Commit Graph

125 Commits

Author SHA1 Message Date
Christoph Hellwig 3825bdb7ed fs: use RCU read side protection in d_validate
d_validate does a purely read lookup in the dentry hash, so use RCU read side
locking instead of dcache_lock.  Split out from a larget patch by
Nick Piggin <npiggin@suse.de>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:13 -04:00
Christoph Hellwig a4633357ac fs: clean up dentry lru modification
Always do a list_del_init on the LRU to make sure the list_empty invariant for
not beeing on the LRU always holds true, and fold dentry_lru_del_init into
dentry_lru_del.  Replace the dentry_lru_add_tail primitive with a
dentry_lru_move_tail operations that simpler when the dentry already is one
the list, which is always is.  Move the list_empty into dentry_lru_add to
fit the scheme of the other lru helpers, and simplify locking once we
move to a separate LRU lock.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:13 -04:00
Christoph Hellwig 3049cfe24e fs: split __shrink_dcache_sb
Currently __shrink_dcache_sb has an extremly awkward calling convention
because it tries to please very different callers.  Split out the
main loop into a shrink_dentry_list helper, which gets called directly
from shrink_dcache_sb for the cases where all dentries need to be pruned,
or from __shrink_dcache_sb for pruning only a certain number of dentries.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:13 -04:00
Nick Piggin 265ac90230 fs: improve DCACHE_REFERENCED usage
dentry referenced bit is only set when installing the dentry back
onto the LRU. However with lazy LRU, the dentry can already be on
the LRU list at dput time, thus missing out on setting the referenced
bit. Fix this.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:12 -04:00
Christoph Hellwig 312d3ca856 fs: use percpu counter for nr_dentry and nr_dentry_unused
The nr_dentry stat is a globally touched cacheline and atomic operation
twice over the lifetime of a dentry. It is used for the benfit of userspace
only. Turn it into a per-cpu counter and always decrement it in d_free instead
of doing various batching operations to reduce lock hold times in the callers.

Based on an earlier patch from Nick Piggin <npiggin@suse.de>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:12 -04:00
Christoph Hellwig 9c82ab9c9e fs: simplify __d_free
Remove d_callback and always call __d_free with a RCU head.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:12 -04:00
Christoph Hellwig be148247cf fs: take dcache_lock inside __d_path
All callers take dcache_lock just around the call to __d_path, so
take the lock into it in preparation of getting rid of dcache_lock.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:12 -04:00
Nick Piggin 99b7db7b8f fs: brlock vfsmount_lock
fs: brlock vfsmount_lock

Use a brlock for the vfsmount lock. It must be taken for write whenever
modifying the mount hash or associated fields, and may be taken for read when
performing mount hash lookups.

A new lock is added for the mnt-id allocator, so it doesn't need to take
the heavy vfsmount write-lock.

The number of atomics should remain the same for fastpath rlock cases, though
code would be slightly slower due to per-cpu access. Scalability is not not be
much improved in common cases yet, due to other locks (ie. dcache_lock) getting
in the way. However path lookups crossing mountpoints should be one case where
scalability is improved (currently requiring the global lock).

The slowpath is slower due to use of brlock. On a 64 core, 64 socket, 32 node
Altix system (high latency to remote nodes), a simple umount microbenchmark
(mount --bind mnt mnt2 ; umount mnt2 loop 1000 times), before this patch it
took 6.8s, afterwards took 7.1s, about 5% slower.

Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 08:35:48 -04:00
Nick Piggin b04f784e5d fs: remove extra lookup in __lookup_hash
fs: remove extra lookup in __lookup_hash

Optimize lookup for create operations, where no dentry should often be
common-case. In cases where it is not, such as unlink, the added overhead
is much smaller than the removed.

