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author | Josef Bacik <jbacik@fusionio.com> | 2012-06-27 17:18:41 -0400 |
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committer | Chris Mason <chris.mason@fusionio.com> | 2012-07-02 15:39:18 -0400 |
commit | 7fd1a3f73f3743b4ffd520effe288a70b0ec47c9 (patch) | |
tree | 176c81896d74f9662d6ebc91b902804921551db7 /fs/btrfs/extent_io.c | |
parent | bdb7d303b33c1648514c9f9461d7513a4c05ce48 (diff) | |
download | blackbird-op-linux-7fd1a3f73f3743b4ffd520effe288a70b0ec47c9.tar.gz blackbird-op-linux-7fd1a3f73f3743b4ffd520effe288a70b0ec47c9.zip |
Btrfs: hold a ref on the inode during writepages
We can race with unlink and not actually be able to do our igrab in
btrfs_add_ordered_extent. This will result in all sorts of problems.
Instead of doing the complicated work to try and handle returning an error
properly from btrfs_add_ordered_extent, just hold a ref to the inode during
writepages. If we cannot grab a ref we know we're freeing this inode anyway
and can just drop the dirty pages on the floor, because screw them we're
going to invalidate them anyway. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Diffstat (limited to 'fs/btrfs/extent_io.c')
-rw-r--r-- | fs/btrfs/extent_io.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index aaa12c1eb348..01c21b6c6d43 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3324,6 +3324,7 @@ static int extent_write_cache_pages(struct extent_io_tree *tree, writepage_t writepage, void *data, void (*flush_fn)(void *)) { + struct inode *inode = mapping->host; int ret = 0; int done = 0; int nr_to_write_done = 0; @@ -3334,6 +3335,18 @@ static int extent_write_cache_pages(struct extent_io_tree *tree, int scanned = 0; int tag; + /* + * We have to hold onto the inode so that ordered extents can do their + * work when the IO finishes. The alternative to this is failing to add + * an ordered extent if the igrab() fails there and that is a huge pain + * to deal with, so instead just hold onto the inode throughout the + * writepages operation. If it fails here we are freeing up the inode + * anyway and we'd rather not waste our time writing out stuff that is + * going to be truncated anyway. + */ + if (!igrab(inode)) + return 0; + pagevec_init(&pvec, 0); if (wbc->range_cyclic) { index = mapping->writeback_index; /* Start from prev offset */ @@ -3428,6 +3441,7 @@ retry: index = 0; goto retry; } + btrfs_add_delayed_iput(inode); return ret; } |