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@xxxxxx>
Index: linux-2.6/fs/buffer.c
===================================================================
--- linux-2.6.orig/fs/buffer.c 2010-05-30 22:32:22.754253961 +0200
+++ linux-2.6/fs/buffer.c 2010-05-30 22:40:16.496254519 +0200
@@ -1833,9 +1833,10 @@ void page_zero_new_buffers(struct page *
}
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
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 +1952,14 @@ static int __block_commit_write(struct i
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);
+}
+
/*
* Filesystems implementing the new truncate sequence should use the
* _newtrunc postfix variant which won't incorrectly call vmtruncate.
@@ -1958,41 +1970,22 @@ int block_write_begin_newtrunc(struct fi
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 +2372,6 @@ 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;
Index: linux-2.6/fs/ext2/dir.c
===================================================================
--- linux-2.6.orig/fs/ext2/dir.c 2010-05-30 22:33:06.790253891 +0200
+++ linux-2.6/fs/ext2/dir.c 2010-05-30 22:36:53.972003647 +0200
@@ -450,8 +450,7 @@ ino_t ext2_inode_by_name(struct inode *d
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 */
Index: linux-2.6/fs/minix/inode.c
===================================================================
--- linux-2.6.orig/fs/minix/inode.c 2010-05-30 22:33:06.810255986 +0200
+++ linux-2.6/fs/minix/inode.c 2010-05-30 22:40:02.980254241 +0200
@@ -359,8 +359,7 @@ static int minix_readpage(struct file *f
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,
Index: linux-2.6/fs/nilfs2/dir.c
===================================================================
--- linux-2.6.orig/fs/nilfs2/dir.c 2010-05-30 22:33:06.880005392 +0200
+++ linux-2.6/fs/nilfs2/dir.c 2010-05-30 22:36:53.982004974 +0200
@@ -83,8 +83,7 @@ static unsigned nilfs_last_byte(struct i
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,
Index: linux-2.6/fs/sysv/itree.c
===================================================================
--- linux-2.6.orig/fs/sysv/itree.c 2010-05-30 22:33:06.832007627 +0200
+++ linux-2.6/fs/sysv/itree.c 2010-05-30 22:40:02.987254172 +0200
@@ -461,8 +461,7 @@ static int sysv_readpage(struct file *fi
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,
Index: linux-2.6/fs/ufs/inode.c
===================================================================
--- linux-2.6.orig/fs/ufs/inode.c 2010-05-30 22:33:06.861257313 +0200
+++ linux-2.6/fs/ufs/inode.c 2010-05-30 22:40:02.996254591 +0200
@@ -561,8 +561,7 @@ static int ufs_readpage(struct file *fil
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,
Index: linux-2.6/include/linux/buffer_head.h
===================================================================
--- linux-2.6.orig/include/linux/buffer_head.h 2010-05-30 22:32:22.783254030 +0200
+++ linux-2.6/include/linux/buffer_head.h 2010-05-30 22:40:03.005253892 +0200
@@ -209,6 +209,8 @@ int block_write_begin_newtrunc(struct fi
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 *);
Index: linux-2.6/fs/ext3/inode.c
===================================================================
--- linux-2.6.orig/fs/ext3/inode.c 2010-05-30 22:28:18.676253821 +0200
+++ linux-2.6/fs/ext3/inode.c 2010-05-30 22:36:54.000003996 +0200
@@ -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;
Index: linux-2.6/fs/ext4/inode.c
===================================================================
--- linux-2.6.orig/fs/ext4/inode.c 2010-05-30 22:28:18.646254240 +0200
+++ linux-2.6/fs/ext4/inode.c 2010-05-30 22:36:54.006004066 +0200
@@ -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);
Index: linux-2.6/fs/reiserfs/inode.c
===================================================================
--- linux-2.6.orig/fs/reiserfs/inode.c 2010-05-30 22:28:18.703254310 +0200
+++ linux-2.6/fs/reiserfs/inode.c 2010-05-30 22:36:54.013004695 +0200
@@ -2587,8 +2587,7 @@ static int reiserfs_write_begin(struct f
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
--
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