Whamcloud - gitweb
LU-359 llite: no close error if application has known failure
[fs/lustre-release.git] / lustre / llite / rw.c
index af18871..310cf45 100644 (file)
@@ -1,6 +1,4 @@
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
+/*
  * GPL HEADER START
  *
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  * GPL HEADER END
  */
 /*
- * Copyright  2008 Sun Microsystems, Inc. All rights reserved
+ * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2012, Whamcloud, Inc.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
  * Lustre Lite I/O page cache routines shared by different kernel revs
  */
 
-#include <linux/autoconf.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/string.h>
 #include <linux/stat.h>
 #include <linux/errno.h>
-#include <linux/smp_lock.h>
 #include <linux/unistd.h>
 #include <linux/version.h>
 #include <asm/system.h>
 #include <asm/uaccess.h>
 #include <linux/mm.h>
 #include <linux/pagemap.h>
-#include <linux/smp_lock.h>
 /* current_is_kswapd() */
 #include <linux/swap.h>
 
 #define DEBUG_SUBSYSTEM S_LLITE
 
-//#include <lustre_mdc.h>
 #include <lustre_lite.h>
 #include <obd_cksum.h>
 #include "llite_internal.h"
  * must be called under ->lli_size_sem */
 void ll_truncate(struct inode *inode)
 {
-        struct ll_inode_info *lli = ll_i2info(inode);
-        loff_t new_size;
         ENTRY;
-        CDEBUG(D_VFSTRACE, "VFS Op:inode=%lu/%u(%p) to %Lu=%#Lx\n",inode->i_ino,
-               inode->i_generation, inode, i_size_read(inode),
-               i_size_read(inode));
-
-        ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_TRUNC, 1);
-        if (lli->lli_size_sem_owner != cfs_current()) {
-                EXIT;
-                return;
-        }
-
-        if (!lli->lli_smd) {
-                CDEBUG(D_INODE, "truncate on inode %lu with no objects\n",
-                       inode->i_ino);
-                GOTO(out_unlock, 0);
-        }
-        LASSERT_SEM_LOCKED(&lli->lli_size_sem);
-
-        if (unlikely((ll_i2sbi(inode)->ll_flags & LL_SBI_CHECKSUM) &&
-                     (i_size_read(inode) & ~CFS_PAGE_MASK))) {
-                /* If the truncate leaves a partial page, update its checksum */
-                struct page *page = find_get_page(inode->i_mapping,
-                                                  i_size_read(inode) >>
-                                                  CFS_PAGE_SHIFT);
-                if (page != NULL) {
-#if 0 /* XXX */
-                        struct ll_async_page *llap = llap_cast_private(page);
-                        if (llap != NULL) {
-                                char *kaddr = kmap_atomic(page, KM_USER0);
-                                llap->llap_checksum =
-                                        init_checksum(OSC_DEFAULT_CKSUM);
-                                llap->llap_checksum =
-                                        compute_checksum(llap->llap_checksum,
-                                                         kaddr, CFS_PAGE_SIZE,
-                                                         OSC_DEFAULT_CKSUM);
-                                kunmap_atomic(kaddr, KM_USER0);
-                        }
-                        page_cache_release(page);
-#endif
-                }
-        }
 
-        new_size = i_size_read(inode);
-        ll_inode_size_unlock(inode, 0);
+        CDEBUG(D_VFSTRACE, "VFS Op:inode=%lu/%u(%p) to %llu\n", inode->i_ino,
+               inode->i_generation, inode, i_size_read(inode));
 
         EXIT;
         return;
-
- out_unlock:
-        ll_inode_size_unlock(inode, 0);
 } /* ll_truncate */
 
 /**
@@ -188,17 +139,28 @@ static struct ll_cl_context *ll_cl_init(struct file *file,
         cio = ccc_env_io(env);
         io = cio->cui_cl.cis_io;
         if (io == NULL && create) {
-                struct vvp_io *vio;
-                loff_t pos;
+               struct inode *inode = vmpage->mapping->host;
+               loff_t pos;
+
+               if (mutex_trylock(&inode->i_mutex)) {
+                       mutex_unlock(&(inode)->i_mutex);
+
+                       /* this is too bad. Someone is trying to write the
+                        * page w/o holding inode mutex. This means we can
+                        * add dirty pages into cache during truncate */
+                       CERROR("Proc %s is dirting page w/o inode lock, this"
+                              "will break truncate.\n", cfs_current()->comm);
+                       libcfs_debug_dumpstack(NULL);
+                       LBUG();
+                       return ERR_PTR(-EIO);
+               }
 
