcpy(buffer, (char *)ei->i_data, buflen);
+       memcpy(buffer, (char *)ei->i_data, buflen);
 
-        return  buflen;
+       return  buflen;
 }
 
 int osd_ldiskfs_read(struct inode *inode, void *buf, int size, loff_t *offs)
 {
-        struct buffer_head *bh;
-        unsigned long block;
-        int osize;
-        int blocksize;
-        int csize;
-        int boffs;
-
-        /* prevent reading after eof */
+       struct buffer_head *bh;
+       unsigned long block;
+       int osize;
+       int blocksize;
+       int csize;
+       int boffs;
+
+       /* prevent reading after eof */
        spin_lock(&inode->i_lock);
        if (i_size_read(inode) < *offs + size) {
                loff_t diff = i_size_read(inode) - *offs;
+
                spin_unlock(&inode->i_lock);
                if (diff < 0) {
-                       CDEBUG(D_EXT2, "size %llu is too short to read @%llu\n",
+                       CDEBUG(D_OTHER,
+                              "size %llu is too short to read @%llu\n",
                               i_size_read(inode), *offs);
                        return -EBADR;
                } else if (diff == 0) {
@@ -1453,17 +1794,16 @@ int osd_ldiskfs_read(struct inode *inode, void *buf, int size, loff_t *offs)
                spin_unlock(&inode->i_lock);
        }
 
-        blocksize = 1 << inode->i_blkbits;
-        osize = size;
-        while (size > 0) {
-                block = *offs >> inode->i_blkbits;
-                boffs = *offs & (blocksize - 1);
-                csize = min(blocksize - boffs, size);
+       blocksize = 1 << inode->i_blkbits;
+       osize = size;
+       while (size > 0) {
+               block = *offs >> inode->i_blkbits;
+               boffs = *offs & (blocksize - 1);
+               csize = min(blocksize - boffs, size);
                bh = __ldiskfs_bread(NULL, inode, block, 0);
                if (IS_ERR(bh)) {
-                       CERROR("%s: can't read %u@%llu on ino %lu: "
-                              "rc = %ld\n", osd_ino2name(inode),
-                              csize, *offs, inode->i_ino,
+                       CERROR("%s: can't read %u@%llu on ino %lu: rc = %ld\n",
+                              osd_ino2name(inode), csize, *offs, inode->i_ino,
                               PTR_ERR(bh));
                        return PTR_ERR(bh);
                }
@@ -1475,29 +1815,37 @@ int osd_ldiskfs_read(struct inode *inode, void *buf, int size, loff_t *offs)
                        memset(buf, 0, csize);
                }
 
-                *offs += csize;
-                buf += csize;
-                size -= csize;
-        }
-        return osize;
+               *offs += csize;
+               buf += csize;
+               size -= csize;
+       }
+       return osize;
 }
 
 static ssize_t osd_read(const struct lu_env *env, struct dt_object *dt,
                        struct lu_buf *buf, loff_t *pos)
 {
-        struct inode *inode = osd_dt_obj(dt)->oo_inode;
-        int           rc;
-
-        /* Read small symlink from inode body as we need to maintain correct
-         * on-disk symlinks for ldiskfs.
-         */
-        if (S_ISLNK(dt->do_lu.lo_header->loh_attr) &&
-            (buf->lb_len < sizeof(LDISKFS_I(inode)->i_data)))
-                rc = osd_ldiskfs_readlink(inode, buf->lb_buf, buf->lb_len);
-        else
-                rc = osd_ldiskfs_read(inode, buf->lb_buf, buf->lb_len, pos);
-
-        return rc;
+       struct inode *inode = osd_dt_obj(dt)->oo_inode;
+       int rc;
+
+       /* Read small symlink from inode body as we need to maintain correct
+        * on-disk symlinks for ldiskfs.
+        */
+       if (S_ISLNK(dt->do_lu.lo_header->loh_attr)) {
+               loff_t size = i_size_read(inode);
+
+               if (buf->lb_len < size)
+                       return -EOVERFLOW;
+
+               if (size < sizeof(LDISKFS_I(inode)->i_data))
+                       rc = osd_ldiskfs_readlink(inode, buf->lb_buf, size);
+               else
+                       rc = osd_ldiskfs_read(inode, buf->lb_buf, size, pos);
+       } else {
+               rc = osd_ldiskfs_read(inode, buf->lb_buf, buf->lb_len, pos);
+       }
+
+       return rc;
 }
 
 static inline int osd_extents_enabled(struct super_block *sb,
@@ -1506,8 +1854,7 @@ static inline int osd_extents_enabled(struct super_block *sb,
        if (inode != NULL) {
                if (LDISKFS_I(inode)->i_flags & LDISKFS_EXTENTS_FL)
                        return 1;
-       } else if (LDISKFS_HAS_INCOMPAT_FEATURE(sb,
-                               LDISKFS_FEATURE_INCOMPAT_EXTENTS)) {
+       } else if (ldiskfs_has_feature_extents(sb)) {
                return 1;
        }
        return 0;
@@ -1524,7 +1871,8 @@ int osd_calc_bkmap_credits(struct super_block *sb, struct inode *inode,
 
        /* legacy blockmap: 3 levels * 3 (bitmap,gd,itself)
         * we do not expect blockmaps on the large files,
-        * so let's shrink it to 2 levels (4GB files) */
+        * so let's shrink it to 2 levels (4GB files)
+        */
 
