Commit Graph

102 Commits

Author SHA1 Message Date
Al Viro 3d23985d6c switch fat to ->s_d_op, close exportfs races there
don't bother with lock_super() in fat_fill_super() callers, while
we are at it - there won't be any concurrency anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:02:43 -05:00
Nick Piggin fb045adb99 fs: dcache reduce branches in lookup path
Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.

Patched with:

git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:28 +11:00
Nick Piggin fa0d7e3de6 fs: icache RCU free inodes
RCU free the struct inode. This will allow:

- Subsequent store-free path walking patch. The inode must be consulted for
  permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
  to take i_lock no longer need to take sb_inode_list_lock to walk the list in
  the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
  page lock to follow page->mapping.

The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.

In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.

The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:26 +11:00
Arnd Bergmann 3768744cfe BKL: Remove BKL from fat
The lock_kernel in fat_put_super is not needed because
it only protects the super block itself and we know that
no other thread can reach it because we are about to
kfree the object.

In the two fill_super functions, this converts the locking
to use lock_super like elsewhere in the fat code. This
is probably not needed either, but is consistent and puts
us on the safe side.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Jan Blunck <jblunck@infradead.org>
2010-10-04 21:10:45 +02:00
Al Viro deee3ce466 covert fatfs to ->evict_inode()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:48:01 -04:00
Christoph Hellwig 282dc17884 get rid of cont_write_begin_newtrunc
Move the call to vmtruncate to get rid of accessive blocks to the callers
in preparation of the new truncate sequence and rename the non-truncating
version to cont_write_begin.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:47:31 -04:00
Christoph Hellwig eafdc7d190 sort out blockdev_direct_IO variants
Move the call to vmtruncate to get rid of accessive blocks to the callers
in prepearation of the new truncate calling sequence.  This was only done
for DIO_LOCKING filesystems, so the __blockdev_direct_IO_newtrunc variant
was not needed anyway.  Get rid of blockdev_direct_IO_no_locking and
its _newtrunc variant while at it as just opencoding the two additional
paramters is shorted than the name suffix.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:47:29 -04:00
npiggin@suse.de 459f6ed3b8 fat: convert to use the new truncate convention.
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-27 22:16:02 -04:00
OGAWA Hirofumi aaa04b4875 fatfs: ratelimit corruption report
Signed-off-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>
2010-05-25 08:07:04 -07:00
OGAWA Hirofumi 1bdb6f9199 fat: Cleanup nls_unload() usage
Other users doesn't check NULL explicitly. So, these doesn't also
check to remove inconsistency.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
2010-03-16 05:49:05 +09:00
Linus Torvalds 9d85929fef Merge git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6:
  fat: Fix stat->f_namelen
  fat: Fix vfat_lookup()
2010-03-12 16:35:21 -08:00
Christoph Hellwig a9185b41a4 pass writeback_control to ->write_inode
This gives the filesystem more information about the writeback that
is happening.  Trond requested this for the NFS unstable write handling,
and other filesystems might benefit from this too by beeing able to
distinguish between the different callers in more detail.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-03-05 13:25:52 -05:00
Kevin Dankwardt eeb5b4ae81 fat: Fix stat->f_namelen
I found that the length of a file name when created cannot exceed 255
characters, yet, pathconf(), via statfs(), returns the maximum as 260.

Signed-off-by: Kevin Dankwardt <k@kcomputing.com>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
2010-02-10 23:49:08 +09:00
Christoph Hellwig 681142f921 fat: make discard a mount option
Currently shipping discard capable SSDs and arrays have rather sub-optimal
implementations of the command and can the use of it can cause massive
slowdowns.  Make issueing these commands option as it's already in btrfs
and gfs2.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[hirofumi@mail.parknet.co.jp: tweaks, and add "discard" to fat_show_options]
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
2009-11-21 20:36:52 +09:00
Linus Torvalds 4c8f1cb266 Merge git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6:
  fat: Check s_dirt in fat_sync_fs()
  vfat: change the default from shortname=lower to shortname=mixed
  fat/nls: Fix handling of utf8 invalid char
2009-09-30 09:31:14 -07:00
Thomas Gleixner 6d729e44a5 fs: Make unload_nls() NULL pointer safe
Most call sites of unload_nls() do:
	if (nls)
		unload_nls(nls);

Check the pointer inside unload_nls() like we do in kfree() and
simplify the call sites.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steve French <sfrench@us.ibm.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Petr Vandrovec <vandrove@vc.cvut.cz>
Cc: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-09-24 07:47:42 -04:00
OGAWA Hirofumi ed248b290d fat: Check s_dirt in fat_sync_fs()
If we didn't check sb->s_dirt, it will update the FSINFO
unconditionally. It will reduce the filetime of flash base device.

