diff options
| -rw-r--r-- | fs/configfs/dir.c | 33 |
1 files changed, 28 insertions, 5 deletions
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c index b11d7342eef..9a37a9b6de3 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -53,11 +53,14 @@ DEFINE_SPINLOCK(configfs_dirent_lock); static void configfs_d_iput(struct dentry * dentry, struct inode * inode) { - struct configfs_dirent * sd = dentry->d_fsdata; + struct configfs_dirent *sd = dentry->d_fsdata; if (sd) { BUG_ON(sd->s_dentry != dentry); + /* Coordinate with configfs_readdir */ + spin_lock(&configfs_dirent_lock); sd->s_dentry = NULL; + spin_unlock(&configfs_dirent_lock); configfs_put(sd); } iput(inode); @@ -1546,7 +1549,7 @@ static int configfs_readdir(struct file * filp, void * dirent, filldir_t filldir struct configfs_dirent * parent_sd = dentry->d_fsdata; struct configfs_dirent *cursor = filp->private_data; struct list_head *p, *q = &cursor->s_sibling; - ino_t ino; + ino_t ino = 0; int i = filp->f_pos; switch (i) { @@ -1574,6 +1577,7 @@ static int configfs_readdir(struct file * filp, void * dirent, filldir_t filldir struct configfs_dirent *next; const char * name; int len; + struct inode *inode = NULL; next = list_entry(p, struct configfs_dirent, s_sibling); @@ -1582,9 +1586,28 @@ static int configfs_readdir(struct file * filp, void * dirent, filldir_t filldir name = configfs_get_name(next); len = strlen(name); - if (next->s_dentry) - ino = next->s_dentry->d_inode->i_ino; - else + + /* + * We'll have a dentry and an inode for + * PINNED items and for open attribute + * files. We lock here to prevent a race + * with configfs_d_iput() clearing + * s_dentry before calling iput(). + * + * Why do we go to the trouble? If + * someone has an attribute file open, + * the inode number should match until + * they close it. Beyond that, we don't + * care. + */ + spin_lock(&configfs_dirent_lock); + dentry = next->s_dentry; + if (dentry) + inode = dentry->d_inode; + if (inode) + ino = inode->i_ino; + spin_unlock(&configfs_dirent_lock); + if (!inode) ino = iunique(configfs_sb, 2); if (filldir(dirent, name, len, filp->f_pos, ino, |