From ea0f04e59543bafb3d2cbe37a0d375acb0bb2c34 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Fri, 4 Jun 2010 11:29:54 +0200
Subject: get rid of nobh_write_begin_newtrunc

Move the call to vmtruncate to get rid of accessive blocks to the only
remaining caller and rename the non-truncating version to nobh_write_begin.

Get rid of the superflous file argument to it while we're at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/buffer.c | 37 ++++---------------------------------
 1 file changed, 4 insertions(+), 33 deletions(-)

(limited to 'fs/buffer.c')

diff --git a/fs/buffer.c b/fs/buffer.c
index d54812b198e..559daf76bca 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2510,11 +2510,11 @@ static void attach_nobh_buffers(struct page *page, struct buffer_head *head)
 }
 
 /*
- * Filesystems implementing the new truncate sequence should use the
- * _newtrunc postfix variant which won't incorrectly call vmtruncate.
+ * On entry, the page is fully not uptodate.
+ * On exit the page is fully uptodate in the areas outside (from,to)
  * The filesystem needs to handle block truncation upon failure.
  */
-int nobh_write_begin_newtrunc(struct file *file, struct address_space *mapping,
+int nobh_write_begin(struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata,
 			get_block_t *get_block)
@@ -2547,7 +2547,7 @@ int nobh_write_begin_newtrunc(struct file *file, struct address_space *mapping,
 		unlock_page(page);
 		page_cache_release(page);
 		*pagep = NULL;
-		return block_write_begin_newtrunc(file, mapping, pos, len,
+		return block_write_begin_newtrunc(NULL, mapping, pos, len,
 					flags, pagep, fsdata, get_block);
 	}
 
@@ -2654,35 +2654,6 @@ out_release:
 
 	return ret;
 }
-EXPORT_SYMBOL(nobh_write_begin_newtrunc);
-
-/*
- * On entry, the page is fully not uptodate.
- * On exit the page is fully uptodate in the areas outside (from,to)
- */
-int nobh_write_begin(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned flags,
-			struct page **pagep, void **fsdata,
-			get_block_t *get_block)
-{
-	int ret;
-
-	ret = nobh_write_begin_newtrunc(file, mapping, pos, len, flags,
-					pagep, fsdata, get_block);
-
-	/*
-	 * prepare_write() may have instantiated a few blocks
-	 * outside i_size.  Trim these off again. Don't need
-	 * i_size_read because we hold i_mutex.
-	 */
-	if (unlikely(ret)) {
-		loff_t isize = mapping->host->i_size;
-		if (pos + len > isize)
-			vmtruncate(mapping->host, isize);
-	}
-
-	return ret;
-}
 EXPORT_SYMBOL(nobh_write_begin);
 
 int nobh_write_end(struct file *file, struct address_space *mapping,
-- 
cgit v1.2.3-70-g09d2


From 282dc178849882289d30e58b54be6b2799b351aa Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Fri, 4 Jun 2010 11:29:55 +0200
Subject: get rid of cont_write_begin_newtrunc

Move the call to vmtruncate to get rid of accessive blocks to the callers
in preparation of the new truncate sequence and rename the non-truncating
version to cont_write_begin.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/adfs/inode.c             | 11 ++++++++++-
 fs/affs/file.c              | 11 ++++++++++-
 fs/buffer.c                 | 21 +--------------------
 fs/fat/inode.c              |  2 +-
 fs/hfs/inode.c              | 11 ++++++++++-
 fs/hfsplus/inode.c          | 11 ++++++++++-
 fs/hpfs/file.c              | 11 ++++++++++-
 fs/qnx4/inode.c             | 11 ++++++++++-
 include/linux/buffer_head.h |  3 ---
 9 files changed, 62 insertions(+), 30 deletions(-)