Also, move comments about __d_lookup racyness to the __d_lookup call site.
d_lookup is intuitive; __d_lookup is what needs commenting. So in that same
vein, add kerneldoc comments to __d_lookup and clean up some of the comments:

- We are interested in how the RCU lookup works here, particularly with
  renames. Make that explicit, and point to the document where it is explained
  in more detail.
- RCU is pretty standard now, and macros make implementations pretty mindless.
  If we want to know about RCU barrier details, we look in RCU code.
- Delete some boring legacy comments because we don't care much about how the
  code used to work, more about the interesting parts of how it works now. So
  comments about lazy LRU may be interesting, but would better be done in the
  LRU or refcount management code.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 08:35:47 -04:00
Randy Dunlap cd956a1c03 fs/dcache: fix function param name in kernel-doc
Fix parameter name in kernel-doc notation (causes a warning).

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-14 16:21:00 -07:00
Miklos Szeredi 8df9d1a414 vfs: show unreachable paths in getcwd and proc
Prepend "(unreachable)" to path strings if the path is not reachable
from the current root.

Two places updated are
 - the return string from getcwd()
 - and symlinks under /proc/$PID.

Other uses of d_path() are left unchanged (we know that some old
software crashes if /proc/mounts is changed).

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-11 00:29:47 -04:00
Miklos Szeredi ffd1f4ed5b vfs: only add " (deleted)" where necessary
__d_path() has 4 callers:

  d_path()
  sys_getcwd()
  seq_path_root()
  tomoyo_realpath_from_path2()

Of these the only one which needs the " (deleted)" ending is d_path().

sys_getcwd() checks for existence before calling __d_path().

seq_path_root() is used to show the mountpoint path in
/proc/PID/mountinfo, which is always a positive.

And tomoyo doesn't want the deleted ending.

Create a helper "path_with_deleted()" as subsequent patches will need
this in multiple places.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-11 00:28:21 -04:00
Miklos Szeredi f2eb6575d5 vfs: add prepend_path() helper
Split off prepend_path() from __d_path().  This new helper takes an
end-of-buffer pointer and buffer-length pointer just like the other
prepend_* functions.  Move the " (deleted)" postfix out to __d_path().

This patch doesn't change any functionality but paves the way for the
following patches.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-11 00:28:21 -04:00
Miklos Szeredi 98dc568bc2 vfs: __d_path: dont prepend the name of the root dentry
In the old times pseudo-filesystems set the name of theroot dentry to
some prefix like "pipe:" and the name of the child dentry to "[123]"
and relied on a hack in __d_path() to replace the preceding slash with
the root's name to get "pipe:[123]".

Then the d_dname() dentry operation was introduced which solved the
same problem without having to pre-fill the name in each dentry.

Currently the following pseudo filesystems exist in the kernel:

perfmon
mtd
anon_inode
bdev
pipe
socket

Of these only perfmon, anon_inode, pipe and socket create
sub-dentries, all of which have now been switched to using d_dname().

bdev and mtd only create inodes.

This means that now the hack to overwrite the slash can be removed, so
for unreachable paths (e.g. within a detached mount) the path string
won't be polluted with garbage.  For these cases a subsequent patch
will add a prefix, indicating that the path is unreachable.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-11 00:28:21 -04:00
Miklos Szeredi f7ad3c6be9 vfs: add helpers to get root and pwd
Add three helpers that retrieve a refcounted copy of the root and cwd
from the supplied fs_struct.

 get_fs_root()
 get_fs_pwd()
 get_fs_root_and_pwd()

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-11 00:28:20 -04:00
Al Viro dca332528b no need for list_for_each_entry_safe()/resetting with superblock list
just delay __put_super() a bit

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:49:02 -04:00
Al Viro c103135c14 new helper: __dentry_path()
builds path relative to fs root, called under dcache_lock,
doesn't append any nonsense to unlinked ones.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:48:13 -04:00
Dave Chinner 7f8275d0d6 mm: add context argument to shrinker callback
The current shrinker implementation requires the registered callback
to have global state to work from. This makes it difficult to shrink
caches that are not global (e.g. per-filesystem caches). Pass the shrinker
structure to the callback so that users can embed the shrinker structure
in the context the shrinker needs to operate on and get back to it in the
callback via container_of().

