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authorYoshihisa Abe <yoshiabe@cs.cmu.edu>2010-10-25 02:03:44 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-25 08:02:40 -0700
commitb5ce1d83a62fc109d8e815b1fc71dcdb0d26bc49 (patch)
treeea537c1b6436c36bee3b33d8b4f750124fd7d661 /fs/coda/dir.c
parent3a99c6319064af3f2e18eb929f638d555dbf7a62 (diff)
Coda: add spin lock to protect accesses to struct coda_inode_info.
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>
Diffstat (limited to 'fs/coda/dir.c')
-rw-r--r--fs/coda/dir.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/coda/dir.c b/fs/coda/dir.c
index ccd98b0f2b0..69fbbea75f1 100644
--- a/fs/coda/dir.c
+++ b/fs/coda/dir.c
@@ -18,6 +18,7 @@
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
+#include <linux/spinlock.h>
#include <asm/uaccess.h>
@@ -617,7 +618,9 @@ static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd)
goto out;
/* clear the flags. */
+ spin_lock(&cii->c_lock);
cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
+ spin_unlock(&cii->c_lock);
bad:
unlock_kernel();
@@ -691,7 +694,10 @@ int coda_revalidate_inode(struct dentry *dentry)
goto return_bad;
coda_flag_inode_children(inode, C_FLUSH);
+
+ spin_lock(&cii->c_lock);
cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
+ spin_unlock(&cii->c_lock);
}
ok: