linux/fs
Steven J. Magnani 21b6633d51 fat (exportfs): move NFS support code
Under memory pressure, the system may evict dentries from cache.  When the
FAT driver receives a NFS request involving an evicted dentry, it is
unable to reconnect it to the filesystem root.  This causes the request to
fail, often with ENOENT.

This is partially due to ineffectiveness of the current FAT NFS
implementation, and partially due to an unimplemented fh_to_parent method.
 The latter can cause file accesses to fail on shares exported with
subtree_check.

This patch set provides the FAT driver with the ability to
reconnect dentries.  NFS file handle generation and lookups are simplified
and made congruent with ext2.

Testing has involved a memory-starved virtual machine running 3.5-rc5 that
exports a ~2 GB vfat filesystem containing a kernel tree (~770 MB, ~40000
files, 9 levels).  Both 'cp -r' and 'ls -lR' operations were performed
from a client, some overlapping, some consecutive.  Exports with
'subtree_check' and 'no_subtree_check' have been tested.

Note that while this patch set improves FAT's NFS support, it does not
eliminate ESTALE errors completely.

The following should be considered for NFS clients who are sensitive to ESTALE:

* Mounting with lookupcache=none
  Unfortunately this can degrade performance severely, particularly for deep
  filesystems.

* Incorporating VFS patches to retry ESTALE failures on the client-side,
  such as https://lkml.org/lkml/2012/6/29/381

* Handling ESTALE errors in client application code

This patch:

Move NFS-related code into its own C file.  No functional changes.

Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06 03:05:09 +09:00
..
9p Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
adfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
affs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
afs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
autofs4 make get_file() return its argument 2012-09-26 21:10:25 -04:00
befs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
bfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
cachefiles fs: cachefiles: add support for large files in filesystem caching 2012-07-30 17:25:21 -07:00
ceph fs: push rcu_barrier() from deactivate_locked_super() to filesystems 2012-10-02 21:35:55 -04:00
cifs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
coda fs: push rcu_barrier() from deactivate_locked_super() to filesystems 2012-10-02 21:35:55 -04:00
configfs userns: Convert configfs to use kuid and kgid where appropriate 2012-09-18 01:01:37 -07:00
cramfs userns: Convert cramfs to use kuid/kgid where appropriate 2012-09-21 03:13:08 -07:00
debugfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-10-02 11:11:09 -07:00
devpts VFS: Pass mount flags to sget() 2012-07-14 16:38:34 +04:00
dlm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2012-10-02 13:38:27 -07:00
ecryptfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
efs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
exofs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
exportfs switch dentry_open() to struct path, make it grab references itself 2012-07-23 00:01:29 +04:00
ext2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
ext3 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2012-10-04 09:14:01 -07:00
ext4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
fat fat (exportfs): move NFS support code 2012-10-06 03:05:09 +09:00
freevxfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
fscache
fuse fs: push rcu_barrier() from deactivate_locked_super() to filesystems 2012-10-02 21:35:55 -04:00
gfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-10-02 11:11:09 -07:00
hfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
hfsplus Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
hostfs userns: Convert hostfs to use kuid and kgid where appropriate 2012-09-21 03:13:23 -07:00
hpfs hpfs: convert to use leXX_add_cpu() 2012-10-06 03:05:08 +09:00
hppfs switch dentry_open() to struct path, make it grab references itself 2012-07-23 00:01:29 +04:00
hugetlbfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
isofs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
jbd jbd: Fix assertion failure in commit code due to lacking transaction credits 2012-09-12 15:52:03 +02:00
jbd2 The following are all bug fixes and regressions. The most notable are 2012-08-17 08:04:47 -07:00
jffs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
jfs JFS TRIM support and some minor fixes 2012-10-03 08:48:21 -07:00
lockd close the race in nlmsvc_free_block() 2012-09-22 20:48:20 -04:00
logfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
minix Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
ncpfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
nfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
nfs_common
nfsd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
nilfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
nls
notify switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
ntfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
ocfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
omfs userns: Convert omfs to use kuid and kgid where appropriate 2012-09-21 03:13:16 -07:00
openpromfs fs: push rcu_barrier() from deactivate_locked_super() to filesystems 2012-10-02 21:35:55 -04:00
proc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
pstore pstore/ram: Make tracing log versioned 2012-07-17 16:48:09 -07:00
qnx4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
qnx6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
quota Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-10-02 11:11:09 -07:00
ramfs don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
reiserfs Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2012-10-04 09:14:01 -07:00
romfs fs: push rcu_barrier() from deactivate_locked_super() to filesystems 2012-10-02 21:35:55 -04:00
squashfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
sysfs sysfs: Fix comment typo "sysf_create_link". 2012-09-04 16:11:31 -07:00
sysv Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
ubifs No big changes for 3.7 in UBIFS: 2012-10-02 20:47:48 -07:00
udf Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2012-10-04 09:14:01 -07:00
ufs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
xfs xfs: update for 3.7-rc1 2012-10-02 20:42:58 -07:00
aio.c aio: now fput() is OK from interrupt context; get rid of manual delayed __fput() 2012-07-22 23:57:59 +04:00
anon_inodes.c
attr.c ima: add inode_post_setattr call 2012-09-07 14:57:46 -04:00
bad_inode.c don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c binfmt_elf: Uninitialized variable 2012-10-06 03:05:00 +09:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio-integrity.c
bio.c Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2012-08-25 11:36:43 -07:00
block_dev.c fs/block-dev.c:fix performance regression in O_DIRECT writes to md block devices 2012-08-02 09:50:39 +02:00
buffer.c block: replace __getblk_slow misfix by grow_dev_page fix 2012-08-23 12:17:36 +02:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
compat.c compat: fs: Generic compat_sys_sendfile implementation 2012-10-02 21:35:55 -04:00
coredump.c coredump: move core dump functionality into its own file 2012-10-02 21:35:55 -04:00
dcache.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
dcookies.c
direct-io.c block: move down direct IO plugging 2012-08-09 15:23:09 +02:00
drop_caches.c
eventfd.c
eventpoll.c epoll: support for disabling items, and a self-test app 2012-10-06 03:05:00 +09:00
exec.c coredump: move core dump functionality into its own file 2012-10-02 21:35:55 -04:00
fcntl.c fcntl: fix misannotations 2012-09-26 22:20:20 -04:00
fhandle.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
fifo.c fifo: Do not restart open() if it already found a partner 2012-07-16 08:33:14 -07:00
file_table.c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2012-10-02 21:38:48 -07:00
file.c export fget_light 2012-09-26 21:10:06 -04:00
filesystems.c
fs_struct.c get rid of ->mnt_longterm 2012-07-14 16:32:47 +04:00
fs-writeback.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-10-01 09:06:36 -07:00
generic_acl.c userns: Pass a userns parameter into posix_acl_to_xattr and posix_acl_from_xattr 2012-09-18 01:01:35 -07:00
inode.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-08-01 10:26:23 -07:00
internal.h fs: Add freezing handling to mnt_want_write() / mnt_drop_write() 2012-07-31 09:40:38 +04:00
ioctl.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
ioprio.c
Kconfig
Kconfig.binfmt
libfs.c vfs: fix kerneldoc for generic_fh_to_parent() 2012-09-05 10:59:30 +02:00
locks.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
Makefile coredump: move core dump functionality into its own file 2012-10-02 21:35:55 -04:00
mbcache.c
mount.h get rid of magic in proc_namespace.c 2012-07-14 16:32:48 +04:00
mpage.c
namei.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
namespace.c do_add_mount()/umount -l races 2012-09-22 20:48:18 -04:00
no-block.c
open.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
pipe.c pipe(2) - race-free error recovery 2012-09-26 21:08:52 -04:00
pnode.c VFS: Make clone_mnt()/copy_tree()/collect_mounts() return errors 2012-07-14 16:37:27 +04:00
pnode.h
posix_acl.c userns: Convert vfs posix_acl support to use kuids and kgids 2012-09-18 01:01:35 -07:00
proc_namespace.c get rid of magic in proc_namespace.c 2012-07-14 16:32:48 +04:00
read_write.c compat: fs: Generic compat_sys_sendfile implementation 2012-10-02 21:35:55 -04:00
read_write.h compat: fs: Generic compat_sys_sendfile implementation 2012-10-02 21:35:55 -04:00
readdir.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
select.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
seq_file.c userns: Make seq_file's user namespace accessible 2012-08-14 21:47:55 -07:00
signalfd.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
splice.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
stack.c
stat.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
statfs.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
super.c idr: rename MAX_LEVEL to MAX_IDR_LEVEL 2012-10-06 03:04:56 +09:00
sync.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
timerfd.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
utimes.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
xattr_acl.c userns: Pass a userns parameter into posix_acl_to_xattr and posix_acl_from_xattr 2012-09-18 01:01:35 -07:00
xattr.c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2012-10-02 21:38:48 -07:00