So, this checks sb->s_dirt. sb->s_dirt is racy, however FSINFO is just
hint. So even if there is race, and we hit it, it would not become big
problem.

And this also is as workaround of suspend problem.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
2009-09-20 01:35:25 +09:00
Paul Wise 955234755c vfat: change the default from shortname=lower to shortname=mixed
Because, with "shortname=lower", copying one FAT filesystem tree to
another FAT filesystem tree using Linux results in semantically
different filesystems. (E.g.: Filenames which were once "all
uppercase" are now "all lowercase").

So, this changes the default of "shortname=lower" to "shortname=mixed".

Signed-off-by: Paul Wise <pabs3@bonedaddy.net>
[change fat_show_options()]
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
2009-08-01 21:35:25 +09:00
OGAWA Hirofumi 3e107603ae fat: Fix the removal of opts->fs_dmask
(ce3b0f8d5c2203301fc87f3aaaed73e5819e2a48: New helper - current_umask())
is removing the opts->fs_dmask, probably it's a cut-and-paste
miss or something.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
2009-06-20 21:50:47 +09:00
Linus Torvalds 23059a0df5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6:
  fat: split fat_generic_ioctl
  FAT: add 'errors' mount option
2009-06-16 11:29:44 -07:00
Christoph Hellwig f83d6d46e7 fat: add ->sync_fs
Add a ->sync_fs method for data integrity syncs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:15 -04:00
Al Viro b522412aea Sanitize ->fsync() for FAT
* mark directory data blocks as assoc. metadata
* add new inode to deal with FAT, mark FAT blocks as assoc. metadata of that
* now ->fsync() is trivial both for files and directories

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:12 -04:00
Christoph Hellwig ebc1ac1645 ->write_super lock_super pushdown
Push down lock_super into ->write_super instances and remove it from the
caller.

Following filesystem don't need ->s_lock in ->write_super and are skipped:

 * bfs, nilfs2 - no other uses of s_lock and have internal locks in
	->write_super
 * ext2 - uses BKL in ext2_write_super and has internal calls without s_lock
 * reiserfs - no other uses of s_lock as has reiserfs_write_lock (BKL) in
 	->write_super
 * xfs - no other uses of s_lock and uses internal lock (buffer lock on
	superblock buffer) to serialize ->write_super.  Also xfs_fs_write_super
	is superflous and will go away in the next merge window

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:09 -04:00
Christoph Hellwig 6cfd014842 push BKL down into ->put_super
Move BKL into ->put_super from the only caller.  A couple of
filesystems had trivial enough ->put_super (only kfree and NULLing of
s_fs_info + stuff in there) to not get any locking: coda, cramfs, efs,
hugetlbfs, omfs, qnx4, shmem, all others got the full treatment.  Most
of them probably don't need it, but I'd rather sort that out individually.
Preferably after all the other BKL pushdowns in that area.

[AV: original used to move lock_super() down as well; these changes are
removed since we don't do lock_super() at all in generic_shutdown_super()
now]
[AV: fuse, btrfs and xfs are known to need no damn BKL, exempt]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:07 -04:00
Christoph Hellwig 8c85e12512 remove ->write_super call in generic_shutdown_super
We just did a full fs writeout using sync_filesystem before, and if
that's not enough for the filesystem it can perform it's own writeout
in ->put_super, which many filesystems already do.

Move a call to foofs_write_super into every foofs_put_super for now to
guarantee identical behaviour until it's cleaned up by the individual
filesystem maintainers.

Exceptions:

 - affs already has identical copy & pasted code at the beginning of
   affs_put_super so no need to do it twice.
 - xfs does the right thing without it and I have changes pending for
   the xfs tree touching this are so I don't really need conflicts
   here..

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:06 -04:00
Denis Karpov 85c7859190 FAT: add 'errors' mount option
On severe errors FAT remounts itself in read-only mode. Allow to
specify FAT fs desired behavior through 'errors' mount option:
panic, continue or remount read-only.

`mount -t [fat|vfat] -o errors=[panic,remount-ro,continue] \
	<bdev> <mount point>`

This is analog to ext2 fs 'errors' mount option.

Signed-off-by: Denis Karpov <ext-denis.2.karpov@nokia.com>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
2009-06-04 02:34:51 +09:00
Linus Torvalds 8fe74cf053 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  Remove two unneeded exports and make two symbols static in fs/mpage.c
  Cleanup after commit 585d3bc06f
  Trim includes of fdtable.h
  Don't crap into descriptor table in binfmt_som
  Trim includes in binfmt_elf
  Don't mess with descriptor table in load_elf_binary()
  Get rid of indirect include of fs_struct.h
  New helper - current_umask()
  check_unsafe_exec() doesn't care about signal handlers sharing
  New locking/refcounting for fs_struct
  Take fs_struct handling to new file (fs/fs_struct.c)
  Get rid of bumping fs_struct refcount in pivot_root(2)
  Kill unsharing fs_struct in __set_personality()
2009-04-02 21:09:10 -07:00
Coly Li aac49b7543 fs/fat: return f_fsid for statfs(2)
Make fat return f_fsid info for statfs(2).

Signed-off-by: Coly Li <coly.li@suse.de>
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>
2009-04-02 19:05:09 -07:00
Al Viro ce3b0f8d5c New helper - current_umask()
current->fs->umask is what most of fs_struct users are doing.
Put that into a helper function.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-31 23:00:26 -04:00
OGAWA Hirofumi 3a95ea1155 Fix _fat_bmap() locking
On swapon() path, it has already i_mutex. So, this uses i_alloc_sem
instead of it.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reported-by: Laurent GUERBY <laurent@guerby.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-11 12:04:18 -07:00
Linus Torvalds ec270e59a7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6:
  fat: make sure to set d_ops in fat_get_parent
  fat: fix duplicate addition of ->llseek handler
  fat: drop negative dentry on rename() path
2008-12-30 20:33:34 -08:00
James Morris 2b82892565 Merge branch 'master' into next
Conflicts:
	security/keys/internal.h
	security/keys/process_keys.c
	security/keys/request_key.c

Fixed conflicts above by using the non 'tsk' versions.

Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 11:29:12 +11:00
David Howells f0ce7ee3a8 CRED: Wrap task credential accesses in the FAT filesystem
Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:38:52 +11:00
Christoph Hellwig 5a6bb10393 fat: make sure to set d_ops in fat_get_parent
fat_get_parent needs to setup the dentry operations, otherwise we might
lose them when the NFS server needs to reconnect out of cache inodes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
2008-11-12 08:51:22 +09:00
OGAWA Hirofumi 9ca59f4c3d fat: ->i_pos race fix
i_pos is 64bits value, hence it's not atomic to update.

Important place is fat_write_inode() only, other places without lock
are just for printk().

This adds lock for "BITS_PER_LONG == 32" kernel.

Signed-off-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>
2008-11-06 15:41:21 -08:00
OGAWA Hirofumi 2bdf67eb16 fat: mmu_private race fix
mmu_private is 64bits value, hence it's not atomic to update.

So, the access rule for mmu_private is we must hold ->i_mutex.  But,
fat_get_block() path doesn't follow the rule on non-allocation path.

This fixes by using i_size instead if non-allocation path.

Signed-off-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>
2008-11-06 15:41:21 -08:00
OGAWA Hirofumi fa93ca18a8 fat: Fix _fat_bmap() race
fat_get_cluster() assumes the requested blocknr isn't truncated during
read. _fat_bmap() doesn't follow this rule.

This protects it by ->i_mutex.

Signed-off-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>
2008-11-06 15:41:21 -08:00
OGAWA Hirofumi dfc209c006 fat: Fix ATTR_RO for directory
FAT has the ATTR_RO (read-only) attribute. But on Windows, the ATTR_RO
of the directory will be just ignored actually, and is used by only
applications as flag. E.g. it's setted for the customized folder by
Explorer.

http://msdn2.microsoft.com/en-us/library/aa969337.aspx

This adds "rodir" option. If user specified it, ATTR_RO is used as
read-only flag even if it's the directory. Otherwise, inode->i_mode
is not used to hold ATTR_RO (i.e. fat_mode_can_save_ro() returns 0).

Signed-off-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>
2008-11-06 15:41:21 -08:00
OGAWA Hirofumi 9c0aa1b87b fat: Cleanup FAT attribute stuff
This adds three helpers:

fat_make_attrs() - makes FAT attributes from inode.
fat_make_mode()  - makes mode_t from FAT attributes.
fat_save_attrs() - saves FAT attributes to inode.

Then this replaces: MSDOS_MKMODE() by fat_make_mode(), fat_attr() by
fat_make_attrs(), ->i_attrs = attr & ATTR_UNUSED by fat_save_attrs().
And for root inode, those is used with ATTR_DIR instead of bogus
ATTR_NONE.

