From 46c7f254543dedcf134ad05091ed2b935a9a597d Mon Sep 17 00:00:00 2001 From: Tao Ma Date: Mon, 10 Dec 2012 14:04:52 -0500 Subject: [PATCH] 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: Tao Ma Signed-off-by: "Theodore Ts'o" --- fs/ext4/inline.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/ext4/inode.c | 31 +++++++++++++++++++++++++++- fs/ext4/xattr.h | 7 +++++++ 3 files changed, 98 insertions(+), 1 deletion(-) diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c index bec68b3..e4a41d5 100644 --- a/fs/ext4/inline.c +++ b/fs/ext4/inline.c @@ -454,6 +454,67 @@ out: 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; diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index e23f114..1668abf 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -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); - return mpage_readpage(page, ext4_get_block); + + 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); diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h index 7ae0d05..646c9b9 100644 --- a/fs/ext4/xattr.h +++ b/fs/ext4/xattr.h @@ -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 -- 2.7.4