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-rw-r--r--fs/sysfs/dir.c144
1 files changed, 78 insertions, 66 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index f05f2303a8b..590717861c7 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -93,7 +93,7 @@ static void sysfs_unlink_sibling(struct sysfs_dirent *sd)
* RETURNS:
* Pointer to @sd on success, NULL on failure.
*/
-static struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
+struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
{
if (unlikely(!sd))
return NULL;
@@ -106,8 +106,10 @@ static struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
return NULL;
t = atomic_cmpxchg(&sd->s_active, v, v + 1);
- if (likely(t == v))
+ if (likely(t == v)) {
+ rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_);
return sd;
+ }
if (t < 0)
return NULL;
@@ -122,7 +124,7 @@ static struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
* Put an active reference to @sd. This function is noop if @sd
* is NULL.
*/
-static void sysfs_put_active(struct sysfs_dirent *sd)
+void sysfs_put_active(struct sysfs_dirent *sd)
{
struct completion *cmpl;
int v;
@@ -130,6 +132,7 @@ static void sysfs_put_active(struct sysfs_dirent *sd)
if (unlikely(!sd))
return;
+ rwsem_release(&sd->dep_map, 1, _RET_IP_);
v = atomic_dec_return(&sd->s_active);
if (likely(v != SD_DEACTIVATED_BIAS))
return;
@@ -142,45 +145,6 @@ static void sysfs_put_active(struct sysfs_dirent *sd)
}
/**
- * sysfs_get_active_two - get active references to sysfs_dirent and parent
- * @sd: sysfs_dirent of interest
- *
- * Get active reference to @sd and its parent. Parent's active
- * reference is grabbed first. This function is noop if @sd is
- * NULL.
- *
- * RETURNS:
- * Pointer to @sd on success, NULL on failure.
- */
-struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd)
-{
- if (sd) {
- if (sd->s_parent && unlikely(!sysfs_get_active(sd->s_parent)))
- return NULL;
- if (unlikely(!sysfs_get_active(sd))) {
- sysfs_put_active(sd->s_parent);
- return NULL;
- }
- }
- return sd;
-}
-
-/**
- * sysfs_put_active_two - put active references to sysfs_dirent and parent
- * @sd: sysfs_dirent of interest
- *
- * Put active references to @sd and its parent. This function is
- * noop if @sd is NULL.
- */
-void sysfs_put_active_two(struct sysfs_dirent *sd)
-{
- if (sd) {
- sysfs_put_active(sd);
- sysfs_put_active(sd->s_parent);
- }
-}
-
-/**
* sysfs_deactivate - deactivate sysfs_dirent
* @sd: sysfs_dirent to deactivate
*
@@ -192,17 +156,27 @@ static void sysfs_deactivate(struct sysfs_dirent *sd)
int v;
BUG_ON(sd->s_sibling || !(sd->s_flags & SYSFS_FLAG_REMOVED));
+
+ if (!(sysfs_type(sd) & SYSFS_ACTIVE_REF))
+ return;
+
sd->s_sibling = (void *)&wait;
+ rwsem_acquire(&sd->dep_map, 0, 0, _RET_IP_);
/* atomic_add_return() is a mb(), put_active() will always see
* the updated sd->s_sibling.
*/
v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active);
- if (v != SD_DEACTIVATED_BIAS)
+ if (v != SD_DEACTIVATED_BIAS) {
+ lock_contended(&sd->dep_map, _RET_IP_);
wait_for_completion(&wait);
+ }
sd->s_sibling = NULL;
+
+ lock_acquired(&sd->dep_map, _RET_IP_);
+ rwsem_release(&sd->dep_map, 1, _RET_IP_);
}
static int sysfs_alloc_ino(ino_t *pino)
@@ -671,7 +645,7 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
}
/* attach dentry and inode */
- inode = sysfs_get_inode(sd);
+ inode = sysfs_get_inode(dir->i_sb, sd);
if (!inode) {
ret = ERR_PTR(-ENOMEM);
goto out_unlock;
@@ -827,11 +801,46 @@ static inline unsigned char dt_type(struct sysfs_dirent *sd)
return (sd->s_mode >> 12) & 15;
}
+static int sysfs_dir_release(struct inode *inode, struct file *filp)
+{
+ sysfs_put(filp->private_data);
+ return 0;
+}
+
+static struct sysfs_dirent *sysfs_dir_pos(struct sysfs_dirent *parent_sd,
+ ino_t ino, struct sysfs_dirent *pos)
+{
+ if (pos) {
+ int valid = !(pos->s_flags & SYSFS_FLAG_REMOVED) &&
+ pos->s_parent == parent_sd &&
+ ino == pos->s_ino;
+ sysfs_put(pos);
+ if (valid)
+ return pos;
+ }
+ pos = NULL;
+ if ((ino > 1) && (ino < INT_MAX)) {
+ pos = parent_sd->s_dir.children;
+ while (pos && (ino > pos->s_ino))
+ pos = pos->s_sibling;
+ }
+ return pos;
+}
+
+static struct sysfs_dirent *sysfs_dir_next_pos(struct sysfs_dirent *parent_sd,
+ ino_t ino, struct sysfs_dirent *pos)
+{
+ pos = sysfs_dir_pos(parent_sd, ino, pos);
+ if (pos)
+ pos = pos->s_sibling;
+ return pos;
+}
+
static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
struct dentry *dentry = filp->f_path.dentry;
struct sysfs_dirent * parent_sd = dentry->d_fsdata;
- struct sysfs_dirent *pos;
+ struct sysfs_dirent *pos = filp->private_data;
ino_t ino;
if (filp->f_pos == 0) {
@@ -847,29 +856,31 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0)
filp->f_pos++;
}
- if ((filp->f_pos > 1) && (filp->f_pos < INT_MAX)) {
- mutex_lock(&sysfs_mutex);
-
- /* Skip the dentries we have already reported */
- pos = parent_sd->s_dir.children;
- while (pos && (filp->f_pos > pos->s_ino))
- pos = pos->s_sibling;
-
- for ( ; pos; pos = pos->s_sibling) {
- const char * name;
- int len;
-
- name = pos->s_name;
- len = strlen(name);
- filp->f_pos = ino = pos->s_ino;
+ mutex_lock(&sysfs_mutex);
+ for (pos = sysfs_dir_pos(parent_sd, filp->f_pos, pos);
+ pos;
+ pos = sysfs_dir_next_pos(parent_sd, filp->f_pos, pos)) {
+ const char * name;
+ unsigned int type;
+ int len, ret;
+
+ name = pos->s_name;
+ len = strlen(name);
+ ino = pos->s_ino;
+ type = dt_type(pos);
+ filp->f_pos = ino;
+ filp->private_data = sysfs_get(pos);
- if (filldir(dirent, name, len, filp->f_pos, ino,
- dt_type(pos)) < 0)
- break;
- }
- if (!pos)
- filp->f_pos = INT_MAX;
mutex_unlock(&sysfs_mutex);
+ ret = filldir(dirent, name, len, filp->f_pos, 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;
+ filp->private_data = NULL;
}
return 0;
}
@@ -878,5 +889,6 @@ static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
const struct file_operations sysfs_dir_operations = {
.read = generic_read_dir,
.readdir = sysfs_readdir,
+ .release = sysfs_dir_release,
.llseek = generic_file_llseek,
};
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-18 08:58:54 +0000