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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-04-29 11:31:50 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-04-29 11:31:50 -0700 |
commit | 2794b5d408c625e104de813d3de7ac0ec34d46d9 (patch) | |
tree | a99e067475ed4e1de27c86a544347be97e7458fb /fs/sysfs/dir.c | |
parent | 4f567cbc957a7cffd1a428a000d93bd903f42349 (diff) | |
parent | 0d1d392f011b284bb4af0411b2d36e5d04e0f058 (diff) | |
download | linux-2794b5d408c625e104de813d3de7ac0ec34d46d9.tar.gz linux-2794b5d408c625e104de813d3de7ac0ec34d46d9.tar.bz2 linux-2794b5d408c625e104de813d3de7ac0ec34d46d9.zip |
Merge tag 'driver-core-3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core update from Greg Kroah-Hartman:
"Here's the merge request for the driver core tree for 3.10-rc1
It's pretty small, just a number of driver core and sysfs updates and
fixes, all of which have been in linux-next for a while now.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
Fixed conflict in kernel/rtmutex-tester.c, the locking tree had a better
fix for the same sysfs file mode problem.
* tag 'driver-core-3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
PM / Runtime: Idle devices asynchronously after probe|release
driver core: handle user namespaces properly with the uid/gid devtmpfs change
driver core: devtmpfs: fix compile failure with CONFIG_UIDGID_STRICT_TYPE_CHECKS
devtmpfs: add base.h include
driver core: add uid and gid to devtmpfs
sysfs: check if one entry has been removed before freeing
sysfs: fix crash_notes_size build warning
sysfs: fix use after free in case of concurrent read/write and readdir
rtmutex-tester: fix mode of sysfs files
Documentation: Add ABI entry for crash_notes and crash_notes_size
sysfs: Add crash_notes_size to export percpu note size
driver core: platform_device.h: fix checkpatch errors and warnings
driver core: platform.c: fix checkpatch errors and warnings
driver core: warn that platform_driver_probe can not use deferred probing
sysfs: use atomic_inc_unless_negative in sysfs_get_active
base: core: WARN() about bogus permissions on device attributes
device: separate all subsys mutexes
Diffstat (limited to 'fs/sysfs/dir.c')
-rw-r--r-- | fs/sysfs/dir.c | 41 |
1 files changed, 21 insertions, 20 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index e14512678c9b..e8e0e71b29d5 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -165,21 +165,8 @@ struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd) if (unlikely(!sd)) return NULL; - while (1) { - int v, t; - - v = atomic_read(&sd->s_active); - if (unlikely(v < 0)) - return NULL; - - t = atomic_cmpxchg(&sd->s_active, v, v + 1); - if (likely(t == v)) - break; - if (t < 0) - return NULL; - - cpu_relax(); - } + if (!atomic_inc_unless_negative(&sd->s_active)) + return NULL; if (likely(!ignore_lockdep(sd))) rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_); @@ -281,6 +268,10 @@ void release_sysfs_dirent(struct sysfs_dirent * sd) */ parent_sd = sd->s_parent; + WARN(!(sd->s_flags & SYSFS_FLAG_REMOVED), + "sysfs: free using entry: %s/%s\n", + parent_sd ? parent_sd->s_name : "", sd->s_name); + if (sysfs_type(sd) == SYSFS_KOBJ_LINK) sysfs_put(sd->s_symlink.target_sd); if (sysfs_type(sd) & SYSFS_COPY_NAME) @@ -399,7 +390,7 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) sd->s_name = name; sd->s_mode = mode; - sd->s_flags = type; + sd->s_flags = type | SYSFS_FLAG_REMOVED; return sd; @@ -479,6 +470,9 @@ int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; } + /* Mark the entry added into directory tree */ + sd->s_flags &= ~SYSFS_FLAG_REMOVED; + return 0; } @@ -1012,6 +1006,7 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) enum kobj_ns_type type; const void *ns; ino_t ino; + loff_t off; type = sysfs_ns_type(parent_sd); ns = sysfs_info(dentry->d_sb)->ns[type]; @@ -1034,6 +1029,7 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) return 0; } mutex_lock(&sysfs_mutex); + off = filp->f_pos; for (pos = sysfs_dir_pos(ns, parent_sd, filp->f_pos, pos); pos; pos = sysfs_dir_next_pos(ns, parent_sd, filp->f_pos, pos)) { @@ -1045,19 +1041,24 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) len = strlen(name); ino = pos->s_ino; type = dt_type(pos); - filp->f_pos = pos->s_hash; + off = filp->f_pos = pos->s_hash; filp->private_data = sysfs_get(pos); mutex_unlock(&sysfs_mutex); - ret = filldir(dirent, name, len, filp->f_pos, ino, type); + ret = filldir(dirent, name, len, off, ino, type); mutex_lock(&sysfs_mutex); if (ret < 0) break; } mutex_unlock(&sysfs_mutex); - if ((filp->f_pos > 1) && !pos) { /* EOF */ - filp->f_pos = INT_MAX; + + /* don't reference last entry if its refcount is dropped */ + if (!pos) { filp->private_data = NULL; + + /* EOF and not changed as 0 or 1 in read/write path */ + if (off == filp->f_pos && off > 1) + filp->f_pos = INT_MAX; } return 0; } |