        /* this is default reservation: 2 levels */
        credits = (blocks + 2) * 3;
@@ -1576,10 +1924,10 @@ static ssize_t osd_declare_write(const struct lu_env *env, struct dt_object *dt,
        ENTRY;
 
        LASSERT(buf != NULL);
-        LASSERT(handle != NULL);
+       LASSERT(handle != NULL);
 
-        oh = container_of0(handle, struct osd_thandle, ot_super);
-        LASSERT(oh->ot_handle == NULL);
+       oh = container_of(handle, struct osd_thandle, ot_super);
+       LASSERT(oh->ot_handle == NULL);
 
        size = buf->lb_len;
        bits = sb->s_blocksize_bits;
@@ -1587,7 +1935,8 @@ static ssize_t osd_declare_write(const struct lu_env *env, struct dt_object *dt,
 
        if (_pos == -1) {
                /* if this is an append, then we
-                * should expect cross-block record */
+                * should expect cross-block record
+                */
                pos = 0;
        } else {
                pos = _pos;
@@ -1619,10 +1968,11 @@ static ssize_t osd_declare_write(const struct lu_env *env, struct dt_object *dt,
                 * level.
                 */
                depth = inode != NULL ? ext_depth(inode) : 0;
-               depth = max(depth, 1) + 1;
+               depth = min(max(depth, 1) + 3, LDISKFS_MAX_EXTENT_DEPTH);
                credits = depth;
                /* if not append, then split may need to modify
-                * existing blocks moving entries into the new ones */
+                * existing blocks moving entries into the new ones
+                */
                if (_pos != -1)
                        credits += depth;
                /* blocks to store data: bitmap,gd,itself */
@@ -1631,7 +1981,8 @@ static ssize_t osd_declare_write(const struct lu_env *env, struct dt_object *dt,
                credits = osd_calc_bkmap_credits(sb, inode, size, _pos, blocks);
        }
        /* if inode is created as part of the transaction,
-        * then it's counted already by the creation method */
+        * then it's counted already by the creation method
+        */
        if (inode != NULL)
                credits++;
 
@@ -1641,12 +1992,17 @@ out:
 
        /* dt_declare_write() is usually called for system objects, such
         * as llog or last_rcvd files. We needn't enforce quota on those
-        * objects, so always set the lqi_space as 0. */
+        * objects, so always set the lqi_space as 0.
+        */
        if (inode != NULL)
                rc = osd_declare_inode_qid(env, i_uid_read(inode),
                                           i_gid_read(inode),
                                           i_projid_read(inode), 0,
                                           oh, obj, NULL, OSD_QID_BLK);
+
+       if (rc == 0)
+               rc = osd_trunc_lock(obj, oh, true);
+
        RETURN(rc);
 }
 
@@ -1660,23 +2016,27 @@ static int osd_ldiskfs_writelink(struct inode *inode, char *buffer, int buflen)
        LDISKFS_I(inode)->i_disksize = buflen;
        i_size_write(inode, buflen);
        spin_unlock(&inode->i_lock);
-       ll_dirty_inode(inode, I_DIRTY_DATASYNC);
+       osd_dirty_inode(inode, I_DIRTY_DATASYNC);
 
        return 0;
 }
 
-int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
-                            int write_NUL, loff_t *offs, handle_t *handle)
+static int osd_ldiskfs_write_record(struct dt_object *dt, void *buf,
+                                   int bufsize, int write_NUL, loff_t *offs,
+                                   handle_t *handle)
 {
-        struct buffer_head *bh        = NULL;
-        loff_t              offset    = *offs;
-        loff_t              new_size  = i_size_read(inode);
-        unsigned long       block;
-        int                 blocksize = 1 << inode->i_blkbits;
-        int                 err = 0;
-        int                 size;
-        int                 boffs;
-        int                 dirty_inode = 0;
+       struct inode *inode = osd_dt_obj(dt)->oo_inode;
+       struct buffer_head *bh        = NULL;
+       loff_t              offset    = *offs;
+       loff_t              new_size  = i_size_read(inode);
+       unsigned long       block;
+       int                 blocksize = 1 << inode->i_blkbits;
+       struct ldiskfs_inode_info *ei = LDISKFS_I(inode);
+       int                 err = 0;
+       int                 size;
+       int                 boffs;
+       int                 dirty_inode = 0;
+       bool create, sparse, sync = false;
 
        if (write_NUL) {
                /*
@@ -1688,8 +2048,18 @@ int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
                ++bufsize;
        }
 
+       /* only the first flag-set matters */
+       dirty_inode = !test_and_set_bit(LDISKFS_INODE_JOURNAL_DATA,
+                                      &ei->i_flags);
+
+       /* sparse checking is racy, but sparse is very rare case, leave as is */
+       sparse = (new_size > 0 && (inode->i_blocks >> (inode->i_blkbits - 9)) <
+                 ((new_size - 1) >> inode->i_blkbits) + 1);
+
        while (bufsize > 0) {
                int credits = handle->h_buffer_credits;
+               unsigned long last_block = (new_size == 0) ? 0 :
+                                          (new_size - 1) >> inode->i_blkbits;
 
