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Date: Fri, 11 Oct 2013 16:33:42 -0700
From: "Darrick J. Wong" <darrick.wong@...cle.com>
To: Zheng Liu <gnehzuil.liu@...il.com>
Cc: linux-ext4@...r.kernel.org, "Theodore Ts'o" <tytso@....edu>,
Zheng Liu <wenqing.lz@...bao.com>
Subject: Re: [PATCH v1 04/22] libext2fs: handle inline data in dir iterator
function
On Fri, Aug 02, 2013 at 05:49:31PM +0800, Zheng Liu wrote:
> From: Zheng Liu <wenqing.lz@...bao.com>
>
> Inline_data is handled in dir iterator because a lot of commands use
> this function to traverse directory entries in debugfs. We need to
> handle inline_data individually because inline_data is saved in two
> places. One is in i_block, and another is in ibody extended attribute.
>
> After applied this commit, the following commands in debugfs can
> support the inline_data feature:
> - ncheck
> - chroot
> - cd
> - ls
> - pwd
> - link*
> - unlink
>
> * If inline_data doesn't expand to ibody extended attribute, link
> command will allocate a new block for this inode instead of using
> extend attribute when we exhaust all space of i_block.
>
> Signed-off-by: Theodore Ts'o <tytso@....edu>
> Signed-off-by: Zheng Liu <wenqing.lz@...bao.com>
> ---
> lib/ext2fs/dir_iterate.c | 102 ++++++++++++++++++++++++++++++++++-
> lib/ext2fs/ext2_err.et.in | 6 +++
> lib/ext2fs/ext2_fs.h | 8 +++
> lib/ext2fs/ext2fs.h | 11 ++++
> lib/ext2fs/ext2fsP.h | 11 ++++
> lib/ext2fs/inline_data.c | 132 +++++++++++++++++++++++++++++++++++++++++++++
> 6 files changed, 268 insertions(+), 2 deletions(-)
>
> diff --git a/lib/ext2fs/dir_iterate.c b/lib/ext2fs/dir_iterate.c
> index 1a4bf5c..7d5b1da 100644
> --- a/lib/ext2fs/dir_iterate.c
> +++ b/lib/ext2fs/dir_iterate.c
> @@ -123,8 +123,14 @@ errcode_t ext2fs_dir_iterate2(ext2_filsys fs,
> ctx.func = func;
> ctx.priv_data = priv_data;
> ctx.errcode = 0;
> - retval = ext2fs_block_iterate3(fs, dir, BLOCK_FLAG_READ_ONLY, 0,
> - ext2fs_process_dir_block, &ctx);
> + if (ext2fs_inode_has_inline_data(fs, dir))
> + retval = ext2fs_inline_data_iterate(fs, dir,
> + BLOCK_FLAG_READ_ONLY, 0,
> + ext2fs_process_dir_inline_data,
> + &ctx);
> + else
> + retval = ext2fs_block_iterate3(fs, dir, BLOCK_FLAG_READ_ONLY, 0,
> + ext2fs_process_dir_block, &ctx);
> if (!block_buf)
> ext2fs_free_mem(&ctx.buf);
> if (retval)
> @@ -282,3 +288,95 @@ next:
> return 0;
> }
>
> +int ext2fs_process_dir_inline_data(ext2_filsys fs,
> + char *buf,
> + unsigned int buf_len,
> + e2_blkcnt_t blockcnt,
> + struct ext2_inode_large *inode,
> + void *priv_data)
> +{
> + struct dir_context *ctx = (struct dir_context *) priv_data;
> + unsigned int offset = 0;
> + unsigned int next_real_entry = 0;
> + int ret = 0;
> + int changed = 0;
> + int do_abort = 0;
> + unsigned int rec_len, size;
> + int entry;
> + struct ext2_dir_entry *dirent;
> +
> + if (blockcnt < 0)
> + return 0;
> +
> + entry = blockcnt ? DIRENT_OTHER_FILE : DIRENT_DOT_FILE;
> +
> + while (offset < buf_len) {
> + dirent = (struct ext2_dir_entry *) (buf + offset);
> + if (ext2fs_get_rec_len(fs, dirent, &rec_len))
> + return BLOCK_ABORT;
> + if (((offset + rec_len) > buf_len) ||
> + (rec_len < 8) ||
> + ((rec_len % 4) != 0) ||
> + ((((unsigned) dirent->name_len & 0xFF)+8) > rec_len)) {
> + ctx->errcode = EXT2_ET_DIR_CORRUPTED;
> + return BLOCK_ABORT;
> + }
> + if (!dirent->inode &&
> + !(ctx->flags & DIRENT_FLAG_INCLUDE_EMPTY))
> + goto next;
> +
> + ret = (ctx->func)(ctx->dir,
> + (next_real_entry > offset) ?