                 /*
                  * Loop-back driver calls ->prepare_write() and ->sendfile()
                  * methods directly, bypassing file system ->write() operation,
                  * so cl_io has to be created here.
                  */
-
-                io = &ccc_env_info(env)->cti_io;
-                vio = vvp_env_io(env);
+                io = ccc_env_thread_io(env);
                 ll_io_init(io, file, 1);
 
                 /* No lock at all for this kind of IO - we can't do it because
@@ -252,7 +214,7 @@ static struct ll_cl_context *ll_cl_init(struct file *file,
                 lcc = ERR_PTR(result);
         }
 
-        CDEBUG(D_VFSTRACE, "%lu@"DFID" -> %i %p %p\n",
+        CDEBUG(D_VFSTRACE, "%lu@"DFID" -> %d %p %p\n",
                vmpage->index, PFID(lu_object_fid(&clob->co_lu)), result,
                env, io);
         return lcc;
@@ -332,7 +294,7 @@ int ll_commit_write(struct file *file, struct page *vmpage, unsigned from,
         struct lu_env    *env;
         struct cl_io     *io;
         struct cl_page   *page;
-        int result;
+        int result = 0;
         ENTRY;
 
         lcc  = ll_cl_get();
@@ -341,11 +303,14 @@ int ll_commit_write(struct file *file, struct page *vmpage, unsigned from,
         io   = lcc->lcc_io;
 
         LASSERT(cl_page_is_owned(page, io));
-        result = cl_io_commit_write(env, io, page, from, to);
+        LASSERT(from <= to);
+        if (from != to) /* handle short write case. */
+                result = cl_io_commit_write(env, io, page, from, to);
         if (cl_page_is_owned(page, io))
                 cl_page_unassume(env, io, page);
+
         /*
-         * Release reference acquired by cl_io_prepare_write().
+         * Release reference acquired by ll_prepare_write().
          */
         lu_ref_del(&page->cp_reference, "prepare_write", cfs_current());
         cl_page_put(env, page);
@@ -363,35 +328,62 @@ struct obd_capa *cl_capa_lookup(struct inode *inode, enum cl_req_type crt)
 
 static void ll_ra_stats_inc_sbi(struct ll_sb_info *sbi, enum ra_stat which);
 
-/* WARNING: This algorithm is used to reduce the contention on
- * sbi->ll_lock. It should work well if the ra_max_pages is much
- * greater than the single file's read-ahead window.
+/**
+ * Get readahead pages from the filesystem readahead pool of the client for a
+ * thread.
  *
- * TODO: There may exist a `global sync problem' in this implementation.
- * Considering the global ra window is 100M, and each file's ra window is 10M,
- * there are over 10 files trying to get its ra budget and reach
- * ll_ra_count_get at the exactly same time. All of them will get a zero ra
- * window, although the global window is 100M. -jay
- */
-static unsigned long ll_ra_count_get(struct ll_sb_info *sbi, unsigned long len)
+ * /param sbi superblock for filesystem readahead state ll_ra_info
+ * /param ria per-thread readahead state
+ * /param pages number of pages requested for readahead for the thread.
+ *
+ * WARNING: This algorithm is used to reduce contention on sbi->ll_lock.
+ * It should work well if the ra_max_pages is much greater than the single
+ * file's read-ahead window, and not too many threads contending for
+ * these readahead pages.
+ *
+ * TODO: There may be a 'global sync problem' if many threads are trying
+ * to get an ra budget that is larger than the remaining readahead pages
+ * and reach here at exactly the same time. They will compute /a ret to
+ * consume the remaining pages, but will fail at atomic_add_return() and
+ * get a zero ra window, although there is still ra space remaining. - Jay */
+
+static unsigned long ll_ra_count_get(struct ll_sb_info *sbi,
+                                     struct ra_io_arg *ria,
+                                     unsigned long pages)
 {
         struct ll_ra_info *ra = &sbi->ll_ra_info;
-        unsigned long ret;
+        long ret;
         ENTRY;
 
