Merge branch 'for-linus' of git://gitorious.org/linux-omap-dss2/linux

[mv-sheeva.git] / fs / sysfs / dir.c

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 699f371b9f12f0f9831f712101e63df948f66350..590717861c7aae3381ce8780c0f4a215f09e4066 100644 (file)
--- 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;
@@ -124,7 +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;
@@ -144,45 +144,6 @@ static void sysfs_put_active(struct sysfs_dirent *sd)
        complete(cmpl);
 }
 
-/**
- *     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
@@ -195,6 +156,10 @@ 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_);
@@ -354,7 +319,6 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
 
        atomic_set(&sd->s_count, 1);
        atomic_set(&sd->s_active, 0);
-       sysfs_dirent_init_lockdep(sd);
 
        sd->s_name = name;
        sd->s_mode = mode;
@@ -681,7 +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;
@@ -837,11 +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) {
@@ -857,29 +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;
 }
@@ -888,5 +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,
 };