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58c904734c
linux/fs
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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
..
9p VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
adfs
affs fs/affs/super.c: fix switch indentation 2015-02-17 14:34:53 -08:00
afs Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block 2015-02-12 13:50:21 -08:00
autofs4 autofs4 copy_dev_ioctl(): keep the value of ->size we'd used for allocation 2015-02-22 11:43:34 -05:00
befs fs/befs/linuxvfs.c: remove unnecessary casting 2015-02-17 14:34:50 -08:00
bfs
btrfs 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
cachefiles Cachefiles: Fix up scripted S_ISDIR/S_ISREG/S_ISLNK conversions 2015-02-22 11:38:41 -05:00
ceph 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
cifs Revert "locks: keep a count of locks on the flctx lists" 2015-02-16 14:32:03 -05:00
coda VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
configfs configfs: Fix potential NULL d_inode dereference 2015-02-20 04:56:43 -05:00
cramfs
debugfs debugfs: leave freeing a symlink body until inode eviction 2015-02-22 11:38:43 -05:00
devpts
dlm netlink: make nlmsg_end() and genlmsg_end() void 2015-01-18 01:03:45 -05:00
ecryptfs VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
efivarfs * Move efivarfs from the misc filesystem section to pseudo filesystem, 2015-01-29 19:16:40 +01:00
efs
exofs vfs: remove get_xip_mem 2015-02-16 17:56:03 -08:00
exportfs VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
ext2 ext2: get rid of most mentions of XIP in ext2 2015-02-16 17:56:04 -08:00
ext3 ext3: destroy sbi mutexes in put_super 2015-01-05 11:13:55 +01:00
ext4 Ext4 bug fixes for 3.20. We also reserved code points for encryption 2015-02-22 18:05:13 -08:00
f2fs Merge tag 'for-f2fs-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs 2015-02-12 19:28:50 -08:00
fat fs: fat: use MSDOS_SB macro to get msdos_sb_info 2015-02-17 14:34:51 -08:00
freevxfs
fscache fs/fscache/object-list.c: use __seq_open_private() 2014-10-13 17:52:21 +01:00
fuse VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
gfs2 VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
hfs fs/hfs/catalog.c: fix comparison bug in hfs_cat_keycmp 2014-12-10 17:41:16 -08:00
hfsplus VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
hostfs
hpfs
hppfs VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
hugetlbfs fs: remove mapping->backing_dev_info 2015-01-20 14:03:05 -07:00
isofs isofs: Fix bug in the way to check if the year is a leap year 2015-01-07 09:51:49 +01:00
jbd jbd: Deletion of an unnecessary check before the function call "iput" 2014-11-18 10:15:29 +01:00
jbd2 jbd2: complain about descriptor block checksum errors 2015-01-19 15:59:58 -05:00
jffs2 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
jfs Merge branch 'lazytime' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-02-17 16:12:34 -08:00
kernfs kernfs: remove KERNFS_STATIC_NAME 2015-02-13 21:21:36 -08:00
lockd Merge branch 'for-3.20' of git://linux-nfs.org/~bfields/linux 2015-02-12 10:39:41 -08:00
logfs
minix
ncpfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-02-17 14:56:45 -08:00
nfs NFSv4.1: Clean up bind_conn_to_session 2015-02-18 13:11:09 -08:00
nfs_common
nfsd VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
nilfs2 Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block 2015-02-12 13:50:21 -08:00
nls
notify fanotify: Fix up scripted S_ISDIR/S_ISREG/S_ISLNK conversions 2015-02-22 11:38:42 -05:00
ntfs fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info 2015-01-20 14:03:04 -07:00
ocfs2 ocfs2: set append dio as a ro compat feature 2015-02-16 17:56:05 -08:00
omfs FS/OMFS: block number sanity check during fill_super operation 2014-10-14 02:18:22 +02:00
openpromfs
overlayfs VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
proc procfs: fix race between symlink removals and traversals 2015-02-22 11:43:12 -05:00
pstore pstore: Fix sprintf format specifier in pstore_dump() 2015-01-16 16:01:29 -08:00
qnx4
qnx6
quota Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2015-02-10 15:52:38 -08:00
ramfs fs: remove mapping->backing_dev_info 2015-01-20 14:03:05 -07:00
reiserfs VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
romfs fs: remove mapping->backing_dev_info 2015-01-20 14:03:05 -07:00
squashfs Squashfs: Add LZ4 compression configuration option 2014-11-27 18:48:44 +00:00
sysfs driver core patches for 3.20-rc1 2015-02-15 11:11:47 -08:00
sysv
ubifs Merge branch 'for-linus-v3.20' of git://git.infradead.org/linux-ubifs 2015-02-15 10:11:39 -08:00
udf udf: remove bool assignment to 0/1 2015-02-05 16:34:25 +01:00
ufs fs/ufs/super.c: fix potential race condition 2015-02-17 14:34:51 -08:00
