Messages in this thread | | | Date | Wed, 23 May 2007 10:21:30 +0200 | From | Tejun Heo <> | Subject | Re: [PATCH 2/2] sysfs: fix race condition around sd->s_dentry, take#2 |
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Greg KH wrote: > On Mon, May 21, 2007 at 10:31:01AM +0530, Maneesh Soni wrote: >> On Thu, May 17, 2007 at 08:16:10PM +0200, Tejun Heo wrote: >>> Allowing attribute and symlink dentries to be reclaimed means >>> sd->s_dentry can change dynamically. However, updates to the field >>> are unsynchronized leading to race conditions. This patch adds >>> sysfs_lock and use it to synchronize updates to sd->s_dentry. >>> >>> Due to the locking around ->d_iput, the check in sysfs_drop_dentry() >>> is complex. sysfs_lock only protect sd->s_dentry pointer itself. The >>> validity of the dentry is protected by dcache_lock, so whether dentry >>> is alive or not can only be tested while holding both locks. >>> >>> This is minimal backport of sysfs_drop_dentry() rewrite in devel >>> branch. >>> >>> DONT APPLY JUST YET >> Looks ok to me.. I have tested it it but unfortunately I couldn't >> recreate the race without the patch also. It would be helpful if >> people actually seeing the race, provide the test results. >> >> Greg, please merge this one once we have some test results. > > Can someone just resend it after those test results are in, with the > proper signed-off-by, so I know it's safe to apply?
I'll resend with S-O-B after someone verifies it fixes the problem.
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