Commit f4e420dc authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Al Viro
Browse files

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: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 282dc178

fs/ext2/dir.c

+12 −12
Original line number Diff line number Diff line
@@ -448,6 +448,12 @@ ino_t ext2_inode_by_name(struct inode *dir, struct qstr *child) 
	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 @@ void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de, 
	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 @@ int ext2_add_link (struct dentry *dentry, struct inode *inode) 
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 @@ out_unlock: 
 */

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 @@ int ext2_delete_entry (struct ext2_dir_entry_2 * dir, struct page * page ) 
		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 @@ out: 
 */

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 @@ int ext2_make_empty(struct inode *inode, struct inode *parent) 
	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;

fs/ext2/ext2.h

+0 −3
Original line number Diff line number Diff line
@@ -127,9 +127,6 @@ extern void ext2_set_inode_flags(struct inode *inode); 
extern void ext2_get_inode_flags(struct ext2_inode_info *);

extern int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,

		       u64 start, u64 len);

int __ext2_write_begin(struct file *file, struct address_space *mapping,

		loff_t pos, unsigned len, unsigned flags,

		struct page **pagep, void **fsdata);



/* ioctl.c */

extern long ext2_ioctl(struct file *, unsigned int, unsigned long);

fs/ext2/inode.c

+2 −9
Original line number Diff line number Diff line
@@ -765,14 +765,6 @@ ext2_readpages(struct file *file, struct address_space *mapping, 
	return mpage_readpages(mapping, pages, nr_pages, ext2_get_block);

}



int __ext2_write_begin(struct file *file, struct address_space *mapping,

		loff_t pos, unsigned len, unsigned flags,

		struct page **pagep, void **fsdata)

{

	return block_write_begin_newtrunc(file, mapping, pos, len, flags,

					pagep, fsdata, ext2_get_block);

}



static int

ext2_write_begin(struct file *file, struct address_space *mapping,

		loff_t pos, unsigned len, unsigned flags,
@@ -781,7 +773,8 @@ ext2_write_begin(struct file *file, struct address_space *mapping, 
	int ret;



	*pagep = NULL;

	ret = __ext2_write_begin(file, mapping, pos, len, flags, pagep, fsdata);

	ret = block_write_begin_newtrunc(file, mapping, pos, len, flags,

					 pagep, fsdata, ext2_get_block);

	if (ret < 0)

		ext2_write_failed(mapping, pos + len);

	return ret;

fs/minix/dir.c

+7 −14
Original line number Diff line number Diff line
@@ -271,8 +271,7 @@ int minix_add_link(struct dentry *dentry, struct inode *inode) 


got_it:

	pos = page_offset(page) + p - (char *)page_address(page);

	err = __minix_write_begin(NULL, page->mapping, pos, sbi->s_dirsize,

					AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);

	err = minix_prepare_chunk(page, pos, sbi->s_dirsize);

	if (err)

		goto out_unlock;

	memcpy (namx, name, namelen);
@@ -297,8 +296,7 @@ out_unlock: 


int minix_delete_entry(struct minix_dir_entry *de, struct page *page)

{

	struct address_space *mapping = page->mapping;

	struct inode *inode = (struct inode*)mapping->host;

	struct inode *inode = page->mapping->host;

	char *kaddr = page_address(page);

	loff_t pos = page_offset(page) + (char*)de - kaddr;

	struct minix_sb_info *sbi = minix_sb(inode->i_sb);
@@ -306,8 +304,7 @@ int minix_delete_entry(struct minix_dir_entry *de, struct page *page) 
	int err;



	lock_page(page);

	err = __minix_write_begin(NULL, mapping, pos, len,

					AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);

	err = minix_prepare_chunk(page, pos, len);

	if (err == 0) {

		if (sbi->s_version == MINIX_V3)

			((minix3_dirent *) de)->inode = 0;
@@ -325,16 +322,14 @@ int minix_delete_entry(struct minix_dir_entry *de, struct page *page) 


int minix_make_empty(struct inode *inode, struct inode *dir)

{

	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);

	struct minix_sb_info *sbi = minix_sb(inode->i_sb);

	char *kaddr;

	int err;



	if (!page)

		return -ENOMEM;

	err = __minix_write_begin(NULL, mapping, 0, 2 * sbi->s_dirsize,

					AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);

	err = minix_prepare_chunk(page, 0, 2 * sbi->s_dirsize);

	if (err) {

		unlock_page(page);

		goto fail;
@@ -425,8 +420,7 @@ not_empty: 
void minix_set_link(struct minix_dir_entry *de, struct page *page,

	struct inode *inode)

{

	struct address_space *mapping = page->mapping;

	struct inode *dir = mapping->host;

	struct inode *dir = page->mapping->host;

	struct minix_sb_info *sbi = minix_sb(dir->i_sb);

	loff_t pos = page_offset(page) +

			(char *)de-(char*)page_address(page);
@@ -434,8 +428,7 @@ void minix_set_link(struct minix_dir_entry *de, struct page *page, 


	lock_page(page);



	err = __minix_write_begin(NULL, mapping, pos, sbi->s_dirsize,

					AOP_FLAG_UNINTERRUPTIBLE, &page, NULL);

	err = minix_prepare_chunk(page, pos, sbi->s_dirsize);

	if (err == 0) {

		if (sbi->s_version == MINIX_V3)

			((minix3_dirent *) de)->inode = inode->i_ino;

fs/minix/inode.c

+5 −6
Original line number Diff line number Diff line
@@ -357,12 +357,10 @@ static int minix_readpage(struct file *file, struct page *page) 
	return block_read_full_page(page,minix_get_block);

}



int __minix_write_begin(struct file *file, struct address_space *mapping,

			loff_t pos, unsigned len, unsigned flags,

			struct page **pagep, void **fsdata)

int minix_prepare_chunk(struct page *page, loff_t pos, unsigned len)

{

	return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,

				minix_get_block);

	return block_write_begin_newtrunc(NULL, page->mapping, pos, len, 0,

					  &page, NULL, minix_get_block);

}



static int minix_write_begin(struct file *file, struct address_space *mapping,
@@ -370,7 +368,8 @@ static int minix_write_begin(struct file *file, struct address_space *mapping, 
			struct page **pagep, void **fsdata)

{

	*pagep = NULL;

	return __minix_write_begin(file, mapping, pos, len, flags, pagep, fsdata);

	return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,

				minix_get_block);

}



static sector_t minix_bmap(struct address_space *mapping, sector_t block)

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