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Commit 46c7f254 authored by Tao Ma's avatar Tao Ma Committed by Theodore Ts'o
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ext4: add read support for inline data 



Let readpage and readpages handle the case when we want to read an
inlined file.

Signed-off-by: default avatarTao Ma <boyu.mt@taobao.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 67cf5b09

fs/ext4/inline.c

+61 −0
Original line number Diff line number Diff line
@@ -454,6 +454,67 @@ static int ext4_destroy_inline_data_nolock(handle_t *handle, 
	return error;

}



static int ext4_read_inline_page(struct inode *inode, struct page *page)

{

	void *kaddr;

	int ret = 0;

	size_t len;

	struct ext4_iloc iloc;



	BUG_ON(!PageLocked(page));

	BUG_ON(!ext4_has_inline_data(inode));

	BUG_ON(page->index);



	if (!EXT4_I(inode)->i_inline_off) {

		ext4_warning(inode->i_sb, "inode %lu doesn't have inline data.",

			     inode->i_ino);

		goto out;

	}



	ret = ext4_get_inode_loc(inode, &iloc);

	if (ret)

		goto out;



	len = min_t(size_t, ext4_get_inline_size(inode), i_size_read(inode));

	kaddr = kmap_atomic(page);

	ret = ext4_read_inline_data(inode, kaddr, len, &iloc);

	flush_dcache_page(page);

	kunmap_atomic(kaddr);

	zero_user_segment(page, len, PAGE_CACHE_SIZE);

	SetPageUptodate(page);

	brelse(iloc.bh);



out:

	return ret;

}



int ext4_readpage_inline(struct inode *inode, struct page *page)

{

	int ret = 0;



	down_read(&EXT4_I(inode)->xattr_sem);

	if (!ext4_has_inline_data(inode)) {

		up_read(&EXT4_I(inode)->xattr_sem);

		return -EAGAIN;

	}



	/*

	 * Current inline data can only exist in the 1st page,

	 * So for all the other pages, just set them uptodate.

	 */

	if (!page->index)

		ret = ext4_read_inline_page(inode, page);

	else if (!PageUptodate(page)) {

		zero_user_segment(page, 0, PAGE_CACHE_SIZE);

		SetPageUptodate(page);

	}



	up_read(&EXT4_I(inode)->xattr_sem);



	unlock_page(page);

	return ret >= 0 ? 0 : ret;

}



int ext4_destroy_inline_data(handle_t *handle, struct inode *inode)

{

	int ret;

fs/ext4/inode.c

+30 −1
Original line number Diff line number Diff line
@@ -649,6 +649,9 @@ static int _ext4_get_block(struct inode *inode, sector_t iblock, 
	int ret = 0, started = 0;

	int dio_credits;



	if (ext4_has_inline_data(inode))

		return -ERANGE;



	map.m_lblk = iblock;

	map.m_len = bh->b_size >> inode->i_blkbits;
@@ -2687,6 +2690,12 @@ static sector_t ext4_bmap(struct address_space *mapping, sector_t block) 
	journal_t *journal;

	int err;



	/*

	 * We can get here for an inline file via the FIBMAP ioctl

	 */

	if (ext4_has_inline_data(inode))

		return 0;



	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&

			test_opt(inode->i_sb, DELALLOC)) {

		/*
@@ -2732,14 +2741,30 @@ static sector_t ext4_bmap(struct address_space *mapping, sector_t block) 


static int ext4_readpage(struct file *file, struct page *page)

{

	int ret = -EAGAIN;

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



	trace_ext4_readpage(page);



	if (ext4_has_inline_data(inode))

		ret = ext4_readpage_inline(inode, page);



	if (ret == -EAGAIN)

		return mpage_readpage(page, ext4_get_block);



	return ret;

}



static int

ext4_readpages(struct file *file, struct address_space *mapping,

		struct list_head *pages, unsigned nr_pages)

{

	struct inode *inode = mapping->host;



	/* If the file has inline data, no need to do readpages. */

	if (ext4_has_inline_data(inode))

		return 0;



	return mpage_readpages(mapping, pages, nr_pages, ext4_get_block);

}
@@ -3078,6 +3103,10 @@ static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb, 
	if (ext4_should_journal_data(inode))

		return 0;



	/* Let buffer I/O handle the inline data case. */

	if (ext4_has_inline_data(inode))

		return 0;



	trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw);

	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))

		ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs);

fs/ext4/xattr.h

+7 −0
Original line number Diff line number Diff line
@@ -139,6 +139,8 @@ extern int ext4_prepare_inline_data(handle_t *handle, struct inode *inode, 
extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,

				 unsigned int len);

extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);



extern int ext4_readpage_inline(struct inode *inode, struct page *page);

# else  /* CONFIG_EXT4_FS_XATTR */



static inline int
@@ -255,6 +257,11 @@ static inline int ext4_destroy_inline_data(handle_t *handle, 
{

	return 0;

}



static inline int ext4_readpage_inline(struct inode *inode, struct page *page)

{

	return 0;

}

# endif  /* CONFIG_EXT4_FS_XATTR */



#ifdef CONFIG_EXT4_FS_SECURITY