                if (bh)
                        brelse(bh);
@@ -1697,7 +2067,40 @@ int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
                block = offset >> inode->i_blkbits;
                boffs = offset & (blocksize - 1);
                size = min(blocksize - boffs, bufsize);
-               bh = __ldiskfs_bread(handle, inode, block, 1);
+               sync = (block > last_block || new_size == 0 || sparse);
+
+               if (sync)
+                       down(&ei->i_append_sem);
+
+               bh = __ldiskfs_bread(handle, inode, block, 0);
+
+               if (unlikely(IS_ERR_OR_NULL(bh) && !sync))
+                       CWARN(
+                             "%s: adding bh without locking off %llu (block %lu, size %d, offs %llu)\n",
+                             osd_ino2name(inode),
+                             offset, block, bufsize, *offs);
+
+               if (IS_ERR_OR_NULL(bh)) {
+                       struct osd_device *osd = osd_obj2dev(osd_dt_obj(dt));
+                       int flags = LDISKFS_GET_BLOCKS_CREATE;
+
+                       /* while the file system is being mounted, avoid
+                        * preallocation otherwise mount can take a long
+                        * time as mballoc cache is cold.
+                        * XXX: this is a workaround until we have a proper
+                        *      fix in mballoc
+                        * XXX: works with extent-based files only */
+                       if (!osd->od_cl_seq)
+                               flags |= LDISKFS_GET_BLOCKS_NO_NORMALIZE;
+                       bh = __ldiskfs_bread(handle, inode, block, flags);
+                       create = true;
+               } else {
+                       if (sync) {
+                               up(&ei->i_append_sem);
+                               sync = false;
+                       }
+                       create = false;
+               }
                if (IS_ERR_OR_NULL(bh)) {
                        if (bh == NULL) {
                                err = -EIO;
@@ -1706,35 +2109,45 @@ int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
                                bh = NULL;
                        }
 
-                       CERROR("%s: error reading offset %llu (block %lu, "
-                              "size %d, offs %llu), credits %d/%d: rc = %d\n",
-                              inode->i_sb->s_id, offset, block, bufsize, *offs,
-                              credits, handle->h_buffer_credits, err);
-                        break;
-                }
-
-                err = ldiskfs_journal_get_write_access(handle, bh);
-                if (err) {
-                        CERROR("journal_get_write_access() returned error %d\n",
-                               err);
-                        break;
-                }
+                       CERROR(
+                              "%s: error reading offset %llu (block %lu, size %d, offs %llu), credits %d/%d: rc = %d\n",
+                              osd_ino2name(inode), offset, block, bufsize,
+                              *offs, credits, handle->h_buffer_credits, err);
+                       break;
+               }
+
+               err = ldiskfs_journal_get_write_access(handle, bh);
+               if (err) {
+                       CERROR("journal_get_write_access() returned error %d\n",
+                              err);
+                       break;
+               }
                LASSERTF(boffs + size <= bh->b_size,
                         "boffs %d size %d bh->b_size %lu\n",
                         boffs, size, (unsigned long)bh->b_size);
-                memcpy(bh->b_data + boffs, buf, size);
+               if (create) {
+                       memset(bh->b_data, 0, bh->b_size);
+                       if (sync) {
+                               up(&ei->i_append_sem);
+                               sync = false;
+                       }
+               }
+               memcpy(bh->b_data + boffs, buf, size);
                err = ldiskfs_handle_dirty_metadata(handle, NULL, bh);
-                if (err)
-                        break;
-
-                if (offset + size > new_size)
-                        new_size = offset + size;
-                offset += size;
-                bufsize -= size;
-                buf += size;
-        }
-        if (bh)
-                brelse(bh);
+               if (err)
+                       break;
+
+               if (offset + size > new_size)
+                       new_size = offset + size;
+               offset += size;
+               bufsize -= size;
+               buf += size;
+       }
+       if (sync)
+               up(&ei->i_append_sem);
+
+       if (bh)
+               brelse(bh);
 
        if (write_NUL)
                --new_size;
@@ -1743,40 +2156,40 @@ int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
                spin_lock(&inode->i_lock);
                if (new_size > i_size_read(inode))
                        i_size_write(inode, new_size);
-               if (i_size_read(inode) > LDISKFS_I(inode)->i_disksize) {
-                       LDISKFS_I(inode)->i_disksize = i_size_read(inode);
+               if (i_size_read(inode) > ei->i_disksize) {
+                       ei->i_disksize = i_size_read(inode);
                        dirty_inode = 1;
                }
                spin_unlock(&inode->i_lock);
-               if (dirty_inode)
-                       ll_dirty_inode(inode, I_DIRTY_DATASYNC);
-        }
+       }
+       if (dirty_inode)
+               osd_dirty_inode(inode, I_DIRTY_DATASYNC);
 
-        if (err == 0)
-                *offs = offset;
-        return err;
+       if (err == 0)
+               *offs = offset;
+       return err;
 }
 
 static ssize_t osd_write(const struct lu_env *env, struct dt_object *dt,
                         const struct lu_buf *buf, loff_t *pos,
-                        struct thandle *handle, int ignore_quota)
+                        struct thandle *handle)
 {
        struct inode            *inode = osd_dt_obj(dt)->oo_inode;
        struct osd_thandle      *oh;
        ssize_t                 result;
        int                     is_link;
 
-        LASSERT(dt_object_exists(dt));
+       LASSERT(dt_object_exists(dt));
 
-        LASSERT(handle != NULL);
+       LASSERT(handle != NULL);
        LASSERT(inode != NULL);
-       ll_vfs_dq_init(inode);
+       dquot_initialize(inode);
 
-        /* XXX: don't check: one declared chunk can be used many times */
+       /* XXX: don't check: one declared chunk can be used many times */
        /* osd_trans_exec_op(env, handle, OSD_OT_WRITE); */
 