> + DIRENT_DELETED_FILE : entry,
> + dirent, offset,
> + buf_len, buf,
> + ctx->priv_data);
> + if (entry < DIRENT_OTHER_FILE)
> + entry++;
> +
> + if (ret & DIRENT_CHANGED) {
> + if (ext2fs_get_rec_len(fs, dirent, &rec_len))
> + return BLOCK_ABORT;
> + changed++;
> + }
> + if (ret & DIRENT_ABORT) {
> + do_abort++;
> + break;
> + }
> +next:
> + if (next_real_entry == offset)
> + next_real_entry += rec_len;
> +
> + if (ctx->flags & DIRENT_FLAG_INCLUDE_REMOVED) {
> + size = ((dirent->name_len & 0xFF) + 11) & ~3;
> +
> + if (rec_len != size) {
> + unsigned int final_offset;
> +
> + final_offset = offset + rec_len;
> + offset += size;
> + while (offset < final_offset &&
> + !ext2fs_validate_entry(fs, buf,
> + offset,
> + final_offset))
> + offset += 4;
> + continue;
> + }
> + }
> + offset += rec_len;
> + }
> +
> + if (changed) {
> + /* change parent ino */
> + if (buf_len == EXT2_DIR_REC_LEN(2))
> + ((struct ext2_dir_entry *)inode->i_block)->inode =
> + dirent->inode;
> + ctx->errcode = ext2fs_write_inode_full(fs, ctx->dir, (void *)inode,
> + EXT2_INODE_SIZE(fs->super));
> + if (ctx->errcode)
> + return BLOCK_ABORT;
> + }
> + if (do_abort)
> + return BLOCK_ABORT;
> + return 0;
> +}
> diff --git a/lib/ext2fs/ext2_err.et.in b/lib/ext2fs/ext2_err.et.in
> index 7e6d6e5..8a19cab 100644
> --- a/lib/ext2fs/ext2_err.et.in
> +++ b/lib/ext2fs/ext2_err.et.in
> @@ -68,6 +68,9 @@ ec EXT2_ET_MAGIC_EXTENT_HANDLE,
> ec EXT2_ET_BAD_MAGIC,
> "Bad magic number in super-block"
>
> +ec EXT2_ET_BAD_EXT_ATTR_MAGIC,
> + "Bad magic number in extend attribute"
"extended attribute"
> +
> ec EXT2_ET_REV_TOO_HIGH,
> "Filesystem revision too high"
>
> @@ -479,4 +482,7 @@ ec EXT2_ET_FILE_EXISTS,
> ec EXT2_ET_EXT_ATTR_CURRUPTED,
> "Extended attribute currupted"
>
> +ec EXT2_ET_BAD_EXTRA_SIZE,
> + "Bad inode extra isizevalue"
"i_extra_isize value"
> +
> end
> diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h
> index 0c0bbcb..d49b95c 100644
> --- a/lib/ext2fs/ext2_fs.h
> +++ b/lib/ext2fs/ext2_fs.h
> @@ -906,4 +906,12 @@ struct mmp_struct {
> */
> #define EXT4_MMP_MIN_CHECK_INTERVAL 5
>
> +struct inline_data {
> + __u16 inline_off;
> + __u16 inline_size;
> +};
> +
> +#define EXT4_MIN_INLINE_DATA_SIZE ((sizeof(__u32) * EXT2_N_BLOCKS))
> +#define EXT4_INLINE_DATA_DOTDOT_SIZE (4)
> +
> #endif /* _LINUX_EXT2_FS_H */
> diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
> index 8c30197..7b05b48 100644
> --- a/lib/ext2fs/ext2fs.h
> +++ b/lib/ext2fs/ext2fs.h
> @@ -1344,6 +1344,17 @@ extern errcode_t ext2fs_get_memalign(unsigned long size,
>
> /* inline_data.c */
> extern int ext2fs_inode_has_inline_data(ext2_filsys fs, ext2_ino_t ino);
> +extern errcode_t ext2fs_inline_data_iterate(ext2_filsys fs,
> + ext2_ino_t ino,