(limited to 'fs/buffer.c')

diff --git a/fs/adfs/inode.c b/fs/adfs/inode.c
index 6f850b06ab6..b3dec193036 100644
--- a/fs/adfs/inode.c
+++ b/fs/adfs/inode.c
@@ -50,10 +50,19 @@ static int adfs_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
+	int ret;
+
 	*pagep = NULL;
-	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 				adfs_get_block,
 				&ADFS_I(mapping->host)->mmu_private);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t _adfs_bmap(struct address_space *mapping, sector_t block)
diff --git a/fs/affs/file.c b/fs/affs/file.c
index 322710c3eed..c4a9875bd1a 100644
--- a/fs/affs/file.c
+++ b/fs/affs/file.c
@@ -406,10 +406,19 @@ static int affs_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
+	int ret;
+
 	*pagep = NULL;
-	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 				affs_get_block,
 				&AFFS_I(mapping->host)->mmu_private);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
diff --git a/fs/buffer.c b/fs/buffer.c
index 559daf76bca..14529ec759b 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2351,7 +2351,7 @@ out:
  * For moronic filesystems that do not allow holes in file.
  * We may have to extend the file.
  */
-int cont_write_begin_newtrunc(struct file *file, struct address_space *mapping,
+int cont_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata,
 			get_block_t *get_block, loff_t *bytes)
@@ -2377,25 +2377,6 @@ int cont_write_begin_newtrunc(struct file *file, struct address_space *mapping,
 out:
 	return err;
 }
-EXPORT_SYMBOL(cont_write_begin_newtrunc);
-
-int cont_write_begin(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned flags,
-			struct page **pagep, void **fsdata,
-			get_block_t *get_block, loff_t *bytes)
-{
-	int ret;
-
-	ret = cont_write_begin_newtrunc(file, mapping, pos, len, flags,
-					pagep, fsdata, get_block, bytes);
-	if (unlikely(ret)) {
-		loff_t isize = mapping->host->i_size;
-		if (pos + len > isize)
-			vmtruncate(mapping->host, isize);
-	}
-
-	return ret;
-}
 EXPORT_SYMBOL(cont_write_begin);
 
 int block_prepare_write(struct page *page, unsigned from, unsigned to,
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index ffe7c6fdc1e..ec6a699a402 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -159,7 +159,7 @@ static int fat_write_begin(struct file *file, struct address_space *mapping,
 	int err;
 
 	*pagep = NULL;
-	err = cont_write_begin_newtrunc(file, mapping, pos, len, flags,
+	err = cont_write_begin(file, mapping, pos, len, flags,
 				pagep, fsdata, fat_get_block,
 				&MSDOS_I(mapping->host)->mmu_private);
 	if (err < 0)
diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
index 07b2464b571..8df18e63eb6 100644
--- a/fs/hfs/inode.c
+++ b/fs/hfs/inode.c
@@ -39,10 +39,19 @@ static int hfs_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
+	int ret;
+
 	*pagep = NULL;
-	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 				hfs_get_block,
 				&HFS_I(mapping->host)->phys_size);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t hfs_bmap(struct address_space *mapping, sector_t block)
diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index 48602177391..88bf1b56264 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -31,10 +31,19 @@ static int hfsplus_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
+	int ret;
+
 	*pagep = NULL;
-	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 				hfsplus_get_block,
 				&HFSPLUS_I(mapping->host).phys_size);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t hfsplus_bmap(struct address_space *mapping, sector_t block)
diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
index a9ae9bfa752..c0340887c7e 100644
--- a/fs/hpfs/file.c
+++ b/fs/hpfs/file.c
@@ -97,10 +97,19 @@ static int hpfs_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
+	int ret;
+
 	*pagep = NULL;
-	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 				hpfs_get_block,
 				&hpfs_i(mapping->host)->mmu_private);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t _hpfs_bmap(struct address_space *mapping, sector_t block)
diff --git a/fs/qnx4/inode.c b/fs/qnx4/inode.c
index 277575ddc05..16829722be9 100644
--- a/fs/qnx4/inode.c
+++ b/fs/qnx4/inode.c
@@ -320,10 +320,19 @@ static int qnx4_write_begin(struct file *file, struct address_space *mapping,
 			struct page **pagep, void **fsdata)
 {
 	struct qnx4_inode_info *qnx4_inode = qnx4_i(mapping->host);
+	int ret;
+
 	*pagep = NULL;
-	return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+	ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
 				qnx4_get_block,
 				&qnx4_inode->mmu_private);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 static sector_t qnx4_bmap(struct address_space *mapping, sector_t block)
 {
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index cfda5f0b2a4..7638647f042 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -217,9 +217,6 @@ int generic_write_end(struct file *, struct address_space *,
 				struct page *, void *);
 void page_zero_new_buffers(struct page *page, unsigned from, unsigned to);
 int block_prepare_write(struct page*, unsigned, unsigned, get_block_t*);
-int cont_write_begin_newtrunc(struct file *, struct address_space *, loff_t,
-			unsigned, unsigned, struct page **, void **,
-			get_block_t *, loff_t *);
 int cont_write_begin(struct file *, struct address_space *, loff_t,
 			unsigned, unsigned, struct page **, void **,
 			get_block_t *, loff_t *);
-- 
cgit v1.2.3-70-g09d2


