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LU-5010 llite: disable readahead optimization
[fs/lustre-release.git] / lustre / llite / rw.c
index b6eb577..355d07e 100644 (file)
@@ -66,7 +66,7 @@
  * Finalizes cl-data before exiting typical address_space operation. Dual to
  * ll_cl_init().
  */
-static void ll_cl_fini(struct ll_cl_context *lcc)
+void ll_cl_fini(struct ll_cl_context *lcc)
 {
         struct lu_env  *env  = lcc->lcc_env;
         struct cl_io   *io   = lcc->lcc_io;
@@ -80,12 +80,6 @@ static void ll_cl_fini(struct ll_cl_context *lcc)
                 cl_page_put(env, page);
         }
 
-        if (io && lcc->lcc_created) {
-                cl_io_end(env, io);
-                cl_io_unlock(env, io);
-                cl_io_iter_fini(env, io);
-                cl_io_fini(env, io);
-        }
         cl_env_put(env, &lcc->lcc_refcheck);
 }
 
@@ -93,8 +87,7 @@ static void ll_cl_fini(struct ll_cl_context *lcc)
  * Initializes common cl-data at the typical address_space operation entry
  * point.
  */
-static struct ll_cl_context *ll_cl_init(struct file *file,
-                                        struct page *vmpage, int create)
+struct ll_cl_context *ll_cl_init(struct file *file, struct page *vmpage)
 {
         struct ll_cl_context *lcc;
         struct lu_env    *env;
@@ -105,8 +98,8 @@ static struct ll_cl_context *ll_cl_init(struct file *file,
         int refcheck;
         int result = 0;
 
-        clob = ll_i2info(vmpage->mapping->host)->lli_clob;
-        LASSERT(clob != NULL);
+       clob = ll_i2info(file->f_dentry->d_inode)->lli_clob;
+       LASSERT(clob != NULL);
 
         env = cl_env_get(&refcheck);
         if (IS_ERR(env))
@@ -120,64 +113,10 @@ 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 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_thread_io(env);
-                ll_io_init(io, file, 1);
-
-                /* No lock at all for this kind of IO - we can't do it because
-                 * we have held page lock, it would cause deadlock.
-                 * XXX: This causes poor performance to loop device - One page
-                 *      per RPC.
-                 *      In order to get better performance, users should use
-                 *      lloop driver instead.
-                 */
-                io->ci_lockreq = CILR_NEVER;
-
-               pos = (vmpage->index << PAGE_CACHE_SHIFT);
-
-               /* Create a temp IO to serve write. */
-               result = cl_io_rw_init(env, io, CIT_WRITE,
-                                      pos, PAGE_CACHE_SIZE);
-                if (result == 0) {
-                        cio->cui_fd = LUSTRE_FPRIVATE(file);
-                        cio->cui_iov = NULL;
-                        cio->cui_nrsegs = 0;
-                        result = cl_io_iter_init(env, io);
-                        if (result == 0) {
-                                result = cl_io_lock(env, io);
-                                if (result == 0)
-                                        result = cl_io_start(env, io);
-                        }
-                } else
-                        result = io->ci_result;
-                lcc->lcc_created = 1;
-        }
-
         lcc->lcc_io = io;
-        if (io == NULL)
-                result = -EIO;
-        if (result == 0) {
+       if (io == NULL)
+               result = -EIO;
+       if (result == 0 && vmpage != NULL) {
                 struct cl_page   *page;
 
                 LASSERT(io != NULL);
@@ -197,100 +136,9 @@ static struct ll_cl_context *ll_cl_init(struct file *file,
                 lcc = ERR_PTR(result);
         }
 
-        CDEBUG(D_VFSTRACE, "%lu@"DFID" -> %d %p %p\n",
-               vmpage->index, PFID(lu_object_fid(&clob->co_lu)), result,
-               env, io);
         return lcc;
 }
 