-        oh = container_of(handle, struct osd_thandle, ot_super);
-        LASSERT(oh->ot_handle->h_transaction != NULL);
+       oh = container_of(handle, struct osd_thandle, ot_super);
+       LASSERT(oh->ot_handle->h_transaction != NULL);
        osd_trans_exec_op(env, handle, OSD_OT_WRITE);
 
        /* Write small symlink to inode body as we need to maintain correct
@@ -1788,9 +2201,8 @@ static ssize_t osd_write(const struct lu_env *env, struct dt_object *dt,
        if (is_link && (buf->lb_len < sizeof(LDISKFS_I(inode)->i_data)))
                result = osd_ldiskfs_writelink(inode, buf->lb_buf, buf->lb_len);
        else
-               result = osd_ldiskfs_write_record(inode, buf->lb_buf,
-                                                 buf->lb_len, is_link, pos,
-                                                 oh->ot_handle);
+               result = osd_ldiskfs_write_record(dt, buf->lb_buf, buf->lb_len,
+                                                 is_link, pos, oh->ot_handle);
        if (result == 0)
                result = buf->lb_len;
 
@@ -1799,25 +2211,264 @@ static ssize_t osd_write(const struct lu_env *env, struct dt_object *dt,
        return result;
 }
 
+static int osd_declare_fallocate(const struct lu_env *env,
+                                struct dt_object *dt, __u64 start, __u64 end,
+                                int mode, struct thandle *th)
+{
+       struct osd_thandle *oh = container_of(th, struct osd_thandle, ot_super);
+       struct osd_device *osd = osd_obj2dev(osd_dt_obj(dt));
+       struct inode *inode = osd_dt_obj(dt)->oo_inode;
+       long long quota_space = 0;
+       /* 5 is max tree depth. (inode + 4 index blocks) */
+       int depth = 5;
+       int rc;
+
+       ENTRY;
+
+       /*
+        * mode == 0 (which is standard prealloc) and PUNCH is supported
+        * Rest of mode options is not supported yet.
+        */
+       if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
+               RETURN(-EOPNOTSUPP);
+
+       /* disable fallocate completely */
+       if (osd_dev(dt->do_lu.lo_dev)->od_fallocate_zero_blocks < 0)
+               RETURN(-EOPNOTSUPP);
+
+       LASSERT(th);
+       LASSERT(inode);
+
+       if (mode & FALLOC_FL_PUNCH_HOLE) {
+               rc = osd_declare_inode_qid(env, i_uid_read(inode),
+                                          i_gid_read(inode),
+                                          i_projid_read(inode), 0, oh,
+                                          osd_dt_obj(dt), NULL, OSD_QID_BLK);
+               if (rc == 0)
+                       rc = osd_trunc_lock(osd_dt_obj(dt), oh, false);
+               RETURN(rc);
+       }
+
+       /* quota space for metadata blocks
+        * approximate metadata estimate should be good enough.
+        */
+       quota_space += PAGE_SIZE;
+       quota_space += depth * LDISKFS_BLOCK_SIZE(osd_sb(osd));
+
+       /* quota space should be reported in 1K blocks */
+       quota_space = toqb(quota_space) + toqb(end - start) +
+                     LDISKFS_META_TRANS_BLOCKS(inode->i_sb);
+
+       /* We don't need to reserve credits for whole fallocate here.
+        * We reserve space only for metadata. Fallocate credits are
+        * extended as required
+        */
+       rc = osd_declare_inode_qid(env, i_uid_read(inode), i_gid_read(inode),
+                                  i_projid_read(inode), quota_space, oh,
+                                  osd_dt_obj(dt), NULL, OSD_QID_BLK);
+       RETURN(rc);
+}
+
+static int osd_fallocate_preallocate(const struct lu_env *env,
+                                    struct dt_object *dt,
+                                    __u64 start, __u64 end, int mode,
+                                    struct thandle *th)
+{
+       struct osd_thandle *oh = container_of(th, struct osd_thandle, ot_super);
+       handle_t *handle = ldiskfs_journal_current_handle();
+       unsigned int save_credits = oh->ot_credits;
+       struct osd_object *obj = osd_dt_obj(dt);
+       struct inode *inode = obj->oo_inode;
+       struct ldiskfs_map_blocks map;
+       unsigned int credits;
+       ldiskfs_lblk_t blen;
+       ldiskfs_lblk_t boff;
+       loff_t new_size = 0;
+       int depth = 0;
+       int flags;
+       int rc = 0;
+
+       ENTRY;
+
+       LASSERT(dt_object_exists(dt));
+       LASSERT(osd_invariant(obj));
+       LASSERT(inode != NULL);
+
+       CDEBUG(D_INODE, "fallocate: inode #%lu: start %llu end %llu mode %d\n",
+              inode->i_ino, start, end, mode);
+
+       dquot_initialize(inode);
+
+       LASSERT(th);
+
+       boff = start >> inode->i_blkbits;
+       blen = (ALIGN(end, 1 << inode->i_blkbits) >> inode->i_blkbits) - boff;
+
+       /* Create and mark new extents as either zero or unwritten */
+       flags = (osd_dev(dt->do_lu.lo_dev)->od_fallocate_zero_blocks ||
+                !ldiskfs_test_inode_flag(inode, LDISKFS_INODE_EXTENTS)) ?
+               LDISKFS_GET_BLOCKS_CREATE_ZERO :
+               LDISKFS_GET_BLOCKS_CREATE_UNWRIT_EXT;
+#ifndef HAVE_LDISKFS_GET_BLOCKS_KEEP_SIZE
+       if (mode & FALLOC_FL_KEEP_SIZE)
+               flags |= LDISKFS_GET_BLOCKS_KEEP_SIZE;
+#endif
+       inode_lock(inode);
+
+       if (!(mode & FALLOC_FL_KEEP_SIZE) && (end > i_size_read(inode) ||
+           end > LDISKFS_I(inode)->i_disksize)) {
+               new_size = end;
+               rc = inode_newsize_ok(inode, new_size);
+               if (rc)
+                       GOTO(out, rc);
+       }
+
+       inode_dio_wait(inode);
+
+       map.m_lblk = boff;
+       map.m_len = blen;
+
+       /* Don't normalize the request if it can fit in one extent so
+        * that it doesn't get unnecessarily split into multiple extents.
+        */
+       if (blen <= EXT_UNWRITTEN_MAX_LEN)
+               flags |= LDISKFS_GET_BLOCKS_NO_NORMALIZE;
+
+       /*
+        * credits to insert 1 extent into extent tree.
+        */
+       credits = osd_chunk_trans_blocks(inode, blen);
+       depth = ext_depth(inode);
+
+       while (rc >= 0 && blen) {
+               loff_t epos;
+
+               /*
+                * Recalculate credits when extent tree depth changes.
+                */
+               if (depth != ext_depth(inode)) {
+                       credits = osd_chunk_trans_blocks(inode, blen);
+                       depth = ext_depth(inode);
+               }
+
+               /* TODO: quota check */
+               rc = osd_extend_restart_trans(handle, credits, inode);
+               if (rc)
+                       break;
+
+               rc = ldiskfs_map_blocks(handle, inode, &map, flags);
+               if (rc <= 0) {
+                       CDEBUG(D_INODE,
+                              "inode #%lu: block %u: len %u: ldiskfs_map_blocks returned %d\n",
+                              inode->i_ino, map.m_lblk, map.m_len, rc);
+                       ldiskfs_mark_inode_dirty(handle, inode);
+                       break;
+               }
+
+               map.m_lblk += rc;
+               map.m_len = blen = blen - rc;
+               epos = (loff_t)map.m_lblk << inode->i_blkbits;
+               inode->i_ctime = current_time(inode);
+               if (new_size) {
+                       if (epos > end)
+                               epos = end;
+                       if (ldiskfs_update_inode_size(inode, epos) & 0x1)
+                               inode->i_mtime = inode->i_ctime;
+#ifndef HAVE_LDISKFS_GET_BLOCKS_KEEP_SIZE
+               } else {
+                       if (epos > inode->i_size)
+                               ldiskfs_set_inode_flag(inode,
+                                                      LDISKFS_INODE_EOFBLOCKS);
+#endif
+               }
+
+               ldiskfs_mark_inode_dirty(handle, inode);
+       }
+
+out:
+       /* extand credits if needed for operations such as attribute set */
+       if (rc >= 0)
+               rc = osd_extend_restart_trans(handle, save_credits, inode);
+
+       inode_unlock(inode);
+
+       RETURN(rc);
+}
+
+static int osd_fallocate_punch(const struct lu_env *env, struct dt_object *dt,
+                              __u64 start, __u64 end, int mode,
+                              struct thandle *th)
+{
+       struct osd_object *obj = osd_dt_obj(dt);
+       struct inode *inode = obj->oo_inode;
+       struct osd_access_lock *al;
+       struct osd_thandle *oh;
+       int rc = 0, found = 0;
+
+       ENTRY;
+
+       LASSERT(dt_object_exists(dt));
+       LASSERT(osd_invariant(obj));
+       LASSERT(inode != NULL);
+
+       dquot_initialize(inode);
+
+       LASSERT(th);
+       oh = container_of(th, struct osd_thandle, ot_super);
+       LASSERT(oh->ot_handle->h_transaction != NULL);
+
+       list_for_each_entry(al, &oh->ot_trunc_locks, tl_list) {
+               if (obj != al->tl_obj)
+                       continue;
+               LASSERT(al->tl_shared == 0);
+               found = 1;
+               /* do actual punch in osd_trans_stop() */
+               al->tl_start = start;
+               al->tl_end = end;
+               al->tl_mode = mode;
+               al->tl_punch = true;
+               break;
+       }
+
+       RETURN(rc);
+}
+
+static int osd_fallocate(const struct lu_env *env, struct dt_object *dt,
+                        __u64 start, __u64 end, int mode, struct thandle *th)
+{
+       int rc;
+
+       ENTRY;
+
+       if (mode & FALLOC_FL_PUNCH_HOLE) {
+               /* punch */
+               rc = osd_fallocate_punch(env, dt, start, end, mode, th);
+       } else {
+               /* standard preallocate */
+               rc = osd_fallocate_preallocate(env, dt, start, end, mode, th);
+       }
+       RETURN(rc);
+}
+
 static int osd_declare_punch(const struct lu_env *env, struct dt_object *dt,
-                             __u64 start, __u64 end, struct thandle *th)
+                            __u64 start, __u64 end, struct thandle *th)
 {
-        struct osd_thandle *oh;
+       struct osd_thandle *oh;
        struct inode       *inode;
        int                 rc;
-        ENTRY;
-
-        LASSERT(th);
-        oh = container_of(th, struct osd_thandle, ot_super);
-
-        /*
-         * we don't need to reserve credits for whole truncate
-         * it's not possible as truncate may need to free too many
-         * blocks and that won't fit a single transaction. instead
-         * we reserve credits to change i_size and put inode onto
-         * orphan list. if needed truncate will extend or restart
-         * transaction
-         */
+       ENTRY;
+
+       LASSERT(th);
+       oh = container_of(th, struct osd_thandle, ot_super);
+
+       /*
+        * we don't need to reserve credits for whole truncate
+        * it's not possible as truncate may need to free too many
+        * blocks and that won't fit a single transaction. instead
+        * we reserve credits to change i_size and put inode onto
+        * orphan list. if needed truncate will extend or restart
+        * transaction
+        */
        osd_trans_declare_op(env, oh, OSD_OT_PUNCH,
                             osd_dto_credits_noquota[DTO_ATTR_SET_BASE] + 3);
 