-        /**
-         * If read-ahead pages left are less than 1M, do not do read-ahead,
+        /* If read-ahead pages left are less than 1M, do not do read-ahead,
          * otherwise it will form small read RPC(< 1M), which hurt server
-         * performance a lot.
-         */
-        ret = min(ra->ra_max_pages - cfs_atomic_read(&ra->ra_cur_pages), len);
-        if ((int)ret < 0 || ret < min((unsigned long)PTLRPC_MAX_BRW_PAGES, len))
+         * performance a lot. */
+        ret = min(ra->ra_max_pages - cfs_atomic_read(&ra->ra_cur_pages), pages);
+        if (ret < 0 || ret < min_t(long, PTLRPC_MAX_BRW_PAGES, pages))
                 GOTO(out, ret = 0);
 
+        /* If the non-strided (ria_pages == 0) readahead window
+         * (ria_start + ret) has grown across an RPC boundary, then trim
+         * readahead size by the amount beyond the RPC so it ends on an
+         * RPC boundary. If the readahead window is already ending on
+         * an RPC boundary (beyond_rpc == 0), or smaller than a full
+         * RPC (beyond_rpc < ret) the readahead size is unchanged.
+         * The (beyond_rpc != 0) check is skipped since the conditional
+         * branch is more expensive than subtracting zero from the result.
+         *
+         * Strided read is left unaligned to avoid small fragments beyond
+         * the RPC boundary from needing an extra read RPC. */
+        if (ria->ria_pages == 0) {
+                long beyond_rpc = (ria->ria_start + ret) % PTLRPC_MAX_BRW_PAGES;
+                if (/* beyond_rpc != 0 && */ beyond_rpc < ret)
+                        ret -= beyond_rpc;
+        }
+
         if (cfs_atomic_add_return(ret, &ra->ra_cur_pages) > ra->ra_max_pages) {
                 cfs_atomic_sub(ret, &ra->ra_cur_pages);
                 ret = 0;
         }
+
 out:
         RETURN(ret);
 }
@@ -541,7 +533,7 @@ static int cl_read_ahead_page(const struct lu_env *env, struct cl_io *io,
  */
 static int ll_read_ahead_page(const struct lu_env *env, struct cl_io *io,
                               struct cl_page_list *queue,
-                              int index, struct address_space *mapping)
+                              pgoff_t index, struct address_space *mapping)
 {
         struct page      *vmpage;
         struct cl_object *clob  = ll_i2info(mapping->host)->lli_clob;
@@ -557,7 +549,7 @@ static int ll_read_ahead_page(const struct lu_env *env, struct cl_io *io,
 #ifdef __GFP_NOWARN
         gfp_mask |= __GFP_NOWARN;
 #endif
-        vmpage = grab_cache_page_nowait_gfp(mapping, index, gfp_mask);
+        vmpage = grab_cache_page_nowait(mapping, index);
         if (vmpage != NULL) {
                 /* Check if vmpage was truncated or reclaimed */
                 if (vmpage->mapping == mapping) {
@@ -625,8 +617,8 @@ static unsigned long
 stride_pg_count(pgoff_t st_off, unsigned long st_len, unsigned long st_pgs,
                 unsigned long off, unsigned long length)
 {
-        unsigned long start = off > st_off ? off - st_off : 0;
-        unsigned long end = off + length > st_off ? off + length - st_off : 0;
+        __u64 start = off > st_off ? off - st_off : 0;
+        __u64 end = off + length > st_off ? off + length - st_off : 0;
         unsigned long start_left = 0;
         unsigned long end_left = 0;
         unsigned long pg_count;
@@ -644,7 +636,7 @@ stride_pg_count(pgoff_t st_off, unsigned long st_len, unsigned long st_pgs,
         if (end_left > st_pgs)
                 end_left = st_pgs;
 