> + int flags,
> + char *block_buf,
> + int (*func)(ext2_filsys fs,
> + char *buf,
> + unsigned int buf_len,
> + e2_blkcnt_t blockcnt,
> + struct ext2_inode_large *inode,
> + void *priv_data),
> + void *priv_data);
>
> /* inode.c */
> extern void ext2fs_free_inode_cache(struct ext2_inode_cache *icache);
> diff --git a/lib/ext2fs/ext2fsP.h b/lib/ext2fs/ext2fsP.h
> index 3de9278..e86d452 100644
> --- a/lib/ext2fs/ext2fsP.h
> +++ b/lib/ext2fs/ext2fsP.h
> @@ -87,6 +87,17 @@ extern int ext2fs_process_dir_block(ext2_filsys fs,
> int ref_offset,
> void *priv_data);
>
> +extern int ext2fs_process_dir_inline_data(ext2_filsys fs,
> + char *buf,
> + unsigned int buf_len,
> + e2_blkcnt_t blockcnt,
> + struct ext2_inode_large *inode,
> + void *priv_data);
> +
> +extern errcode_t ext2fs_inline_data_find(ext2_filsys fs,
> + struct ext2_inode_large *inode,
> + struct inline_data *data);
> +
> /* Generic numeric progress meter */
>
> struct ext2fs_numeric_progress_struct {
> diff --git a/lib/ext2fs/inline_data.c b/lib/ext2fs/inline_data.c
> index fcf82b5..922c959 100644
> --- a/lib/ext2fs/inline_data.c
> +++ b/lib/ext2fs/inline_data.c
> @@ -14,10 +14,60 @@
> #include <time.h>
>
> #include "ext2_fs.h"
> +#include "ext2_ext_attr.h"
>
> #include "ext2fs.h"
> #include "ext2fsP.h"
>
> +static void *ext2fs_get_inline_xattr_pos(struct ext2_inode_large *inode,
> + struct inline_data *data);
> +
> +errcode_t ext2fs_inline_data_find(ext2_filsys fs,
> + struct ext2_inode_large *inode,
> + struct inline_data *data)
> +{
> + errcode_t retval;
> +
> + struct ext2_ext_attr_search s = {
> + .not_found = ENODATA,
> + };
> + struct ext2_ext_attr_info i = {
> + .name_index = EXT4_EXT_ATTR_INDEX_SYSTEM,
> + .name = EXT4_EXT_ATTR_SYSTEM_DATA,
> + };
> +
> + data->inline_off = 0;
> + if (inode->i_extra_isize > (EXT2_INODE_SIZE(fs->super) -
> + EXT2_GOOD_OLD_INODE_SIZE))
> + return EXT2_ET_BAD_EXTRA_SIZE;
> +
> + retval = ext2fs_ext_attr_ibody_find(fs, inode, &i, &s);
> + if (retval)
> + return retval;
> +
> + if (!s.not_found) {
> + data->inline_off = (__u16)((char *)s.here - (char *)inode);
> + data->inline_size = EXT4_MIN_INLINE_DATA_SIZE +
> + s.here->e_value_size;
> + return 0;
> + }
> +
> + return EXT2_ET_BAD_EXT_ATTR_MAGIC;
> +}
> +
> +static void *ext2fs_get_inline_xattr_pos(struct ext2_inode_large *inode,
> + struct inline_data *data)
> +{
> + struct ext2_ext_attr_entry *entry;
> + struct ext2_ext_attr_ibody_header *header;
> +
> + header = IHDR(inode);
> + entry = (struct ext2_ext_attr_entry *)
> + ((char *)inode + data->inline_off);
> +
> + return (void *) (IFIRST(header) + entry->e_value_offs);
> +}
> +
> int ext2fs_inode_has_inline_data(ext2_filsys fs, ext2_ino_t ino)
> {
> struct ext2_inode inode;