@@ -1827,73 +2478,91 @@ static int osd_declare_punch(const struct lu_env *env, struct dt_object *dt,
        rc = osd_declare_inode_qid(env, i_uid_read(inode), i_gid_read(inode),
                                   i_projid_read(inode), 0, oh, osd_dt_obj(dt),
                                   NULL, OSD_QID_BLK);
+
+       if (rc == 0)
+               rc = osd_trunc_lock(osd_dt_obj(dt), oh, false);
+
        RETURN(rc);
 }
 
 static int osd_punch(const struct lu_env *env, struct dt_object *dt,
                     __u64 start, __u64 end, struct thandle *th)
 {
+       struct osd_object *obj = osd_dt_obj(dt);
+       struct osd_device *osd = osd_obj2dev(obj);
+       struct inode *inode = obj->oo_inode;
+       struct osd_access_lock *al;
        struct osd_thandle *oh;
-       struct osd_object  *obj = osd_dt_obj(dt);
-       struct inode       *inode = obj->oo_inode;
-       handle_t           *h;
-       tid_t               tid;
-       int                rc = 0, rc2 = 0;
+       int rc = 0, found = 0;
+       bool grow = false;
        ENTRY;
 
-       LASSERT(end == OBD_OBJECT_EOF);
        LASSERT(dt_object_exists(dt));
        LASSERT(osd_invariant(obj));
        LASSERT(inode != NULL);
-       ll_vfs_dq_init(inode);
+       dquot_initialize(inode);
 
        LASSERT(th);
        oh = container_of(th, struct osd_thandle, ot_super);
        LASSERT(oh->ot_handle->h_transaction != NULL);
 
-       osd_trans_exec_op(env, th, OSD_OT_PUNCH);
+       /* we used to skip truncate to current size to
+        * optimize truncates on OST. with DoM we can
+        * get attr_set to set specific size (MDS_REINT)
+        * and then get truncate RPC which essentially
+        * would be skipped. this is bad.. so, disable
+        * this optimization on MDS till the client stop
+        * to sent MDS_REINT (LU-11033) -bzzz
+        */
+       if (osd->od_is_ost && i_size_read(inode) == start)
+               RETURN(0);
 
-       tid = oh->ot_handle->h_transaction->t_tid;
+       osd_trans_exec_op(env, th, OSD_OT_PUNCH);
 
        spin_lock(&inode->i_lock);
+       if (i_size_read(inode) < start)
+               grow = true;
        i_size_write(inode, start);
        spin_unlock(&inode->i_lock);
+       /* if object holds encrypted content, we need to make sure we truncate
+        * on an encryption unit boundary, or subsequent reads will get
+        * corrupted content
+        */
+       if (obj->oo_lma_flags & LUSTRE_ENCRYPT_FL &&
+           start & ~LUSTRE_ENCRYPTION_MASK)
+               start = (start & LUSTRE_ENCRYPTION_MASK) +
+                       LUSTRE_ENCRYPTION_UNIT_SIZE;
        ll_truncate_pagecache(inode, start);
-#ifdef HAVE_INODEOPS_TRUNCATE
-       if (inode->i_op->truncate) {
-               inode->i_op->truncate(inode);
-       } else
-#endif
-               ldiskfs_truncate(inode);
 
-       /*
-        * For a partial-page truncate, flush the page to disk immediately to
-        * avoid data corruption during direct disk write.  b=17397
+       /* optimize grow case */
+       if (grow) {
+               osd_execute_truncate(obj);
+               GOTO(out, rc);
+       }
+
+       inode_lock(inode);
+       /* add to orphan list to ensure truncate completion
+        * if this transaction succeed. ldiskfs_truncate()
+        * will take the inode out of the list
         */
-       if ((start & ~PAGE_MASK) != 0)
-                rc = filemap_fdatawrite_range(inode->i_mapping, start, start+1);
-
-        h = journal_current_handle();
-        LASSERT(h != NULL);
-        LASSERT(h == oh->ot_handle);
-
-       /* do not check credits with osd_trans_exec_check() as the truncate
-        * can restart the transaction internally and we restart the
-        * transaction in this case */
-
-        if (tid != h->h_transaction->t_tid) {
-                int credits = oh->ot_credits;
-                /*
-                 * transaction has changed during truncate
-                 * we need to restart the handle with our credits
-                 */
-                if (h->h_buffer_credits < credits) {
-                        if (ldiskfs_journal_extend(h, credits))
-                                rc2 = ldiskfs_journal_restart(h, credits);
-                }
-        }
-
-        RETURN(rc == 0 ? rc2 : rc);
+       rc = ldiskfs_orphan_add(oh->ot_handle, inode);
+       inode_unlock(inode);
+       if (rc != 0)
+               GOTO(out, rc);
+
+       list_for_each_entry(al, &oh->ot_trunc_locks, tl_list) {
+               if (obj != al->tl_obj)
+                       continue;
+               LASSERT(al->tl_shared == 0);
+               found = 1;
+               /* do actual truncate in osd_trans_stop() */
+               al->tl_truncate = 1;
+               break;
+       }
+       LASSERT(found);
+
+out:
+       RETURN(rc);
 }
 
 static int fiemap_check_ranges(struct inode *inode,
@@ -1934,7 +2603,6 @@ static int osd_fiemap_get(const struct lu_env *env, struct dt_object *dt,
        u64 len;
        int rc;
 