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-07-19 14:56:17 +10:00
npiggin@suse.de 57439f878a fs: fix superblock iteration race
list_for_each_entry_safe is not suitable to protect against concurrent
modification of the list. 6754af6 introduced a race in sb walking.

list_for_each_entry can use the trick of pinning the current entry in
the list before we drop and retake the lock because it subsequently
follows cur->next. However list_for_each_entry_safe saves n=cur->next
for following before entering the loop body, so when the lock is
dropped, n may be deleted.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Frank Mayhar <fmayhar@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-06-29 10:38:22 -07:00
Al Viro 79893c17b4 fix prune_dcache()/umount() race
... and get rid of the last __put_super_and_need_restart() caller

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21 18:31:16 -04:00
Al Viro 551de6f34d Leave superblocks on s_list until the end
We used to remove from s_list and s_instances at the same
time.  So let's *not* do the former and skip superblocks
that have empty s_instances in the loops over s_list.

The next step, of course, will be to get rid of rescan logics
in those loops.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21 18:31:14 -04:00
Al Viro 13e3c5e5b9 clean DCACHE_CANT_MOUNT in d_delete()
We set the "it's dead, don't mount on it" flag _and_ do not remove it if
we turn the damn thing negative and leave it around.  And if it goes
positive afterwards, well...

Fortunately, there's only one place where that needs to be caught:
only d_delete() can turn the sucker negative without immediately freeing
it; all other places that can lead to ->d_iput() call are followed by
unconditionally freeing struct dentry in question.  So the fix is obvious:

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16014
Reported-by: Adam Tkac <vonsch@gmail.com>
Tested-by: Adam Tkac <vonsch@gmail.com>
Cc: <stable@kernel.org>         [2.6.34.x]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21 18:31:12 -04:00
Al Viro 4919c5e45a fix race in d_splice_alias()
rehashing the negative placeholder opens a race with d_lookup();
we unhash it almost immediately (by d_move()), but the race
window is there.  Since d_move() doesn't rely on target being
hashed, we don't need that d_rehash() at all.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-03-03 14:13:08 -05:00
Al Viro 2096f759ab New helper: path_is_under(path1, path2)
Analog of is_subdir for vfsmount,dentry pairs, moved from audit_tree.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-03-03 14:07:55 -05:00
H Hartley Sweeten ec4f860597 fs/dcache.c: CodingStyle cleanup
Cleanup EXPORT* macros according to Documantation/CodingStyle.

Move EXPORT* macros to the line immediately after the closing
function brace.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-03-03 13:00:19 -05:00
H Hartley Sweeten ef26ca97e8 libfs: move EXPORT_SYMBOL for d_alloc_name
The EXPORT_SYMBOL for d_alloc_name is in fs/libfs.c but the function
is in fs/dcache.c.  Move the EXPORT_SYMBOL to the line immediately
after the closing function brace line in fs/dcache.c as mentioned
in Documentation/CodingStyle.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16 12:16:48 -05:00
Frederic Weisbecker 613afbf832 sched: Pull up the might_sleep() check into cond_resched()
might_sleep() is called late-ish in cond_resched(), after the
need_resched()/preempt enabled/system running tests are
checked.

It's better to check the sleeps while atomic earlier and not
depend on some environment datas that reduce the chances to
detect a problem.

Also define cond_resched_*() helpers as macros, so that the
FILE/LINE reported in the sleeping while atomic warning
displays the real origin and not sched.h

Changes in v2:

 - Call __might_sleep() directly instead of might_sleep() which
   may call cond_resched()

 - Turn cond_resched() into a macro so that the file:line
   couple reported refers to the caller of cond_resched() and
   not __cond_resched() itself.

