From 65d165d9366dbf783d0102177006d47c8859ba31 Mon Sep 17 00:00:00 2001 From: Tao Ma Date: Mon, 10 Dec 2012 14:05:59 -0500 Subject: [PATCH] ext4: let ext4_readdir handle inline data For "." and "..", we just call filldir by ourselves instead of iterating the real dir entry. Signed-off-by: Tao Ma Signed-off-by: "Theodore Ts'o" --- fs/ext4/dir.c | 25 +++++---- fs/ext4/ext4.h | 12 +++++ fs/ext4/inline.c | 136 +++++++++++++++++++++++++++++++++++++++++++++++ fs/ext4/xattr.h | 9 ++++ 4 files changed, 169 insertions(+), 13 deletions(-) diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c index 7c9d08b0f2fe..b8d877f6c1fa 100644 --- a/fs/ext4/dir.c +++ b/fs/ext4/dir.c @@ -27,23 +27,11 @@ #include #include #include "ext4.h" - -static unsigned char ext4_filetype_table[] = { - DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK -}; +#include "xattr.h" static int ext4_dx_readdir(struct file *filp, void *dirent, filldir_t filldir); -static unsigned char get_dtype(struct super_block *sb, int filetype) -{ - if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) || - (filetype >= EXT4_FT_MAX)) - return DT_UNKNOWN; - - return (ext4_filetype_table[filetype]); -} - /** * Check if the given dir-inode refers to an htree-indexed directory * (or a directory which chould potentially get coverted to use htree @@ -68,6 +56,9 @@ static int is_dx_dir(struct inode *inode) * 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, @@ -124,6 +115,14 @@ static int ext4_readdir(struct file *filp, int ret = 0; int dir_has_error = 0; + if (ext4_has_inline_data(inode)) { + int has_inline_data = 1; + ret = ext4_read_inline_dir(filp, dirent, filldir, + &has_inline_data); + if (has_inline_data) + return ret; + } + if (is_dx_dir(inode)) { err = ext4_dx_readdir(filp, dirent, filldir); if (err != ERR_BAD_DX_DIR) { diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 689ce1d696b8..e3a74658c63c 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1989,6 +1989,18 @@ static inline void ext4_update_dx_flag(struct inode *inode) EXT4_FEATURE_COMPAT_DIR_INDEX)) ext4_clear_inode_flag(inode, EXT4_INODE_INDEX); } +static unsigned char ext4_filetype_table[] = { + DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK +}; + +static inline unsigned char get_dtype(struct super_block *sb, int filetype) +{ + if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) || + (filetype >= EXT4_FT_MAX)) + return DT_UNKNOWN; + + return ext4_filetype_table[filetype]; +} /* fsync.c */ extern int ext4_sync_file(struct file *, loff_t, loff_t, int); diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c index bf7322818738..471504133c76 100644 --- a/fs/ext4/inline.c +++ b/fs/ext4/inline.c @@ -1288,6 +1288,142 @@ out: return ret; } +int ext4_read_inline_dir(struct file *filp, + void *dirent, filldir_t filldir, + int *has_inline_data) +{ + int error = 0; + unsigned int offset, parent_ino; + 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 = 0; + struct ext4_iloc iloc; + void *dir_buf = NULL; + + ret = ext4_get_inode_loc(inode, &iloc); + if (ret) + return ret; + + down_read(&EXT4_I(inode)->xattr_sem); + if (!ext4_has_inline_data(inode)) { + up_read(&EXT4_I(inode)->xattr_sem); + *has_inline_data = 0; + goto out; + } + + inline_size = ext4_get_inline_size(inode); + dir_buf = kmalloc(inline_size, GFP_NOFS); + if (!dir_buf) { + ret = -ENOMEM; + up_read(&EXT4_I(inode)->xattr_sem); + goto out; + } + + ret = ext4_read_inline_data(inode, dir_buf, inline_size, &iloc); + up_read(&EXT4_I(inode)->xattr_sem); + if (ret < 0) + goto out; + + sb = inode->i_sb; + stored = 0; + parent_ino = le32_to_cpu(((struct ext4_dir_entry_2 *)dir_buf)->inode); + + 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 inline + * dir to make sure. + */ + if (filp->f_version != inode->i_version) { + for (i = 0; + i < inode->i_size && i < offset;) { + if (!i) { + /* skip "." and ".." if needed. */ + i += EXT4_INLINE_DOTDOT_SIZE; + continue; + } + de = (struct ext4_dir_entry_2 *) + (dir_buf + 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) { + if (filp->f_pos == 0) { + error = filldir(dirent, ".", 1, 0, inode->i_ino, + DT_DIR); + if (error) + break; + stored++; + + error = filldir(dirent, "..", 2, 0, parent_ino, + DT_DIR); + if (error) + break; + stored++; + + filp->f_pos = offset = EXT4_INLINE_DOTDOT_SIZE; + continue; + } + + de = (struct ext4_dir_entry_2 *)(dir_buf + offset); + if (ext4_check_dir_entry(inode, filp, de, + iloc.bh, dir_buf, + 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: + kfree(dir_buf); + brelse(iloc.bh); + return ret; +} + /* * Try to create the inline data for the new dir. * If it succeeds, return 0, otherwise return the error. diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h index 397ef4bbaf1e..539e6a08c95f 100644 --- a/fs/ext4/xattr.h +++ b/fs/ext4/xattr.h @@ -168,6 +168,9 @@ extern int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry, extern int ext4_try_create_inline_dir(handle_t *handle, struct inode *parent, struct inode *inode); +extern int ext4_read_inline_dir(struct file *filp, + void *dirent, filldir_t filldir, + int *has_inline_data); # else /* CONFIG_EXT4_FS_XATTR */ static inline int @@ -346,6 +349,12 @@ static inline int ext4_try_create_inline_dir(handle_t *handle, { return 0; } +static inline int ext4_read_inline_dir(struct file *filp, + void *dirent, filldir_t filldir, + int *has_inline_data) +{ + return 0; +} # endif /* CONFIG_EXT4_FS_XATTR */ #ifdef CONFIG_EXT4_FS_SECURITY -- 2.20.1