summaryrefslogtreecommitdiff
path: root/fs/btrfs/ioctl.c
diff options
context:
space:
mode:
authorMark Fasheh <mfasheh@suse.de>2015-06-09 01:05:25 +0300
committerChris Mason <clm@fb.com>2015-06-10 17:02:50 +0300
commite1d227a42ea2b4664f94212bd1106b9a3413ffb8 (patch)
treee14df0ebdf2241ee848607f06fc39cef6d5c1db4 /fs/btrfs/ioctl.c
parent070034bdf98544b23a7fcf500618fd31dec06ab2 (diff)
downloadlinux-e1d227a42ea2b4664f94212bd1106b9a3413ffb8.tar.xz
btrfs: Handle unaligned length in extent_same
The extent-same code rejects requests with an unaligned length. This poses a problem when we want to dedupe the tail extent of files as we skip cloning the portion between i_size and the extent boundary. If we don't clone the entire extent, it won't be deleted. So the combination of these behaviors winds up giving us worst-case dedupe on many files. We can fix this by allowing a length that extents to i_size and internally aligining those to the end of the block. This is what btrfs_ioctl_clone() so we can just copy that check over. Signed-off-by: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Chris Mason <clm@fb.com>
Diffstat (limited to 'fs/btrfs/ioctl.c')
-rw-r--r--fs/btrfs/ioctl.c20
1 files changed, 14 insertions, 6 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 9041f154cc32..c86b835da7a8 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2889,12 +2889,19 @@ static int btrfs_cmp_data(struct inode *src, u64 loff, struct inode *dst,
return ret;
}
-static int extent_same_check_offsets(struct inode *inode, u64 off, u64 len)
+static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
+ u64 olen)
{
+ u64 len = *plen;
u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
- if (off + len > inode->i_size || off + len < off)
+ if (off + olen > inode->i_size || off + olen < off)
return -EINVAL;
+
+ /* if we extend to eof, continue to block boundary */
+ if (off + len == inode->i_size)
+ *plen = len = ALIGN(inode->i_size, bs) - off;
+
/* Check that we are block aligned - btrfs_clone() requires this */
if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
return -EINVAL;
@@ -2902,10 +2909,11 @@ static int extent_same_check_offsets(struct inode *inode, u64 off, u64 len)
return 0;
}
-static int btrfs_extent_same(struct inode *src, u64 loff, u64 len,
+static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
struct inode *dst, u64 dst_loff)
{
int ret;
+ u64 len = olen;
/*
* btrfs_clone() can't handle extents in the same file
@@ -2920,11 +2928,11 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 len,
btrfs_double_lock(src, loff, dst, dst_loff, len);
- ret = extent_same_check_offsets(src, loff, len);
+ ret = extent_same_check_offsets(src, loff, &len, olen);
if (ret)
goto out_unlock;
- ret = extent_same_check_offsets(dst, dst_loff, len);
+ ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
if (ret)
goto out_unlock;
@@ -2937,7 +2945,7 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 len,
ret = btrfs_cmp_data(src, loff, dst, dst_loff, len);
if (ret == 0)
- ret = btrfs_clone(src, dst, loff, len, len, dst_loff);
+ ret = btrfs_clone(src, dst, loff, olen, len, dst_loff);
out_unlock:
btrfs_double_unlock(src, loff, dst, dst_loff, len);