Changes in v3:

 - Also propagate this __might_sleep() pull up to
   cond_resched_lock() and cond_resched_softirq()

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1247725694-6082-6-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-18 15:51:44 +02:00
Alexey Dobriyan f3da392e9f dcache: extrace and use d_unlinked()
d_unlinked() will be used in middle-term to ban checkpointing when opened
but unlinked file is detected, and in long term, to detect such situation
and special case on it.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:06 -04:00
npiggin@suse.de c490d79bb7 fs: dcache fix LRU ordering
Fix ordering of LRU when moving referenced dentries to the head of the list
(they should go to the head of the list in the same order as they were found
from the tail, rather than reverse order).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-05-09 10:49:40 -04:00
Al Viro 24b6f16ecf No need for crossing to mountpoint in audit_tag_tree()
is_under() will DTRT anyway.  And yes, is_subdir() behaviour
is intentional.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-04-20 23:01:15 -04:00
Al Viro e5824c97a9 Trim includes of fdtable.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-31 23:00:28 -04:00
Al Viro 5ad4e53bd5 Get rid of indirect include of fs_struct.h
Don't pull it in sched.h; very few files actually need it and those
can include directly.  sched.h itself only needs forward declaration
of struct fs_struct;

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-31 23:00:27 -04:00
Christoph Hellwig b6520c8193 cleanup d_add_ci
Make sure that comments describe what's going on and not how, and always
use __d_instantiate instead of two separate branches, one with
d_instantiate and one with __d_instantiate.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-27 14:43:57 -04:00
Benny Halevy adc487204a EXPORT_SYMBOL(d_obtain_alias) rather than EXPORT_SYMBOL_GPL
Commit 4ea3ada295 declares d_obtain_alias()
as EXPORT_SYMBOL_GPL where it's supposed to replace d_alloc_anon which was
previously declared as EXPORT_SYMBOL and thus available to any loadable
module.

This patch reverts that.

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: 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>
2009-02-27 16:26:20 -08:00
Heiko Carstens 3cdad42884 [CVE-2009-0029] System call wrappers part 20
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-01-14 14:15:26 +01:00
Wu Fengguang 9a8d5bb4ad generic swap(): dcache: use swap() instead of private do_switch()
Use the new generic implementation.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
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>
2009-01-08 08:31:15 -08:00
Eric Dumazet b6b3fdead2 filp_cachep can be static in fs/file_table.c
Instead of creating the "filp" kmem_cache in vfs_caches_init(),
we can do it a litle be later in files_init(), so that filp_cachep
is static to fs/file_table.c

Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-31 18:07:42 -05:00
Arjan van de Ven 52afeefb9d expand some comments (d_path / seq_path)
Explain that you really need to use the return value of d_path rather than
the buffer you passed into it.

Also fix the comment for seq_path(), the function arguments changed
recently but the comment hadn't been updated in sync.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-31 18:07:41 -05:00
Zhaolei be42c4c433 correct wrong function name of d_put in kernel document and source comment
no function named d_put(), it should be dput().

Impact: fix document and comment, no functionality changed

Signed-off-by: Zhao Lei <zhaolei@cn.fuijtsu.com>
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-31 18:07:40 -05:00
Al Viro dc711ca35f fix switch_names() breakage in short-to-short case
We want ->name.len to match the resulting name on *both*
source and target

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-31 18:07:40 -05:00
Nick Piggin c2452f3278 shrink struct dentry
struct dentry is one of the most critical structures in the kernel. So it's
sad to see it going neglected.

With CONFIG_PROFILING turned on (which is probably the common case at least
for distros and kernel developers), sizeof(struct dcache) == 208 here
(64-bit). This gives 19 objects per slab.

I packed d_mounted into a hole, and took another 4 bytes off the inline
name length to take the padding out from the end of the structure. This
shinks it to 200 bytes. I could have gone the other way and increased the
length to 40, but I'm aiming for a magic number, read on...

