more pgio cleanup

nfs_page_find_head_request_locked looks through the regular nfs commit lists when the page is swapped out, but doesn't look through the pnfs commit lists.

I'm not sure if anyone has hit any issues caused by this.

Suggested-by Peng Tao <[email protected]>

Signed-off-by Weston Andros Adamson <[email protected]>

Signed-off-by Trond Myklebust <[email protected]>

---
 fs/nfs/filelayout/filelayout.c | 31 ++++++++++++++++++++++++++
 fs/nfs/pnfs.h                  | 20 +++++++++++++++++
 fs/nfs/write.c                 | 49 +++++++++++++++++++++++++++++++-----------
 3 files changed, 88 insertions(+), 12 deletions(-)

fs/nfs/filelayout/filelayout.c +31 -0

index 2576d28b..524e66f 100644
@@ -1237,6 +1237,36 @@ restart:
 	spin_unlock(cinfo->lock);
 }
 
+/* filelayout_search_commit_reqs - Search lists in @cinfo for the head reqest
+ *				   for @page
+ * @cinfo - commit info for current inode
+ * @page - page to search for matching head request
+ *
+ * Returns a the head request if one is found, otherwise returns NULL.
+ */
+static struct nfs_page *
+filelayout_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
+{
+	struct nfs_page *freq, *t;
+	struct pnfs_commit_bucket *b;
+	int i;
+
+	/* Linearly search the commit lists for each bucket until a matching
+	 * request is found */
+	for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
+		list_for_each_entry_safe(freq, t, &b->written, wb_list) {
+			if (freq->wb_page == page)
+				return freq->wb_head;
+		}
+		list_for_each_entry_safe(freq, t, &b->committing, wb_list) {
+			if (freq->wb_page == page)
+				return freq->wb_head;
+		}
+	}
+
+	return NULL;
+}
+
 static void filelayout_retry_commit(struct nfs_commit_info *cinfo, int idx)
 {
 	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;

@@ -1386,6 +1416,7 @@ static struct pnfs_layoutdriver_type filelayout_type = {
 	.clear_request_commit	= filelayout_clear_request_commit,
 	.scan_commit_lists	= filelayout_scan_commit_lists,
 	.recover_commit_reqs	= filelayout_recover_commit_reqs,
+	.search_commit_reqs	= filelayout_search_commit_reqs,
 	.commit_pagelist	= filelayout_commit_pagelist,
 	.read_pagelist		= filelayout_read_pagelist,
 	.write_pagelist		= filelayout_write_pagelist,

fs/nfs/pnfs.h +20 -0

index 27ddecd..203b6c9 100644
@@ -104,6 +104,8 @@ struct pnfs_layoutdriver_type {
 				  int max);
 	void (*recover_commit_reqs) (struct list_head *list,
 				     struct nfs_commit_info *cinfo);
+	struct nfs_page * (*search_commit_reqs)(struct nfs_commit_info *cinfo,
+						struct page *page);
 	int (*commit_pagelist)(struct inode *inode,
 			       struct list_head *mds_pages,
 			       int how,

@@ -341,6 +343,17 @@ pnfs_recover_commit_reqs(struct inode *inode, struct list_head *list,
 	NFS_SERVER(inode)->pnfs_curr_ld->recover_commit_reqs(list, cinfo);
 }
 
+static inline struct nfs_page *
+pnfs_search_commit_reqs(struct inode *inode, struct nfs_commit_info *cinfo,
+			struct page *page)
+{
+	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
+
+	if (ld == NULL || ld->search_commit_reqs == NULL)
+		return NULL;
+	return ld->search_commit_reqs(cinfo, page);
+}
+
 /* Should the pNFS client commit and return the layout upon a setattr */
 static inline bool
 pnfs_ld_layoutret_on_setattr(struct inode *inode)

@@ -492,6 +505,13 @@ pnfs_recover_commit_reqs(struct inode *inode, struct list_head *list,
 {
 }
 
+static inline struct nfs_page *
+pnfs_search_commit_reqs(struct inode *inode, struct nfs_commit_info *cinfo,
+			struct page *page)
+{
+	return NULL;
+}
+
 static inline int pnfs_layoutcommit_inode(struct inode *inode, bool sync)
 {
 	return 0;

fs/nfs/write.c +8 -0

index e6bc5b5..ba41769 100644
@@ -47,6 +47,8 @@ static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops;
 static const struct nfs_commit_completion_ops nfs_commit_completion_ops;
 static const struct nfs_rw_ops nfs_rw_write_ops;
 static void nfs_clear_request_commit(struct nfs_page *req);
+static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
+				      struct inode *inode);
 
 static struct kmem_cache *nfs_wdata_cachep;
 static mempool_t *nfs_wdata_mempool;

