LU-1337 llite: take trunc_sem outside cl_io_loop for mkwrite

In truncate path it acquires lli_trunc_sem and then dlm lock, so
in page_mkwrite we should take it in the same sequence to avoid
dead lock.

This is a fix for f78805dbf041bb42b250fe754dff7b864856203f .

Signed-off-by: Liu Xuezhao <xuezhao.liu@emc.com>
Change-Id: Idb5574bffdaf00461befd43b867cdd9b3e549efe
Reviewed-on: http://review.whamcloud.com/4485
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Jinshan Xiong <jinshan.xiong@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/llite/llite_mmap.c b/lustre/llite/llite_mmap.c
index 5310b14..3a0c077 100644 (file)
--- a/lustre/llite/llite_mmap.c
+++ b/lustre/llite/llite_mmap.c
@@ -172,38 +172,51 @@ struct cl_io *ll_fault_io_init(struct vm_area_struct *vma,
 static int ll_page_mkwrite0(struct vm_area_struct *vma, struct page *vmpage,
                             bool *retry)
 {
-        struct lu_env           *env;
-        struct cl_io            *io;
-        struct vvp_io           *vio;
-        struct cl_env_nest       nest;
-        int                      result;
+       struct lu_env           *env;
+       struct cl_io            *io;
+       struct vvp_io           *vio;
+       struct cl_env_nest       nest;
+       int                      result;
        cfs_sigset_t             set;
-        ENTRY;
+       struct inode             *inode;
+       struct ll_inode_info     *lli;
+       ENTRY;
 
-        LASSERT(vmpage != NULL);
+       LASSERT(vmpage != NULL);
 
-        io = ll_fault_io_init(vma, &env,  &nest, vmpage->index, NULL);
-        if (IS_ERR(io))
-                GOTO(out, result = PTR_ERR(io));
+       io = ll_fault_io_init(vma, &env,  &nest, vmpage->index, NULL);
+       if (IS_ERR(io))
+               GOTO(out, result = PTR_ERR(io));
 
-        result = io->ci_result;
-        if (result < 0)
-                GOTO(out, result);
+       result = io->ci_result;
+       if (result < 0)
+               GOTO(out, result);
 
-        /* Don't enqueue new locks for page_mkwrite().
-         * If the lock has been cancelled then page must have been
-         * truncated, in that case, kernel will handle it.
-         */
-        io->ci_lockreq = CILR_PEEK;
-        io->u.ci_fault.ft_mkwrite = 1;
-        io->u.ci_fault.ft_writable = 1;
+       /* Don't enqueue new locks for page_mkwrite().
+        * If the lock has been cancelled then page must have been
+        * truncated, in that case, kernel will handle it.
+        */
+       io->ci_lockreq = CILR_PEEK;
+       io->u.ci_fault.ft_mkwrite = 1;
+       io->u.ci_fault.ft_writable = 1;
 
-        vio = vvp_env_io(env);
-        vio->u.fault.ft_vma    = vma;
-        vio->u.fault.ft_vmpage = vmpage;
+       vio = vvp_env_io(env);
+       vio->u.fault.ft_vma    = vma;
+       vio->u.fault.ft_vmpage = vmpage;
 
        set = cfs_block_sigsinv(sigmask(SIGKILL) | sigmask(SIGTERM));
+
+       /* we grab lli_trunc_sem to exclude truncate case.
+        * Otherwise, we could add dirty pages into osc cache
+        * while truncate is on-going. */
+       inode = ccc_object_inode(io->ci_obj);
+       lli = ll_i2info(inode);
+       cfs_down_read(&lli->lli_trunc_sem);
+
        result = cl_io_loop(env, io);
+
+       cfs_up_read(&lli->lli_trunc_sem);
+
        cfs_restore_sigs(set);
 
         if (result == -ENODATA) /* peek failed, no lock caching. */

diff --git a/lustre/llite/vvp_io.c b/lustre/llite/vvp_io.c
index a656e71..46644c8 100644 (file)
--- a/lustre/llite/vvp_io.c
+++ b/lustre/llite/vvp_io.c
@@ -663,7 +663,6 @@ static int vvp_io_fault_start(const struct lu_env *env,
        struct cl_io        *io      = ios->cis_io;
        struct cl_object    *obj     = io->ci_obj;
        struct inode        *inode   = ccc_object_inode(obj);
-       struct ll_inode_info *lli    = ll_i2info(inode);
        struct cl_fault_io  *fio     = &io->u.ci_fault;
        struct vvp_fault_io *cfio    = &vio->u.fault;
        loff_t               offset;
@@ -688,11 +687,6 @@ static int vvp_io_fault_start(const struct lu_env *env,
 
        /* must return locked page */
        if (fio->ft_mkwrite) {
-               /* we grab lli_trunc_sem to exclude truncate case.
-                * Otherwise, we could add dirty pages into osc cache
-                * while truncate is on-going. */
-               cfs_down_read(&lli->lli_trunc_sem);
-
                LASSERT(cfio->ft_vmpage != NULL);
                lock_page(cfio->ft_vmpage);
        } else {
@@ -777,8 +771,6 @@ out:
        /* return unlocked vmpage to avoid deadlocking */
        if (vmpage != NULL)
                unlock_page(vmpage);
-       if (fio->ft_mkwrite)
-               cfs_up_read(&lli->lli_trunc_sem);
 #ifdef HAVE_VM_OP_FAULT
        cfio->fault.ft_flags &= ~VM_FAULT_LOCKED;
 #endif