linux-hardened/fs/xfs
Dave Chinner 58c904734c xfs: inodes are new until the dentry cache is set up
Al Viro noticed a generic set of issues to do with filehandle lookup
racing with dentry cache setup. They involve a filehandle lookup
occurring while an inode is being created and the filehandle lookup
racing with the dentry creation for the real file. This can lead to
multiple dentries for the one path being instantiated. There are a
host of other issues around this same set of paths.

The underlying cause is that file handle lookup only waits on inode
cache instantiation rather than full dentry cache instantiation. XFS
is mostly immune to the problems discovered due to it's own internal
inode cache, but there are a couple of corner cases where races can
happen.

We currently clear the XFS_INEW flag when the inode is fully set up
after insertion into the cache. Newly allocated inodes are inserted
locked and so aren't usable until the allocation transaction
commits. This, however, occurs before the dentry and security
information is fully initialised and hence the inode is unlocked and
available for lookups to find too early.

To solve the problem, only clear the XFS_INEW flag for newly created
inodes once the dentry is fully instantiated. This means lookups
will retry until the XFS_INEW flag is removed from the inode and
hence avoids the race conditions in questions.

THis also means that xfs_create(), xfs_create_tmpfile() and
xfs_symlink() need to finish the setup of the inode in their error
paths if we had allocated the inode but failed later in the creation
process. xfs_symlink(), in particular, needed a lot of help to make
it's error handling match that of xfs_create().