-        CDEBUG(D_READA, "start %lu, end %lu start_left %lu end_left %lu \n",
+        CDEBUG(D_READA, "start "LPU64", end "LPU64" start_left %lu end_left %lu \n",
                start, end, start_left, end_left);
 
         if (start == end)
@@ -676,7 +668,8 @@ static int ras_inside_ra_window(unsigned long idx, struct ra_io_arg *ria)
          * For stride I/O mode, just check whether the idx is inside
          * the ria_pages. */
         return ria->ria_length == 0 || ria->ria_length == ria->ria_pages ||
-               (idx - ria->ria_stoff) % ria->ria_length < ria->ria_pages;
+               (idx >= ria->ria_stoff && (idx - ria->ria_stoff) %
+                ria->ria_length < ria->ria_pages);
 }
 
 static int ll_read_ahead_pages(const struct lu_env *env,
@@ -712,10 +705,10 @@ static int ll_read_ahead_pages(const struct lu_env *env,
                         /* FIXME: This assertion only is valid when it is for
                          * forward read-ahead, it will be fixed when backward
                          * read-ahead is implemented */
-                        LASSERTF(page_idx > ria->ria_stoff, "since %lu in the"
-                                " gap of ra window,it should bigger than stride"
-                                " offset %lu \n", page_idx, ria->ria_stoff);
-
+                        LASSERTF(page_idx > ria->ria_stoff, "Invalid page_idx %lu"
+                                "rs %lu re %lu ro %lu rl %lu rp %lu\n", page_idx,
+                                ria->ria_start, ria->ria_end, ria->ria_stoff,
+                                ria->ria_length, ria->ria_pages);
                         offset = page_idx - ria->ria_stoff;
                         offset = offset % (ria->ria_length);
                         if (offset > ria->ria_pages) {
@@ -784,8 +777,28 @@ int ll_readahead(const struct lu_env *env, struct cl_io *io,
                 end = ras->ras_window_start + ras->ras_window_len - 1;
         }
         if (end != 0) {
+                unsigned long rpc_boundary;
+                /*
+                 * Align RA window to an optimal boundary.
+                 *
+                 * XXX This would be better to align to cl_max_pages_per_rpc
+                 * instead of PTLRPC_MAX_BRW_PAGES, because the RPC size may
+                 * be aligned to the RAID stripe size in the future and that
+                 * is more important than the RPC size.
+                 */
+                /* Note: we only trim the RPC, instead of extending the RPC
+                 * to the boundary, so to avoid reading too much pages during
+                 * random reading. */
+                rpc_boundary = ((end + 1) & (~(PTLRPC_MAX_BRW_PAGES - 1)));
+                if (rpc_boundary > 0)
+                        rpc_boundary--;
+
+                if (rpc_boundary  > start)
+                        end = rpc_boundary;
+
                 /* Truncate RA window to end of file */
                 end = min(end, (unsigned long)((kms - 1) >> CFS_PAGE_SHIFT));
+
                 ras->ras_next_readahead = max(end, end + 1);
                 RAS_CDEBUG(ras);
         }
@@ -807,12 +820,13 @@ int ll_readahead(const struct lu_env *env, struct cl_io *io,
         if (len == 0)
                 RETURN(0);
 
-        reserved = ll_ra_count_get(ll_i2sbi(inode), len);
-
+        reserved = ll_ra_count_get(ll_i2sbi(inode), ria, len);
         if (reserved < len)
                 ll_ra_stats_inc(mapping, RA_STAT_MAX_IN_FLIGHT);
 
-        CDEBUG(D_READA, "reserved page %lu \n", reserved);
+        CDEBUG(D_READA, "reserved page %lu ra_cur %d ra_max %lu\n", reserved,
+               cfs_atomic_read(&ll_i2sbi(inode)->ll_ra_info.ra_cur_pages),
+               ll_i2sbi(inode)->ll_ra_info.ra_max_pages);
 
         ret = ll_read_ahead_pages(env, io, queue,
                                   ria, &reserved, mapping, &ra_end);
@@ -1000,7 +1014,6 @@ void ras_update(struct ll_sb_info *sbi, struct inode *inode,
         int zero = 0, stride_detect = 0, ra_miss = 0;
         ENTRY;
 
