| Date | Wed, 16 Dec 2009 19:55:54 -0800 | From | Greg KH <> | Subject | [057/151] NFS: Fix nfs_migrate_page() |
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2.6.32-stable review patch. If anyone has any objections, please let us know.
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From: Trond Myklebust <Trond.Myklebust@netapp.com>
commit 190f38e5cedc910940b1da9015f00458c18f97b4 upstream.
The call to migrate_page() will cause the page->private field to be cleared. Also fix up the locking around the page->private transfer, so that we ensure that calls to nfs_page_find_request() don't end up racing.
Finally, fix up a double free bug: nfs_unlock_request() already calls nfs_release_request() for us...
Reported-by: Wu Fengguang <fengguang.wu@intel.com> Tested-by: Andi Kleen <andi@firstfloor.org> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- fs/nfs/write.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -1612,15 +1612,16 @@ int nfs_migrate_page(struct address_spac if (ret) goto out_unlock; page_cache_get(newpage); + spin_lock(&mapping->host->i_lock); req->wb_page = newpage; SetPagePrivate(newpage); - set_page_private(newpage, page_private(page)); + set_page_private(newpage, (unsigned long)req); ClearPagePrivate(page); set_page_private(page, 0); + spin_unlock(&mapping->host->i_lock); page_cache_release(page); out_unlock: nfs_clear_page_tag_locked(req); - nfs_release_request(req); out: return ret; }
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