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authorFilipe Manana <fdmanana@gmail.com>2014-02-15 15:55:58 +0000
committerJosef Bacik <jbacik@fb.com>2014-03-10 15:16:47 -0400
commit12870f1c9b2de7d475d22e73fd7db1b418599725 (patch)
treef4f0661e0c937ab01f0113e81e366f6ad16f80e0
parent85fdfdf6118dc00c2fcea8907815e48c98ee6c1d (diff)
Btrfs: don't insert useless holes when punching beyond the inode's size
If we punch beyond the size of an inode, we'll correctly remove any prealloc extents, but we'll also insert file extent items representing holes (disk bytenr == 0) that start with a key offset that lies beyond the inode's size and are not contiguous with the last file extent item. Example: $XFS_IO_PROG -f -c "truncate 118811" $SCRATCH_MNT/foo $XFS_IO_PROG -c "fpunch 582007 864596" $SCRATCH_MNT/foo $XFS_IO_PROG -c "pwrite -S 0x0d -b 39987 92267 39987" $SCRATCH_MNT/foo btrfs-debug-tree output: item 4 key (257 INODE_ITEM 0) itemoff 15885 itemsize 160 inode generation 6 transid 6 size 132254 block group 0 mode 100600 links 1 item 5 key (257 INODE_REF 256) itemoff 15872 itemsize 13 inode ref index 2 namelen 3 name: foo item 6 key (257 EXTENT_DATA 0) itemoff 15819 itemsize 53 extent data disk byte 0 nr 0 gen 6 extent data offset 0 nr 90112 ram 122880 extent compression 0 item 7 key (257 EXTENT_DATA 90112) itemoff 15766 itemsize 53 extent data disk byte 12845056 nr 4096 gen 6 extent data offset 0 nr 45056 ram 45056 extent compression 2 item 8 key (257 EXTENT_DATA 585728) itemoff 15713 itemsize 53 extent data disk byte 0 nr 0 gen 6 extent data offset 0 nr 860160 ram 860160 extent compression 0 The last extent item, which represents a hole, is useless as it lies beyond the inode's size. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fb.com>
-rw-r--r--fs/btrfs/file.c28
1 files changed, 17 insertions, 11 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 6acccc4a7f2a..762ca32bd988 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -2168,6 +2168,7 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
bool same_page = ((offset >> PAGE_CACHE_SHIFT) ==
((offset + len - 1) >> PAGE_CACHE_SHIFT));
bool no_holes = btrfs_fs_incompat(root->fs_info, NO_HOLES);
+ u64 ino_size = round_up(inode->i_size, PAGE_CACHE_SIZE);
ret = btrfs_wait_ordered_range(inode, offset, len);
if (ret)
@@ -2183,14 +2184,14 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
* entire page.
*/
if (same_page && len < PAGE_CACHE_SIZE) {
- if (offset < round_up(inode->i_size, PAGE_CACHE_SIZE))
+ if (offset < ino_size)
ret = btrfs_truncate_page(inode, offset, len, 0);
mutex_unlock(&inode->i_mutex);
return ret;
}
/* zero back part of the first page */
- if (offset < round_up(inode->i_size, PAGE_CACHE_SIZE)) {
+ if (offset < ino_size) {
ret = btrfs_truncate_page(inode, offset, 0, 0);
if (ret) {
mutex_unlock(&inode->i_mutex);
@@ -2199,7 +2200,7 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
}
/* zero the front end of the last page */
- if (offset + len < round_up(inode->i_size, PAGE_CACHE_SIZE)) {
+ if (offset + len < ino_size) {
ret = btrfs_truncate_page(inode, offset + len, 0, 1);
if (ret) {
mutex_unlock(&inode->i_mutex);
@@ -2288,10 +2289,13 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
trans->block_rsv = &root->fs_info->trans_block_rsv;
- ret = fill_holes(trans, inode, path, cur_offset, drop_end);
- if (ret) {
- err = ret;
- break;
+ if (cur_offset < ino_size) {
+ ret = fill_holes(trans, inode, path, cur_offset,
+ drop_end);
+ if (ret) {
+ err = ret;
+ break;
+ }
}
cur_offset = drop_end;
@@ -2324,10 +2328,12 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
}
trans->block_rsv = &root->fs_info->trans_block_rsv;
- ret = fill_holes(trans, inode, path, cur_offset, drop_end);
- if (ret) {
- err = ret;
- goto out_trans;
+ if (cur_offset < ino_size) {
+ ret = fill_holes(trans, inode, path, cur_offset, drop_end);
+ if (ret) {
+ err = ret;
+ goto out_trans;
+ }
}
out_trans: