From: Tao Ma Subject: [PATCH V1 11/17] ext4: Let ext4_readdir handle inline data. Date: Wed, 26 Oct 2011 15:34:22 +0800 Message-ID: <1319614468-11227-11-git-send-email-tm@tao.ma> References: <4EA7B788.3040503@tao.ma> <1319614468-11227-1-git-send-email-tm@tao.ma> Cc: tytso@mit.edu, linux-kernel@vger.kernel.org, adilger@dilger.ca To: linux-ext4@vger.kernel.org Return-path: Received: from oproxy7-pub.bluehost.com ([67.222.55.9]:53815 "HELO oproxy7-pub.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754842Ab1JZHlV (ORCPT ); Wed, 26 Oct 2011 03:41:21 -0400 In-Reply-To: <1319614468-11227-1-git-send-email-tm@tao.ma> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Tao Ma Signed-off-by: Tao Ma --- fs/ext4/dir.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 101 insertions(+), 0 deletions(-) diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c index 6c2199e..8b88cfa 100644 --- a/fs/ext4/dir.c +++ b/fs/ext4/dir.c @@ -27,6 +27,7 @@ #include #include #include "ext4.h" +#include "xattr.h" static unsigned char ext4_filetype_table[] = { DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK @@ -64,6 +65,9 @@ static unsigned char get_dtype(struct super_block *sb, int filetype) * Return 0 if the directory entry is OK, and 1 if there is a problem * * Note: this is the opposite of what ext2 and ext3 historically returned... + * + * bh passed here can be an inode block or a dir data block, depending + * on the inode inline data flag. */ int __ext4_check_dir_entry(const char *function, unsigned int line, struct inode *dir, struct file *filp, @@ -107,6 +111,100 @@ int __ext4_check_dir_entry(const char *function, unsigned int line, return 1; } +static int ext4_read_inline_dir(struct file *filp, + void *dirent, filldir_t filldir) +{ + int error = 0; + unsigned int offset; + int i, stored; + struct ext4_dir_entry_2 *de; + struct super_block *sb; + struct inode *inode = filp->f_path.dentry->d_inode; + int ret, inline_size; + void *inline_pos; + struct ext4_iloc iloc; + + ret = ext4_get_inode_loc(inode, &iloc); + if (ret) + return ret; + + sb = inode->i_sb; + stored = 0; + offset = filp->f_pos & (sb->s_blocksize - 1); + inline_pos = ext4_get_inline_data_pos(inode, &iloc); + inline_size = ext4_get_max_inline_size(inode); + + ext4_show_inline_dir(inode, iloc.bh, inline_pos, inline_size); + + while (!error && !stored && filp->f_pos < inode->i_size) { +revalidate: + /* If the version has changed since the last call to + * readdir(2), then we might be pointing to an invalid + * dirent right now. Scan from the start of the block + * to make sure. */ + if (filp->f_version != inode->i_version) { + for (i = 0; i < inode->i_size && i < offset; ) { + de = (struct ext4_dir_entry_2 *) + (inline_pos + i); + /* It's too expensive to do a full + * dirent test each time round this + * loop, but we do have to test at + * least that it is non-zero. A + * failure will be detected in the + * dirent test below. */ + if (ext4_rec_len_from_disk(de->rec_len, + inline_size) < EXT4_DIR_REC_LEN(1)) + break; + i += ext4_rec_len_from_disk(de->rec_len, + inline_size); + } + offset = i; + filp->f_pos = offset; + filp->f_version = inode->i_version; + } + + while (!error && filp->f_pos < inode->i_size + && offset < inline_size) { + de = (struct ext4_dir_entry_2 *) (inline_pos + offset); + if (ext4_check_dir_entry(inode, filp, de, + iloc.bh, inline_pos, + inline_size, offset)) { + ret = stored; + goto out; + } + offset += ext4_rec_len_from_disk(de->rec_len, + inline_size); + if (le32_to_cpu(de->inode)) { + /* We might block in the next section + * if the data destination is + * currently swapped out. So, use a + * version stamp to detect whether or + * not the directory has been modified + * during the copy operation. + */ + u64 version = filp->f_version; + + error = filldir(dirent, de->name, + de->name_len, + filp->f_pos, + le32_to_cpu(de->inode), + get_dtype(sb, de->file_type)); + if (error) + break; + if (version != filp->f_version) + goto revalidate; + stored++; + } + filp->f_pos += ext4_rec_len_from_disk(de->rec_len, + inline_size); + } + offset = 0; + } +out: + brelse(iloc.bh); + return ret; +} + static int ext4_readdir(struct file *filp, void *dirent, filldir_t filldir) { @@ -122,6 +220,9 @@ static int ext4_readdir(struct file *filp, sb = inode->i_sb; + if (ext4_has_inline_data(inode)) + return ext4_read_inline_dir(filp, dirent, filldir); + if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb, EXT4_FEATURE_COMPAT_DIR_INDEX) && ((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) || -- 1.7.0.4