Commit 65d165d9 authored by Tao Ma's avatar Tao Ma Committed by Theodore Ts'o
Browse files

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: default avatarTao Ma <boyu.mt@taobao.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 3c47d541

fs/ext4/dir.c

+12 −13
Original line number Diff line number Diff line
@@ -27,23 +27,11 @@ 
#include <linux/slab.h>

#include <linux/rbtree.h>

#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) {

fs/ext4/ext4.h

+12 −0
Original line number Diff line number Diff line
@@ -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);

fs/ext4/inline.c

+136 −0
Original line number Diff line number Diff line
@@ -1288,6 +1288,142 @@ int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry, 
	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.

fs/ext4/xattr.h

+9 −0
Original line number Diff line number Diff line
@@ -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