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| author | Trond Myklebust <trond.myklebust@primarydata.com> | 2014-05-29 11:45:57 -0400 |
|---|---|---|
| committer | Trond Myklebust <trond.myklebust@primarydata.com> | 2014-05-29 12:12:27 -0400 |
| commit | f868089b09b51bd17ee41dedb96f98a1d0952fec (patch) | |
| tree | bb7b2c8503616cea06eba345d7b47cc479695d24 /fs/nfs | |
| parent | c1109558ae0f07a3434357cd26203bfc7adfea75 (diff) | |
| download | lwn-f868089b09b51bd17ee41dedb96f98a1d0952fec.tar.gz lwn-f868089b09b51bd17ee41dedb96f98a1d0952fec.zip | |
NFS: Fix a potential busy wait in nfs_page_group_lock
We cannot allow nfs_page_group_lock to use TASK_KILLABLE here, since
the loop would cause a busy wait if somebody kills the task.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'fs/nfs')
| -rw-r--r-- | fs/nfs/pagelist.c | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 0b8446f1008d..a8759825ac76 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -138,6 +138,12 @@ nfs_iocounter_wait(struct nfs_io_counter *c) return __nfs_iocounter_wait(c); } +static int nfs_wait_bit_uninterruptible(void *word) +{ + io_schedule(); + return 0; +} + /* * nfs_page_group_lock - lock the head of the page group * @req - request in group that is to be locked @@ -148,13 +154,12 @@ void nfs_page_group_lock(struct nfs_page *req) { struct nfs_page *head = req->wb_head; - int err = -EAGAIN; WARN_ON_ONCE(head != head->wb_head); - while (err) - err = wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK, - nfs_wait_bit_killable, TASK_KILLABLE); + wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK, + nfs_wait_bit_uninterruptible, + TASK_UNINTERRUPTIBLE); } /* @@ -410,12 +415,6 @@ void nfs_release_request(struct nfs_page *req) kref_put(&req->wb_kref, nfs_page_group_destroy); } -static int nfs_wait_bit_uninterruptible(void *word) -{ - io_schedule(); - return 0; -} - /** * nfs_wait_on_request - Wait for a request to complete. * @req: request to wait upon. |