-static struct ll_cl_context *ll_cl_get(void)
-{
-        struct ll_cl_context *lcc;
-        struct lu_env *env;
-        int refcheck;
-
-        env = cl_env_get(&refcheck);
-        LASSERT(!IS_ERR(env));
-        lcc = &vvp_env_info(env)->vti_io_ctx;
-        LASSERT(env == lcc->lcc_env);
-        LASSERT(current == lcc->lcc_cookie);
-        cl_env_put(env, &refcheck);
-
-        /* env has got in ll_cl_init, so it is still usable. */
-        return lcc;
-}
-
-/**
- * ->prepare_write() address space operation called by generic_file_write()
- * for every page during write.
- */
-int ll_prepare_write(struct file *file, struct page *vmpage, unsigned from,
-                     unsigned to)
-{
-        struct ll_cl_context *lcc;
-        int result;
-        ENTRY;
-
-        lcc = ll_cl_init(file, vmpage, 1);
-        if (!IS_ERR(lcc)) {
-                struct lu_env  *env = lcc->lcc_env;
-                struct cl_io   *io  = lcc->lcc_io;
-                struct cl_page *page = lcc->lcc_page;
-
-                cl_page_assume(env, io, page);
-                
-               result = cl_io_prepare_write(env, io, page, from, to);
-                if (result == 0) {
-                        /*
-                         * Add a reference, so that page is not evicted from
-                         * the cache until ->commit_write() is called.
-                         */
-                        cl_page_get(page);
-                        lu_ref_add(&page->cp_reference, "prepare_write",
-                                   cfs_current());
-                } else {
-                        cl_page_unassume(env, io, page);
-                        ll_cl_fini(lcc);
-                }
-                /* returning 0 in prepare assumes commit must be called
-                 * afterwards */
-        } else {
-                result = PTR_ERR(lcc);
-        }
-        RETURN(result);
-}
-
-int ll_commit_write(struct file *file, struct page *vmpage, unsigned from,
-                    unsigned to)
-{
-        struct ll_cl_context *lcc;
-        struct lu_env    *env;
-        struct cl_io     *io;
-        struct cl_page   *page;
-        int result = 0;
-        ENTRY;
-
-        lcc  = ll_cl_get();
-        env  = lcc->lcc_env;
-        page = lcc->lcc_page;
-        io   = lcc->lcc_io;
-
-        LASSERT(cl_page_is_owned(page, io));
-        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 ll_prepare_write().
-         */
-        lu_ref_del(&page->cp_reference, "prepare_write", cfs_current());
-        cl_page_put(env, page);
-        ll_cl_fini(lcc);
-        RETURN(result);
-}
-
 struct obd_capa *cl_capa_lookup(struct inode *inode, enum cl_req_type crt)
 {
         __u64 opc;
@@ -321,8 +169,8 @@ static void ll_ra_stats_inc_sbi(struct ll_sb_info *sbi, enum ra_stat which);
  * 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 ra_io_arg *ria,
+                                    unsigned long pages, unsigned long min)
 {
         struct ll_ra_info *ra = &sbi->ll_ra_info;
         long ret;
@@ -331,7 +179,7 @@ static unsigned long ll_ra_count_get(struct ll_sb_info *sbi,
         /* 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), pages);
+       ret = min(ra->ra_max_pages - atomic_read(&ra->ra_cur_pages), pages);
         if (ret < 0 || ret < min_t(long, PTLRPC_MAX_BRW_PAGES, pages))
                 GOTO(out, ret = 0);
 
@@ -352,19 +200,24 @@ static unsigned long ll_ra_count_get(struct ll_sb_info *sbi,
                         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;
-        }
+       if (atomic_add_return(ret, &ra->ra_cur_pages) > ra->ra_max_pages) {
+               atomic_sub(ret, &ra->ra_cur_pages);
+               ret = 0;
+       }
 
 out:
-        RETURN(ret);
+       if (ret < min) {
+               /* override ra limit for maximum performance */
+               atomic_add(min - ret, &ra->ra_cur_pages);
+               ret = min;
+       }
+       RETURN(ret);
 }
 
 void ll_ra_count_put(struct ll_sb_info *sbi, unsigned long len)
 {
-        struct ll_ra_info *ra = &sbi->ll_ra_info;
-        cfs_atomic_sub(len, &ra->ra_cur_pages);
+       struct ll_ra_info *ra = &sbi->ll_ra_info;
+       atomic_sub(len, &ra->ra_cur_pages);
 }
 
 static void ll_ra_stats_inc_sbi(struct ll_sb_info *sbi, enum ra_stat which)
@@ -373,10 +226,10 @@ static void ll_ra_stats_inc_sbi(struct ll_sb_info *sbi, enum ra_stat which)
         lprocfs_counter_incr(sbi->ll_ra_stats, which);
 }
 