From 6e1db88d536adcbbfe562b2d4b7d6425784fff12 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Fri, 4 Jun 2010 11:29:57 +0200
Subject: introduce __block_write_begin

Split up the block_write_begin implementation - __block_write_begin is a new
trivial wrapper for block_prepare_write that always takes an already
allocated page and can be either called from block_write_begin or filesystem
code that already has a page allocated.  Remove the handling of already
allocated pages from block_write_begin after switching all callers that
do it to __block_write_begin.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/buffer.c                 | 69 +++++++++++++++++----------------------------
 fs/ext2/dir.c               |  3 +-
 fs/ext3/inode.c             |  3 +-
 fs/ext4/inode.c             | 11 +++-----
 fs/minix/inode.c            |  3 +-
 fs/nilfs2/dir.c             |  3 +-
 fs/reiserfs/inode.c         |  3 +-
 fs/sysv/itree.c             |  3 +-
 fs/ufs/inode.c              |  3 +-
 include/linux/buffer_head.h |  2 ++
 10 files changed, 39 insertions(+), 64 deletions(-)

(limited to 'fs/buffer.c')

diff --git a/fs/buffer.c b/fs/buffer.c
index 14529ec759b..c319c49da51 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1833,9 +1833,10 @@ void page_zero_new_buffers(struct page *page, unsigned from, unsigned to)
 }
 EXPORT_SYMBOL(page_zero_new_buffers);
 
-static int __block_prepare_write(struct inode *inode, struct page *page,
-		unsigned from, unsigned to, get_block_t *get_block)
+int block_prepare_write(struct page *page, unsigned from, unsigned to,
+		get_block_t *get_block)
 {
+	struct inode *inode = page->mapping->host;
 	unsigned block_start, block_end;
 	sector_t block;
 	int err = 0;
@@ -1908,10 +1909,13 @@ static int __block_prepare_write(struct inode *inode, struct page *page,
 		if (!buffer_uptodate(*wait_bh))
 			err = -EIO;
 	}
-	if (unlikely(err))
+	if (unlikely(err)) {
 		page_zero_new_buffers(page, from, to);
+		ClearPageUptodate(page);
+	}
 	return err;
 }
+EXPORT_SYMBOL(block_prepare_write);
 
 static int __block_commit_write(struct inode *inode, struct page *page,
 		unsigned from, unsigned to)
@@ -1948,6 +1952,15 @@ static int __block_commit_write(struct inode *inode, struct page *page,
 	return 0;
 }
 
+int __block_write_begin(struct page *page, loff_t pos, unsigned len,
+		get_block_t *get_block)
+{
+	unsigned start = pos & (PAGE_CACHE_SIZE - 1);
+
+	return block_prepare_write(page, start, start + len, get_block);
+}
+EXPORT_SYMBOL(__block_write_begin);
+
 /*
  * Filesystems implementing the new truncate sequence should use the
  * _newtrunc postfix variant which won't incorrectly call vmtruncate.
@@ -1958,41 +1971,22 @@ int block_write_begin_newtrunc(struct file *file, struct address_space *mapping,
 			struct page **pagep, void **fsdata,
 			get_block_t *get_block)
 {
-	struct inode *inode = mapping->host;
-	int status = 0;
+	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
 	struct page *page;
-	pgoff_t index;
-	unsigned start, end;
-	int ownpage = 0;
+	int status;
 
