diff options
| author | Olof Johansson <olof@lixom.net> | 2014-07-22 09:17:18 -0700 |
|---|---|---|
| committer | Olof Johansson <olof@lixom.net> | 2014-07-22 09:17:18 -0700 |
| commit | e9a86d96be0dff611156ea89fbb6eb91478bddab (patch) | |
| tree | ad38c21c76e1c275264cb20482a7f2bdd54618ba /fs/kernfs/mount.c | |
| parent | fc3791f3a95df5b76ecbda6952c13ff67251fd10 (diff) | |
| parent | ad8adbf2c7d6269d0100f7f460f4837ece060977 (diff) | |
Merge tag 'sti-defconfig-for-v3.17-1' of git://git.stlinux.com/devel/kernel/linux-sti into next/defconfig
Merge "ARM: STi: defconfig changes for v3.17" from Maxime Coquelin:
STi defconfig updates for v3.17
- Enable ST's Thermal controller driver
- Enable ST's Keyscan driver
- Enable ST's MiPHY365 Phy driver for STiH416 SATA & PCIe
- Enable ST's AHCI driver.
* tag 'sti-defconfig-for-v3.17-1' of git://git.stlinux.com/devel/kernel/linux-sti:
ARM: multi_v7_defconfig: Enable MiPHY365x - ST's Generic (SATA & PCIe) PHY
ARM: multi_v7_defconfig: Enable ST's (S)ATA driver
ARM: multi_v7_defconfig: add ST Keyscan driver
ARM: update multi_v7_defconfig for STI
ARM: multi_v7_defconfig: Configure in ST's Thermal Controller
+ Linux 3.16-rc6
Signed-off-by: Olof Johansson <olof@lixom.net>
Diffstat (limited to 'fs/kernfs/mount.c')
| -rw-r--r-- | fs/kernfs/mount.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index d171b98a6cdd..f973ae9b05f1 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -211,6 +211,36 @@ void kernfs_kill_sb(struct super_block *sb) kernfs_put(root_kn); } +/** + * kernfs_pin_sb: try to pin the superblock associated with a kernfs_root + * @kernfs_root: the kernfs_root in question + * @ns: the namespace tag + * + * Pin the superblock so the superblock won't be destroyed in subsequent + * operations. This can be used to block ->kill_sb() which may be useful + * for kernfs users which dynamically manage superblocks. + * + * Returns NULL if there's no superblock associated to this kernfs_root, or + * -EINVAL if the superblock is being freed. + */ +struct super_block *kernfs_pin_sb(struct kernfs_root *root, const void *ns) +{ + struct kernfs_super_info *info; + struct super_block *sb = NULL; + + mutex_lock(&kernfs_mutex); + list_for_each_entry(info, &root->supers, node) { + if (info->ns == ns) { + sb = info->sb; + if (!atomic_inc_not_zero(&info->sb->s_active)) + sb = ERR_PTR(-EINVAL); + break; + } + } + mutex_unlock(&kernfs_mutex); + return sb; +} + void __init kernfs_init(void) { kernfs_node_cache = kmem_cache_create("kernfs_node_cache", |