@@ -93,6 +95,38 @@ static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)
 }
 
 /*
+ * nfs_page_search_commits_for_head_request_locked
+ *
+ * Search through commit lists on @inode for the head request for @page.
+ * Must be called while holding the inode (which is cinfo) lock.
+ *
+ * Returns the head request if found, or NULL if not found.

fs/nfs/write.c +19 -12

+
+	/* search through pnfs commit lists */
+	freq = pnfs_search_commit_reqs(inode, &cinfo, page);
+	if (freq)
+		return freq->wb_head;
+
+	/* Linearly search the commit list for the correct request */
+	list_for_each_entry_safe(freq, t, &cinfo.mds->list, wb_list) {
+		if (freq->wb_page == page)
+			return freq->wb_head;
+	}
+
+	return NULL;
+}
+
+/*
  * nfs_page_find_head_request_locked - find head request associated with @page
  *
  * must be called while holding the inode lock.

@@ -106,21 +140,12 @@ nfs_page_find_head_request_locked(struct nfs_inode *nfsi, struct page *page)
 
 	if (PagePrivate(page))
 		req = (struct nfs_page *)page_private(page);
-	else if (unlikely(PageSwapCache(page))) {
-		struct nfs_page *freq, *t;
-
-		/* Linearly search the commit list for the correct req */
-		list_for_each_entry_safe(freq, t, &nfsi->commit_info.list, wb_list) {
-			if (freq->wb_page == page) {
-				req = freq->wb_head;
-				break;
-			}
-		}
-	}
+	else if (unlikely(PageSwapCache(page)))
+		req = nfs_page_search_commits_for_head_request_locked(nfsi,
+			page);
 
 	if (req) {
 		WARN_ON_ONCE(req->wb_head != req);
-
 		kref_get(&req->wb_kref);
 	}
 

Quoted 131 lines · Weston Andros Adamson

nfs_page_find_head_request_locked looks through the regular nfs commit lists when the page is swapped out, but doesn't look through the pnfs commit lists.

I'm not sure if anyone has hit any issues caused by this.

Suggested-by Peng Tao <[email protected]>

Signed-off-by Weston Andros Adamson <[email protected]>

Signed-off-by Trond Myklebust <[email protected]>

---

fs/nfs/filelayout/filelayout.c | 31 ++++++++++++++++++++++++++
fs/nfs/pnfs.h                  | 20 +++++++++++++++++
fs/nfs/write.c                 | 49 +++++++++++++++++++++++++++++++-----------
3 files changed, 88 insertions(+), 12 deletions(-)

fs/nfs/filelayout/filelayout.c +31 -0

index 2576d28b..524e66f 100644
@@ -1237,6 +1237,36 @@ restart:
 	spin_unlock(cinfo->lock);
 }
 
+/* filelayout_search_commit_reqs - Search lists in @cinfo for the head reqest
+ *				   for @page
+ * @cinfo - commit info for current inode
+ * @page - page to search for matching head request
+ *
+ * Returns a the head request if one is found, otherwise returns NULL.
+ */
+static struct nfs_page *
+filelayout_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
+{
+	struct nfs_page *freq, *t;
+	struct pnfs_commit_bucket *b;
+	int i;
+
+	/* Linearly search the commit lists for each bucket until a matching
+	 * request is found */
+	for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
+		list_for_each_entry_safe(freq, t, &b->written, wb_list) {
+			if (freq->wb_page == page)
+				return freq->wb_head;
+		}
+		list_for_each_entry_safe(freq, t, &b->committing, wb_list) {
+			if (freq->wb_page == page)
+				return freq->wb_head;
+		}
+	}
+
+	return NULL;
+}
+
 static void filelayout_retry_commit(struct nfs_commit_info *cinfo, int idx)
 {
 	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;

@@ -1386,6 +1416,7 @@ static struct pnfs_layoutdriver_type filelayout_type = {
 	.clear_request_commit	= filelayout_clear_request_commit,
 	.scan_commit_lists	= filelayout_scan_commit_lists,
 	.recover_commit_reqs	= filelayout_recover_commit_reqs,
+	.search_commit_reqs	= filelayout_search_commit_reqs,
 	.commit_pagelist	= filelayout_commit_pagelist,
 	.read_pagelist		= filelayout_read_pagelist,
 	.write_pagelist		= filelayout_write_pagelist,

fs/nfs/pnfs.h +13 -0

index 27ddecd..203b6c9 100644
@@ -104,6 +104,8 @@ struct pnfs_layoutdriver_type {
 				  int max);
 	void (*recover_commit_reqs) (struct list_head *list,
 				     struct nfs_commit_info *cinfo);
+	struct nfs_page * (*search_commit_reqs)(struct nfs_commit_info *cinfo,
+						struct page *page);
 	int (*commit_pagelist)(struct inode *inode,
 			       struct list_head *mds_pages,
 			       int how,

@@ -341,6 +343,17 @@ pnfs_recover_commit_reqs(struct inode *inode, struct list_head *list,
 	NFS_SERVER(inode)->pnfs_curr_ld->recover_commit_reqs(list, cinfo);
 }
 
+static inline struct nfs_page *
+pnfs_search_commit_reqs(struct inode *inode, struct nfs_commit_info *cinfo,
+			struct page *page)
+{
+	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
+
+	if (ld == NULL || ld->search_commit_reqs == NULL)
+		return NULL;
+	return ld->search_commit_reqs(cinfo, page);
+}
+
 /* Should the pNFS client commit and return the layout upon a setattr */

static inline bool
pnfs_ld_layoutret_on_setattr(struct inode *inode)

fs/nfs/pnfs.h +7 -0

@@ -492,6 +505,13 @@ pnfs_recover_commit_reqs(struct inode *inode, struct list_head *list,
 {
 }
 
+static inline struct nfs_page *
+pnfs_search_commit_reqs(struct inode *inode, struct nfs_commit_info *cinfo,
+			struct page *page)
+{
+	return NULL;
+}
+
 static inline int pnfs_layoutcommit_inode(struct inode *inode, bool sync)
 {
 	return 0;

fs/nfs/write.c +8 -0

index e6bc5b5..ba41769 100644
@@ -47,6 +47,8 @@ static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops;
 static const struct nfs_commit_completion_ops nfs_commit_completion_ops;
 static const struct nfs_rw_ops nfs_rw_write_ops;
 static void nfs_clear_request_commit(struct nfs_page *req);
+static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
+				      struct inode *inode);
 
 static struct kmem_cache *nfs_wdata_cachep;
 static mempool_t *nfs_wdata_mempool;

@@ -93,6 +95,38 @@ static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)
 }
 
 /*
+ * nfs_page_search_commits_for_head_request_locked
+ *
+ * Search through commit lists on @inode for the head request for @page.
+ * Must be called while holding the inode (which is cinfo) lock.
+ *
+ * Returns the head request if found, or NULL if not found.

fs/nfs/write.c static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error) · line 113

Quoted 10 lines

fs/nfs/write.c +10 -0

+ */
+static struct nfs_page *
+nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
+						struct page *page)
+{
+	struct nfs_page *freq, *t;
+	struct nfs_commit_info cinfo;
+	struct inode *inode = &nfsi->vfs_inode;
+
+	nfs_init_cinfo_from_inode(&cinfo, inode);

This has a compiler warning when CONFIG_NFS_V4=n, CONFIG_NFS_V3=n, CONFIG_NFS_V2=y:

fs/nfs/write.c: In function ‘nfs_page_find_head_request_locked.isra.16’:
include/linux/kernel.h:834:39: error: ‘cinfo.mds’ may be used uninitialized in this function [-Werror=maybe-uninitialized]

 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
                                      ^

fs/nfs/write.c:110:25: note: ‘cinfo.mds’ was declared here
struct nfs_commit_info cinfo;

Probably because nfs_init_cinfo_from_inode() is empty without v3 or v4.

Anna

Quoted 43 lines

fs/nfs/write.c +19 -12

+
+	/* search through pnfs commit lists */
+	freq = pnfs_search_commit_reqs(inode, &cinfo, page);
+	if (freq)
+		return freq->wb_head;
+
+	/* Linearly search the commit list for the correct request */
+	list_for_each_entry_safe(freq, t, &cinfo.mds->list, wb_list) {
+		if (freq->wb_page == page)
+			return freq->wb_head;
+	}
+
+	return NULL;
+}
+
+/*
 * nfs_page_find_head_request_locked - find head request associated with @page
 *
 * must be called while holding the inode lock.