Signed-off-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>
2008-11-06 15:41:21 -08:00
OGAWA Hirofumi a993b542bb fat: use fat_detach() in fat_clear_inode()
Use fat_detach() instead of opencoding it.

Signed-off-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>
2008-11-06 15:41:20 -08:00
OGAWA Hirofumi d3dfa8228f fat: improve fat_hash()
fat_hash() is using the algorithm known as bad. Instead of it, this
uses hash_32(). The following is the summary of test.

old hash:
	hash func (1000 times): 33489 cycles
	total inodes in hash table: 70926
	largest bucket contains: 696
	smallest bucket contains: 54

new hash:
	hash func (1000 times): 33129 cycles
	total inodes in hash table: 70926
	largest bucket contains: 315
	smallest bucket contains: 236

Signed-off-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>
2008-11-06 15:41:20 -08:00
OGAWA Hirofumi 7decd1cb03 fat: Fix and cleanup timestamp conversion
This cleans date_dos2unix()/fat_date_unix2dos() up. New code should be
much more readable.

And this fixes those old functions. Those doesn't handle 2100
correctly. 2100 isn't leap year, but old one handles it as leap year.
Also, with this, centi sec is handled and is fixed.

Signed-off-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>
2008-11-06 15:41:20 -08:00
OGAWA Hirofumi 9e975dae29 fat: split include/msdos_fs.h
This splits __KERNEL__ stuff in include/msdos_fs.h into fs/fat/fat.h.

Signed-off-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>
2008-11-06 15:41:20 -08:00
Nick Piggin 4e02ed4b4a fs: remove prepare_write/commit_write
Nothing uses prepare_write or commit_write. Remove them from the tree
completely.

[akpm@linux-foundation.org: schedule simple_prepare_write() for unexporting]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-30 11:38:45 -07:00
Christoph Hellwig 440037287c [PATCH] switch all filesystems over to d_obtain_alias
Switch all users of d_alloc_anon to d_obtain_alias.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-23 05:13:01 -04:00
Steven Whitehouse a447c09324 vfs: Use const for kernel parser table
This is a much better version of a previous patch to make the parser
tables constant. Rather than changing the typedef, we put the "const" in
all the various places where its required, allowing the __initconst
exception for nfsroot which was the cause of the previous trouble.

This was posted for review some time ago and I believe its been in -mm
since then.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 10:10:37 -07:00
Linus Torvalds 5f22ca9b13 vfat: fix 'sync' mount deadlock due to BKL->lock_super conversion
There was another FAT BKL conversion deadlock reported by Bart
Trojanowski due to the BKL being used as a recursive lock by FAT, which
was missed because it only triggers with 'sync' (or 'dirsync') mounts.

The recursion worked for the BKL, but after the conversion to lock_super
(which uses a mutex), it just deadlocks.

Thanks to Bart for debugging this and testing the fix.  The lock
debugging information from the original report:

  =============================================
  [ INFO: possible recursive locking detected ]
  2.6.27-rc3-bisect-00448-ga7f5aaf #16
  ---------------------------------------------
  mv/4020 is trying to acquire lock:
   (&type->s_lock_key#9){--..}, at: [<c01a90fe>] lock_super+0x1e/0x20

  but task is already holding lock:
   (&type->s_lock_key#9){--..}, at: [<c01a90fe>] lock_super+0x1e/0x20

  other info that might help us debug this:
  3 locks held by mv/4020:
   #0:  (&sb->s_type->i_mutex_key#9/1){--..}, at: [<c01b2336>] do_unlinkat+0x66/0x140
   #1:  (&sb->s_type->i_mutex_key#9){--..}, at: [<c01b0954>] vfs_unlink+0x84/0x110
   #2:  (&type->s_lock_key#9){--..}, at: [<c01a90fe>] lock_super+0x1e/0x20