-	index = pos >> PAGE_CACHE_SHIFT;
-	start = pos & (PAGE_CACHE_SIZE - 1);
-	end = start + len;
-
-	page = *pagep;
-	if (page == NULL) {
-		ownpage = 1;
-		page = grab_cache_page_write_begin(mapping, index, flags);
-		if (!page) {
-			status = -ENOMEM;
-			goto out;
-		}
-		*pagep = page;
-	} else
-		BUG_ON(!PageLocked(page));
+	page = grab_cache_page_write_begin(mapping, index, flags);
+	if (!page)
+		return -ENOMEM;
 
-	status = __block_prepare_write(inode, page, start, end, get_block);
+	status = __block_write_begin(page, pos, len, get_block);
 	if (unlikely(status)) {
-		ClearPageUptodate(page);
-
-		if (ownpage) {
-			unlock_page(page);
-			page_cache_release(page);
-			*pagep = NULL;
-		}
+		unlock_page(page);
+		page_cache_release(page);
+		page = NULL;
 	}
 
-out:
+	*pagep = page;
 	return status;
 }
 EXPORT_SYMBOL(block_write_begin_newtrunc);
@@ -2379,17 +2373,6 @@ out:
 }
 EXPORT_SYMBOL(cont_write_begin);
 
-int block_prepare_write(struct page *page, unsigned from, unsigned to,
-			get_block_t *get_block)
-{
-	struct inode *inode = page->mapping->host;
-	int err = __block_prepare_write(inode, page, from, to, get_block);
-	if (err)
-		ClearPageUptodate(page);
-	return err;
-}
-EXPORT_SYMBOL(block_prepare_write);
-
 int block_commit_write(struct page *page, unsigned from, unsigned to)
 {
 	struct inode *inode = page->mapping->host;
diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index 6b946bae11c..764109886ec 100644
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -450,8 +450,7 @@ ino_t ext2_inode_by_name(struct inode *dir, struct qstr *child)
 
 static int ext2_prepare_chunk(struct page *page, loff_t pos, unsigned len)
 {
-	return block_write_begin_newtrunc(NULL, page->mapping, pos, len, 0,
-					  &page, NULL, ext2_get_block);
+	return __block_write_begin(page, pos, len, ext2_get_block);
 }
 
 /* Releases the page */
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index a66f3fe3367..5c6f07eefa4 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1196,8 +1196,7 @@ retry:
 		ret = PTR_ERR(handle);
 		goto out;
 	}
-	ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
-							ext3_get_block);
+	ret = __block_write_begin(page, pos, len, ext3_get_block);
 	if (ret)
 		goto write_begin_failed;
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index d6a7701018a..3da3c9646e5 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1578,11 +1578,9 @@ retry:
 	*pagep = page;
 
 	if (ext4_should_dioread_nolock(inode))
-		ret = block_write_begin(file, mapping, pos, len, flags, pagep,
-				fsdata, ext4_get_block_write);
+		ret = __block_write_begin(page, pos, len, ext4_get_block_write);
 	else
-		ret = block_write_begin(file, mapping, pos, len, flags, pagep,
-				fsdata, ext4_get_block);
+		ret = __block_write_begin(page, pos, len, ext4_get_block);
 
 	if (!ret && ext4_should_journal_data(inode)) {
 		ret = walk_page_buffers(handle, page_buffers(page),
@@ -1593,7 +1591,7 @@ retry:
 		unlock_page(page);
 		page_cache_release(page);
 		/*
-		 * block_write_begin may have instantiated a few blocks
+		 * __block_write_begin may have instantiated a few blocks
 		 * outside i_size.  Trim these off again. Don't need
 		 * i_size_read because we hold i_mutex.
 		 *
@@ -3185,8 +3183,7 @@ retry:
 	}
 	*pagep = page;
 