-void ll_ra_stats_inc(struct address_space *mapping, enum ra_stat which)
+void ll_ra_stats_inc(struct inode *inode, enum ra_stat which)
 {
-        struct ll_sb_info *sbi = ll_i2sbi(mapping->host);
-        ll_ra_stats_inc_sbi(sbi, which);
+       struct ll_sb_info *sbi = ll_i2sbi(inode);
+       ll_ra_stats_inc_sbi(sbi, which);
 }
 
 #define RAS_CDEBUG(ras) \
@@ -423,7 +276,7 @@ void ll_ra_read_in(struct file *f, struct ll_ra_read *rar)
        ras->ras_consecutive_requests++;
        rar->lrr_reader = current;
 
-       cfs_list_add(&rar->lrr_linkage, &ras->ras_read_beads);
+       list_add(&rar->lrr_linkage, &ras->ras_read_beads);
        spin_unlock(&ras->ras_lock);
 }
 
@@ -434,7 +287,7 @@ void ll_ra_read_ex(struct file *f, struct ll_ra_read *rar)
        ras = ll_ras_get(f);
 
        spin_lock(&ras->ras_lock);
-       cfs_list_del_init(&rar->lrr_linkage);
+       list_del_init(&rar->lrr_linkage);
        spin_unlock(&ras->ras_lock);
 }
 
@@ -442,7 +295,7 @@ static struct ll_ra_read *ll_ra_read_get_locked(struct ll_readahead_state *ras)
 {
         struct ll_ra_read *scan;
 
-        cfs_list_for_each_entry(scan, &ras->ras_read_beads, lrr_linkage) {
+       list_for_each_entry(scan, &ras->ras_read_beads, lrr_linkage) {
                 if (scan->lrr_reader == current)
                         return scan;
         }
@@ -463,36 +316,43 @@ struct ll_ra_read *ll_ra_read_get(struct file *f)
 }
 
 static int cl_read_ahead_page(const struct lu_env *env, struct cl_io *io,
-                              struct cl_page_list *queue, struct cl_page *page,
-                              struct page *vmpage)
+                             struct cl_page_list *queue, struct cl_page *page,
+                             struct cl_object *clob, pgoff_t *max_index)
 {
-        struct ccc_page *cp;
-        int              rc;
+       struct page *vmpage = page->cp_vmpage;
+       struct ccc_page *cp;
+       int              rc;
 
-        ENTRY;
+       ENTRY;
 
-        rc = 0;
-        cl_page_assume(env, io, page);
-       lu_ref_add(&page->cp_reference, "ra", cfs_current());
-       cp = cl2ccc_page(cl_page_at(page, &vvp_device_type));
+       rc = 0;
+       cl_page_assume(env, io, page);
+       lu_ref_add(&page->cp_reference, "ra", current);
+       cp = cl2ccc_page(cl_object_page_slice(clob, page));
        if (!cp->cpg_defer_uptodate && !PageUptodate(vmpage)) {
-               rc = cl_page_is_under_lock(env, io, page);
-                if (rc == -EBUSY) {
-                        cp->cpg_defer_uptodate = 1;
-                        cp->cpg_ra_used = 0;
-                        cl_page_list_add(queue, page);
-                        rc = 1;
-                } else {
-                        cl_page_delete(env, page);
-                        rc = -ENOLCK;
-                }
+               CDEBUG(D_READA, "page index %lu, max_index: %lu\n",
+                      ccc_index(cp), *max_index);
+               /* Disable the optimization on prefetching maximum readahead
+                * index because there is a race with lock cancellation. This
+                * optimization will be revived later.
+                * if (*max_index == 0 || ccc_index(cp) > *max_index) */
+               rc = cl_page_is_under_lock(env, io, page, max_index);
+               if (rc == 0) {
+                       cp->cpg_defer_uptodate = 1;
+                       cp->cpg_ra_used = 0;
+                       cl_page_list_add(queue, page);
+                       rc = 1;
+               } else {
+                       cl_page_discard(env, io, page);
+                       rc = -ENOLCK;
+               }
        } else {
                /* skip completed pages */
                cl_page_unassume(env, io, page);
        }
-        lu_ref_del(&page->cp_reference, "ra", cfs_current());
-        cl_page_put(env, page);
-        RETURN(rc);
+       lu_ref_del(&page->cp_reference, "ra", current);
+       cl_page_put(env, page);
+       RETURN(rc);
 }
 