  stack backtrace:
  Pid: 4020, comm: mv Not tainted 2.6.27-rc3-bisect-00448-ga7f5aaf #16
   [<c014e694>] validate_chain+0x984/0xea0
   [<c0108d70>] ? native_sched_clock+0x0/0xf0
   [<c014ee9c>] __lock_acquire+0x2ec/0x9b0
   [<c014f5cf>] lock_acquire+0x6f/0x90
   [<c01a90fe>] ? lock_super+0x1e/0x20
   [<c044e5fd>] mutex_lock_nested+0xad/0x300
   [<c01a90fe>] ? lock_super+0x1e/0x20
   [<c01a90fe>] ? lock_super+0x1e/0x20
   [<c01a90fe>] lock_super+0x1e/0x20
   [<f8b3a700>] fat_write_inode+0x60/0x2b0 [fat]
   [<c0450878>] ? _spin_unlock_irqrestore+0x48/0x80
   [<f8b3a953>] ? fat_sync_inode+0x3/0x20 [fat]
   [<f8b3a962>] fat_sync_inode+0x12/0x20 [fat]
   [<f8b37c7e>] fat_remove_entries+0xbe/0x120 [fat]
   [<f8b422ef>] vfat_unlink+0x5f/0x90 [vfat]
   [<f8b42290>] ? vfat_unlink+0x0/0x90 [vfat]
   [<c01b0968>] vfs_unlink+0x98/0x110
   [<c01b2400>] do_unlinkat+0x130/0x140
   [<c016a8f5>] ? audit_syscall_entry+0x105/0x150
   [<c01b253b>] sys_unlinkat+0x3b/0x40
   [<c01040d3>] sysenter_do_call+0x12/0x3f
   =======================

where the deadlock is due to the nesting of lock_super from vfat_unlink
to fat_write_inode:

 - do_unlinkat
   - vfs_unlink
     - vfat_unlink
       * lock_super
       - fat_remove_entries
         - fat_sync_inode
           - fat_write_inode
             * lock_super

and the fix is to simply remove the use of lock_super() in fat_write_inode.

The lock_super() there had been just an automatic conversion of the
kernel lock to the superblock lock, but no locking was actually needed
there, since the code in fat_write_inode already protected all relevant
accesses with a spinlock (sbi->inode_hash_lock to be exact).  The only
code inside the BKL (and thus the superblock lock) was accesses tp local
variables or calls to functions that have long been SMP-safe (i.e.
sb_bread, mark_buffe_dirty and brlese).

Bart reports:
 "Looks good.  I ran 10 parallel processes creating 1M files truncating
  them, writing to them again and then deleting them.  This patch fixes
  the issue I ran into.

  Signed-off-by: Bart Trojanowski <bart@jukie.net>"

Reported-and-tested-by: Bart Trojanowski <bart@jukie.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-20 08:31:19 -07:00
Alexey Dobriyan 51cc50685a SL*B: drop kmem cache argument from constructor
Kmem cache passed to constructor is only needed for constructors that are
themselves multiplexeres.  Nobody uses this "feature", nor does anybody uses
passed kmem cache in non-trivial way, so pass only pointer to object.

Non-trivial places are:
	arch/powerpc/mm/init_64.c
	arch/powerpc/mm/hugetlbpage.c

This is flag day, yes.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Jon Tollefson <kniht@linux.vnet.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Matt Mackall <mpm@selenic.com>
[akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c]
[akpm@linux-foundation.org: fix mm/slab.c]
[akpm@linux-foundation.org: fix ubifs]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:07 -07:00
Joe Peterson b271e067c8 fatfs: add UTC timestamp option
Provide a new mount option ("tz=UTC") for DOS (vfat/msdos) filesystems,
allowing timestamps to be in coordinated universal time (UTC) rather than
local time in applications where doing this is advantageous.

In particular, portable devices that use fat/vfat (such as digital
cameras) can benefit from using UTC in their internal clocks, thus
avoiding daylight saving time errors and general time ambiguity issues.
The user of the device does not have to worry about changing the time when
moving from place or when daylight saving changes.

The new mount option, when set, disables the counter-adjustment that Linux
currently makes to FAT timestamp info in anticipation of the normal
userspace time zone correction.  When used in this new mode, all daylight
saving time and time zone handling is done in userspace as is normal for
many other filesystems (like ext3).  The default mode, which remains
unchanged, is still appropriate when mounting volumes written in Windows
(because of its use of local time).

I originally based this patch on one submitted last year by Paul Collins,
but I updated it to work with current source and changed variable/option
naming.  Ogawa Hirofumi (who maintains these filesystems) and I discussed
this patch at length on lkml, and he suggested using the option name in
the attached version of the patch.  Barry Bouwsma pointed out a good
addition to the patch as well.

Signed-off-by: Joe Peterson <joe@skyrush.com>
Signed-off-by: Paul Collins <paul@ondioline.org>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Barry Bouwsma <free_beer_for_all@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:34 -07:00
OGAWA Hirofumi 8d44d9741f fat: fix parse_options()
Current parse_options() exits too early.  We need to run the code of
bottom in this function even if users doesn't specify options.

Signed-off-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>
2008-07-25 10:53:34 -07:00