@@ -106,21 +140,12 @@ nfs_page_find_head_request_locked(struct nfs_inode *nfsi, struct page *page)
 
 	if (PagePrivate(page))
 		req = (struct nfs_page *)page_private(page);
-	else if (unlikely(PageSwapCache(page))) {
-		struct nfs_page *freq, *t;
-
-		/* Linearly search the commit list for the correct req */
-		list_for_each_entry_safe(freq, t, &nfsi->commit_info.list, wb_list) {
-			if (freq->wb_page == page) {
-				req = freq->wb_head;
-				break;
-			}
-		}
-	}
+	else if (unlikely(PageSwapCache(page)))
+		req = nfs_page_search_commits_for_head_request_locked(nfsi,
+			page);
 
 	if (req) {
 		WARN_ON_ONCE(req->wb_head != req);
-
 		kref_get(&req->wb_kref);
 	}

Thanks Anna, I’ll fix it up.

-dros

Quoted 197 lines · Anna Schumaker

Quoted 131 lines · Weston Andros Adamson

nfs_page_find_head_request_locked looks through the regular nfs commit lists when the page is swapped out, but doesn't look through the pnfs commit lists.

I'm not sure if anyone has hit any issues caused by this.

Suggested-by Peng Tao <[email protected]>

Signed-off-by Weston Andros Adamson <[email protected]>

Signed-off-by Trond Myklebust <[email protected]>

---

fs/nfs/filelayout/filelayout.c | 31 ++++++++++++++++++++++++++
fs/nfs/pnfs.h                  | 20 +++++++++++++++++
fs/nfs/write.c                 | 49 +++++++++++++++++++++++++++++++-----------
3 files changed, 88 insertions(+), 12 deletions(-)

fs/nfs/filelayout/filelayout.c +31 -0

index 2576d28b..524e66f 100644
@@ -1237,6 +1237,36 @@ restart:
 	spin_unlock(cinfo->lock);
 }
 
+/* filelayout_search_commit_reqs - Search lists in @cinfo for the head reqest
+ *				   for @page
+ * @cinfo - commit info for current inode
+ * @page - page to search for matching head request
+ *
+ * Returns a the head request if one is found, otherwise returns NULL.
+ */
+static struct nfs_page *
+filelayout_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
+{
+	struct nfs_page *freq, *t;
+	struct pnfs_commit_bucket *b;
+	int i;
+
+	/* Linearly search the commit lists for each bucket until a matching
+	 * request is found */
+	for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
+		list_for_each_entry_safe(freq, t, &b->written, wb_list) {
+			if (freq->wb_page == page)
+				return freq->wb_head;
+		}
+		list_for_each_entry_safe(freq, t, &b->committing, wb_list) {
+			if (freq->wb_page == page)
+				return freq->wb_head;
+		}
+	}
+
+	return NULL;
+}
+
 static void filelayout_retry_commit(struct nfs_commit_info *cinfo, int idx)
 {
 	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;

@@ -1386,6 +1416,7 @@ static struct pnfs_layoutdriver_type filelayout_type = {
 	.clear_request_commit	= filelayout_clear_request_commit,
 	.scan_commit_lists	= filelayout_scan_commit_lists,
 	.recover_commit_reqs	= filelayout_recover_commit_reqs,
+	.search_commit_reqs	= filelayout_search_commit_reqs,
 	.commit_pagelist	= filelayout_commit_pagelist,
 	.read_pagelist		= filelayout_read_pagelist,
 	.write_pagelist		= filelayout_write_pagelist,

fs/nfs/pnfs.h +13 -0

index 27ddecd..203b6c9 100644
@@ -104,6 +104,8 @@ struct pnfs_layoutdriver_type {
 				  int max);
 	void (*recover_commit_reqs) (struct list_head *list,
 				     struct nfs_commit_info *cinfo);
+	struct nfs_page * (*search_commit_reqs)(struct nfs_commit_info *cinfo,
+						struct page *page);
 	int (*commit_pagelist)(struct inode *inode,
 			       struct list_head *mds_pages,
 			       int how,

