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| author | Chris Mason <clm@fb.com> | 2016-07-19 05:52:36 -0700 |
|---|---|---|
| committer | Chris Mason <clm@fb.com> | 2016-07-21 04:03:40 -0700 |
| commit | 8b8b08cbfb9021af4b54b4175fc4c51d655aac8c (patch) | |
| tree | 1b53d06941d504cef36b4e85ac874717d78e21c3 | |
| parent | bac357dcec2956f01df9da5365be257741b534dc (diff) | |
| download | linux-8b8b08cbfb9021af4b54b4175fc4c51d655aac8c.tar.gz linux-8b8b08cbfb9021af4b54b4175fc4c51d655aac8c.tar.bz2 linux-8b8b08cbfb9021af4b54b4175fc4c51d655aac8c.zip | |
Btrfs: fix delalloc accounting after copy_from_user faults
Commit 56244ef151c3cd11 was almost but not quite enough to fix the
reservation math after btrfs_copy_from_user returned partial copies.
Some users are still seeing warnings in btrfs_destroy_inode, and with a
long enough test run I'm able to trigger them as well.
This patch fixes the accounting math again, bringing it much closer to
the way it was before the sectorsize conversion Chandan did. The
problem is accounting for the offset into the page/sector when we do a
partial copy. This one just uses the dirty_sectors variable which
should already be updated properly.
Signed-off-by: Chris Mason <clm@fb.com>
cc: stable@vger.kernel.org # v4.6+
| -rw-r--r-- | fs/btrfs/file.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index f3f61d1ad18a..bcfb4a27ddd4 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1629,13 +1629,11 @@ again: * managed to copy. */ if (num_sectors > dirty_sectors) { - /* - * we round down because we don't want to count - * any partial blocks actually sent through the - * IO machines - */ - release_bytes = round_down(release_bytes - copied, - root->sectorsize); + + /* release everything except the sectors we dirtied */ + release_bytes -= dirty_sectors << + root->fs_info->sb->s_blocksize_bits; + if (copied > 0) { spin_lock(&BTRFS_I(inode)->lock); BTRFS_I(inode)->outstanding_extents++; |