ocfs2: Read from an unwritten extent returns zeros

Return an optional extent flags field from our lookup functions and wire up
callers to treat unwritten regions as holes for the purpose of returning
zeros to the user.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index 0eab0d328289cbfe0a63f6d9489203124e60da69..412a2888a3ed3e80effbb8293fb2c4a3d282dea1 100644 (file)
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -3487,6 +3487,7 @@ static int ocfs2_grab_eof_pages(struct inode *inode, loff_t isize, struct page *
 {
        int i, numpages = 0, ret = 0;
        unsigned int csize = OCFS2_SB(inode->i_sb)->s_clustersize;
+       unsigned int ext_flags;
        struct super_block *sb = inode->i_sb;
        struct address_space *mapping = inode->i_mapping;
        unsigned long index;
@@ -3499,7 +3500,7 @@ static int ocfs2_grab_eof_pages(struct inode *inode, loff_t isize, struct page *
                goto out;
 
        ret = ocfs2_extent_map_get_blocks(inode, isize >> sb->s_blocksize_bits,
-                                         phys, NULL);
+                                         phys, NULL, &ext_flags);
        if (ret) {
                mlog_errno(ret);
                goto out;
@@ -3509,6 +3510,11 @@ static int ocfs2_grab_eof_pages(struct inode *inode, loff_t isize, struct page *
        if (*phys == 0)
                goto out;
 
+       /* Tail is marked as unwritten, we can count on write to zero
+        * in that case. */
+       if (ext_flags & OCFS2_EXT_UNWRITTEN)
+               goto out;
+
        next_cluster_bytes = ocfs2_align_bytes_to_clusters(inode->i_sb, isize);
        index = isize >> PAGE_CACHE_SHIFT;
        do {
@@ -3579,9 +3585,6 @@ int ocfs2_zero_tail_for_truncate(struct inode *inode, handle_t *handle,
                goto out;
        }
 
-       /*
-        * Truncate on an i_size boundary - nothing more to do.
-        */
        if (numpages == 0)
                goto out;
 

diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 014f4f52809cddf6fe6b1119ccb72e1a7d20345a..eb67c902b002a2b3212f42cc0d9677fa47d614ad 100644 (file)
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -137,6 +137,7 @@ static int ocfs2_get_block(struct inode *inode, sector_t iblock,
                           struct buffer_head *bh_result, int create)
 {
        int err = 0;
+       unsigned int ext_flags;
        u64 p_blkno, past_eof;
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
 
@@ -153,7 +154,8 @@ static int ocfs2_get_block(struct inode *inode, sector_t iblock,
                goto bail;
        }
 
-       err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, NULL);
+       err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, NULL,
+                                         &ext_flags);
        if (err) {
                mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
                     "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
@@ -171,7 +173,8 @@ static int ocfs2_get_block(struct inode *inode, sector_t iblock,
                        "ino %lu, iblock %llu\n", inode->i_ino,
                        (unsigned long long)iblock);
 
-       if (p_blkno)
+       /* Treat the unwritten extent as a hole for zeroing purposes. */
+       if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
                map_bh(bh_result, inode->i_sb, p_blkno);
 
        if (!ocfs2_sparse_alloc(osb)) {
@@ -396,7 +399,7 @@ static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
                down_read(&OCFS2_I(inode)->ip_alloc_sem);
        }
 
-       err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL);
+       err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL, NULL);
 
        if (!INODE_JOURNAL(inode)) {
                up_read(&OCFS2_I(inode)->ip_alloc_sem);
@@ -438,6 +441,7 @@ static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
        int ret;
        u64 p_blkno, inode_blocks;
        int contig_blocks;
+       unsigned int ext_flags;
        unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
        unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
 
@@ -458,7 +462,7 @@ static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
        /* This figures out the size of the next contiguous block, and
         * our logical offset */
        ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno,
-                                         &contig_blocks);
+                                         &contig_blocks, &ext_flags);
        if (ret) {
                mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
                     (unsigned long long)iblock);
@@ -478,8 +482,10 @@ static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
        /*
         * get_more_blocks() expects us to describe a hole by clearing
         * the mapped bit on bh_result().
+        *
+        * Consider an unwritten extent as a hole.
         */
-       if (p_blkno)
+       if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
                map_bh(bh_result, inode->i_sb, p_blkno);
        else {
                /*
@@ -1111,7 +1117,8 @@ static ssize_t ocfs2_write(struct file *file, u32 phys, handle_t *handle,
                }
        }
 
