clean up write_begin usage for directories in pagecache
For filesystem that implement directories in pagecache we call
block_write_begin with an already allocated page for this code, while the
normal regular file write path uses the default block_write_begin behaviour.
Get rid of the __foofs_write_begin helper and opencode the normal write_begin
call in foofs_write_begin, while adding a new foofs_prepare_chunk helper for
the directory code. The added benefit is that foofs_prepare_chunk has
a much saner calling convention.
Note that the interruptible flag passed into block_write_begin is always
ignored if we already pass in a page (see next patch for details), and
we never were doing truncations of exessive blocks for this case either so we
can switch directly to block_write_begin_newtrunc.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index 7516957..6b946ba 100644
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -448,6 +448,12 @@
return res;
}
+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);
+}
+
/* Releases the page */
void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
struct page *page, struct inode *inode, int update_times)
@@ -458,8 +464,7 @@
int err;
lock_page(page);
- err = __ext2_write_begin(NULL, page->mapping, pos, len,
- AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);
+ err = ext2_prepare_chunk(page, pos, len);
BUG_ON(err);
de->inode = cpu_to_le32(inode->i_ino);
ext2_set_de_type(de, inode);
@@ -542,8 +547,7 @@
got_it:
pos = page_offset(page) +
(char*)de - (char*)page_address(page);
- err = __ext2_write_begin(NULL, page->mapping, pos, rec_len, 0,
- &page, NULL);
+ err = ext2_prepare_chunk(page, pos, rec_len);
if (err)
goto out_unlock;
if (de->inode) {
@@ -576,8 +580,7 @@
*/
int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page )
{
- struct address_space *mapping = page->mapping;
- struct inode *inode = mapping->host;
+ struct inode *inode = page->mapping->host;
char *kaddr = page_address(page);
unsigned from = ((char*)dir - kaddr) & ~(ext2_chunk_size(inode)-1);
unsigned to = ((char *)dir - kaddr) +
@@ -601,8 +604,7 @@
from = (char*)pde - (char*)page_address(page);
pos = page_offset(page) + from;
lock_page(page);
- err = __ext2_write_begin(NULL, page->mapping, pos, to - from, 0,
- &page, NULL);
+ err = ext2_prepare_chunk(page, pos, to - from);
BUG_ON(err);
if (pde)
pde->rec_len = ext2_rec_len_to_disk(to - from);
@@ -621,8 +623,7 @@
*/
int ext2_make_empty(struct inode *inode, struct inode *parent)
{
- struct address_space *mapping = inode->i_mapping;
- struct page *page = grab_cache_page(mapping, 0);
+ struct page *page = grab_cache_page(inode->i_mapping, 0);
unsigned chunk_size = ext2_chunk_size(inode);
struct ext2_dir_entry_2 * de;
int err;
@@ -631,8 +632,7 @@
if (!page)
return -ENOMEM;
- err = __ext2_write_begin(NULL, page->mapping, 0, chunk_size, 0,
- &page, NULL);
+ err = ext2_prepare_chunk(page, 0, chunk_size);
if (err) {
unlock_page(page);
goto fail;