diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-06-16 18:45:47 +0900 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-06-16 18:45:47 +0900 |
| commit | ab2789b72df3cf7a01e30636ea86cbbf44ba2e99 (patch) | |
| tree | 98f5359551b9497c51e8429b1dc489a440e30c3f | |
| parent | 20223f0f39ea9d31ece08f04ac79f8c4e8d98246 (diff) | |
| parent | 19e72d3abb63cb16d021a4066ce1a18880509e99 (diff) | |
Merge tag 'configfs-for-4.12' of git://git.infradead.org/users/hch/configfs
Pull configfs updates from Christoph Hellwig:
"A fix from Nic for a race seen in production (including a stable tag).
And while I'm sending you this I'm also sneaking in a trivial new
helper from Bart so that we don't need inter-tree dependencies for the
next merge window"
* tag 'configfs-for-4.12' of git://git.infradead.org/users/hch/configfs:
configfs: Introduce config_item_get_unless_zero()
configfs: Fix race between create_link and configfs_rmdir
| -rw-r--r-- | fs/configfs/item.c | 8 | ||||
| -rw-r--r-- | fs/configfs/symlink.c | 3 | ||||
| -rw-r--r-- | include/linux/configfs.h | 3 |
3 files changed, 11 insertions, 3 deletions
diff --git a/fs/configfs/item.c b/fs/configfs/item.c index 8b2a994042dd..a66f6624d899 100644 --- a/fs/configfs/item.c +++ b/fs/configfs/item.c @@ -138,6 +138,14 @@ struct config_item *config_item_get(struct config_item *item) } EXPORT_SYMBOL(config_item_get); +struct config_item *config_item_get_unless_zero(struct config_item *item) +{ + if (item && kref_get_unless_zero(&item->ci_kref)) + return item; + return NULL; +} +EXPORT_SYMBOL(config_item_get_unless_zero); + static void config_item_cleanup(struct config_item *item) { struct config_item_type *t = item->ci_type; diff --git a/fs/configfs/symlink.c b/fs/configfs/symlink.c index a6ab012a2c6a..c8aabba502f6 100644 --- a/fs/configfs/symlink.c +++ b/fs/configfs/symlink.c @@ -83,14 +83,13 @@ static int create_link(struct config_item *parent_item, ret = -ENOMEM; sl = kmalloc(sizeof(struct configfs_symlink), GFP_KERNEL); if (sl) { - sl->sl_target = config_item_get(item); spin_lock(&configfs_dirent_lock); if (target_sd->s_type & CONFIGFS_USET_DROPPING) { spin_unlock(&configfs_dirent_lock); - config_item_put(item); kfree(sl); return -ENOENT; } + sl->sl_target = config_item_get(item); list_add(&sl->sl_list, &target_sd->s_links); spin_unlock(&configfs_dirent_lock); ret = configfs_create_link(sl, parent_item->ci_dentry, diff --git a/include/linux/configfs.h b/include/linux/configfs.h index 2319b8c108e8..c96709049683 100644 --- a/include/linux/configfs.h +++ b/include/linux/configfs.h @@ -74,7 +74,8 @@ extern void config_item_init_type_name(struct config_item *item, const char *name, struct config_item_type *type); -extern struct config_item * config_item_get(struct config_item *); +extern struct config_item *config_item_get(struct config_item *); +extern struct config_item *config_item_get_unless_zero(struct config_item *); extern void config_item_put(struct config_item *); struct config_item_type { |