@@ -341,6 +343,17 @@ pnfs_recover_commit_reqs(struct inode *inode, struct list_head *list,
 	NFS_SERVER(inode)->pnfs_curr_ld->recover_commit_reqs(list, cinfo);
 }
 
+static inline struct nfs_page *
+pnfs_search_commit_reqs(struct inode *inode, struct nfs_commit_info *cinfo,
+			struct page *page)
+{
+	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
+
+	if (ld == NULL || ld->search_commit_reqs == NULL)
+		return NULL;
+	return ld->search_commit_reqs(cinfo, page);
+}
+
 /* Should the pNFS client commit and return the layout upon a setattr */

static inline bool
pnfs_ld_layoutret_on_setattr(struct inode *inode)

fs/nfs/pnfs.h +7 -0

@@ -492,6 +505,13 @@ pnfs_recover_commit_reqs(struct inode *inode, struct list_head *list,
 {
 }
 
+static inline struct nfs_page *
+pnfs_search_commit_reqs(struct inode *inode, struct nfs_commit_info *cinfo,
+			struct page *page)
+{
+	return NULL;
+}
+
 static inline int pnfs_layoutcommit_inode(struct inode *inode, bool sync)
 {
 	return 0;

fs/nfs/write.c +8 -0

index e6bc5b5..ba41769 100644
@@ -47,6 +47,8 @@ static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops;
 static const struct nfs_commit_completion_ops nfs_commit_completion_ops;
 static const struct nfs_rw_ops nfs_rw_write_ops;
 static void nfs_clear_request_commit(struct nfs_page *req);
+static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
+				      struct inode *inode);
 
 static struct kmem_cache *nfs_wdata_cachep;
 static mempool_t *nfs_wdata_mempool;

@@ -93,6 +95,38 @@ static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)
 }
 
 /*
+ * nfs_page_search_commits_for_head_request_locked
+ *
+ * Search through commit lists on @inode for the head request for @page.
+ * Must be called while holding the inode (which is cinfo) lock.
+ *
+ * Returns the head request if found, or NULL if not found.

fs/nfs/write.c static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error) · line 113

Quoted 10 lines

fs/nfs/write.c +10 -0

+ */
+static struct nfs_page *
+nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
+						struct page *page)
+{
+	struct nfs_page *freq, *t;
+	struct nfs_commit_info cinfo;
+	struct inode *inode = &nfsi->vfs_inode;
+
+	nfs_init_cinfo_from_inode(&cinfo, inode);

This has a compiler warning when CONFIG_NFS_V4=n, CONFIG_NFS_V3=n, CONFIG_NFS_V2=y:

fs/nfs/write.c: In function ‘nfs_page_find_head_request_locked.isra.16’:
include/linux/kernel.h:834:39: error: ‘cinfo.mds’ may be used uninitialized in this function [-Werror=maybe-uninitialized]

const typeof( ((type *)0)->member ) *__mptr = (ptr); \
                                     ^

fs/nfs/write.c:110:25: note: ‘cinfo.mds’ was declared here struct nfs_commit_info cinfo;

Probably because nfs_init_cinfo_from_inode() is empty without v3 or v4.

Anna

Quoted 43 lines

fs/nfs/write.c +19 -12

+
+	/* search through pnfs commit lists */
+	freq = pnfs_search_commit_reqs(inode, &cinfo, page);
+	if (freq)
+		return freq->wb_head;
+
+	/* Linearly search the commit list for the correct request */
+	list_for_each_entry_safe(freq, t, &cinfo.mds->list, wb_list) {
+		if (freq->wb_page == page)
+			return freq->wb_head;
+	}
+
+	return NULL;
+}
+
+/*
 * nfs_page_find_head_request_locked - find head request associated with @page
 *
 * must be called while holding the inode lock.