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-02-23 22:38:08 +11:00
..
libxfs Merge branch 'xfs-buf-type-fixes' into for-next 2015-01-22 09:51:30 +11:00
Kconfig xfs: require 64-bit sector_t 2014-07-30 09:12:05 +10:00
kmem.c xfs: change kmem_free to use generic kvfree() 2015-02-02 09:54:18 +11:00
kmem.h xfs: change kmem_free to use generic kvfree() 2015-02-02 09:54:18 +11:00
Makefile xfs: implement pNFS export operations 2015-02-16 11:49:23 +11:00
mrlock.h
uuid.c
uuid.h
xfs.h
xfs_acl.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_acl.h xfs: move acl structures to xfs_format.h 2014-11-28 14:24:37 +11:00
xfs_aops.c xfs: don't allocate an ioend for direct I/O completions 2015-02-02 10:02:09 +11:00
xfs_aops.h xfs: don't allocate an ioend for direct I/O completions 2015-02-02 10:02:09 +11:00
xfs_attr.h xfs: kill xfs_vnodeops.[ch] 2013-08-12 16:53:39 -05:00
xfs_attr_inactive.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_attr_list.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_bit.c xfs: fix static and extern sparse warnings 2013-10-30 13:59:56 -05:00
xfs_bmap_util.c Merge branch 'xfs-consolidate-format-defs' into for-next 2014-11-28 14:52:16 +11:00
xfs_bmap_util.h xfs: move xfs_bmap_finish prototype 2015-01-09 10:47:14 +11:00
xfs_buf.c list_lru: add helpers to isolate items 2015-02-12 18:54:10 -08:00
xfs_buf.h xfs: split metadata and log buffer completion to separate workqueues 2014-12-04 09:43:17 +11:00
xfs_buf_item.c Merge branch 'xfs-buf-type-fixes' into for-next 2015-01-22 09:51:30 +11:00
xfs_buf_item.h xfs: decouple inode and bmap btree header files 2013-10-23 16:28:49 -05:00
xfs_dir2_readdir.c Merge branch 'xfs-misc-fixes-for-3.19-2' into for-next 2014-12-04 09:46:17 +11:00
xfs_discard.c xfs: merge xfs_ag.h into xfs_format.h 2014-11-28 14:25:04 +11:00
xfs_discard.h
xfs_dquot.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_dquot.h xfs: fix implicit bool to int conversion 2015-01-09 10:48:58 +11:00
xfs_dquot_item.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_dquot_item.h xfs: remove the quotaoff log format from the quotaoff log item 2013-12-13 11:34:08 +11:00
xfs_error.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_error.h xfs: global error sign conversion 2014-06-25 14:58:08 +10:00
xfs_export.c xfs: implement pNFS export operations 2015-02-16 11:49:23 +11:00
xfs_export.h
xfs_extent_busy.c xfs: merge xfs_ag.h into xfs_format.h 2014-11-28 14:25:04 +11:00
xfs_extent_busy.h xfs: decouple inode and bmap btree header files 2013-10-23 16:28:49 -05:00
xfs_extfree_item.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_extfree_item.h xfs: split out EFI/EFD log item format definition 2013-08-12 16:07:13 -05:00
xfs_file.c xfs: pnfs block layout support for 3.20-rc1 2015-02-21 14:09:38 -08:00
xfs_filestream.c xfs: merge xfs_inum.h into xfs_format.h 2014-11-28 14:27:10 +11:00
xfs_filestream.h xfs: add filestream allocator tracepoints 2014-04-23 07:11:52 +10:00
xfs_fsops.c xfs: implement pNFS export operations 2015-02-16 11:49:23 +11:00
xfs_fsops.h
xfs_globals.c xfs: export log_recovery_delay to delay mount time log recovery 2014-09-09 11:56:13 +10:00
xfs_icache.c xfs: inodes are new until the dentry cache is set up 2015-02-23 22:38:08 +11:00
xfs_icache.h xfs: merge xfs_ag.h into xfs_format.h 2014-11-28 14:25:04 +11:00
xfs_icreate_item.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_icreate_item.h xfs: separate icreate log format definitions from xfs_icreate_item.h 2013-08-12 16:10:35 -05:00
xfs_inode.c xfs: inodes are new until the dentry cache is set up 2015-02-23 22:38:08 +11:00
xfs_inode.h xfs: inodes are new until the dentry cache is set up 2015-02-23 22:38:08 +11:00
xfs_inode_item.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_inode_item.h xfs: remove the inode log format from the inode log item 2013-12-13 11:34:05 +11:00
xfs_ioctl.c Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-02-22 17:42:14 -08:00
xfs_ioctl.h xfs: consolidate extent swap code 2013-08-12 16:56:06 -05:00
xfs_ioctl32.c xfs: remove incorrect error negation in attr_multi ioctl 2015-01-22 10:04:24 +11:00
xfs_ioctl32.h xfs: compat_xfs_bstat does not have forkoff 2014-10-02 09:17:58 +10:00
xfs_iomap.c xfs: pass a 64-bit count argument to xfs_iomap_write_unwritten 2015-01-09 10:48:12 +11:00
xfs_iomap.h xfs: pass a 64-bit count argument to xfs_iomap_write_unwritten 2015-01-09 10:48:12 +11:00
xfs_iops.c xfs: inodes are new until the dentry cache is set up 2015-02-23 22:38:08 +11:00
xfs_iops.h xfs: inodes are new until the dentry cache is set up 2015-02-23 22:38:08 +11:00
xfs_itable.c Merge branch 'xfs-misc-fixes-for-3.19-2' into for-next 2014-12-04 09:46:17 +11:00
xfs_itable.h xfs: bulkstat chunk formatting cursor is broken 2014-11-07 08:30:30 +11:00
xfs_linux.h xfs: merge xfs_dinode.h into xfs_format.h 2014-11-28 14:24:06 +11:00
xfs_log.c Merge branch 'xfs-sb-logging-rework' into for-next 2015-01-22 09:20:53 +11:00
xfs_log.h xfs: log vector rounding leaks log space 2014-05-20 08:18:09 +10:00
xfs_log_cil.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_log_priv.h xfs: add xlog sysfs kobject and attribute handlers 2014-07-15 08:07:29 +10:00
xfs_log_recover.c Merge branch 'xfs-misc-fixes-for-3.19-2' into for-next 2014-12-04 09:46:17 +11:00
xfs_message.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_message.h
xfs_mount.c xfs: sanitise sb_bad_features2 handling 2015-01-22 09:10:33 +11:00
xfs_mount.h xfs: implement pNFS export operations 2015-02-16 11:49:23 +11:00
xfs_mru_cache.c xfs: mark all internal workqueues as freezable 2014-09-09 11:44:46 +10:00
xfs_mru_cache.h xfs: embedd mru_elem into parent structure 2014-04-23 07:11:51 +10:00
xfs_pnfs.c xfs: recall pNFS layouts on conflicting access 2015-02-16 11:59:50 +11:00
xfs_pnfs.h xfs: recall pNFS layouts on conflicting access 2015-02-16 11:59:50 +11:00
xfs_qm.c xfs: inodes are new until the dentry cache is set up 2015-02-23 22:38:08 +11:00
xfs_qm.h xfs: update for 3.20-rc1 2015-02-10 16:15:17 -08:00
xfs_qm_bhv.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_qm_syscalls.c xfs: update for 3.20-rc1 2015-02-10 16:15:17 -08:00
xfs_quota.h xfs: split dquot buffer operations out 2013-10-23 14:28:35 -05:00
xfs_quotaops.c quota: Split ->set_xstate callback into two 2015-01-30 12:49:40 +01:00
xfs_rtalloc.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_rtalloc.h xfs: combine xfs_rtmodify_summary and xfs_rtget_summary 2014-09-09 11:58:42 +10:00
xfs_stats.c xfs: support the XFS_BTNUM_FINOBT free inode btree type 2014-04-24 16:00:52 +10:00
xfs_stats.h xfs: support the XFS_BTNUM_FINOBT free inode btree type 2014-04-24 16:00:52 +10:00
xfs_super.c fs: consolidate {nr,free}_cached_objects args in shrink_control 2015-02-12 18:54:08 -08:00
xfs_super.h xfs: require 64-bit sector_t 2014-07-30 09:12:05 +10:00
xfs_symlink.c xfs: inodes are new until the dentry cache is set up 2015-02-23 22:38:08 +11:00
xfs_symlink.h xfs: push down inactive transaction mgmt for remote symlinks 2013-10-08 14:53:02 -05:00
xfs_sysctl.c xfs: remove deprecated sysctls 2015-01-09 10:47:43 +11:00
xfs_sysctl.h xfs: export log_recovery_delay to delay mount time log recovery 2014-09-09 11:56:13 +10:00
xfs_sysfs.c xfs: export log_recovery_delay to delay mount time log recovery 2014-09-09 11:56:13 +10:00
xfs_sysfs.h xfs: add debug sysfs attribute set 2014-09-09 11:52:42 +10:00
xfs_trace.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_trace.h xfs: introduce xfs_buf_submit[_wait] 2014-10-02 09:05:14 +10:00
xfs_trans.c xfs: set superblock buffer type correctly 2015-01-22 09:30:23 +11:00
xfs_trans.h xfs: format log items write directly into the linear CIL buffer 2013-12-13 11:34:02 +11:00
xfs_trans_ail.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_trans_buf.c xfs: only trace buffer items if they exist 2015-02-10 09:23:40 +11:00
xfs_trans_dquot.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_trans_extfree.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_trans_inode.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00
xfs_trans_priv.h xfs: remove unused ail pointer arg from xfs_trans_ail_cursor_done() 2014-04-14 19:06:05 +10:00
xfs_xattr.c xfs: move most of xfs_sb.h to xfs_format.h 2014-11-28 14:27:09 +11:00