xfs xfs: inodes are new until the dentry cache is set up 2015-02-23 22:38:08 +11:00
aio.c fs/aio.c: Remove duplicate function name in pr_debug messages 2015-02-20 04:56:44 -05:00
anon_inodes.c
attr.c
bad_inode.c don't bother with most of the bad_file_ops methods 2015-02-20 04:03:58 -05:00
binfmt_aout.c assorted conversions to %p[dD] 2014-11-19 13:01:20 -05:00
binfmt_elf_fdpic.c handle suicide on late failure exits in execve() in search_binary_handler() 2014-10-09 02:39:00 -04:00
binfmt_elf.c x86, mm/ASLR: Fix stack randomization on 64-bit systems 2015-02-19 12:21:36 +01:00
binfmt_em86.c syscalls: implement execveat() system call 2014-12-13 12:42:51 -08:00
binfmt_flat.c
binfmt_misc.c unfuck binfmt_misc.c (broken by commit e6084d4) 2014-12-17 08:27:14 -05:00
binfmt_script.c syscalls: implement execveat() system call 2014-12-13 12:42:51 -08:00
block_dev.c Merge branch 'for-3.20/core' of git://git.kernel.dk/linux-block 2015-02-12 14:13:23 -08:00
buffer.c fs: clarify rate limit suppressed buffer I/O errors 2014-10-21 13:55:11 -06:00
char_dev.c fs: introduce f_op->mmap_capabilities for nommu mmap support 2015-01-20 14:02:58 -07:00
compat_binfmt_elf.c
compat_ioctl.c
compat.c vfs: make first argument of dir_context.actor typed 2014-10-31 17:48:54 -04:00
coredump.c coredump: Fix typo in comment 2015-02-20 04:56:44 -05:00
dax.c dax: add dax_zero_page_range 2015-02-16 17:56:04 -08:00
dcache.c VFS: Split DCACHE_FILE_TYPE into regular and special types 2015-02-22 11:38:38 -05:00
dcookies.c
direct-io.c
drop_caches.c vmscan: per memory cgroup slab shrinkers 2015-02-12 18:54:09 -08:00
eventfd.c eventfd: don't take the spinlock in eventfd_poll 2015-02-17 14:34:52 -08:00
eventpoll.c epoll: optimize setting task running after blocking 2015-02-13 21:21:40 -08:00
exec.c fs: create proper filename objects using getname_kernel() 2015-01-23 00:22:20 -05:00
fcntl.c vfs: renumber FMODE_NONOTIFY and add to uniqueness check 2015-01-08 15:10:52 -08:00
fhandle.c
file_table.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-10-13 11:28:42 +02:00
file.c fs/file.c: replace get_unused_fd() with get_unused_fd_flags(0) 2014-12-10 17:41:10 -08:00
filesystems.c
fs_pin.c switch the IO-triggering parts of umount to fs_pin 2015-01-25 23:17:29 -05:00
fs_struct.c
fs-writeback.c trylock_super(): replacement for grab_super_passive() 2015-02-22 11:38:42 -05:00
inode.c Merge branch 'lazytime' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-02-17 16:12:34 -08:00
internal.h trylock_super(): replacement for grab_super_passive() 2015-02-22 11:38:42 -05:00
ioctl.c fsioctl.c: make generic_block_fiemap() signal-tolerant 2015-02-10 14:30:30 -08:00
Kconfig dax: does not work correctly with virtual aliasing caches 2015-02-16 17:56:04 -08:00
Kconfig.binfmt fs/binfmt_som: Drop kernel support for HP-UX SOM binaries 2015-02-17 16:29:36 +01:00
libfs.c VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
locks.c locks: fix list insertion when lock is split in two 2015-02-17 17:08:23 -05:00
Makefile Merge branch 'parisc-3.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2015-02-17 14:25:58 -08:00
mbcache.c
mount.h switch the IO-triggering parts of umount to fs_pin 2015-01-25 23:17:29 -05:00
mpage.c vfs: guard end of device for mpage interface 2014-10-09 22:25:53 -04:00
namei.c VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
namespace.c VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
no-block.c
nsfs.c take the targets of /proc/*/ns/* symlinks to separate fs 2014-12-10 21:30:20 -05:00
open.c Merge branch 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-02-17 15:27:47 -08:00
pipe.c
pnode.c mnt: Move the clear of MNT_LOCKED from copy_tree to it's callers. 2014-12-02 10:46:50 -06:00
pnode.h
posix_acl.c VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) 2015-02-22 11:38:41 -05:00
proc_namespace.c vfs: add support for a lazytime mount option 2015-02-05 02:45:00 -05:00
read_write.c Merge branch 'iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-02-17 15:48:33 -08:00
readdir.c vfs: make first argument of dir_context.actor typed 2014-10-31 17:48:54 -04:00
select.c all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
seq_file.c bitmap, cpumask, nodemask: remove dedicated formatting functions 2015-02-13 21:21:39 -08:00
signalfd.c fs: Convert show_fdinfo functions to void 2014-11-05 14:13:23 -05:00
splice.c fs: add vfs_iter_{read,write} helpers 2015-01-29 00:13:13 -05:00
stack.c
stat.c
statfs.c
super.c trylock_super(): replacement for grab_super_passive() 2015-02-22 11:38:42 -05:00
sync.c vfs: add support for a lazytime mount option 2015-02-05 02:45:00 -05:00
timerfd.c fs: Convert show_fdinfo functions to void 2014-11-05 14:13:23 -05:00
utimes.c
xattr.c new helper: audit_file() 2014-11-19 13:01:26 -05:00