diff options
| author | Tejun Heo <tj@kernel.org> | 2013-10-01 17:41:58 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-10-05 17:15:48 -0700 |
| commit | c75ec764cf4746a2406278ffa16f590c5db290a7 (patch) | |
| tree | e1d8787906ed20dce25ce1f119c95382d6cdf21e /fs/sysfs | |
| parent | 375b611e60f7c1ce6913417ca254efe5523f1a72 (diff) | |
| download | linux-c75ec764cf4746a2406278ffa16f590c5db290a7.tar.bz2 | |
sysfs: add sysfs_open_file_mutex
Add a separate mutex to protect sysfs_open_dirent->buffers list. This
will allow performing sleepable operations while traversing
sysfs_buffers, which will be renamed to sysfs_open_file.
Note that currently sysfs_open_dirent->buffers list isn't being used
for anything and this patch doesn't make any functional difference.
It will be used to merge regular and bin file supports.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/sysfs')
| -rw-r--r-- | fs/sysfs/file.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 7dfcc3317490..499cff8554fc 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -25,15 +25,17 @@ #include "sysfs.h" /* - * There's one sysfs_buffer for each open file and one - * sysfs_open_dirent for each sysfs_dirent with one or more open - * files. + * There's one sysfs_buffer for each open file and one sysfs_open_dirent + * for each sysfs_dirent with one or more open files. * - * filp->private_data points to sysfs_buffer and - * sysfs_dirent->s_attr.open points to sysfs_open_dirent. s_attr.open - * is protected by sysfs_open_dirent_lock. + * sysfs_dirent->s_attr.open points to sysfs_open_dirent. s_attr.open is + * protected by sysfs_open_dirent_lock. + * + * filp->private_data points to sysfs_buffer which is chained at + * sysfs_open_dirent->buffers, which is protected by sysfs_open_file_mutex. */ static DEFINE_SPINLOCK(sysfs_open_dirent_lock); +static DEFINE_MUTEX(sysfs_open_file_mutex); struct sysfs_open_dirent { atomic_t refcnt; @@ -272,6 +274,7 @@ static int sysfs_get_open_dirent(struct sysfs_dirent *sd, struct sysfs_open_dirent *od, *new_od = NULL; retry: + mutex_lock(&sysfs_open_file_mutex); spin_lock_irq(&sysfs_open_dirent_lock); if (!sd->s_attr.open && new_od) { @@ -286,6 +289,7 @@ static int sysfs_get_open_dirent(struct sysfs_dirent *sd, } spin_unlock_irq(&sysfs_open_dirent_lock); + mutex_unlock(&sysfs_open_file_mutex); if (od) { kfree(new_od); @@ -321,6 +325,7 @@ static void sysfs_put_open_dirent(struct sysfs_dirent *sd, struct sysfs_open_dirent *od = sd->s_attr.open; unsigned long flags; + mutex_lock(&sysfs_open_file_mutex); spin_lock_irqsave(&sysfs_open_dirent_lock, flags); list_del(&buffer->list); @@ -330,6 +335,7 @@ static void sysfs_put_open_dirent(struct sysfs_dirent *sd, od = NULL; spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags); + mutex_unlock(&sysfs_open_file_mutex); kfree(od); } |