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sysfs: consolidate sysfs spinlocks

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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 <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Tejun Heo 2007-06-14 04:27:23 +09:00 committed by Greg Kroah-Hartman
parent 608e266a2d
commit 5f9953237f
4 changed files with 21 additions and 23 deletions
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19
fs/sysfs/dir.c
View File

@ -15,8 +15,7 @@
#include "sysfs.h"
DECLARE_RWSEM(sysfs_rename_sem);
spinlock_t sysfs_lock = SPIN_LOCK_UNLOCKED;
spinlock_t kobj_sysfs_assoc_lock = SPIN_LOCK_UNLOCKED;
spinlock_t sysfs_assoc_lock = SPIN_LOCK_UNLOCKED;
static spinlock_t sysfs_ino_lock = SPIN_LOCK_UNLOCKED;
static DEFINE_IDA(sysfs_ino_ida);
@ -236,10 +235,10 @@ static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
struct sysfs_dirent * sd = dentry->d_fsdata;
if (sd) {
/* sd->s_dentry is protected with sysfs_lock. This
* allows sysfs_drop_dentry() to dereference it.
/* sd->s_dentry is protected with sysfs_assoc_lock.
* This allows sysfs_drop_dentry() to dereference it.
*/
spin_lock(&sysfs_lock);
spin_lock(&sysfs_assoc_lock);
/* The dentry might have been deleted or another
* lookup could have happened updating sd->s_dentry to
@ -248,7 +247,7 @@ static void sysfs_d_iput(struct dentry * dentry, struct inode * inode)
*/
if (sd->s_dentry == dentry)
sd->s_dentry = NULL;
spin_unlock(&sysfs_lock);
spin_unlock(&sysfs_assoc_lock);
sysfs_put(sd);
}
iput(inode);
@ -298,9 +297,9 @@ static void sysfs_attach_dentry(struct sysfs_dirent *sd, struct dentry *dentry)
dentry->d_fsdata = sysfs_get(sd);
/* protect sd->s_dentry against sysfs_d_iput */
spin_lock(&sysfs_lock);
spin_lock(&sysfs_assoc_lock);
sd->s_dentry = dentry;
spin_unlock(&sysfs_lock);
spin_unlock(&sysfs_assoc_lock);
d_rehash(dentry);
}
@ -603,9 +602,9 @@ void sysfs_remove_dir(struct kobject * kobj)
{
struct sysfs_dirent *sd = kobj->sd;
spin_lock(&kobj_sysfs_assoc_lock);
spin_lock(&sysfs_assoc_lock);
kobj->sd = NULL;
spin_unlock(&kobj_sysfs_assoc_lock);
spin_unlock(&sysfs_assoc_lock);
__sysfs_remove_dir(sd);
}

16
fs/sysfs/inode.c
View File

@ -211,11 +211,11 @@ void sysfs_instantiate(struct dentry *dentry, struct inode *inode)
* parent on entry to this function such that it can't be looked
* up anymore.
*
* @sd->s_dentry which is protected with sysfs_lock points to the
* currently associated dentry but we're not holding a reference
* to it and racing with dput(). Grab dcache_lock and verify
* dentry before dropping it. If @sd->s_dentry is NULL or dput()
* beats us, no need to bother.
* @sd->s_dentry which is protected with sysfs_assoc_lock points
* to the currently associated dentry but we're not holding a
* reference to it and racing with dput(). Grab dcache_lock and
* verify dentry before dropping it. If @sd->s_dentry is NULL or
* dput() beats us, no need to bother.
*/
void sysfs_drop_dentry(struct sysfs_dirent *sd)
{
@ -224,9 +224,9 @@ void sysfs_drop_dentry(struct sysfs_dirent *sd)
struct inode *inode;
/* We're not holding a reference to ->s_dentry dentry but the
* field will stay valid as long as sysfs_lock is held.
* field will stay valid as long as sysfs_assoc_lock is held.
*/
spin_lock(&sysfs_lock);
spin_lock(&sysfs_assoc_lock);
spin_lock(&dcache_lock);
/* drop dentry if it's there and dput() didn't kill it yet */
@ -238,7 +238,7 @@ void sysfs_drop_dentry(struct sysfs_dirent *sd)
}
spin_unlock(&dcache_lock);
spin_unlock(&sysfs_lock);
spin_unlock(&sysfs_assoc_lock);
dput(dentry);
/* XXX: unpin if directory, this will go away soon */

6
fs/sysfs/symlink.c
View File

@ -82,12 +82,12 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char
return -EFAULT;
/* target->sd can go away beneath us but is protected with
* kobj_sysfs_assoc_lock. Fetch target_sd from it.
* sysfs_assoc_lock. Fetch target_sd from it.
*/
spin_lock(&kobj_sysfs_assoc_lock);
spin_lock(&sysfs_assoc_lock);
if (target->sd)
target_sd = sysfs_get(target->sd);
spin_unlock(&kobj_sysfs_assoc_lock);
spin_unlock(&sysfs_assoc_lock);
if (!target_sd)
return -ENOENT;

3
fs/sysfs/sysfs.h
View File

@ -81,8 +81,7 @@ extern void sysfs_remove_subdir(struct sysfs_dirent *sd);
extern void sysfs_drop_dentry(struct sysfs_dirent *sd);
extern int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);
extern spinlock_t sysfs_lock;
extern spinlock_t kobj_sysfs_assoc_lock;
extern spinlock_t sysfs_assoc_lock;
extern struct rw_semaphore sysfs_rename_sem;
extern struct super_block * sysfs_sb;
extern const struct file_operations sysfs_dir_operations;