-	ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
-				ext4_da_get_block_prep);
+	ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep);
 	if (ret < 0) {
 		unlock_page(page);
 		ext4_journal_stop(handle);
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index f4abe45229b..6b29e73f0ca 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -359,8 +359,7 @@ static int minix_readpage(struct file *file, struct page *page)
 
 int minix_prepare_chunk(struct page *page, loff_t pos, unsigned len)
 {
-	return block_write_begin_newtrunc(NULL, page->mapping, pos, len, 0,
-					  &page, NULL, minix_get_block);
+	return __block_write_begin(page, pos, len, minix_get_block);
 }
 
 static int minix_write_begin(struct file *file, struct address_space *mapping,
diff --git a/fs/nilfs2/dir.c b/fs/nilfs2/dir.c
index fc2bcfa599a..d14e3b94d81 100644
--- a/fs/nilfs2/dir.c
+++ b/fs/nilfs2/dir.c
@@ -83,8 +83,7 @@ static unsigned nilfs_last_byte(struct inode *inode, unsigned long page_nr)
 static int nilfs_prepare_chunk(struct page *page, unsigned from, unsigned to)
 {
 	loff_t pos = page_offset(page) + from;
-	return block_write_begin_newtrunc(NULL, page->mapping, pos, to - from,
-					  0, &page, NULL, nilfs_get_block);
+	return __block_write_begin(page, pos, to - from, nilfs_get_block);
 }
 
 static void nilfs_commit_chunk(struct page *page,
diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index 4c1fb548ab6..045729f5674 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -2585,8 +2585,7 @@ static int reiserfs_write_begin(struct file *file,
 		old_ref = th->t_refcount;
 		th->t_refcount++;
 	}
-	ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
-				reiserfs_get_block);
+	ret = __block_write_begin(page, pos, len, reiserfs_get_block);
 	if (ret && reiserfs_transaction_running(inode->i_sb)) {
 		struct reiserfs_transaction_handle *th = current->journal_info;
 		/* this gets a little ugly.  If reiserfs_get_block returned an
diff --git a/fs/sysv/itree.c b/fs/sysv/itree.c
index 4068f485cfd..82a005c3d7e 100644
--- a/fs/sysv/itree.c
+++ b/fs/sysv/itree.c
@@ -461,8 +461,7 @@ static int sysv_readpage(struct file *file, struct page *page)
 
 int sysv_prepare_chunk(struct page *page, loff_t pos, unsigned len)
 {
-	return block_write_begin_newtrunc(NULL, page->mapping, pos, len, 0,
-					  &page, NULL, get_block);
+	return __block_write_begin(page, pos, len, get_block);
 }
 
 static int sysv_write_begin(struct file *file, struct address_space *mapping,
diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
index a9555b1ffd2..45ce32391f8 100644
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -560,8 +560,7 @@ static int ufs_readpage(struct file *file, struct page *page)
 
 int ufs_prepare_chunk(struct page *page, loff_t pos, unsigned len)
 {
-	return block_write_begin_newtrunc(NULL, page->mapping, pos, len, 0,
-					  &page, NULL, ufs_getfrag_block);
+	return __block_write_begin(page, pos, len, ufs_getfrag_block);
 }
 
 static int ufs_write_begin(struct file *file, struct address_space *mapping,
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 7638647f042..accc9f81bb6 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -209,6 +209,8 @@ int block_write_begin_newtrunc(struct file *, struct address_space *,
 int block_write_begin(struct file *, struct address_space *,
 				loff_t, unsigned, unsigned,
 				struct page **, void **, get_block_t*);
+int __block_write_begin(struct page *page, loff_t pos, unsigned len,
+		get_block_t *get_block);
 int block_write_end(struct file *, struct address_space *,
 				loff_t, unsigned, unsigned,
 				struct page *, void *);
-- 
cgit v1.2.3-70-g09d2


From 155130a4f7848b1aac439cab6bda1a175507c71c Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Fri, 4 Jun 2010 11:29:58 +0200
Subject: get rid of block_write_begin_newtrunc

Move the call to vmtruncate to get rid of accessive blocks to the callers
in preparation of the new truncate sequence and rename the non-truncating
version to block_write_begin.