@@ -106,21 +140,12 @@ nfs_page_find_head_request_locked(struct nfs_inode *nfsi, struct page *page)
 
 	if (PagePrivate(page))
 		req = (struct nfs_page *)page_private(page);
-	else if (unlikely(PageSwapCache(page))) {
-		struct nfs_page *freq, *t;
-
-		/* Linearly search the commit list for the correct req */
-		list_for_each_entry_safe(freq, t, &nfsi->commit_info.list, wb_list) {
-			if (freq->wb_page == page) {
-				req = freq->wb_head;
-				break;
-			}
-		}
-	}
+	else if (unlikely(PageSwapCache(page)))
+		req = nfs_page_search_commits_for_head_request_locked(nfsi,
+			page);
 
 	if (req) {
 		WARN_ON_ONCE(req->wb_head != req);
-
 		kref_get(&req->wb_kref);
 	}

For some reason I can�t reproduce this with:

CONFIG_NFS_FS=m
CONFIG_NFS_V2=m
# CONFIG_NFS_V3 is not set
# CONFIG_NFS_V4 is not set

Are you compiling with some special option? It�s not in the output of make W=1, W=3 or W=3.

It looks like there are several places that call nfs_init_cinfo_from_inode without any ifdef logic�

We could just fix all of them and be done with it, but I�m wondering why you get the warning and I don�t.

-dros

Quoted 205 lines · Weston Andros Adamson

Thanks Anna, I�ll fix it up.

-dros

Quoted 197 lines · Anna Schumaker

Quoted 131 lines · Weston Andros Adamson

nfs_page_find_head_request_locked looks through the regular nfs commit lists when the page is swapped out, but doesn't look through the pnfs commit lists.

I'm not sure if anyone has hit any issues caused by this.

Suggested-by Peng Tao <[email protected]>

Signed-off-by Weston Andros Adamson <[email protected]>

Signed-off-by Trond Myklebust <[email protected]>

---

fs/nfs/filelayout/filelayout.c | 31 ++++++++++++++++++++++++++
fs/nfs/pnfs.h                  | 20 +++++++++++++++++
fs/nfs/write.c                 | 49 +++++++++++++++++++++++++++++++-----------
3 files changed, 88 insertions(+), 12 deletions(-)

fs/nfs/filelayout/filelayout.c +31 -0

index 2576d28b..524e66f 100644
@@ -1237,6 +1237,36 @@ restart:
 	spin_unlock(cinfo->lock);
 }
 
+/* filelayout_search_commit_reqs - Search lists in @cinfo for the head reqest
+ *				   for @page
+ * @cinfo - commit info for current inode
+ * @page - page to search for matching head request
+ *
+ * Returns a the head request if one is found, otherwise returns NULL.
+ */
+static struct nfs_page *
+filelayout_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
+{
+	struct nfs_page *freq, *t;
+	struct pnfs_commit_bucket *b;
+	int i;
+
+	/* Linearly search the commit lists for each bucket until a matching
+	 * request is found */
+	for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
+		list_for_each_entry_safe(freq, t, &b->written, wb_list) {
+			if (freq->wb_page == page)
+				return freq->wb_head;
+		}
+		list_for_each_entry_safe(freq, t, &b->committing, wb_list) {
+			if (freq->wb_page == page)
+				return freq->wb_head;
+		}
+	}
+
+	return NULL;
+}
+
 static void filelayout_retry_commit(struct nfs_commit_info *cinfo, int idx)
 {
 	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;

@@ -1386,6 +1416,7 @@ static struct pnfs_layoutdriver_type filelayout_type = {
 	.clear_request_commit	= filelayout_clear_request_commit,
 	.scan_commit_lists	= filelayout_scan_commit_lists,
 	.recover_commit_reqs	= filelayout_recover_commit_reqs,
+	.search_commit_reqs	= filelayout_search_commit_reqs,
 	.commit_pagelist	= filelayout_commit_pagelist,
 	.read_pagelist		= filelayout_read_pagelist,
 	.write_pagelist		= filelayout_write_pagelist,

fs/nfs/pnfs.h +13 -0

index 27ddecd..203b6c9 100644
@@ -104,6 +104,8 @@ struct pnfs_layoutdriver_type {
 				  int max);
 	void (*recover_commit_reqs) (struct list_head *list,
 				     struct nfs_commit_info *cinfo);
+	struct nfs_page * (*search_commit_reqs)(struct nfs_commit_info *cinfo,
+						struct page *page);
 	int (*commit_pagelist)(struct inode *inode,
 			       struct list_head *mds_pages,
 			       int how,

@@ -341,6 +343,17 @@ pnfs_recover_commit_reqs(struct inode *inode, struct list_head *list,
 	NFS_SERVER(inode)->pnfs_curr_ld->recover_commit_reqs(list, cinfo);
 }
 
+static inline struct nfs_page *
+pnfs_search_commit_reqs(struct inode *inode, struct nfs_commit_info *cinfo,
+			struct page *page)
+{
+	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
+
+	if (ld == NULL || ld->search_commit_reqs == NULL)
+		return NULL;
+	return ld->search_commit_reqs(cinfo, page);
+}
+
 /* Should the pNFS client commit and return the layout upon a setattr */

static inline bool
pnfs_ld_layoutret_on_setattr(struct inode *inode)

fs/nfs/pnfs.h +7 -0

@@ -492,6 +505,13 @@ pnfs_recover_commit_reqs(struct inode *inode, struct list_head *list,
 {
 }
 
+static inline struct nfs_page *
+pnfs_search_commit_reqs(struct inode *inode, struct nfs_commit_info *cinfo,
+			struct page *page)
+{
+	return NULL;
+}
+
 static inline int pnfs_layoutcommit_inode(struct inode *inode, bool sync)
 {
 	return 0;

fs/nfs/write.c +8 -0

index e6bc5b5..ba41769 100644
@@ -47,6 +47,8 @@ static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops;
 static const struct nfs_commit_completion_ops nfs_commit_completion_ops;
 static const struct nfs_rw_ops nfs_rw_write_ops;
 static void nfs_clear_request_commit(struct nfs_page *req);
+static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo,
+				      struct inode *inode);
 
 static struct kmem_cache *nfs_wdata_cachep;
 static mempool_t *nfs_wdata_mempool;

@@ -93,6 +95,38 @@ static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error)
 }
 
 /*
+ * nfs_page_search_commits_for_head_request_locked
+ *
+ * Search through commit lists on @inode for the head request for @page.
+ * Must be called while holding the inode (which is cinfo) lock.
+ *
+ * Returns the head request if found, or NULL if not found.

fs/nfs/write.c static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error) · line 113

Quoted 10 lines

fs/nfs/write.c +10 -0

+ */
+static struct nfs_page *
+nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi,
+						struct page *page)
+{
+	struct nfs_page *freq, *t;
+	struct nfs_commit_info cinfo;
+	struct inode *inode = &nfsi->vfs_inode;
+
+	nfs_init_cinfo_from_inode(&cinfo, inode);

This has a compiler warning when CONFIG_NFS_V4=n, CONFIG_NFS_V3=n, CONFIG_NFS_V2=y:

fs/nfs/write.c: In function �nfs_page_find_head_request_locked.isra.16�:
include/linux/kernel.h:834:39: error: �cinfo.mds� may be used uninitialized in this function [-Werror=maybe-uninitialized]

const typeof( ((type *)0)->member ) *__mptr = (ptr); \
                                     ^

fs/nfs/write.c:110:25: note: �cinfo.mds� was declared here struct nfs_commit_info cinfo;

Probably because nfs_init_cinfo_from_inode() is empty without v3 or v4.

Anna

Quoted 43 lines

fs/nfs/write.c +19 -12

+
+	/* search through pnfs commit lists */
+	freq = pnfs_search_commit_reqs(inode, &cinfo, page);
+	if (freq)
+		return freq->wb_head;
+
+	/* Linearly search the commit list for the correct request */
+	list_for_each_entry_safe(freq, t, &cinfo.mds->list, wb_list) {
+		if (freq->wb_page == page)
+			return freq->wb_head;
+	}
+
+	return NULL;
+}
+
+/*
 * nfs_page_find_head_request_locked - find head request associated with @page
 *
 * must be called while holding the inode lock.

@@ -106,21 +140,12 @@ nfs_page_find_head_request_locked(struct nfs_inode *nfsi, struct page *page)
 
 	if (PagePrivate(page))
 		req = (struct nfs_page *)page_private(page);
-	else if (unlikely(PageSwapCache(page))) {
-		struct nfs_page *freq, *t;
-
-		/* Linearly search the commit list for the correct req */
-		list_for_each_entry_safe(freq, t, &nfsi->commit_info.list, wb_list) {
-			if (freq->wb_page == page) {
-				req = freq->wb_head;
-				break;
-			}
-		}
-	}
+	else if (unlikely(PageSwapCache(page)))
+		req = nfs_page_search_commits_for_head_request_locked(nfsi,
+			page);
 
 	if (req) {
 		WARN_ON_ONCE(req->wb_head != req);
-
 		kref_get(&req->wb_kref);
 	}