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>
diff --git a/fs/buffer.c b/fs/buffer.c
index 14529ec..c319c49 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1833,9 +1833,10 @@
}
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 @@
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 @@
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 @@
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 = grab_cache_page_write_begin(mapping, index, flags);
+ if (!page)
+ return -ENOMEM;
- 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));
-
- 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 @@
}
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 6b946ba..7641098 100644
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -450,8 +450,7 @@
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 a66f3fe..5c6f07e 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1196,8 +1196,7 @@
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 d6a7701..3da3c96 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1578,11 +1578,9 @@
*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 @@
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 @@
}
*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 f4abe45..6b29e73 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -359,8 +359,7 @@
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 fc2bcfa..d14e3b9 100644
--- a/fs/nilfs2/dir.c
+++ b/fs/nilfs2/dir.c
@@ -83,8 +83,7 @@
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 4c1fb54..045729f 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -2585,8 +2585,7 @@
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 4068f48..82a005c 100644
--- a/fs/sysv/itree.c
+++ b/fs/sysv/itree.c
@@ -461,8 +461,7 @@
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 a9555b1..45ce323 100644
--- a/fs/ufs/inode.c
+++ b/fs/ufs/inode.c
@@ -560,8 +560,7 @@
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,