While we're at it also remove several unused arguments to block_write_begin.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/bfs/file.c               | 14 ++++++++---
 fs/block_dev.c              |  5 ++--
 fs/buffer.c                 | 61 +++++++--------------------------------------
 fs/ext2/inode.c             |  5 ++--
 fs/minix/inode.c            | 12 +++++++--
 fs/nilfs2/inode.c           | 12 ++++++---
 fs/nilfs2/recovery.c        | 11 +++++---
 fs/omfs/file.c              | 14 ++++++++---
 fs/sysv/itree.c             | 13 +++++++---
 fs/udf/inode.c              | 13 +++++++---
 fs/ufs/inode.c              | 12 +++++++--
 fs/xfs/linux-2.6/xfs_aops.c | 14 ++++++++---
 include/linux/buffer_head.h |  8 ++----
 13 files changed, 103 insertions(+), 91 deletions(-)

(limited to 'fs/buffer.c')

diff --git a/fs/bfs/file.c b/fs/bfs/file.c
index 88b9a3ff44e..8fc2e9c9739 100644
--- a/fs/bfs/file.c
+++ b/fs/bfs/file.c
@@ -168,9 +168,17 @@ static int bfs_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
-	*pagep = NULL;
-	return block_write_begin(file, mapping, pos, len, flags,
-					pagep, fsdata, bfs_get_block);
+	int ret;
+
+	ret = block_write_begin(mapping, pos, len, flags, pagep,
+				bfs_get_block);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t bfs_bmap(struct address_space *mapping, sector_t block)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 65a0c26508e..63c9d607620 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -308,9 +308,8 @@ static int blkdev_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
-	*pagep = NULL;
-	return block_write_begin_newtrunc(file, mapping, pos, len, flags,
-				pagep, fsdata, blkdev_get_block);
+	return block_write_begin(mapping, pos, len, flags, pagep,
+				 blkdev_get_block);
 }
 
 static int blkdev_write_end(struct file *file, struct address_space *mapping,
diff --git a/fs/buffer.c b/fs/buffer.c
index c319c49da51..50efa339e05 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1962,14 +1962,13 @@ int __block_write_begin(struct page *page, loff_t pos, unsigned len,
 EXPORT_SYMBOL(__block_write_begin);
 
 /*
- * Filesystems implementing the new truncate sequence should use the
- * _newtrunc postfix variant which won't incorrectly call vmtruncate.
+ * block_write_begin takes care of the basic task of block allocation and
+ * bringing partial write blocks uptodate first.
+ *
  * The filesystem needs to handle block truncation upon failure.
  */
-int block_write_begin_newtrunc(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned flags,
-			struct page **pagep, void **fsdata,
-			get_block_t *get_block)
+int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len,
+		unsigned flags, struct page **pagep, get_block_t *get_block)
 {
 	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
 	struct page *page;
@@ -1989,44 +1988,6 @@ int block_write_begin_newtrunc(struct file *file, struct address_space *mapping,
 	*pagep = page;
 	return status;
 }
-EXPORT_SYMBOL(block_write_begin_newtrunc);
-
-/*
- * block_write_begin takes care of the basic task of block allocation and
- * bringing partial write blocks uptodate first.
- *
- * If *pagep is not NULL, then block_write_begin uses the locked page
- * at *pagep rather than allocating its own. In this case, the page will
- * not be unlocked or deallocated on failure.
- */
-int block_write_begin(struct file *file, struct address_space *mapping,
-			loff_t pos, unsigned len, unsigned flags,
-			struct page **pagep, void **fsdata,
-			get_block_t *get_block)
-{
-	int ret;
-
-	ret = block_write_begin_newtrunc(file, mapping, pos, len, flags,
-					pagep, fsdata, get_block);
-
-	/*
-	 * prepare_write() may have instantiated a few blocks
-	 * outside i_size.  Trim these off again. Don't need
-	 * i_size_read because we hold i_mutex.
-	 *
-	 * Filesystems which pass down their own page also cannot
-	 * call into vmtruncate here because it would lead to lock
-	 * inversion problems (*pagep is locked). This is a further
-	 * example of where the old truncate sequence is inadequate.
-	 */
-	if (unlikely(ret) && *pagep == NULL) {
-		loff_t isize = mapping->host->i_size;
-		if (pos + len > isize)
-			vmtruncate(mapping->host, isize);
-	}
-
-	return ret;
-}
 EXPORT_SYMBOL(block_write_begin);
 