-
        LASSERT(inode);
        if (inode->i_op->fiemap == NULL)
                return -EOPNOTSUPP;
@@ -1963,17 +2631,16 @@ static int osd_fiemap_get(const struct lu_env *env, struct dt_object *dt,
 static int osd_ladvise(const struct lu_env *env, struct dt_object *dt,
                       __u64 start, __u64 end, enum lu_ladvise_type advice)
 {
-       int              rc = 0;
-       struct inode    *inode = osd_dt_obj(dt)->oo_inode;
+       struct osd_object *obj = osd_dt_obj(dt);
+       int rc = 0;
        ENTRY;
 
        switch (advice) {
        case LU_LADVISE_DONTNEED:
-               if (end == 0)
-                       break;
-               invalidate_mapping_pages(inode->i_mapping,
-                                        start >> PAGE_CACHE_SHIFT,
-                                        (end - 1) >> PAGE_CACHE_SHIFT);
+               if (end)
+                       invalidate_mapping_pages(obj->oo_inode->i_mapping,
+                                                start >> PAGE_SHIFT,
+                                                (end - 1) >> PAGE_SHIFT);
                break;
        default:
                rc = -ENOTSUPP;
@@ -1983,12 +2650,49 @@ static int osd_ladvise(const struct lu_env *env, struct dt_object *dt,
        RETURN(rc);
 }
 
+static loff_t osd_lseek(const struct lu_env *env, struct dt_object *dt,
+                       loff_t offset, int whence)
+{
+       struct osd_object *obj = osd_dt_obj(dt);
+       struct osd_device *dev = osd_obj2dev(obj);
+       struct inode *inode = obj->oo_inode;
+       struct file *file;
+       loff_t result;
+
+       ENTRY;
+       LASSERT(dt_object_exists(dt));
+       LASSERT(osd_invariant(obj));
+       LASSERT(inode);
+       LASSERT(offset >= 0);
+
+       file = alloc_file_pseudo(inode, dev->od_mnt, "/", O_NOATIME,
+                                inode->i_fop);
+       if (IS_ERR(file))
+               RETURN(PTR_ERR(file));
+
+       file->f_mode |= FMODE_64BITHASH;
+       result = file->f_op->llseek(file, offset, whence);
+       ihold(inode);
+       fput(file);
+       /*
+        * If 'offset' is beyond end of object file then treat it as not error
+        * but valid case for SEEK_HOLE and return 'offset' as result.
+        * LOV will decide if it is beyond real end of file or not.
+        */
+       if (whence == SEEK_HOLE && result == -ENXIO)
+               result = offset;
+
+       CDEBUG(D_INFO, "seek %s from %lld: %lld\n", whence == SEEK_HOLE ?
+                      "hole" : "data", offset, result);
+       RETURN(result);
+}
+
 /*
  * in some cases we may need declare methods for objects being created
  * e.g., when we create symlink
  */
 const struct dt_body_operations osd_body_ops_new = {
-        .dbo_declare_write = osd_declare_write,
+       .dbo_declare_write = osd_declare_write,
 };
 
