linux.git/fs/sysfs/sysfs.h, branch v2.6.23

sysfs: make sysfs_init_inode() static

2007-07-18T22:49:49+00:00

With sysfs_fill_super() converted to use sysfs_get_inode(), there is
no user of sysfs_init_inode() outside of fs/sysfs/inode.c.  Make it
static.

Signed-off-by: Tejun Heo 
Acked-by: Jean Delvare 
Signed-off-by: Greg Kroah-Hartman

sysfs: make directory dentries and inodes reclaimable

2007-07-11T23:09:09+00:00

This patch makes dentries and inodes for sysfs directories
reclaimable.

* sysfs_notify() is modified to walk sysfs_dirent tree instead of
  dentry tree.

* sysfs_update_file() and sysfs_chmod_file() use sysfs_get_dentry() to
  grab the victim dentry.

* sysfs_rename_dir() and sysfs_move_dir() grab all dentries using
  sysfs_get_dentry() on startup.

* Dentries for all shadowed directories are pinned in memory to serve
  as lookup start point.

Signed-off-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

sysfs: implement sysfs_get_dentry()

2007-07-11T23:09:09+00:00

Some sysfs operations require dentry and inode.  sysfs_get_dentry()
looks up and gets dentry for the specified sysfs_dirent.  It finds the
first ancestor with dentry attached and starts looking up dentries
from there.

Looking up from the nearest ancestor is necessary to support shadowed
directories because we can't reliably lookup dentry for one of the
shadows.  Dentries for each shadow will be pinned in memory such that
they can serve as the starting point for dentry lookup.

Signed-off-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

sysfs: move sysfs_drop_dentry() to dir.c and make it static

2007-07-11T23:09:09+00:00

After add/remove path restructuring, the only user of
sysfs_drop_dentry() is sysfs_addrm_finish().  Move sysfs_drop_dentry()
to dir.c and make it static.

Signed-off-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

sysfs: restructure add/remove paths and fix inode update

2007-07-11T23:09:09+00:00

The original add/remove code had the following problems.

* parent's timestamps are updated on dentry instantiation.  this is
  incorrect with reclaimable files.

* updating parent's timestamps isn't synchronized.

* parent nlink update assumes the inode is accessible which won't be
  true once directory dentries are made reclaimable.

This patch restructures add/remove paths to resolve the above
problems.  Add/removal are done in the following steps.

1. sysfs_addrm_start() : acquire locks including sysfs_mutex and other
   resources.

2-a. sysfs_add_one() : add new sd.  linking the new sd into the
     children list is caller's responsibility.

2-b. sysfs_remove_one() : remove a sd.  unlinking the sd from the
     children list is caller's responsibility.

3. sysfs_addrm_finish() : release all resources and clean up.

Steps 2-a and/or 2-b can be repeated multiple times.

Parent's inode is looked up during sysfs_addrm_start().  If available
(always at the moment), it's pinned and nlink is updated as sd's are
added and removed.  Timestamps are updated during finish if any sd has
been added or removed.  If parent's inode is not available during
start, sysfs_mutex ensures that parent inode is not created till
add/remove is complete.

All the complexity is contained inside the helper functions.
Especially, dentry/inode handling is properly hidden from the rest of
sysfs which now mostly operate on sysfs_dirents.  As an added bonus,
codes which use these helpers to add and remove sysfs_dirents are now
more structured and simpler.

Signed-off-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

sysfs: use sysfs_mutex to protect the sysfs_dirent tree

2007-07-11T23:09:08+00:00

As kobj sysfs dentries and inodes are gonna be made reclaimable,
i_mutex can't be used to protect sysfs_dirent tree.  Use sysfs_mutex
globally instead.  As the whole tree is protected with sysfs_mutex,
there is no reason to keep sysfs_rename_sem.  Drop it.

While at it, add docbook comments to functions which require
sysfs_mutex locking.

Signed-off-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

sysfs: consolidate sysfs spinlocks

2007-07-11T23:09:08+00:00

Replace sysfs_lock and kobj_sysfs_assoc_lock with sysfs_assoc_lock.
sysfs_lock was originally to be used to protect sysfs_dirent tree but
mutex seems better choice, so there is no reason to keep sysfs_lock
separate.  Merge the two spinlocks into one.

Signed-off-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

sysfs: make kobj point to sysfs_dirent instead of dentry

2007-07-11T23:09:08+00:00

As kobj sysfs dentries and inodes are gonna be made reclaimable,
dentry can't be used as naming token for sysfs file/directory, replace
kobj->dentry with kobj->sd.  The only external interface change is
shadow directory handling.  All other changes are contained in kobj
and sysfs.

Signed-off-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

sysfs: implement sysfs_find_dirent() and sysfs_get_dirent()

2007-07-11T23:09:08+00:00

Implement sysfs_find_dirent() and sysfs_get_dirent().
sysfs_dirent_exist() is replaced by sysfs_find_dirent().  These will
be used to make directory entries reclamiable.

Signed-off-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

sysfs: rename sysfs_dirent->s_type to s_flags and make room for flags

2007-07-11T23:09:08+00:00

Rename sysfs_dirent->s_type to s_flags, pack type into lower eight
bits and reserve the rest for flags.  sysfs_type() can used to access
the type.  All existing sd->s_type accesses are converted to use
sysfs_type().  While at it, type test is changed to equality test
instead of bit-and test where appropriate.

Signed-off-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman