fs/lustre: do not rely on page->mapping get it from the context

This patch remove most dereference of page->mapping and get the mapping
from the call context (either already available in the function or by
adding it to function arguments).

Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: Tejun Heo <tj@kernel.org>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: James Simmons <jsimmons@infradead.org>
Cc: lustre-devel@lists.lustre.org

10 files changed, 41 insertions, 33 deletions

diff --git a/drivers/staging/lustre/lustre/include/lustre_patchless_compat.h b/drivers/staging/lustre/lustre/include/lustre_patchless_compat.h
index 15fe1cfe1487..cf39848ffabc 100644
--- a/drivers/staging/lustre/lustre/include/lustre_patchless_compat.h
+++ b/drivers/staging/lustre/lustre/include/lustre_patchless_compat.h
@@ -49,8 +49,7 @@ truncate_complete_page(struct address_space *mapping, struct page *page)
 		return;
 
 	if (PagePrivate(page))
-		page->mapping->a_ops->invalidatepage(mapping, page,
-						     0, PAGE_SIZE);
+		mapping->a_ops->invalidatepage(mapping, page, 0, PAGE_SIZE);
 
 	cancel_dirty_page(page);
 	ClearPageMappedToDisk(page);
diff --git a/drivers/staging/lustre/lustre/llite/dir.c b/drivers/staging/lustre/lustre/llite/dir.c
index 99b0b77c75f5..1b6afde4a701 100644
--- a/drivers/staging/lustre/lustre/llite/dir.c
+++ b/drivers/staging/lustre/lustre/llite/dir.c
@@ -167,8 +167,8 @@ void ll_release_page(struct inode *inode, struct page *page, bool remove)
 
 	if (remove) {
 		lock_page(page);
-		if (likely(page->mapping))
-			truncate_complete_page(page->mapping, page);
+		if (likely(!!page->mapping))
+			truncate_complete_page(inode->i_mapping, page);
 		unlock_page(page);
 	}
 	put_page(page);
diff --git a/drivers/staging/lustre/lustre/llite/llite_internal.h b/drivers/staging/lustre/lustre/llite/llite_internal.h
index 5cc0e9308d3a..8754d1c7ca20 100644
--- a/drivers/staging/lustre/lustre/llite/llite_internal.h
+++ b/drivers/staging/lustre/lustre/llite/llite_internal.h
@@ -814,7 +814,8 @@ int ll_flush_ctx(struct inode *inode);
 void ll_umount_begin(struct super_block *sb);
 int ll_remount_fs(struct super_block *sb, int *flags, char *data);
 int ll_show_options(struct seq_file *seq, struct dentry *dentry);
-void ll_dirty_page_discard_warn(struct page *page, int ioret);
+void ll_dirty_page_discard_warn(struct address_space *mapping,
+				struct page *page, int ioret);
 int ll_prep_inode(struct inode **inode, struct ptlrpc_request *req,
 		  struct super_block *sb, struct lookup_intent *it);
 int ll_obd_statfs(struct inode *inode, void __user *arg);
@@ -923,13 +924,13 @@ void policy_from_vma(union ldlm_policy_data *policy, struct vm_area_struct *vma,
 struct vm_area_struct *our_vma(struct mm_struct *mm, unsigned long addr,
 			       size_t count);
 
-static inline void ll_invalidate_page(struct page *vmpage)
+static inline void ll_invalidate_page(struct address_space *mapping,
+				      struct page *vmpage)
 {
-	struct address_space *mapping = vmpage->mapping;
 	loff_t offset = vmpage->index << PAGE_SHIFT;
 
 	LASSERT(PageLocked(vmpage));
-	if (!mapping)
+	if (!vmpage->mapping)
 		return;
 
