xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Coda: add spin lock to protect accesses to struct coda_inode_info.

Browse Source 
We mostly need it to protect cached user permissions. The c_flags field
is advisory, reading the wrong value is harmless and in the worst case
we hit a slow path where we have to make an extra upcall to the
userspace cache manager when revalidating a dentry or inode.

Signed-off-by: Yoshihisa Abe <yoshiabe@cs.cmu.edu>
Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Yoshihisa Abe
2010-10-25 02:03:44 -04:00
committed by Linus Torvalds
parent 3a99c63190
commit b5ce1d83a6
7 changed files with 58 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
include/linux/coda_fs_i.h
View File

@@ -10,19 +10,24 @@
#include <linux/types.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/coda.h>
/*
* coda fs inode data
* c_lock protects accesses to c_flags, c_mapcount, c_cached_epoch, c_uid and
* c_cached_perm.
* vfs_inode is set only when the inode is created and never changes.
* c_fid is set when the inode is created and should be considered immutable.
*/
struct coda_inode_info {
struct CodaFid c_fid; /* Coda identifier */
u_short c_flags; /* flags (see below) */
struct list_head c_cilist; /* list of all coda inodes */
struct CodaFid c_fid; /* Coda identifier */
u_short c_flags; /* flags (see below) */
unsigned int c_mapcount; /* nr of times this inode is mapped */
unsigned int c_cached_epoch; /* epoch for cached permissions */
vuid_t c_uid; /* fsuid for cached permissions */
unsigned int c_cached_perm; /* cached access permissions */
unsigned int c_cached_perm; /* cached access permissions */
spinlock_t c_lock;
struct inode vfs_inode;
};