-       ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL);
+       ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL,
+                                         NULL);
        if (ret < 0) {
 
                /*
@@ -1215,7 +1222,7 @@ ssize_t ocfs2_buffered_write_cluster(struct file *file, loff_t pos,
         */
        down_write(&OCFS2_I(inode)->ip_alloc_sem);
 
-       ret = ocfs2_get_clusters(inode, wc.w_cpos, &phys, NULL);
+       ret = ocfs2_get_clusters(inode, wc.w_cpos, &phys, NULL, NULL);
        if (ret) {
                mlog_errno(ret);
                goto out_meta;

diff --git a/fs/ocfs2/dir.c b/fs/ocfs2/dir.c
index c91490670ffa02ceed45c9676a017743e8b1531e..8d22e1e4a88d36a086f5e63bc710ccf4c32f154e 100644 (file)
--- a/fs/ocfs2/dir.c
+++ b/fs/ocfs2/dir.c
@@ -379,7 +379,7 @@ int ocfs2_do_extend_dir(struct super_block *sb,
 
        status = ocfs2_extent_map_get_blocks(dir, (dir->i_blocks >>
                                                   (sb->s_blocksize_bits - 9)),
-                                            &p_blkno, NULL);
+                                            &p_blkno, NULL, NULL);
        if (status < 0) {
                mlog_errno(status);
                goto bail;

diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
index ea0ce41d4193130408baa98e4c6523dd1a78ba35..eef6c1887708042586a04e8a1e7a6e87bc583f69 100644 (file)
--- a/fs/ocfs2/extent_map.c
+++ b/fs/ocfs2/extent_map.c
@@ -70,9 +70,11 @@ static int ocfs2_search_extent_list(struct ocfs2_extent_list *el,
 }
 
 int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
-                      u32 *p_cluster, u32 *num_clusters)
+                      u32 *p_cluster, u32 *num_clusters,
+                      unsigned int *extent_flags)
 {
        int ret, i;
+       unsigned int flags = 0;
        struct buffer_head *di_bh = NULL;
        struct buffer_head *eb_bh = NULL;
        struct ocfs2_dinode *di;
@@ -142,8 +144,13 @@ int ocfs2_get_clusters(struct inode *inode, u32 v_cluster,
 
                if (num_clusters)
                        *num_clusters = ocfs2_rec_clusters(el, rec) - coff;
+
+               flags = rec->e_flags;
        }
 
+       if (extent_flags)
+               *extent_flags = flags;
+
 out:
        brelse(di_bh);
        brelse(eb_bh);
@@ -155,7 +162,7 @@ out:
  * all while the map is in the process of being updated.
  */
 int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,
-                               int *ret_count)
+                               int *ret_count, unsigned int *extent_flags)
 {
        int ret;
        int bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
@@ -164,7 +171,8 @@ int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,
 
        cpos = ocfs2_blocks_to_clusters(inode->i_sb, v_blkno);
 
-       ret = ocfs2_get_clusters(inode, cpos, &p_cluster, &num_clusters);
+       ret = ocfs2_get_clusters(inode, cpos, &p_cluster, &num_clusters,
+                                extent_flags);
        if (ret) {
                mlog_errno(ret);
                goto out;

diff --git a/fs/ocfs2/extent_map.h b/fs/ocfs2/extent_map.h
index 625d0ee5e04a5e16876672092fde54a6c1623006..0031c59c347f3f33440211a983e8a81189b8de4a 100644 (file)
--- a/fs/ocfs2/extent_map.h
+++ b/fs/ocfs2/extent_map.h
@@ -26,8 +26,8 @@
 #define _EXTENT_MAP_H
 
 int ocfs2_get_clusters(struct inode *inode, u32 v_cluster, u32 *p_cluster,
-                      u32 *num_clusters);
+                      u32 *num_clusters, unsigned int *extent_flags);
 int ocfs2_extent_map_get_blocks(struct inode *inode, u64 v_blkno, u64 *p_blkno,
-                               int *ret_count);
+                               int *ret_count, unsigned int *extent_flags);
 
