android_kernel_xiaomi_sm7250/fs
Jeff Layton cea218054a [CIFS] Fix potential data corruption when writing out cached dirty pages
Fix RedHat bug 329431

The idea here is separate "conscious" from "unconscious" flushes.
Conscious flushes are those due to a fsync() or close(). Unconscious
ones are flushes that occur as a side effect of some other operation or
due to memory pressure.

Currently, when an error occurs during an unconscious flush (ENOSPC or
EIO), we toss out the page and don't preserve that error to report to
the user when a conscious flush occurs. If after the unconscious flush,
there are no more dirty pages for the inode, the conscious flush will
simply return success even though there were previous errors when writing
out pages. This can lead to data corruption.

The easiest way to reproduce this is to mount up a CIFS share that's
very close to being full or where the user is very close to quota. mv
a file to the share that's slightly larger than the quota allows. The
writes will all succeed (since they go to pagecache). The mv will do a
setattr to set the new file's attributes. This calls
filemap_write_and_wait,
which will return an error since all of the pages can't be written out.
Then later, when the flush and release ops occur, there are no more
dirty pages in pagecache for the file and those operations return 0. mv
then assumes that the file was written out correctly and deletes the
original.

CIFS already has a write_behind_rc variable where it stores the results
from earlier flushes, but that value is only reported in cifs_close.
Since the VFS ignores the return value from the release operation, this
isn't helpful. We should be reporting this error during the flush
operation.

This patch does the following:

1) changes cifs_fsync to use filemap_write_and_wait and cifs_flush and also
sync to check its return code. If it returns successful, they then check
the value of write_behind_rc to see if an earlier flush had reported any
errors. If so, they return that error and clear write_behind_rc.

2) sets write_behind_rc in a few other places where pages are written
out as a side effect of other operations and the code waits on them.

3) changes cifs_setattr to only call filemap_write_and_wait for
ATTR_SIZE changes.

4) makes cifs_writepages accurately distinguish between EIO and ENOSPC
errors when writing out pages.

Some simple testing indicates that the patch works as expected and that
it fixes the reproduceable known problem.

