]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
xfs: fix locking in xfs_iget_cache_hit
authorChristoph Hellwig <hch@infradead.org>
Mon, 17 Aug 2009 00:36:34 +0000 (20:36 -0400)
committerFelix Blyakher <felixb@sgi.com>
Mon, 17 Aug 2009 06:23:48 +0000 (01:23 -0500)
commitbc990f5cb424cdca9dda866785d088e2c2110ecc
tree4264beb9538533d136e41f0e93933160fe925008
parent894ef820b10d77e2d6d717342fc408bdd9825139
xfs: fix locking in xfs_iget_cache_hit

The locking in xfs_iget_cache_hit currently has numerous problems:

 - we clear the reclaim tag without i_flags_lock which protects
   modifications to it
 - we call inode_init_always which can sleep with pag_ici_lock
   held (this is oss.sgi.com BZ #819)
 - we acquire and drop i_flags_lock a lot and thus provide no
   consistency between the various flags we set/clear under it

This patch fixes all that with a major revamp of the locking in
the function.  The new version acquires i_flags_lock early and
only drops it once we need to call into inode_init_always or before
calling xfs_ilock.

This patch fixes a bug seen in the wild where we race modifying the
reclaim tag.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
fs/xfs/linux-2.6/xfs_sync.c
fs/xfs/linux-2.6/xfs_sync.h
fs/xfs/xfs_iget.c