 #endif  /* _EXTENT_MAP_H */

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 36176018b4b44a1eb93d3ce6c83a78e9965ae1a9..f516619a374481eb8a507b687a8cd6cbc5901dc9 100644 (file)
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1127,6 +1127,7 @@ static int ocfs2_check_range_for_holes(struct inode *inode, loff_t pos,
                                       size_t count)
 {
        int ret = 0;
+       unsigned int extent_flags;
        u32 cpos, clusters, extent_len, phys_cpos;
        struct super_block *sb = inode->i_sb;
 
@@ -1134,13 +1135,14 @@ static int ocfs2_check_range_for_holes(struct inode *inode, loff_t pos,
        clusters = ocfs2_clusters_for_bytes(sb, pos + count) - cpos;
 
        while (clusters) {
-               ret = ocfs2_get_clusters(inode, cpos, &phys_cpos, &extent_len);
+               ret = ocfs2_get_clusters(inode, cpos, &phys_cpos, &extent_len,
+                                        &extent_flags);
                if (ret < 0) {
                        mlog_errno(ret);
                        goto out;
                }
 
-               if (phys_cpos == 0) {
+               if (phys_cpos == 0 || (extent_flags & OCFS2_EXT_UNWRITTEN)) {
                        ret = 1;
                        break;
                }

diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
index 78c99b5050df52dee1fb09888da994f071d72796..310049bf7f6bc5a44f42aa7bb1d854670b915418 100644 (file)
--- a/fs/ocfs2/inode.c
+++ b/fs/ocfs2/inode.c
@@ -1105,7 +1105,8 @@ struct buffer_head *ocfs2_bread(struct inode *inode,
                return NULL;
        }
 
-       tmperr = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL);
+       tmperr = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
+                                            NULL);
        if (tmperr < 0) {
                mlog_errno(tmperr);
                goto fail;

diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index 2e2e04fe97381b34cdaab87274938b07c2101dae..db77e0996bb74b648b73907acc823de40a6869d9 100644 (file)
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -670,7 +670,7 @@ static int ocfs2_force_read_journal(struct inode *inode)
               (inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9))) {
 
                status = ocfs2_extent_map_get_blocks(inode, v_blkno,
-                                                    &p_blkno, &p_blocks);
+                                                    &p_blkno, &p_blocks, NULL);
                if (status < 0) {
                        mlog_errno(status);
                        goto bail;

diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index 5755e07482562492f8eaef8c3b7295e5c59b6ae4..395859edb51f5d1769bd46c83562ff22024f409e 100644 (file)
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -1511,7 +1511,8 @@ static int ocfs2_create_symlink_data(struct ocfs2_super *osb,
                goto bail;
        }
 
-       status = ocfs2_extent_map_get_blocks(inode, 0, &p_blkno, &p_blocks);
+       status = ocfs2_extent_map_get_blocks(inode, 0, &p_blkno, &p_blocks,
+                                            NULL);
        if (status < 0) {
                mlog_errno(status);
                goto bail;

diff --git a/fs/ocfs2/slot_map.c b/fs/ocfs2/slot_map.c
index f4416e7330e162540d82b288849dc58ed1ba0c1b..d921a28329dcb81e21525b51e0da41a2aceeec9e 100644 (file)
--- a/fs/ocfs2/slot_map.c
+++ b/fs/ocfs2/slot_map.c
@@ -197,7 +197,7 @@ int ocfs2_init_slot_info(struct ocfs2_super *osb)
                goto bail;
        }
 
-       status = ocfs2_extent_map_get_blocks(inode, 0ULL, &blkno, NULL);
+       status = ocfs2_extent_map_get_blocks(inode, 0ULL, &blkno, NULL, NULL);
        if (status < 0) {
                mlog_errno(status);
                goto bail;