 	/*
diff --git a/drivers/staging/lustre/lustre/llite/llite_lib.c b/drivers/staging/lustre/lustre/llite/llite_lib.c
index 6735a6f006d2..d0c87ee295ca 100644
--- a/drivers/staging/lustre/lustre/llite/llite_lib.c
+++ b/drivers/staging/lustre/lustre/llite/llite_lib.c
@@ -2436,24 +2436,25 @@ char *ll_get_fsname(struct super_block *sb, char *buf, int buflen)
 	return buf;
 }
 
-void ll_dirty_page_discard_warn(struct page *page, int ioret)
+void ll_dirty_page_discard_warn(struct address_space *mapping,
+				struct page *page, int ioret)
 {
 	char *buf, *path = NULL;
 	struct dentry *dentry = NULL;
-	struct vvp_object *obj = cl_inode2vvp(page->mapping->host);
+	struct vvp_object *obj = cl_inode2vvp(mapping->host);
 
 	/* this can be called inside spin lock so use GFP_ATOMIC. */
 	buf = (char *)__get_free_page(GFP_ATOMIC);
 	if (buf) {
-		dentry = d_find_alias(page->mapping->host);
+		dentry = d_find_alias(mapping->host);
 		if (dentry)
 			path = dentry_path_raw(dentry, buf, PAGE_SIZE);
 	}
 
 	CDEBUG(D_WARNING,
 	       "%s: dirty page discard: %s/fid: " DFID "/%s may get corrupted (rc %d)\n",
-	       ll_get_fsname(page->mapping->host->i_sb, NULL, 0),
-	       s2lsi(page->mapping->host->i_sb)->lsi_lmd->lmd_dev,
+	       ll_get_fsname(mapping->host->i_sb, NULL, 0),
+	       s2lsi(mapping->host->i_sb)->lsi_lmd->lmd_dev,
 	       PFID(&obj->vob_header.coh_lu.loh_fid),
 	       (path && !IS_ERR(path)) ? path : "", ioret);
 
diff --git a/drivers/staging/lustre/lustre/llite/rw.c b/drivers/staging/lustre/lustre/llite/rw.c
index ffd901cac652..a4eba3878400 100644
--- a/drivers/staging/lustre/lustre/llite/rw.c
+++ b/drivers/staging/lustre/lustre/llite/rw.c
@@ -903,7 +903,7 @@ out_unlock:
 int ll_writepage(struct address_space *mapping, struct page *vmpage,
 		 struct writeback_control *wbc)
 {
-	struct inode	       *inode = vmpage->mapping->host;
+	struct inode	       *inode = mapping->host;
 	struct ll_inode_info   *lli   = ll_i2info(inode);
 	struct lu_env	  *env;
 	struct cl_io	   *io;
diff --git a/drivers/staging/lustre/lustre/llite/rw26.c b/drivers/staging/lustre/lustre/llite/rw26.c
index 19636e84192e..366ba0afbd0e 100644
--- a/drivers/staging/lustre/lustre/llite/rw26.c
+++ b/drivers/staging/lustre/lustre/llite/rw26.c
@@ -86,7 +86,7 @@ static void ll_invalidatepage(struct address_space *mapping,
 		/* See the comment in ll_releasepage() */
 		env = cl_env_percpu_get();
 		LASSERT(!IS_ERR(env));
-		inode = vmpage->mapping->host;
+		inode = mapping->host;
 		obj = ll_i2info(inode)->lli_clob;
 		if (obj) {
 			page = cl_vmpage_page(vmpage, obj);
@@ -114,8 +114,7 @@ static int ll_releasepage(struct address_space *mapping,
 	if (PageWriteback(vmpage) || PageDirty(vmpage))
 		return 0;
 