 const struct dt_body_operations osd_body_ops = {
@@ -2005,4 +2709,188 @@ const struct dt_body_operations osd_body_ops = {
        .dbo_punch                      = osd_punch,
        .dbo_fiemap_get                 = osd_fiemap_get,
        .dbo_ladvise                    = osd_ladvise,
+       .dbo_declare_fallocate          = osd_declare_fallocate,
+       .dbo_fallocate                  = osd_fallocate,
+       .dbo_lseek                      = osd_lseek,
 };
+
+/**
+ * Get a truncate lock
+ *
+ * In order to take multi-transaction truncate out of main transaction we let
+ * the caller grab a lock on the object passed. the lock can be shared (for
+ * writes) and exclusive (for truncate). It's not allowed to mix truncate
+ * and write in the same transaction handle (do not confuse with big ldiskfs
+ * transaction containing lots of handles).
+ * The lock must be taken at declaration.
+ *
+ * \param obj          object to lock
+ * \oh                 transaction
+ * \shared             shared or exclusive
+ *
+ * \retval 0           lock is granted
+ * \retval -NOMEM      no memory to allocate lock
+ */
+int osd_trunc_lock(struct osd_object *obj, struct osd_thandle *oh, bool shared)
+{
+       struct osd_access_lock *al, *tmp;
+
+       LASSERT(obj);
+       LASSERT(oh);
+
+       list_for_each_entry(tmp, &oh->ot_trunc_locks, tl_list) {
+               if (tmp->tl_obj != obj)
+                       continue;
+               LASSERT(tmp->tl_shared == shared);
+               /* found same lock */
+               return 0;
+       }
+
+       OBD_ALLOC_PTR(al);
+       if (unlikely(al == NULL))
+               return -ENOMEM;
+       al->tl_obj = obj;
+       al->tl_truncate = false;
+       if (shared)
+               down_read(&obj->oo_ext_idx_sem);
+       else
+               down_write(&obj->oo_ext_idx_sem);
+       al->tl_shared = shared;
+       lu_object_get(&obj->oo_dt.do_lu);
+
+       list_add(&al->tl_list, &oh->ot_trunc_locks);
+
+       return 0;
+}
+
+void osd_trunc_unlock_all(const struct lu_env *env, struct list_head *list)
+{
+       struct osd_access_lock *al, *tmp;
+
+       list_for_each_entry_safe(al, tmp, list, tl_list) {
+               if (al->tl_shared)
+                       up_read(&al->tl_obj->oo_ext_idx_sem);
+               else
+                       up_write(&al->tl_obj->oo_ext_idx_sem);
+               osd_object_put(env, al->tl_obj);
+               list_del(&al->tl_list);
+               OBD_FREE_PTR(al);
+       }
+}
+
+/* For a partial-page punch, flush punch range to disk immediately */
+static void osd_partial_page_flush_punch(struct osd_device *d,
+                                        struct inode *inode, loff_t start,
+                                        loff_t end)
+{
+       if (osd_use_page_cache(d)) {
+               filemap_fdatawrite_range(inode->i_mapping, start, end);
+       } else {
+               /* Notice we use "wait" version to ensure I/O is complete */
+               filemap_write_and_wait_range(inode->i_mapping, start,
+                                            end);
+               invalidate_mapping_pages(inode->i_mapping, start >> PAGE_SHIFT,
+                                        end >> PAGE_SHIFT);
+       }
+}
+
+/*
+ * For a partial-page truncate, flush the page to disk immediately to
+ * avoid data corruption during direct disk write.  b=17397
+ */
+static void osd_partial_page_flush(struct osd_device *d, struct inode *inode,
+                                  loff_t offset)
+{
+       if (!(offset & ~PAGE_MASK))
+               return;
+
+       if (osd_use_page_cache(d)) {
+               filemap_fdatawrite_range(inode->i_mapping, offset, offset + 1);
+       } else {
+               /* Notice we use "wait" version to ensure I/O is complete */
+               filemap_write_and_wait_range(inode->i_mapping, offset,
+                                            offset + 1);
+               invalidate_mapping_pages(inode->i_mapping, offset >> PAGE_SHIFT,
+                                        offset >> PAGE_SHIFT);
+       }
+}
+
+void osd_execute_truncate(struct osd_object *obj)
+{
+       struct osd_device *d = osd_obj2dev(obj);
+       struct inode *inode = obj->oo_inode;
+       __u64 size;
+
+       /* simulate crash before (in the middle) of delayed truncate */
+       if (OBD_FAIL_CHECK(OBD_FAIL_OSD_FAIL_AT_TRUNCATE)) {
+               struct ldiskfs_inode_info *ei = LDISKFS_I(inode);
+               struct ldiskfs_sb_info *sbi = LDISKFS_SB(inode->i_sb);
+
+               mutex_lock(&sbi->s_orphan_lock);
+               list_del_init(&ei->i_orphan);
+               mutex_unlock(&sbi->s_orphan_lock);
+               return;
+       }
+
+       size = i_size_read(inode);
+       inode_lock(inode);
+       /* if object holds encrypted content, we need to make sure we truncate
+        * on an encryption unit boundary, or block content will get corrupted
+        */
+       if (obj->oo_lma_flags & LUSTRE_ENCRYPT_FL &&
+           size & ~LUSTRE_ENCRYPTION_MASK)
+               inode->i_size = (size & LUSTRE_ENCRYPTION_MASK) +
+                       LUSTRE_ENCRYPTION_UNIT_SIZE;
+       ldiskfs_truncate(inode);
+       inode_unlock(inode);
+       if (inode->i_size != size) {
+               spin_lock(&inode->i_lock);
+               i_size_write(inode, size);
+               LDISKFS_I(inode)->i_disksize = size;
+               spin_unlock(&inode->i_lock);
+               osd_dirty_inode(inode, I_DIRTY_DATASYNC);
+       }
+       osd_partial_page_flush(d, inode, size);
+}
+
+static int osd_execute_punch(const struct lu_env *env, struct osd_object *obj,
+                            loff_t start, loff_t end, int mode)
+{
+       struct osd_device *d = osd_obj2dev(obj);
+       struct inode *inode = obj->oo_inode;
+       struct file *file;
+       int rc;
+
+       file = alloc_file_pseudo(inode, d->od_mnt, "/", O_NOATIME,
+                                inode->i_fop);
+       if (IS_ERR(file))
+               RETURN(PTR_ERR(file));
+
+       file->f_mode |= FMODE_64BITHASH;
+       rc = file->f_op->fallocate(file, mode, start, end - start);
+       ihold(inode);
+       fput(file);
+       if (rc == 0)
+               osd_partial_page_flush_punch(d, inode, start, end - 1);
+       return rc;
+}
+
+int osd_process_truncates(const struct lu_env *env, struct list_head *list)
+{
+       struct osd_access_lock *al;
+       int rc = 0;
+
+       LASSERT(!journal_current_handle());
+
+       list_for_each_entry(al, list, tl_list) {
+               if (al->tl_shared)
+                       continue;
+               if (al->tl_truncate)
+                       osd_execute_truncate(al->tl_obj);
+               else if (al->tl_punch)
+                       rc = osd_execute_punch(env, al->tl_obj, al->tl_start,
+                                              al->tl_end, al->tl_mode);
+       }
+
+       return rc;
+}