Acked-by: Dave Kleikamp <shaggy@austin.rr.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2007-11-20 23:19:03 +00:00
..
9p 9p: use copy of the options value instead of original 2007-11-06 08:02:53 -06:00
adfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
affs fs: mark nibblemap const 2007-10-17 08:42:47 -07:00
afs fs/afs/vlocation.c: fix off-by-one 2007-11-05 15:12:32 -08:00
autofs Use task_pid_nr() instead of pid_nr(task_pid()) 2007-10-19 11:53:43 -07:00
autofs4 pid namespaces: round up the API 2007-10-19 11:53:37 -07:00
befs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
bfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
cifs [CIFS] Fix potential data corruption when writing out cached dirty pages 2007-11-20 23:19:03 +00:00
coda pid namespaces: round up the API 2007-10-19 11:53:37 -07:00
configfs r/o bind mounts: filesystem helpers for custom 'struct file's 2007-10-17 08:43:04 -07:00
cramfs fs/cramfs/inode.c: replace hardcoded value with preprocessor constant 2007-10-18 14:37:29 -07:00
debugfs [PATCH] pass dentry to audit_inode()/audit_inode_child() 2007-10-21 02:37:18 -04:00
devpts devpts: add fsnotify create event 2007-05-08 11:14:59 -07:00
dlm [DLM] lowcomms: Do not muck with sysctl_rmem_max. 2007-11-07 04:11:42 -08:00
ecryptfs eCryptfs: release mutex on hash error path 2007-11-05 15:12:33 -08:00
efs exportfs: make struct export_operations const 2007-10-22 08:13:21 -07:00
exportfs exportfs: update documentation 2007-10-22 08:13:21 -07:00
ext2 Revert "ext2/ext3/ext4: add block bitmap validation" 2007-11-13 08:09:11 -08:00
ext3 Revert "ext2/ext3/ext4: add block bitmap validation" 2007-11-13 08:09:11 -08:00
ext4 Revert "ext2/ext3/ext4: add block bitmap validation" 2007-11-13 08:09:11 -08:00
fat exportfs: make struct export_operations const 2007-10-22 08:13:21 -07:00
freevxfs mm: Remove slab destructors from kmem_cache_create(). 2007-07-20 10:11:58 +09:00
fuse fuse: add blksize field to fuse_attr 2007-10-18 14:37:31 -07:00
gfs2 exportfs: make struct export_operations const 2007-10-22 08:13:21 -07:00
hfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
hfsplus Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
hostfs uml: fix hostfs style 2007-10-16 09:43:07 -07:00
hpfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
hppfs
hugetlbfs r/o bind mounts: filesystem helpers for custom 'struct file's 2007-10-17 08:43:04 -07:00
isofs exportfs: make struct export_operations const 2007-10-22 08:13:21 -07:00
jbd JBD: Fix JBD warnings when compiling with CONFIG_JBD_DEBUG 2007-10-19 11:53:35 -07:00
jbd2 JBD2: debug code cleanup. 2007-10-17 18:49:59 -04:00
jffs2 [JFFS2] Prevent return of initialised variable in jffs2_init_acl_post() 2007-10-27 10:36:44 -04:00
jfs exportfs: make struct export_operations const 2007-10-22 08:13:21 -07:00
lockd NFS/SUNRPC: use transport protocol naming 2007-10-09 17:17:53 -04:00
minix limit minixfs printks on corrupted dir i_size 2007-10-17 08:42:53 -07:00
msdos
ncpfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
nfs NFS: Fix for bug in handling of errors for O_DIRECT writes 2007-10-23 16:41:21 -07:00
nfs_common
nfsd nfsd4: recheck for secure ports in fh_verify 2007-11-12 14:28:08 -08:00
nls sparse pointer use of zero as null 2007-10-18 14:37:31 -07:00
ntfs NTFS: Fix read regression. 2007-11-03 12:27:21 -07:00
ocfs2 [NET]: Add the helper kernel_sock_shutdown() 2007-11-12 18:10:39 -08:00
openpromfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
partitions fs/partitions/sun.c endianness annotations 2007-10-14 12:41:51 -07:00
proc [NET]: Move unneeded data to initdata section. 2007-11-13 03:23:50 -08:00
qnx4 Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
ramfs Remove valueless definition of hard-selected RAMFS option 2007-10-17 08:42:56 -07:00
reiserfs exportfs: make struct export_operations const 2007-10-22 08:13:21 -07:00
romfs fs/romfs/inode.c: trivial improvements 2007-10-17 08:42:47 -07:00
smbfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
sysfs sysfs: make sysfs_{get,put}_active() static 2007-10-30 21:52:33 -07:00
sysv Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
udf fs/udf/balloc.c: mark a variable as uninitialized_var() 2007-10-17 08:43:00 -07:00
ufs revert "ufs: Fix mount check in ufs_fill_super()" 2007-10-30 08:06:55 -07:00
vfat
xfs exportfs: make struct export_operations const 2007-10-22 08:13:21 -07:00
aio.c Remove struct task_struct::io_wait 2007-10-18 14:37:20 -07:00
anon_inodes.c anon-inodes use open coded atomic_inc for the shared inode 2007-10-17 08:43:00 -07:00
attr.c VFS: make notify_change pass ATTR_KILL_S*ID to setattr operations 2007-10-18 14:37:22 -07:00
bad_inode.c sendfile: remove bad_sendfile() from bad_file_ops 2007-07-10 08:04:15 +02:00
binfmt_aout.c core_pattern: ignore RLIMIT_CORE if core_pattern is a pipe 2007-10-17 08:42:50 -07:00
binfmt_elf_fdpic.c pid namespaces: changes to show virtual ids to user 2007-10-19 11:53:40 -07:00
