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authorAmir Goldstein <amir73il@gmail.com>2017-06-21 15:28:32 +0300
committerMiklos Szeredi <mszeredi@redhat.com>2017-07-04 22:03:16 +0200
commitad0af7104dadccd55cd2b390271677fac142650f (patch)
tree1e377c42709b12efc4e01507143ebba09f389bc7 /include/linux/fs.h
parent04a01ac7ed3c5cd718713ef6341249a143c96b10 (diff)
downloadop-kernel-dev-ad0af7104dadccd55cd2b390271677fac142650f.zip
op-kernel-dev-ad0af7104dadccd55cd2b390271677fac142650f.tar.gz
vfs: introduce inode 'inuse' lock
Added an i_state flag I_INUSE and helpers to set/clear/test the bit. The 'inuse' lock is an 'advisory' inode lock, that can be used to extend exclusive create protection beyond parent->i_mutex lock among cooperating users. This is going to be used by overlayfs to get exclusive ownership on upper and work dirs among overlayfs mounts. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'include/linux/fs.h')
-rw-r--r--include/linux/fs.h4
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 3e68cab..75a5faf 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1930,6 +1930,9 @@ static inline bool HAS_UNMAPPED_ID(struct inode *inode)
* wb stat updates to grab mapping->tree_lock. See
* inode_switch_wb_work_fn() for details.
*
+ * I_OVL_INUSE Used by overlayfs to get exclusive ownership on upper
+ * and work dirs among overlayfs mounts.
+ *
* Q: What is the difference between I_WILL_FREE and I_FREEING?
*/
#define I_DIRTY_SYNC (1 << 0)
@@ -1950,6 +1953,7 @@ static inline bool HAS_UNMAPPED_ID(struct inode *inode)
#define __I_DIRTY_TIME_EXPIRED 12
#define I_DIRTY_TIME_EXPIRED (1 << __I_DIRTY_TIME_EXPIRED)
#define I_WB_SWITCH (1 << 13)
+#define I_OVL_INUSE (1 << 14)
#define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES)
#define I_DIRTY_ALL (I_DIRTY | I_DIRTY_TIME)
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