 /**
@@ -506,11 +366,12 @@ static int cl_read_ahead_page(const struct lu_env *env, struct cl_io *io,
  * \retval  -ve, 0: page wasn't added to \a queue for other reason.
  */
 static int ll_read_ahead_page(const struct lu_env *env, struct cl_io *io,
-                              struct cl_page_list *queue,
-                              pgoff_t index, struct address_space *mapping)
+                             struct cl_page_list *queue,
+                             pgoff_t index, pgoff_t *max_index)
 {
+       struct cl_object *clob  = io->ci_obj;
+       struct inode     *inode = ccc_object_inode(clob);
         struct page      *vmpage;
-        struct cl_object *clob  = ll_i2info(mapping->host)->lli_clob;
         struct cl_page   *page;
         enum ra_stat      which = _NR_RA_STAT; /* keep gcc happy */
         unsigned int      gfp_mask;
@@ -523,15 +384,15 @@ 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(mapping, index);
-        if (vmpage != NULL) {
-                /* Check if vmpage was truncated or reclaimed */
-                if (vmpage->mapping == mapping) {
-                        page = cl_page_find(env, clob, vmpage->index,
-                                            vmpage, CPT_CACHEABLE);
-                        if (!IS_ERR(page)) {
-                                rc = cl_read_ahead_page(env, io, queue,
-                                                        page, vmpage);
+       vmpage = grab_cache_page_nowait(inode->i_mapping, index);
+       if (vmpage != NULL) {
+               /* Check if vmpage was truncated or reclaimed */
+               if (vmpage->mapping == inode->i_mapping) {
+                       page = cl_page_find(env, clob, vmpage->index,
+                                           vmpage, CPT_CACHEABLE);
+                       if (!IS_ERR(page)) {
+                               rc = cl_read_ahead_page(env, io, queue,
+                                                       page, clob, max_index);
                                 if (rc == -ENOLCK) {
                                         which = RA_STAT_FAILED_MATCH;
                                         msg   = "lock match failed";
@@ -551,11 +412,11 @@ static int ll_read_ahead_page(const struct lu_env *env, struct cl_io *io,
                 which = RA_STAT_FAILED_GRAB_PAGE;
                 msg   = "g_c_p_n failed";
         }
-        if (msg != NULL) {
-                ll_ra_stats_inc(mapping, which);
-                CDEBUG(D_READA, "%s\n", msg);
-        }
-        RETURN(rc);
+       if (msg != NULL) {
+               ll_ra_stats_inc(inode, which);
+               CDEBUG(D_READA, "%s\n", msg);
+       }
+       RETURN(rc);
 }
 