-	mapping = vmpage->mapping;
-	if (!mapping)
+	if (!vmpage->mapping)
 		return 1;
 
 	obj = ll_i2info(mapping->host)->lli_clob;
diff --git a/drivers/staging/lustre/lustre/llite/vvp_dev.c b/drivers/staging/lustre/lustre/llite/vvp_dev.c
index 987c03b058e6..bffd2dbde90f 100644
--- a/drivers/staging/lustre/lustre/llite/vvp_dev.c
+++ b/drivers/staging/lustre/lustre/llite/vvp_dev.c
@@ -502,6 +502,7 @@ static loff_t vvp_pgcache_find(const struct lu_env *env,
 } while (0)
 
 static void vvp_pgcache_page_show(const struct lu_env *env,
+				  struct address_space *mapping,
 				  struct seq_file *seq, struct cl_page *page)
 {
 	struct vvp_page *vpg;
@@ -516,8 +517,8 @@ static void vvp_pgcache_page_show(const struct lu_env *env,
 		   "none",
 		   vpg->vpg_defer_uptodate ? "du" : "- ",
 		   PageWriteback(vmpage) ? "wb" : "-",
-		   vmpage, PFID(ll_inode2fid(vmpage->mapping->host)),
-		   vmpage->mapping->host, vmpage->index,
+		   vmpage, PFID(ll_inode2fid(mapping->host)),
+		   mapping->host, vmpage->index,
 		   page_count(vmpage));
 	has_flags = 0;
 	seq_page_flag(seq, vmpage, locked, has_flags);
@@ -563,7 +564,8 @@ static int vvp_pgcache_show(struct seq_file *f, void *v)
 			seq_printf(f, "%8x@" DFID ": ", id.vpi_index,
 				   PFID(lu_object_fid(&clob->co_lu)));
 			if (page) {
-				vvp_pgcache_page_show(env, f, page);
+				vvp_pgcache_page_show(env, inode->i_mapping,
+						      f, page);
 				cl_page_put(env, page);
 			} else {
 				seq_puts(f, "missing\n");
diff --git a/drivers/staging/lustre/lustre/llite/vvp_io.c b/drivers/staging/lustre/lustre/llite/vvp_io.c
index e7a4778e02e4..aaa06ba38b4c 100644
--- a/drivers/staging/lustre/lustre/llite/vvp_io.c
+++ b/drivers/staging/lustre/lustre/llite/vvp_io.c
@@ -1098,7 +1098,7 @@ static int vvp_io_fault_start(const struct lu_env *env,
 	LASSERT(PageLocked(vmpage));
 
 	if (OBD_FAIL_CHECK(OBD_FAIL_LLITE_FAULT_TRUNC_RACE))
-		ll_invalidate_page(vmpage);
+		ll_invalidate_page(inode->i_mapping, vmpage);
 
 	size = i_size_read(inode);
 	/* Though we have already held a cl_lock upon this page, but
@@ -1127,7 +1127,7 @@ static int vvp_io_fault_start(const struct lu_env *env,
 		if (last_index < fio->ft_index) {
 			CDEBUG(D_PAGE,
 			       "llite: mkwrite and truncate race happened: %p: 0x%lx 0x%lx\n",
-			       vmpage->mapping, fio->ft_index, last_index);
+			       inode->i_mapping, fio->ft_index, last_index);
 			/*
 			 * We need to return if we are
 			 * passed the end of the file. This will propagate
diff --git a/drivers/staging/lustre/lustre/llite/vvp_page.c b/drivers/staging/lustre/lustre/llite/vvp_page.c
index 6eb0565ddc22..27f58069a1a3 100644
--- a/drivers/staging/lustre/lustre/llite/vvp_page.c
+++ b/drivers/staging/lustre/lustre/llite/vvp_page.c
@@ -138,6 +138,9 @@ static void vvp_page_discard(const struct lu_env *env,
 			     const struct cl_page_slice *slice,
 			     struct cl_io *unused)
 {
+	struct cl_object *obj = slice->cpl_obj;
+	struct inode *inode = vvp_object_inode(obj);
+	struct address_space *mapping = inode->i_mapping;
 	struct page	   *vmpage  = cl2vm_page(slice);
 	struct vvp_page      *vpg     = cl2vvp_page(slice);
 
