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btrfs: remove inode_dio_wait() calls when starting reflink operations

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When starting a reflink operation we have these calls to inode_dio_wait()
which used to be needed because direct IO writes that don't cross the
i_size boundary did not take the inode's VFS lock, so we could race with
them and end up with ordered extents in target range after calling
btrfs_wait_ordered_range().

However that is not the case anymore, because the inode's VFS lock was
changed from a mutex to a rw semaphore, by commit 9902af79c0
("parallel lookups: actual switch to rwsem"), and several years later we
started to lock the inode's VFS lock in shared mode for direct IO writes
that don't cross the i_size boundary (commit e9adabb971 ("btrfs: use
shared lock for direct writes within EOF")).

So remove those inode_dio_wait() calls.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Filipe Manana 2022-03-15 15:22:37 +00:00 committed by David Sterba
parent 831e1ee602
commit 1c6cbbbeee
1 changed files with 0 additions and 10 deletions
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10
fs/btrfs/reflink.c
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@ -771,7 +771,6 @@ static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in,
struct inode *inode_in = file_inode(file_in);
struct inode *inode_out = file_inode(file_out);
u64 bs = BTRFS_I(inode_out)->root->fs_info->sb->s_blocksize;
bool same_inode = inode_out == inode_in;
u64 wb_len;
int ret;
@ -809,15 +808,6 @@ static int btrfs_remap_file_range_prep(struct file *file_in, loff_t pos_in,
else
wb_len = ALIGN(*len, bs);
/*
* Since we don't lock ranges, wait for ongoing lockless dio writes (as
* any in progress could create its ordered extents after we wait for
* existing ordered extents below).
*/
inode_dio_wait(inode_in);
if (!same_inode)
inode_dio_wait(inode_out);
/*
* Workaround to make sure NOCOW buffered write reach disk as NOCOW.
*