 #define RIA_DEBUG(ria)                                                       \
@@ -660,25 +521,26 @@ static int ll_read_ahead_pages(const struct lu_env *env,
                                struct cl_io *io, struct cl_page_list *queue,
                                struct ra_io_arg *ria,
                                unsigned long *reserved_pages,
-                               struct address_space *mapping,
                                unsigned long *ra_end)
 {
-        int rc, count = 0, stride_ria;
-        unsigned long page_idx;
-
-        LASSERT(ria != NULL);
-        RIA_DEBUG(ria);
-
-        stride_ria = ria->ria_length > ria->ria_pages && ria->ria_pages > 0;
-        for (page_idx = ria->ria_start; page_idx <= ria->ria_end &&
-                        *reserved_pages > 0; page_idx++) {
-                if (ras_inside_ra_window(page_idx, ria)) {
-                        /* If the page is inside the read-ahead window*/
-                        rc = ll_read_ahead_page(env, io, queue,
-                                                page_idx, mapping);
+       int rc, count = 0;
+       bool stride_ria;
+       pgoff_t page_idx;
+       pgoff_t max_index = 0;
+
+       LASSERT(ria != NULL);
+       RIA_DEBUG(ria);
+
+       stride_ria = ria->ria_length > ria->ria_pages && ria->ria_pages > 0;
+       for (page_idx = ria->ria_start;
+            page_idx <= ria->ria_end && *reserved_pages > 0; page_idx++) {
+               if (ras_inside_ra_window(page_idx, ria)) {
+                       /* If the page is inside the read-ahead window*/
+                       rc = ll_read_ahead_page(env, io, queue,
+                                               page_idx, &max_index);
                         if (rc == 1) {
                                 (*reserved_pages)--;
-                                count ++;
+                                count++;
                         } else if (rc == -ENOLCK)
                                 break;
                 } else if (stride_ria) {
@@ -708,40 +570,38 @@ static int ll_read_ahead_pages(const struct lu_env *env,
 }
 
 int ll_readahead(const struct lu_env *env, struct cl_io *io,
-                 struct ll_readahead_state *ras, struct address_space *mapping,
-                 struct cl_page_list *queue, int flags)
+                struct cl_page_list *queue, struct ll_readahead_state *ras,
+                bool hit)
 {
-        struct vvp_io *vio = vvp_env_io(env);
-        struct vvp_thread_info *vti = vvp_env_info(env);
-        struct cl_attr *attr = ccc_env_thread_attr(env);
-        unsigned long start = 0, end = 0, reserved;
-        unsigned long ra_end, len;
-        struct inode *inode;
-        struct ll_ra_read *bead;
-        struct ra_io_arg *ria = &vti->vti_ria;
-        struct ll_inode_info *lli;
-        struct cl_object *clob;
-        int ret = 0;
-        __u64 kms;
-        ENTRY;
+       struct vvp_io *vio = vvp_env_io(env);
+       struct vvp_thread_info *vti = vvp_env_info(env);
+       struct cl_attr *attr = ccc_env_thread_attr(env);
+       unsigned long start = 0, end = 0, reserved;
+       unsigned long ra_end, len, mlen = 0;
+       struct inode *inode;
+       struct ll_ra_read *bead;
+       struct ra_io_arg *ria = &vti->vti_ria;
+       struct cl_object *clob;
+       int ret = 0;
+       __u64 kms;
+       ENTRY;
 
-        inode = mapping->host;
-        lli = ll_i2info(inode);
-        clob = lli->lli_clob;
+       clob = io->ci_obj;
+       inode = ccc_object_inode(clob);
 
-        memset(ria, 0, sizeof *ria);
+       memset(ria, 0, sizeof *ria);
 
-        cl_object_attr_lock(clob);
-        ret = cl_object_attr_get(env, clob, attr);
-        cl_object_attr_unlock(clob);
+       cl_object_attr_lock(clob);
+       ret = cl_object_attr_get(env, clob, attr);
+       cl_object_attr_unlock(clob);
 
-        if (ret != 0)
-                RETURN(ret);
-        kms = attr->cat_kms;
-        if (kms == 0) {
-                ll_ra_stats_inc(mapping, RA_STAT_ZERO_LEN);
-                RETURN(0);
-        }
+       if (ret != 0)
+               RETURN(ret);
+       kms = attr->cat_kms;
+       if (kms == 0) {
+               ll_ra_stats_inc(inode, RA_STAT_ZERO_LEN);
+               RETURN(0);
+       }
 
        spin_lock(&ras->ras_lock);
         if (vio->cui_ra_window_set)
@@ -796,41 +656,60 @@ int ll_readahead(const struct lu_env *env, struct cl_io *io,
         }
        spin_unlock(&ras->ras_lock);
 