> @@ -29,3 +79,85 @@ int ext2fs_inode_has_inline_data(ext2_filsys fs, ext2_ino_t ino)
>
> return (inode.i_flags & EXT4_INLINE_DATA_FL);
> }
> +
> +errcode_t ext2fs_inline_data_iterate(ext2_filsys fs,
> + ext2_ino_t ino,
> + int flags,
> + char *block_buf,
> + int (*func)(ext2_filsys fs,
> + char *buf,
> + unsigned int buf_len,
> + e2_blkcnt_t blockcnt,
> + struct ext2_inode_large *inode,
> + void *priv_data),
> + void *priv_data)
> +{
> + struct dir_context *ctx;
> + struct ext2_inode_large *inode;
> + struct ext2_dir_entry dirent;
> + struct inline_data data;
> + errcode_t retval = 0;
> + e2_blkcnt_t blockcnt = 0;
> + void *inline_start;
> + int inline_size;
> +
> + ctx = (struct dir_context *)priv_data;
> +
> + retval = ext2fs_get_mem(EXT2_INODE_SIZE(fs->super), &inode);
> + if (retval)
> + return retval;
> +
> + retval = ext2fs_read_inode_full(fs, ino, (void *)inode,
> + EXT2_INODE_SIZE(fs->super));
> + if (retval)
> + goto out;
> +
> + if (inode->i_size == 0)
> + goto out;
> +
> + /* we first check '.' and '..' dir */
> + dirent.inode = ino;
> + dirent.name_len = 1;
> + ext2fs_set_rec_len(fs, EXT2_DIR_REC_LEN(2), &dirent);
> + dirent.name[0] = '.';
> + dirent.name[1] = '\0';
> + retval |= (*func)(fs, (void *)&dirent, dirent.rec_len, blockcnt++,
> + inode, priv_data);
> + if (retval & BLOCK_ABORT)
> + goto out;
> +
> + dirent.inode = (__u32)*inode->i_block;
> + dirent.name_len = 2;
> + ext2fs_set_rec_len(fs, EXT2_DIR_REC_LEN(3), &dirent);
> + dirent.name[0] = '.';
> + dirent.name[1] = '.';
> + dirent.name[2] = '\0';
> + retval |= (*func)(fs, (void *)&dirent, dirent.rec_len, blockcnt++,
> + inode, priv_data);
> + if (retval & BLOCK_ABORT)
> + goto out;
Perhaps this function should be called ext2fs_inline_dirblock_iterate()?
The name alone makes me think this function could work for regular inline_data
files, if such things ever exist.
--D
> +
> + inline_start = (char *)inode->i_block + EXT4_INLINE_DATA_DOTDOT_SIZE;
> + inline_size = EXT4_MIN_INLINE_DATA_SIZE - EXT4_INLINE_DATA_DOTDOT_SIZE;
> + retval |= (*func)(fs, inline_start, inline_size, blockcnt++,
> + inode, priv_data);
> + if (retval & BLOCK_ABORT)
> + goto out;
> +
> + retval = ext2fs_inline_data_find(fs, inode, &data);
> + if (retval)
> + goto out;
> + if (data.inline_size > EXT4_MIN_INLINE_DATA_SIZE) {
> + inline_start = ext2fs_get_inline_xattr_pos(inode, &data);
> + inline_size = data.inline_size - EXT4_MIN_INLINE_DATA_SIZE;
> + retval |= (*func)(fs, inline_start, inline_size, blockcnt++,
> + inode, priv_data);
> + if (retval & BLOCK_ABORT)
> + goto out;
> + }
> +
> +out:
> + retval |= BLOCK_ERROR;
> + ext2fs_free_mem(&inode);
> + return retval & BLOCK_ERROR ? ctx->errcode : 0;
> +}
> --
> 1.7.9.7
>
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