@@ -145,23 +148,24 @@ static void vvp_page_discard(const struct lu_env *env,
 	LASSERT(PageLocked(vmpage));
 
 	if (vpg->vpg_defer_uptodate && !vpg->vpg_ra_used)
-		ll_ra_stats_inc(vmpage->mapping->host, RA_STAT_DISCARDED);
+		ll_ra_stats_inc(mapping->host, RA_STAT_DISCARDED);
 
-	ll_invalidate_page(vmpage);
+	ll_invalidate_page(mapping, vmpage);
 }
 
 static void vvp_page_delete(const struct lu_env *env,
 			    const struct cl_page_slice *slice)
 {
 	struct page       *vmpage = cl2vm_page(slice);
-	struct inode     *inode  = vmpage->mapping->host;
 	struct cl_object *obj    = slice->cpl_obj;
+	struct inode *inode = vvp_object_inode(obj);
+	struct address_space *mapping = inode->i_mapping;
 	struct cl_page   *page   = slice->cpl_page;
 	int refc;
 
 	LASSERT(PageLocked(vmpage));
 	LASSERT((struct cl_page *)vmpage->private == page);
-	LASSERT(inode == vvp_object_inode(obj));
+	LASSERT(vmpage->mapping == mapping);
 
 	/* Drop the reference count held in vvp_page_init */
 	refc = atomic_dec_return(&page->cp_ref);
@@ -243,7 +247,8 @@ static void vvp_vmpage_error(struct inode *inode, struct page *vmpage,
 		if ((ioret == -ESHUTDOWN || ioret == -EINTR) &&
 		    obj->vob_discard_page_warned == 0) {
 			obj->vob_discard_page_warned = 1;
-			ll_dirty_page_discard_warn(vmpage, ioret);
+			ll_dirty_page_discard_warn(inode->i_mapping,
+						   vmpage, ioret);
 		}
 	}
 }
diff --git a/drivers/staging/lustre/lustre/mdc/mdc_request.c b/drivers/staging/lustre/lustre/mdc/mdc_request.c
index 4814ef083824..15060fa67025 100644
--- a/drivers/staging/lustre/lustre/mdc/mdc_request.c
+++ b/drivers/staging/lustre/lustre/mdc/mdc_request.c
@@ -914,12 +914,13 @@ restart_bulk:
 	return 0;
 }
 
-static void mdc_release_page(struct page *page, int remove)
+static void mdc_release_page(struct address_space *mapping, struct page *page,
+			     int remove)
 {
 	if (remove) {
 		lock_page(page);
-		if (likely(page->mapping))
-			truncate_complete_page(page->mapping, page);
+		if (likely(!!page->mapping))
+			truncate_complete_page(mapping, page);
 		unlock_page(page);
 	}
 	put_page(page);
@@ -973,7 +974,7 @@ static struct page *mdc_page_locate(struct address_space *mapping, __u64 *hash,
 			       offset, *start, *end, *hash);
 			if (*hash > *end) {
 				kunmap(page);
-				mdc_release_page(page, 0);
+				mdc_release_page(mapping, page, 0);
 				page = NULL;
 			} else if (*end != *start && *hash == *end) {
 				/*
@@ -983,7 +984,7 @@ static struct page *mdc_page_locate(struct address_space *mapping, __u64 *hash,
 				 * fetch the page we want.
 				 */
 				kunmap(page);
-				mdc_release_page(page,
+				mdc_release_page(mapping, page,
 						 le32_to_cpu(dp->ldp_flags) & LDF_COLLIDE);
 				page = NULL;
 			}
@@ -1357,7 +1358,7 @@ out_unlock:
 	return rc;
 fail:
 	kunmap(page);
-	mdc_release_page(page, 1);
+	mdc_release_page(mapping, page, 1);
 	rc = -EIO;
 	goto out_unlock;
 }