-        if (end == 0) {
-                ll_ra_stats_inc(mapping, RA_STAT_ZERO_WINDOW);
-                RETURN(0);
-        }
-        len = ria_page_count(ria);
-        if (len == 0)
-                RETURN(0);
+       if (end == 0) {
+               ll_ra_stats_inc(inode, RA_STAT_ZERO_WINDOW);
+               RETURN(0);
+       }
+       len = ria_page_count(ria);
+       if (len == 0) {
+               ll_ra_stats_inc(inode, RA_STAT_ZERO_WINDOW);
+               RETURN(0);
+       }
 
-        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, DFID": ria: %lu/%lu, bead: %lu/%lu, hit: %d\n",
+              PFID(lu_object_fid(&clob->co_lu)),
+              ria->ria_start, ria->ria_end,
+              bead == NULL ? 0 : bead->lrr_start,
+              bead == NULL ? 0 : bead->lrr_count,
+              hit);
+
+       /* at least to extend the readahead window to cover current read */
+       if (!hit && bead != NULL &&
+           bead->lrr_start + bead->lrr_count > ria->ria_start) {
+               /* to the end of current read window. */
+               mlen = bead->lrr_start + bead->lrr_count - ria->ria_start;
+               /* trim to RPC boundary */
+               start = ria->ria_start & (PTLRPC_MAX_BRW_PAGES - 1);
+               mlen = min(mlen, PTLRPC_MAX_BRW_PAGES - start);
+       }
+
+       reserved = ll_ra_count_get(ll_i2sbi(inode), ria, len, mlen);
+       if (reserved < len)
+               ll_ra_stats_inc(inode, RA_STAT_MAX_IN_FLIGHT);
 
-        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);
+       CDEBUG(D_READA, "reserved pages: %lu/%lu/%lu, ra_cur %d, ra_max %lu\n",
+              reserved, len, mlen,
+              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);
+       ret = ll_read_ahead_pages(env, io, queue, ria, &reserved, &ra_end);
 
-        LASSERTF(reserved >= 0, "reserved %lu\n", reserved);
-        if (reserved != 0)
-                ll_ra_count_put(ll_i2sbi(inode), reserved);
+       if (reserved != 0)
+               ll_ra_count_put(ll_i2sbi(inode), reserved);
 
        if (ra_end == end + 1 && ra_end == (kms >> PAGE_CACHE_SHIFT))
-                ll_ra_stats_inc(mapping, RA_STAT_EOF);
+               ll_ra_stats_inc(inode, RA_STAT_EOF);
 
-        /* if we didn't get to the end of the region we reserved from
-         * the ras we need to go back and update the ras so that the
-         * next read-ahead tries from where we left off.  we only do so
-         * if the region we failed to issue read-ahead on is still ahead
-         * of the app and behind the next index to start read-ahead from */
-        CDEBUG(D_READA, "ra_end %lu end %lu stride end %lu \n",
-               ra_end, end, ria->ria_end);
+       /* if we didn't get to the end of the region we reserved from
+        * the ras we need to go back and update the ras so that the
+        * next read-ahead tries from where we left off.  we only do so
+        * if the region we failed to issue read-ahead on is still ahead
+        * of the app and behind the next index to start read-ahead from */
+       CDEBUG(D_READA, "ra_end %lu end %lu stride end %lu \n",
+              ra_end, end, ria->ria_end);
 
        if (ra_end != end + 1) {
+               ll_ra_stats_inc(inode, RA_STAT_FAILED_REACH_END);
                spin_lock(&ras->ras_lock);
                if (ra_end < ras->ras_next_readahead &&
                    index_in_window(ra_end, ras->ras_window_start, 0,
@@ -878,7 +757,7 @@ void ll_readahead_init(struct inode *inode, struct ll_readahead_state *ras)
        spin_lock_init(&ras->ras_lock);
        ras_reset(inode, ras, 0);
        ras->ras_requests = 0;
-       CFS_INIT_LIST_HEAD(&ras->ras_read_beads);
+       INIT_LIST_HEAD(&ras->ras_read_beads);
 }
 