-        cfs_spin_lock(&sbi->ll_lock);
         cfs_spin_lock(&ras->ras_lock);
 
         ll_ra_stats_inc_sbi(sbi, hit ? RA_STAT_HIT : RA_STAT_MISS);
@@ -1100,8 +1113,16 @@ void ras_update(struct ll_sb_info *sbi, struct inode *inode,
         ras->ras_consecutive_pages++;
         ras->ras_last_readpage = index;
         ras_set_start(ras, index);
-        ras->ras_next_readahead = max(ras->ras_window_start,
-                                      ras->ras_next_readahead);
+
+        if (stride_io_mode(ras))
+                /* Since stride readahead is sentivite to the offset
+                 * of read-ahead, so we use original offset here,
+                 * instead of ras_window_start, which is 1M aligned*/
+                ras->ras_next_readahead = max(index,
+                                              ras->ras_next_readahead);
+        else
+                ras->ras_next_readahead = max(ras->ras_window_start,
+                                              ras->ras_next_readahead);
         RAS_CDEBUG(ras);
 
         /* Trigger RA in the mmap case where ras_consecutive_requests
@@ -1133,38 +1154,38 @@ out_unlock:
         RAS_CDEBUG(ras);
         ras->ras_request_index++;
         cfs_spin_unlock(&ras->ras_lock);
-        cfs_spin_unlock(&sbi->ll_lock);
         return;
 }
 
-int ll_writepage(struct page *vmpage, struct writeback_control *unused)
+int ll_writepage(struct page *vmpage, struct writeback_control *wbc)
 {
-        struct inode           *inode = vmpage->mapping->host;
+       struct inode           *inode = vmpage->mapping->host;
+       struct ll_inode_info   *lli   = ll_i2info(inode);
         struct lu_env          *env;
         struct cl_io           *io;
         struct cl_page         *page;
         struct cl_object       *clob;
-        struct cl_2queue       *queue;
         struct cl_env_nest      nest;
+       bool redirtied = false;
+       bool unlocked = false;
         int result;
         ENTRY;
 
         LASSERT(PageLocked(vmpage));
         LASSERT(!PageWriteback(vmpage));
 
-        if (ll_i2dtexp(inode) == NULL)
-                RETURN(-EINVAL);
+       LASSERT(ll_i2dtexp(inode) != NULL);
 
-        env = cl_env_nested_get(&nest);
-        if (IS_ERR(env))
-                RETURN(PTR_ERR(env));
+       env = cl_env_nested_get(&nest);
+       if (IS_ERR(env))
+               GOTO(out, result = PTR_ERR(env));
 
-        io    = &ccc_env_info(env)->cti_io;
-        queue = &vvp_env_info(env)->vti_queue;
         clob  = ll_i2info(inode)->lli_clob;
         LASSERT(clob != NULL);
 
