[PATCH] cifs: fix actimeo=0 corner case when cifs_i->time == jiffies

[Jeff Layton]

actimeo=0 is supposed to be a special case that ensures that inode
attributes are always refetched from the server instead of trusting the
cache. The cifs code however uses time_in_range() to determine whether
the attributes have timed out. In the case where cifs_i->time equals
jiffies, this leads to the cifs code not refetching the inode attributes
when it should.

Fix this by explicitly testing for actimeo=0, and handling it as a
special case.

Reported-and-Tested-by: Tetsuo Handa <penguin-kernel-JPay3/***@public.gmane.org>
Signed-off-by: Jeff Layton <jlayton-H+wXaHxf7aLQT0dZR+***@public.gmane.org>
---
fs/cifs/inode.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index aadc2b68678b..a22d667f1069 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1737,6 +1737,9 @@ cifs_inode_needs_reval(struct inode *inode)
if (cifs_i->time == 0)
return true;

+ if (!cifs_sb->actimeo)
+ return true;
+
if (!time_in_range(jiffies, cifs_i->time,
cifs_i->time + cifs_sb->actimeo))
return true;

[Steve French]

Fixed minor typo in comments and merged into cifs-2.6.git

Post by Jeff Layton
actimeo=0 is supposed to be a special case that ensures that inode
attributes are always refetched from the server instead of trusting the
cache. The cifs code however uses time_in_range() to determine whether
the attributes have timed out. In the case where cifs_i->time equals
jiffies, this leads to the cifs code not refetching the inode attributes
when it should.
Fix this by explicitly testing for actimeo=0, and handling it as a
special case.
---
fs/cifs/inode.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index aadc2b68678b..a22d667f1069 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1737,6 +1737,9 @@ cifs_inode_needs_reval(struct inode *inode)
if (cifs_i->time == 0)
return true;
+ if (!cifs_sb->actimeo)
+ return true;
+
if (!time_in_range(jiffies, cifs_i->time,
cifs_i->time + cifs_sb->actimeo))
return true;
--
1.8.5.3