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authorLinus Torvalds <torvalds@linux-foundation.org>2020-01-28 15:18:23 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-01-28 15:18:23 -0800
commitb5f7ab6b1c4ed967fb76258f79251193cb1ad41d (patch)
tree1c9173f1fecabc5ccca6e8321df6a2128f004484
parent81a046b18b331ed6192e6fd9ff6d12a1f18058cf (diff)
parent831d2fa25ab8e27592b1b0268dae6f2dfaf7cc43 (diff)
downloadlinux-b5f7ab6b1c4ed967fb76258f79251193cb1ad41d.tar.bz2
Merge tag 'fs-dedupe-last-block-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull fs deduplication fix from David Sterba: "This is a fix for deduplication bug: the last block of two files is allowed to deduplicated. This got broken in 5.1 by lifting some generic checks to VFS layer. The affected filesystems are btrfs and xfs. The patches are marked for stable as the bug decreases deduplication effectivity" * tag 'fs-dedupe-last-block-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Btrfs: make deduplication with range including the last block work fs: allow deduplication of eof block into the end of the destination file
-rw-r--r--fs/btrfs/ioctl.c3
-rw-r--r--fs/read_write.c10
2 files changed, 6 insertions, 7 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 1b1b6ff855aa..4f4b13830b25 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3243,6 +3243,7 @@ static void btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 len,
struct inode *dst, u64 dst_loff)
{
+ const u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
int ret;
/*
@@ -3250,7 +3251,7 @@ static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 len,
* source range to serialize with relocation.
*/
btrfs_double_extent_lock(src, loff, dst, dst_loff, len);
- ret = btrfs_clone(src, dst, loff, len, len, dst_loff, 1);
+ ret = btrfs_clone(src, dst, loff, len, ALIGN(len, bs), dst_loff, 1);
btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
return ret;
diff --git a/fs/read_write.c b/fs/read_write.c
index 5bbf587f5bc1..7458fccc59e1 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1777,10 +1777,9 @@ static int remap_verify_area(struct file *file, loff_t pos, loff_t len,
* else. Assume that the offsets have already been checked for block
* alignment.
*
- * For deduplication we always scale down to the previous block because we
- * can't meaningfully compare post-EOF contents.
- *
- * For clone we only link a partial EOF block above the destination file's EOF.
+ * For clone we only link a partial EOF block above or at the destination file's
+ * EOF. For deduplication we accept a partial EOF block only if it ends at the
+ * destination file's EOF (can not link it into the middle of a file).
*
* Shorten the request if possible.
*/
@@ -1796,8 +1795,7 @@ static int generic_remap_check_len(struct inode *inode_in,
if ((*len & blkmask) == 0)
return 0;
- if ((remap_flags & REMAP_FILE_DEDUP) ||
- pos_out + *len < i_size_read(inode_out))
+ if (pos_out + *len < i_size_read(inode_out))
new_len &= ~blkmask;
if (new_len == *len)