+        io = ccc_env_thread_io(env);
         io->ci_obj = clob;
+       io->ci_ignore_layout = 1;
         result = cl_io_init(env, io, CIT_MISC, clob);
         if (result == 0) {
                 page = cl_page_find(env, clob, vmpage->index,
@@ -1173,42 +1194,101 @@ int ll_writepage(struct page *vmpage, struct writeback_control *unused)
                         lu_ref_add(&page->cp_reference, "writepage",
                                    cfs_current());
                         cl_page_assume(env, io, page);
-                        /*
-                         * Mark page dirty, because this is what
-                         * ->vio_submit()->cpo_prep_write() assumes.
-                         *
-                         * XXX better solution is to detect this from within
-                         * cl_io_submit_rw() somehow.
-                         */
-                        set_page_dirty(vmpage);
-                        cl_2queue_init_page(queue, page);
-                        result = cl_io_submit_rw(env, io, CRT_WRITE,
-                                                 queue, CRP_NORMAL);
-                        cl_page_list_disown(env, io, &queue->c2_qin);
-                        if (result != 0) {
-                                /*
-                                 * There is no need to clear PG_writeback, as
-                                 * cl_io_submit_rw() calls completion callback
-                                 * on failure.
-                                 */
-                                /*
-                                 * Re-dirty page on error so it retries write,
-                                 * but not in case when IO has actually
-                                 * occurred and completed with an error.
-                                 */
-                                if (!PageError(vmpage))
-                                        set_page_dirty(vmpage);
-                        }
-                        LASSERT(!cl_page_is_owned(page, io));
+                       result = cl_page_flush(env, io, page);
+                       if (result != 0) {
+                               /*
+                                * Re-dirty page on error so it retries write,
+                                * but not in case when IO has actually
+                                * occurred and completed with an error.
+                                */
+                               if (!PageError(vmpage)) {
+                                       redirty_page_for_writepage(wbc, vmpage);
+                                       result = 0;
+                                       redirtied = true;
+                               }
+                       }
+                       cl_page_disown(env, io, page);
+                       unlocked = true;
                         lu_ref_del(&page->cp_reference,
                                    "writepage", cfs_current());
                         cl_page_put(env, page);
-                        cl_2queue_fini(env, queue);
-                }
+               } else {
+                       result = PTR_ERR(page);
+               }
         }
         cl_io_fini(env, io);
+
+       if (redirtied && wbc->sync_mode == WB_SYNC_ALL) {
+               loff_t offset = cl_offset(clob, vmpage->index);
+
+               /* Flush page failed because the extent is being written out.
+                * Wait for the write of extent to be finished to avoid
+                * breaking kernel which assumes ->writepage should mark
+                * PageWriteback or clean the page. */
+               result = cl_sync_file_range(inode, offset,
+                                           offset + CFS_PAGE_SIZE - 1,
+                                           CL_FSYNC_LOCAL);
+               if (result > 0) {
+                       /* actually we may have written more than one page.
+                        * decreasing this page because the caller will count
+                        * it. */
+                       wbc->nr_to_write -= result - 1;
+                       result = 0;
+               }
+       }
+
         cl_env_nested_put(&nest, env);
-        RETURN(result);
+       GOTO(out, result);
+
+out:
+       if (result < 0) {
+               if (!lli->lli_async_rc)
+                       lli->lli_async_rc = result;
+               SetPageError(vmpage);
+               if (!unlocked)
+                       unlock_page(vmpage);
+       }
+       return result;
+}
+
+int ll_writepages(struct address_space *mapping, struct writeback_control *wbc)
+{
+       struct inode *inode = mapping->host;
+       loff_t start;
+       loff_t end;
+       enum cl_fsync_mode mode;
+       int range_whole = 0;
+       int result;
+       ENTRY;
+
+       if (wbc->range_cyclic) {
+               start = mapping->writeback_index << CFS_PAGE_SHIFT;
+               end = OBD_OBJECT_EOF;
+       } else {
+               start = wbc->range_start;
+               end = wbc->range_end;
+               if (end == LLONG_MAX) {
+                       end = OBD_OBJECT_EOF;
+                       range_whole = start == 0;
+               }
+       }
+
+       mode = CL_FSYNC_NONE;
+       if (wbc->sync_mode == WB_SYNC_ALL)
+               mode = CL_FSYNC_LOCAL;
+
+       result = cl_sync_file_range(inode, start, end, mode);
+       if (result > 0) {
+               wbc->nr_to_write -= result;
+               result = 0;
+        }
+
+       if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) {
+               if (end == OBD_OBJECT_EOF)
+                       end = i_size_read(inode);
+               mapping->writeback_index = (end >> CFS_PAGE_SHIFT) + 1;
+       }
+       RETURN(result);
 }
 
 int ll_readpage(struct file *file, struct page *vmpage)
@@ -1229,12 +1309,13 @@ int ll_readpage(struct file *file, struct page *vmpage)
                         result = cl_io_read_page(env, io, page);
                 } else {
                         /* Page from a non-object file. */
-                        LASSERT(!ll_i2info(vmpage->mapping->host)->lli_smd);
+                       LASSERT(!ll_i2info(vmpage->mapping->host)->lli_has_smd);
                         unlock_page(vmpage);
                         result = 0;
                 }
                 ll_cl_fini(lcc);
         } else {
+                unlock_page(vmpage);
                 result = PTR_ERR(lcc);
         }
         RETURN(result);