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| author | Jan Kara <jack@suse.cz> | 2012-05-03 14:48:01 +0200 |
|---|---|---|
| committer | Fengguang Wu <fengguang.wu@intel.com> | 2012-05-06 07:43:40 +0200 |
| commit | 7994e6f7254354e03028a11f98a27bd67dace9f1 (patch) | |
| tree | b93db15bf5e4cd890670db0fd36575b5efce2366 | |
| parent | writeback: Refactor writeback_single_inode() (diff) | |
| download | linux-7994e6f7254354e03028a11f98a27bd67dace9f1.tar.xz linux-7994e6f7254354e03028a11f98a27bd67dace9f1.zip | |
vfs: Move waiting for inode writeback from end_writeback() to evict_inode()
Currently, I_SYNC can never be set when evict_inode() (and thus
end_writeback()) is called because flusher thread holds inode reference while
inode is under writeback. As a result inode_sync_wait() in those places
currently does nothing. However that is going to change and unveils problems
with calling inode_sync_wait() from end_writeback(). Several filesystems call
end_writeback() after they have deleted the inode (btrfs, gfs2, ...) and other
filesystems (ext3, ext4, reiserfs, ...) can deadlock when waiting for I_SYNC
because they call end_writeback() from within a transaction.
To avoid these issues, we move inode_sync_wait() into evict_inode() before
calling ->evict_inode(). That way we preserve the current property that
->evict_inode() and writeback never run in parallel and all filesystems are
safe.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
| -rw-r--r-- | fs/inode.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/inode.c b/fs/inode.c index 9f4f5fecc096..501fc5daf6f4 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -500,7 +500,6 @@ void end_writeback(struct inode *inode) BUG_ON(!list_empty(&inode->i_data.private_list)); BUG_ON(!(inode->i_state & I_FREEING)); BUG_ON(inode->i_state & I_CLEAR); - inode_sync_wait(inode); /* don't need i_lock here, no concurrent mods to i_state */ inode->i_state = I_FREEING | I_CLEAR; } @@ -531,6 +530,8 @@ static void evict(struct inode *inode) inode_sb_list_del(inode); + inode_sync_wait(inode); + if (op->evict_inode) { op->evict_inode(inode); } else { |