linux/fs
Artem Bityutskiy 020ac5b6be fat: introduce special inode for managing the FSINFO block
This is patchset makes fatfs stop using the VFS '->write_super()' method
for writing out the FSINFO block.

The final goal is to get rid of the 'sync_supers()' kernel thread.  This
kernel thread wakes up every 5 seconds (by default) and calls
'->write_super()' for all mounted file-systems.  And the bad thing is that
this is done even if all the superblocks are clean.  Moreover, some
file-systems do not even need this end they do not register the
'->write_super()' method at all (e.g., btrfs).

So 'sync_supers()' most often just generates useless wake-ups and wastes
power.  I am trying to make all file-systems independent of
'->write_super()' and plan to remove 'sync_supers()' and '->write_super'
completely once there are no more users.

The '->write_supers()' method is mostly used by baroque file-systems like
hfs, udf, etc.  Modern file-systems like btrfs and xfs do not use it.
This justifies removing this stuff from VFS completely and make every FS
self-manage own superblock.

Tested with xfstests.

This patch:

Preparation for further changes.  It introduces a special inode
('fsinfo_inode') in FAT file-system which we'll later use for managing the
FSINFO block.  Note, this there is already one special inode ('fat_inode')
which is used for managing the FAT tables.

Introduce new 'MSDOS_FSINFO_INO' constant for this special inode.  It is
safe to do because FAT file-system does not store inode numbers on the
media but generates them run-time.