I then got rid of the d_cookie pointer. This shrinks it to 192 bytes. Rant:
why was this ever a good idea? The cookie system should increase its hash
size or use a tree or something if lookups are a problem. Also the "fast
dcookie lookups" in oprofile should be moved into the dcookie code -- how
can oprofile possibly care about the dcookie_mutex? It gets dropped after
get_dcookie() returns so it can't be providing any sort of protection.

At 192 bytes, 21 objects fit into a 4K page, saving about 3MB on my system
with ~140 000 entries allocated. 192 is also a multiple of 64, so we get
nice cacheline alignment on 64 and 32 byte line systems -- any given dentry
will now require 3 cachelines to touch all fields wheras previously it
would require 4.

I know the inline name size was chosen quite carefully, however with the
reduction in cacheline footprint, it should actually be just about as fast
to do a name lookup for a 36 character name as it was before the patch (and
faster for other sizes). The memory footprint savings for names which are
<= 32 or > 36 bytes long should more than make up for the memory cost for
33-36 byte names.

Performance is a feature...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-31 18:07:38 -05:00
Arjan van de Ven fd217f4d70 [PATCH] fs: add a sanity check in d_free
Hi Al,

remember that debug session we did at KS? You suggested this patch back
then....

From 7751eaf30474b8cbfaea64795805a17eab05ac53 Mon Sep 17 00:00:00 2001
From: Arjan van de Ven <arjan@linux.intel.com>
Date: Tue, 16 Sep 2008 16:51:17 -0700
Subject: [PATCH] fs: add a sanity check in d_free

we're seeing some corruption in the dentry->d_alias list that
appears like a free of an entry still on the list; this patch
adds a WARN_ON() to catch this scenario, as suggested by Al Viro

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
2008-10-23 05:17:12 -04:00
Qinghuang Feng 5cec56deb6 [PATCH] fs/dcache.c: update comment of d_validate()
Parameters @hash and @len have been removed since 2.4.3,
now just to delete them.

Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com>
2008-10-23 05:13:24 -04:00
OGAWA Hirofumi 8f3dfaa5ba [PATCH vfs-2.6 4/6] vfs: remove unnecessary fsnotify_d_instantiate()
This calls d_move(), so fsnotify_d_instantiate() is unnecessary like
rename path.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
2008-10-23 05:13:18 -04:00
OGAWA Hirofumi 360da90029 [PATCH vfs-2.6 3/6] vfs: add __d_instantiate() helper
This adds __d_instantiate() for users which is already taking
dcache_lock, and replace with it.

The part of d_add_ci() isn't equivalent. But it should be needed
fsnotify_d_instantiate() actually, because the path is to add the
inode to negative dentry.  fsnotify_d_instantiate() should be called
after change from negative to positive.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
2008-10-23 05:13:17 -04:00
OGAWA Hirofumi e2761a1167 [PATCH vfs-2.6 2/6] vfs: add d_ancestor()
This adds d_ancestor() instead of d_isparent(), then use it.

If new_dentry == old_dentry, is_subdir() returns 1, looks strange.
"new_dentry == old_dentry" is not subdir obviously. But I'm not
checking callers for now, so this keeps current behavior.

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
2008-10-23 05:13:16 -04:00
OGAWA Hirofumi 871c0067d5 [PATCH vfs-2.6 1/6] vfs: replace parent == dentry->d_parent by IS_ROOT()
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
2008-10-23 05:13:16 -04:00
Christoph Hellwig 9308a6128d [PATCH] kill d_alloc_anon
Remove d_alloc_anon now that no users are left.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-10-23 05:13:02 -04:00
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
Christoph Hellwig 4ea3ada295 [PATCH] new helper: d_obtain_alias
The calling conventions of d_alloc_anon are rather unfortunate for all
users, and it's name is not very descriptive either.

Add d_obtain_alias as a new exported helper that drops the inode
reference in the failure case, too and allows to pass-through NULL
pointers and inodes to allow for tail-calls in the export operations.

Incidentally this helper already existed as a private function in
libfs.c as exportfs_d_alloc so kill that one and switch the callers
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 05:13:00 -04:00