linux-toradex.git/include/linux/dcache.h, branch tegra-9.12.15

dcache: extrace and use d_unlinked()

2009-06-12T01:36:06+00:00

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 
Signed-off-by: Al Viro

switch lookup_mnt()

2009-06-12T01:36:01+00:00

Signed-off-by: Al Viro

fsnotify: parent event notification

2009-06-11T18:57:53+00:00

inotify and dnotify both use a similar parent notification mechanism.  We
add a generic parent notification mechanism to fsnotify for both of these
to use.  This new machanism also adds the dentry flag optimization which
exists for inotify to dnotify.

Signed-off-by: Eric Paris 
Acked-by: Al Viro 
Cc: Christoph Hellwig

fs: make struct dentry->d_op const

2009-03-27T18:43:59+00:00

This change will allow for tagging many dentry_operations const in the
source tree.

Signed-off-by: Jan Engelhardt 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Al Viro

shrink struct dentry

2008-12-31T23:07:38+00:00

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

[PATCH vfs-2.6 2/6] vfs: add d_ancestor()

2008-10-23T09:13:16+00:00

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

[PATCH] kill d_alloc_anon

2008-10-23T09:13:02+00:00

Remove d_alloc_anon now that no users are left.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Al Viro

[PATCH] new helper: d_obtain_alias

2008-10-23T09:13:00+00:00

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 
Signed-off-by: Al Viro

[PATCH] change d_add_ci argument ordering

2008-08-25T05:18:05+00:00

As pointed out during review d_add_ci argument order should match d_add,
so switch the dentry and inode arguments.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Al Viro

dcache: Add case-insensitive support d_ci_add() routine

2008-07-28T06:58:39+00:00

This add a dcache entry to the dcache for lookup, but changing the name
that is associated with the entry rather than the one passed in to the
lookup routine.

First, it sees if the case-exact match already exists in the dcache and
uses it if one exists. Otherwise, it allocates a new node with the new
name and splices it into the dcache.

Original code from ntfs_lookup in fs/ntfs/namei.c by Anton Altaparmakov.

Signed-off-by: Barry Naujok 
Signed-off-by: Anton Altaparmakov 
Acked-by: Christoph Hellwig