 /*
@@ -1102,14 +981,17 @@ void ras_update(struct ll_sb_info *sbi, struct inode *inode,
        ras->ras_last_readpage = index;
        ras_set_start(inode, ras, index);
 
-       if (stride_io_mode(ras))
+       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 RPC 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);
+       } else {
+               if (ras->ras_next_readahead < ras->ras_window_start)
+                       ras->ras_next_readahead = ras->ras_window_start;
+               if (!hit)
+                       ras->ras_next_readahead = index + 1;
+       }
        RAS_CDEBUG(ras);
 
        /* Trigger RA in the mmap case where ras_consecutive_requests
@@ -1177,10 +1059,10 @@ int ll_writepage(struct page *vmpage, struct writeback_control *wbc)
         if (result == 0) {
                 page = cl_page_find(env, clob, vmpage->index,
                                     vmpage, CPT_CACHEABLE);
-                if (!IS_ERR(page)) {
-                        lu_ref_add(&page->cp_reference, "writepage",
-                                   cfs_current());
-                        cl_page_assume(env, io, page);
+               if (!IS_ERR(page)) {
+                       lu_ref_add(&page->cp_reference, "writepage",
+                                  current);
+                       cl_page_assume(env, io, page);
                        result = cl_page_flush(env, io, page);
                        if (result != 0) {
                                /*
@@ -1196,9 +1078,9 @@ int ll_writepage(struct page *vmpage, struct writeback_control *wbc)
                        }
                        cl_page_disown(env, io, page);
                        unlocked = true;
-                        lu_ref_del(&page->cp_reference,
-                                   "writepage", cfs_current());
-                        cl_page_put(env, page);
+                       lu_ref_del(&page->cp_reference,
+                                  "writepage", current);
+                       cl_page_put(env, page);
                } else {
                        result = PTR_ERR(page);
                }
@@ -1271,6 +1153,10 @@ int ll_writepages(struct address_space *mapping, struct writeback_control *wbc)
                 * evicted to avoid hitting LBUG when truncate_inode_pages()
                 * is called later on. */
                ignore_layout = 1;
+
+       if (cl_i2info(inode)->lli_clob == NULL)
+               RETURN(0);
+
        result = cl_sync_file_range(inode, start, end, mode, ignore_layout);
        if (result > 0) {
                wbc->nr_to_write -= result;
@@ -1279,8 +1165,9 @@ int ll_writepages(struct address_space *mapping, struct writeback_control *wbc)
 
        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 >> PAGE_CACHE_SHIFT) + 1;
+                       mapping->writeback_index = 0;
+               else
+                       mapping->writeback_index = (end >> PAGE_CACHE_SHIFT) +1;
        }
        RETURN(result);
 }
@@ -1291,7 +1178,7 @@ int ll_readpage(struct file *file, struct page *vmpage)
         int result;
         ENTRY;
 
-        lcc = ll_cl_init(file, vmpage, 0);
+        lcc = ll_cl_init(file, vmpage);
         if (!IS_ERR(lcc)) {
                 struct lu_env  *env  = lcc->lcc_env;
                 struct cl_io   *io   = lcc->lcc_io;
@@ -1314,3 +1201,27 @@ int ll_readpage(struct file *file, struct page *vmpage)
         RETURN(result);
 }
 
+int ll_page_sync_io(const struct lu_env *env, struct cl_io *io,
+                   struct cl_page *page, enum cl_req_type crt)
+{
+       struct cl_2queue  *queue;
+       int result;
+
+       LASSERT(io->ci_type == CIT_READ || io->ci_type == CIT_WRITE);
+
+       queue = &io->ci_queue;
+       cl_2queue_init_page(queue, page);
+
+       result = cl_io_submit_sync(env, io, crt, queue, 0);
+       LASSERT(cl_page_is_owned(page, io));
+
+       if (crt == CRT_READ)
+               /*
+                * in CRT_WRITE case page is left locked even in case of
+                * error.
+                */
+               cl_page_list_disown(env, io, &queue->c2_qin);
+       cl_2queue_fini(env, queue);
+
+       return result;
+}