Commit 832ee62d authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

ext4: Use scoped memory APIs in ext4_write_begin() 



Instead of setting AOP_FLAG_NOFS, use memalloc_nofs_save() and
memalloc_nofs_restore() to prevent GFP_FS allocations recursing
into the filesystem with a journal already started.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 36d116e9

fs/ext4/ext4.h

+0 −1
Original line number Diff line number Diff line
@@ -3591,7 +3591,6 @@ extern int ext4_readpage_inline(struct inode *inode, struct page *page); 
extern int ext4_try_to_write_inline_data(struct address_space *mapping,

					 struct inode *inode,

					 loff_t pos, unsigned len,

					 unsigned flags,

					 struct page **pagep);

extern int ext4_write_inline_data_end(struct inode *inode,

				      loff_t pos, unsigned len,

fs/ext4/inline.c

+10 −11
Original line number Diff line number Diff line
@@ -527,13 +527,13 @@ int ext4_readpage_inline(struct inode *inode, struct page *page) 
}



static int ext4_convert_inline_data_to_extent(struct address_space *mapping,

					      struct inode *inode,

					      unsigned flags)

					      struct inode *inode)

{

	int ret, needed_blocks, no_expand;

	handle_t *handle = NULL;

	int retries = 0, sem_held = 0;

	struct page *page = NULL;

	unsigned int flags;

	unsigned from, to;

	struct ext4_iloc iloc;
@@ -562,9 +562,9 @@ static int ext4_convert_inline_data_to_extent(struct address_space *mapping, 


	/* We cannot recurse into the filesystem as the transaction is already

	 * started */

	flags |= AOP_FLAG_NOFS;



	page = grab_cache_page_write_begin(mapping, 0, flags);

	flags = memalloc_nofs_save();

	page = grab_cache_page_write_begin(mapping, 0, 0);

	memalloc_nofs_restore(flags);

	if (!page) {

		ret = -ENOMEM;

		goto out;
@@ -649,11 +649,11 @@ static int ext4_convert_inline_data_to_extent(struct address_space *mapping, 
int ext4_try_to_write_inline_data(struct address_space *mapping,

				  struct inode *inode,

				  loff_t pos, unsigned len,

				  unsigned flags,

				  struct page **pagep)

{

	int ret;

	handle_t *handle;

	unsigned int flags;

	struct page *page;

	struct ext4_iloc iloc;
@@ -691,9 +691,9 @@ int ext4_try_to_write_inline_data(struct address_space *mapping, 
	if (ret)

		goto out;



	flags |= AOP_FLAG_NOFS;



	page = grab_cache_page_write_begin(mapping, 0, flags);

	flags = memalloc_nofs_save();

	page = grab_cache_page_write_begin(mapping, 0, 0);

	memalloc_nofs_restore(flags);

	if (!page) {

		ret = -ENOMEM;

		goto out;
@@ -727,8 +727,7 @@ int ext4_try_to_write_inline_data(struct address_space *mapping, 
	brelse(iloc.bh);

	return ret;

convert:

	return ext4_convert_inline_data_to_extent(mapping,

						  inode, flags);

	return ext4_convert_inline_data_to_extent(mapping, inode);

}



int ext4_write_inline_data_end(struct inode *inode, loff_t pos, unsigned len,

fs/ext4/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -1156,7 +1156,7 @@ static int ext4_write_begin(struct file *file, struct address_space *mapping, 


	if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {

		ret = ext4_try_to_write_inline_data(mapping, inode, pos, len,

						    flags, pagep);

						    pagep);

		if (ret < 0)

			return ret;

		if (ret == 1)