binfmt_elf.c pid namespaces: changes to show virtual ids to user 2007-10-19 11:53:40 -07:00
binfmt_em86.c Convert files to UTF-8 and some cleanups 2007-10-19 23:21:04 +02:00
binfmt_flat.c binfmt_flat: warning fixes 2007-10-17 08:42:54 -07:00
binfmt_misc.c Convert files to UTF-8 and some cleanups 2007-10-19 23:21:04 +02:00
binfmt_script.c Convert files to UTF-8 and some cleanups 2007-10-19 23:21:04 +02:00
binfmt_som.c core_pattern: ignore RLIMIT_CORE if core_pattern is a pipe 2007-10-17 08:42:50 -07:00
bio.c bio: make freeing of ->bi_io_vec conditional in bio_free() 2007-10-16 11:03:52 +02:00
block_dev.c Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
buffer.c nobh: nobh_write_end fix 2007-10-21 08:54:05 -07:00
char_dev.c mm: bdi init hooks 2007-10-17 08:42:45 -07:00
compat_ioctl.c [COMPAT]: Fix new dev_ifname32 returning -EFAULT 2007-10-30 21:29:42 -07:00
compat.c mm: variable length argument support 2007-07-19 10:04:45 -07:00
dcache.c dcache: don't expose uninitialized memory in /proc/<pid>/fd/<fd> 2007-10-22 08:13:18 -07:00
dcookies.c Remove fs.h from mm.h 2007-07-29 17:09:29 -07:00
direct-io.c remove ZERO_PAGE 2007-10-16 09:42:53 -07:00
dnotify.c mm: Remove slab destructors from kmem_cache_create(). 2007-07-20 10:11:58 +09:00
dquot.c quota: send messages via netlink 2007-10-17 08:42:56 -07:00
drop_caches.c invalidate_mapping_pages(): add cond_resched 2007-07-16 09:05:36 -07:00
eventfd.c eventfd use waitqueue lock ... 2007-05-18 13:09:34 -07:00
eventpoll.c fs/eventpoll.c: use list_for_each_entry() instead of list_for_each() 2007-10-19 11:53:38 -07:00
exec.c core dump: remain dumpable 2007-11-12 10:32:29 -08:00
fcntl.c pid namespaces: changes to show virtual ids to user 2007-10-19 11:53:40 -07:00
fifo.c Detach sched.h from mm.h 2007-05-21 09:18:19 -07:00
file_table.c fs/file_table.c: use list_for_each_entry() instead of list_for_each() 2007-10-19 11:53:38 -07:00
file.c
filesystems.c add filesystem subtype support 2007-05-08 11:15:01 -07:00
fs-writeback.c Use helpers to obtain task pid in printks 2007-10-19 11:53:43 -07:00
generic_acl.c Introduce is_owner_or_cap() to wrap CAP_FOWNER use with fsuid check 2007-07-17 12:00:03 -07:00
inode.c introduce I_SYNC 2007-10-17 08:43:02 -07:00
inotify_user.c change inotifyfs magic as the same magic is used for futexfs 2007-10-17 08:43:00 -07:00
inotify.c [PATCH] new helper - inotify_evict_watch() 2007-10-21 02:37:38 -04:00
internal.h cleanup compat ioctl handling 2007-05-08 11:15:09 -07:00
ioctl.c drop obsolete sys_ioctl export 2007-07-16 09:05:48 -07:00
ioprio.c ioprio: allow sys_ioprio_set() value of 0 to reset ioprio setting 2007-11-07 13:54:07 +01:00
Kconfig Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6 2007-11-12 11:11:39 -08:00
Kconfig.binfmt fs: Kill sh dependency for binfmt_flat. 2007-05-21 14:34:00 +09:00
libfs.c exportfs: add new methods 2007-10-22 08:13:19 -07:00
locks.c locks: fix possible infinite loop in posix deadlock detection 2007-10-30 09:04:18 -07:00
Makefile Remove valueless definition of hard-selected RAMFS option 2007-10-17 08:42:56 -07:00
mbcache.c fs: Fix to correct the mbcache entries counter 2007-10-25 15:18:29 -07:00
mpage.c mm: buffered write cleanup 2007-10-16 09:42:54 -07:00
namei.c [PATCH] pass dentry to audit_inode()/audit_inode_child() 2007-10-21 02:37:18 -04:00
namespace.c [PATCH] new helpers - collect_mounts() and release_collected_mounts() 2007-10-21 02:37:25 -04:00
nfsctl.c nfsctl: use vfs_path_lookup 2007-07-19 10:04:45 -07:00
no-block.c
open.c [PATCH] pass dentry to audit_inode()/audit_inode_child() 2007-10-21 02:37:18 -04:00
pipe.c sched: affine sync wakeups 2007-10-15 17:00:19 +02:00
pnode.c Introduce a handy list_first_entry macro 2007-05-08 11:15:11 -07:00
pnode.h [PATCH] new helpers - collect_mounts() and release_collected_mounts() 2007-10-21 02:37:25 -04:00
posix_acl.c
quota_v1.c
quota_v2.c
quota.c [IA64] Fix build failure in fs/quota.c 2007-07-27 15:40:13 -07:00
read_write.c Cleanup macros for distinguishing mandatory locks 2007-10-09 18:32:46 -04:00
read_write.h
readdir.c ROUND_UP macro cleanup in fs/(select|compat|readdir).c 2007-05-08 11:15:09 -07:00
select.c fs/select, remove unused macros 2007-10-19 11:53:41 -07:00
seq_file.c [FS] seq_file: Introduce the seq_open_private() 2007-10-10 16:55:33 -07:00
signalfd.c rename signalfd_siginfo fields 2007-10-17 08:43:01 -07:00
splice.c Implement file posix capabilities 2007-10-17 08:43:07 -07:00
stack.c
stat.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
super.c Convert files to UTF-8 and some cleanups 2007-10-19 23:21:04 +02:00
sync.c Introduce fixed sys_sync_file_range2() syscall, implement on PowerPC and ARM 2007-06-28 11:38:30 -07:00
timerfd.c make timerfd return a u64 and fix the __put_user 2007-07-26 11:35:17 -07:00
utimes.c VFS: check nanoseconds in utimensat 2007-10-17 08:42:52 -07:00
xattr_acl.c
xattr.c [PATCH] pass dentry to audit_inode()/audit_inode_child() 2007-10-21 02:37:18 -04:00