From: Liu Xuezhao <xuezhao.liu@emc.com>
Date: Wed, 7 Nov 2012 03:17:44 +0000 (+0800)
Subject: LU-1337 llite: take trunc_sem outside cl_io_loop for mkwrite
X-Git-Tag: 2.3.57~62
X-Git-Url: https://git.whamcloud.com/gitweb?a=commitdiff_plain;h=77e2f09e3ba863018ff373e198ac0e62487aa675;p=fs%2Flustre-release.git

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
--- 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
--- 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