 int block_write_end(struct file *file, struct address_space *mapping,
@@ -2357,7 +2318,7 @@ int cont_write_begin(struct file *file, struct address_space *mapping,
 
 	err = cont_expand_zero(file, mapping, pos, bytes);
 	if (err)
-		goto out;
+		return err;
 
 	zerofrom = *bytes & ~PAGE_CACHE_MASK;
 	if (pos+len > *bytes && zerofrom & (blocksize-1)) {
@@ -2365,11 +2326,7 @@ int cont_write_begin(struct file *file, struct address_space *mapping,
 		(*bytes)++;
 	}
 
-	*pagep = NULL;
-	err = block_write_begin_newtrunc(file, mapping, pos, len,
-				flags, pagep, fsdata, get_block);
-out:
-	return err;
+	return block_write_begin(mapping, pos, len, flags, pagep, get_block);
 }
 EXPORT_SYMBOL(cont_write_begin);
 
@@ -2511,8 +2468,8 @@ int nobh_write_begin(struct address_space *mapping,
 		unlock_page(page);
 		page_cache_release(page);
 		*pagep = NULL;
-		return block_write_begin_newtrunc(NULL, mapping, pos, len,
-					flags, pagep, fsdata, get_block);
+		return block_write_begin(mapping, pos, len, flags, pagep,
+					 get_block);
 	}
 
 	if (PageMappedToDisk(page))
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 2f4dfbcd769..74dfe5f7333 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -772,9 +772,8 @@ ext2_write_begin(struct file *file, struct address_space *mapping,
 {
 	int ret;
 
-	*pagep = NULL;
-	ret = block_write_begin_newtrunc(file, mapping, pos, len, flags,
-					 pagep, fsdata, ext2_get_block);
+	ret = block_write_begin(mapping, pos, len, flags, pagep,
+				ext2_get_block);
 	if (ret < 0)
 		ext2_write_failed(mapping, pos + len);
 	return ret;
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index 6b29e73f0ca..125062f55ef 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -366,9 +366,17 @@ static int minix_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
-	*pagep = NULL;
-	return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+	int ret;
+
+	ret = block_write_begin(mapping, pos, len, flags, pagep,
 				minix_get_block);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t minix_bmap(struct address_space *mapping, sector_t block)
diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index 1dd9e6a7d78..5c694ece172 100644
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -197,11 +197,15 @@ static int nilfs_write_begin(struct file *file, struct address_space *mapping,
 	if (unlikely(err))
 		return err;
 
-	*pagep = NULL;
-	err = block_write_begin(file, mapping, pos, len, flags, pagep,
-				fsdata, nilfs_get_block);
-	if (unlikely(err))
+	err = block_write_begin(mapping, pos, len, flags, pagep,
+				nilfs_get_block);
+	if (unlikely(err)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+
 		nilfs_transaction_abort(inode->i_sb);
+	}
 	return err;
 }
 
diff --git a/fs/nilfs2/recovery.c b/fs/nilfs2/recovery.c
index bae2a516b4e..2f11f0868d8 100644
--- a/fs/nilfs2/recovery.c
+++ b/fs/nilfs2/recovery.c
@@ -505,11 +505,14 @@ static int recover_dsync_blocks(struct nilfs_sb_info *sbi,
 		}
 
