diff options
| author | Dave Chinner <david@fromorbit.com> | 2010-01-11 11:45:21 +0000 |
|---|---|---|
| committer | Alex Elder <aelder@sgi.com> | 2010-01-15 13:46:02 -0600 |
| commit | 4b6a46882cca8349e8942e2650c33b11bc571c92 (patch) | |
| tree | 5a5ab0783340fa4acd75a172d857d0077a527809 | |
| parent | 126976c7c17d3bdfbc1fe9e0af8bee9f62d14cc6 (diff) | |
xfs: fix stale inode flush avoidance
When reclaiming stale inodes, we need to guarantee that inodes are
unpinned before returning with a "clean" status. If we don't we can
reclaim inodes that are pinned, leading to use after free in the
transaction subsystem as transactions complete.
Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
| -rw-r--r-- | fs/xfs/xfs_inode.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index 391d36b0e68..ef77fd88c8e 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -2842,13 +2842,9 @@ xfs_iflush( /* * If the inode isn't dirty, then just release the inode flush lock and - * do nothing. Treat stale inodes the same; we cannot rely on the - * backing buffer remaining stale in cache for the remaining life of - * the stale inode and so xfs_itobp() below may give us a buffer that - * no longer contains inodes below. Doing this stale check here also - * avoids forcing the log on pinned, stale inodes. + * do nothing. */ - if (xfs_inode_clean(ip) || xfs_iflags_test(ip, XFS_ISTALE)) { + if (xfs_inode_clean(ip)) { xfs_ifunlock(ip); return 0; } @@ -2872,6 +2868,19 @@ xfs_iflush( xfs_iunpin_wait(ip); /* + * For stale inodes we cannot rely on the backing buffer remaining + * stale in cache for the remaining life of the stale inode and so + * xfs_itobp() below may give us a buffer that no longer contains + * inodes below. We have to check this after ensuring the inode is + * unpinned so that it is safe to reclaim the stale inode after the + * flush call. + */ + if (xfs_iflags_test(ip, XFS_ISTALE)) { + xfs_ifunlock(ip); + return 0; + } + + /* * This may have been unpinned because the filesystem is shutting * down forcibly. If that's the case we must not write this inode * to disk, because the log record didn't make it to disk! |