I've also cleaned up the comment to existing 'MSDOS_ROOT_INO' constant,
while on it.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-31 17:49:27 -07:00
..
9p vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
adfs switch open-coded instances of d_make_root() to new helper 2012-03-20 21:29:35 -04:00
affs vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
afs vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
autofs4 avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
befs switch open-coded instances of d_make_root() to new helper 2012-03-20 21:29:35 -04:00
bfs vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
btrfs avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
cachefiles switch touch_atime to struct path 2012-03-20 21:29:41 -04:00
ceph introduce SIZE_MAX 2012-05-31 17:49:26 -07:00
cifs avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
coda vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
configfs make configfs_pin_fs() return root dentry on success 2012-03-20 21:29:48 -04:00
cramfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-03-21 13:36:41 -07:00
debugfs debugfs: Add support to print u32 array in debugfs 2012-04-17 00:18:36 -04:00
devpts userns: Convert devpts to use kuid/kgid where appropriate 2012-05-15 14:59:26 -07:00
dlm dlm: NULL dereference on failure in kmem_cache_create() 2012-05-15 10:39:28 -05:00
ecryptfs avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
efs switch open-coded instances of d_make_root() to new helper 2012-03-20 21:29:35 -04:00
exofs Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd 2012-05-28 13:10:41 -07:00
exportfs
ext2 avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
ext3 avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
ext4 avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
fat fat: introduce special inode for managing the FSINFO block 2012-05-31 17:49:27 -07:00
freevxfs vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
fscache
fuse avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
gfs2 avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
hfs vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
hfsplus avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
hostfs vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
hpfs HPFS: remove PRINTK() macro 2012-05-31 17:49:27 -07:00
hppfs vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
hugetlbfs avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
isofs switch open-coded instances of d_make_root() to new helper 2012-03-20 21:29:35 -04:00
jbd jbd: Write journal superblock with WRITE_FUA after checkpointing 2012-05-15 23:34:37 +02:00
jbd2 jbd2: use GFP_NOFS for blkdev_issue_flush 2012-04-23 21:43:41 -04:00
jffs2 avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
jfs vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
lockd lockd: fix the endianness bug 2012-04-13 13:50:52 -04:00
logfs vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
minix vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
ncpfs vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
nfs NFS client updates for Linux 3.5 2012-05-29 10:43:51 -07:00
nfs_common
nfsd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-05-23 17:42:39 -07:00
nilfs2 nilfs2: flush disk caches in syncing 2012-05-31 17:49:27 -07:00
nls
notify fs/notify/notification.c: make subsys_initcall function static 2012-03-23 16:58:31 -07:00
ntfs vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
ocfs2 avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
omfs vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
openpromfs switch open-coded instances of d_make_root() to new helper 2012-03-20 21:29:35 -04:00
proc mm, oom: normalize oom scores to oom_score_adj scale only for userspace 2012-05-29 16:22:24 -07:00
pstore avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
qnx4 qnx4: new helper - try_extent() 2012-03-20 21:29:52 -04:00
qnx6 fs: initial qnx6fs addition 2012-03-20 21:29:38 -04:00
quota quota: Get rid of nested I_MUTEX_QUOTA locking subclass 2012-05-15 23:34:39 +02:00
ramfs tidy up after d_make_root() conversion 2012-03-20 21:29:37 -04:00
reiserfs avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
romfs MTD merge for 3.4 2012-03-30 17:31:56 -07:00
squashfs Add an extra mount time sanity check, plus some code cleanups and bug fixes. 2012-03-28 18:05:54 -07:00
sysfs avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
sysv vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
ubifs avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
udf avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
ufs avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
xfs avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
aio.c vfs: make AIO use the proper rw_verify_area() area helpers 2012-05-21 16:06:20 -07:00
anon_inodes.c anon_inodes: move allocation of anon_inode into ->mount() 2012-03-20 21:29:45 -04:00
attr.c userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs 2012-05-03 03:29:34 -07:00
bad_inode.c mm/fs: remove truncate_range 2012-05-29 16:22:23 -07:00
binfmt_aout.c VM: add "vm_mmap()" helper function 2012-04-20 17:29:13 -07:00
binfmt_elf_fdpic.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-05-23 17:42:39 -07:00
binfmt_elf.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-05-23 17:42:39 -07:00
binfmt_em86.c __register_binfmt() made void 2012-03-20 21:29:46 -04:00
binfmt_flat.c VM: add "vm_mmap()" helper function 2012-04-20 17:29:13 -07:00
binfmt_misc.c vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
binfmt_script.c __register_binfmt() made void 2012-03-20 21:29:46 -04:00
binfmt_som.c VM: add "vm_mmap()" helper function 2012-04-20 17:29:13 -07:00
bio-integrity.c fs: remove the second argument of k[un]map_atomic() 2012-03-20 21:48:21 +08:00
bio.c bio allocation failure due to bio_get_nr_vecs() 2012-05-11 16:45:12 +02:00
block_dev.c avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
buffer.c block: don't mark buffers beyond end of disk as mapped 2012-05-11 16:42:14 +02:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c The following text was taken from the original review request: 2012-03-24 10:24:31 -07:00
compat.c userns: Convert stat to return values mapped from kuids and kgids 2012-05-15 14:08:35 -07:00
dcache.c mm: add a low limit to alloc_large_system_hash 2012-05-24 00:28:21 -04:00
dcookies.c fs: reduce the use of module.h wherever possible 2012-02-28 19:31:58 -05:00
direct-io.c
drop_caches.c
eventfd.c fs: reduce the use of module.h wherever possible 2012-02-28 19:31:58 -05:00
eventpoll.c epoll: Fix user space breakage related to EPOLLWAKEUP 2012-05-22 20:57:06 +02:00
exec.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-05-23 17:42:39 -07:00
fcntl.c userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs 2012-05-03 03:29:34 -07:00
fhandle.c
fifo.c
file_table.c vfs: drop_file_write_access() made static 2012-03-20 21:29:32 -04:00
file.c Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-29 18:12:23 -07:00
filesystems.c
fs_struct.c The following text was taken from the original review request: 2012-03-24 10:24:31 -07:00
fs-writeback.c writeback: Avoid iput() from flusher thread 2012-05-06 13:43:41 +08:00
generic_acl.c
inode.c avoid iput() from flusher thread 2012-05-28 09:54:45 -07:00
internal.h
ioctl.c fs: reduce the use of module.h wherever possible 2012-02-28 19:31:58 -05:00
ioprio.c userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs 2012-05-03 03:29:34 -07:00
Kconfig Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-03-21 13:36:41 -07:00
Kconfig.binfmt C6X: add support to build with BINFMT_ELF_FDPIC 2012-05-15 09:17:34 -04:00
libfs.c vfs: make it possible to access the dentry hash/len as one 64-bit entry 2012-05-10 19:54:35 -07:00
locks.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-05-23 17:42:39 -07:00
Makefile fs: initial qnx6fs addition 2012-03-20 21:29:38 -04:00
mbcache.c
mount.h
mpage.c fs: reduce the use of module.h wherever possible 2012-02-28 19:31:58 -05:00
namei.c word-at-a-time: make the interfaces truly generic 2012-05-26 11:33:40 -07:00
namespace.c
no-block.c
open.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-05-23 17:42:39 -07:00
pipe.c pipe: return -ENOIOCTLCMD instead of -EINVAL on unknown ioctl command 2012-05-31 17:49:27 -07:00
pnode.c
pnode.h
posix_acl.c fs: reduce the use of module.h wherever possible 2012-02-28 19:31:58 -05:00
proc_namespace.c
read_write.c fs: reduce the use of module.h wherever possible 2012-02-28 19:31:58 -05:00
read_write.h
readdir.c fs: reduce the use of module.h wherever possible 2012-02-28 19:31:58 -05:00
select.c Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-29 18:12:23 -07:00
seq_file.c The following text was taken from the original review request: 2012-03-24 10:24:31 -07:00
signalfd.c
splice.c tcp: tcp_sendpages() should call tcp_push() once 2012-04-05 19:04:27 -04:00
stack.c fs: reduce the use of module.h wherever possible 2012-02-28 19:31:58 -05:00
stat.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-05-23 17:42:39 -07:00
statfs.c fs: reduce the use of module.h wherever possible 2012-02-28 19:31:58 -05:00
super.c The following text was taken from the original review request: 2012-03-24 10:24:31 -07:00
sync.c fs: reduce the use of module.h wherever possible 2012-02-28 19:31:58 -05:00
timerfd.c
utimes.c
xattr_acl.c fs: reduce the use of module.h wherever possible 2012-02-28 19:31:58 -05:00
xattr.c fs/xattr.c:setxattr(): improve handling of allocation failures 2012-04-05 15:25:50 -07:00