 		pos = rb->blkoff << inode->i_blkbits;
-		page = NULL;
-		err = block_write_begin(NULL, inode->i_mapping, pos, blocksize,
-					0, &page, NULL, nilfs_get_block);
-		if (unlikely(err))
+		err = block_write_begin(inode->i_mapping, pos, blocksize,
+					0, &page, nilfs_get_block);
+		if (unlikely(err)) {
+			loff_t isize = inode->i_size;
+			if (pos + blocksize > isize)
+				vmtruncate(inode, isize);
 			goto failed_inode;
+		}
 
 		err = nilfs_recovery_copy_block(sbi, rb, page);
 		if (unlikely(err))
diff --git a/fs/omfs/file.c b/fs/omfs/file.c
index 6e7a3291bbe..810cff34646 100644
--- a/fs/omfs/file.c
+++ b/fs/omfs/file.c
@@ -312,9 +312,17 @@ static int omfs_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
-	*pagep = NULL;
-	return block_write_begin(file, mapping, pos, len, flags,
-				pagep, fsdata, omfs_get_block);
+	int ret;
+
+	ret = block_write_begin(mapping, pos, len, flags, pagep,
+				omfs_get_block);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t omfs_bmap(struct address_space *mapping, sector_t block)
diff --git a/fs/sysv/itree.c b/fs/sysv/itree.c
index 82a005c3d7e..9ca66276315 100644
--- a/fs/sysv/itree.c
+++ b/fs/sysv/itree.c
@@ -468,9 +468,16 @@ static int sysv_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
-	*pagep = NULL;
-	return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
-				get_block);
+	int ret;
+
+	ret = block_write_begin(mapping, pos, len, flags, pagep, get_block);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t sysv_bmap(struct address_space *mapping, sector_t block)
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index 124852bcf6f..ecddcc2ed74 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -127,9 +127,16 @@ static int udf_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
-	*pagep = NULL;
-	return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
-				udf_get_block);
+	int ret;
+
+	ret = block_write_begin(mapping, pos, len, flags, pagep, udf_get_block);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t udf_bmap(struct address_space *mapping, sector_t block)
diff --git a/fs/ufs/inode.c b/fs/ufs/inode.c
index 45ce32391f8..45cafa937a4 100644
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -567,9 +567,17 @@ static int ufs_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
-	*pagep = NULL;
-	return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+	int ret;
+
+	ret = block_write_begin(mapping, pos, len, flags, pagep,
 				ufs_getfrag_block);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 static sector_t ufs_bmap(struct address_space *mapping, sector_t block)
diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index 7968d41e27a..bf7aad0d78b 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -1504,9 +1504,17 @@ xfs_vm_write_begin(
 	struct page		**pagep,
 	void			**fsdata)
 {
-	*pagep = NULL;
-	return block_write_begin(file, mapping, pos, len, flags | AOP_FLAG_NOFS,
-				 pagep, fsdata, xfs_get_blocks);
+	int			ret;
+
+	ret = block_write_begin(mapping, pos, len, flags | AOP_FLAG_NOFS,
+				pagep, xfs_get_blocks);
+	if (unlikely(ret)) {
+		loff_t isize = mapping->host->i_size;
+		if (pos + len > isize)
+			vmtruncate(mapping->host, isize);
+	}
+
+	return ret;
 }
 
 STATIC sector_t
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index accc9f81bb6..3f69054f86d 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -203,12 +203,8 @@ int block_write_full_page_endio(struct page *page, get_block_t *get_block,
 int block_read_full_page(struct page*, get_block_t*);
 int block_is_partially_uptodate(struct page *page, read_descriptor_t *desc,
 				unsigned long from);
-int block_write_begin_newtrunc(struct file *, struct address_space *,
-				loff_t, unsigned, unsigned,
-				struct page **, void **, get_block_t*);
-int block_write_begin(struct file *, struct address_space *,
-				loff_t, unsigned, unsigned,
-				struct page **, void **, get_block_t*);
+int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len,
+		unsigned flags, struct page **pagep, get_block_t *get_block);
 int __block_write_begin(struct page *page, loff_t pos, unsigned len,
 		get_block_t *get_block);
 int block_write_end(struct file *, struct address_space *,
-- 
cgit v1.2.3-70-g09d2