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Date: Mon, 3 Mar 2014 15:31:54 -0800
From: "Darrick J. Wong" <darrick.wong@...cle.com>
To: "Theodore Ts'o" <tytso@....edu>
Cc: Zheng Liu <gnehzuil.liu@...il.com>, linux-ext4@...r.kernel.org,
Zheng Liu <wenqing.lz@...bao.com>
Subject: Re: [PATCH v3 11/30] libext2fs: handle inline data in dir iterator
function
On Mon, Mar 03, 2014 at 05:16:53PM -0500, Theodore Ts'o wrote:
> As I mentioend on today's call, there are some pretty serious issues
> with ext2fs_inline_data_dir_iterate(). In some places, it is
> returning an errcode_t, and in some cases, it was returning the
> BLOCK_ABORT, et. al flags (which would be an int).
Sorry I missed this week's call, I wasn't feeling well.
> Also, all of the callers of ext2fs_inline_data_dir_iterate() pass in
> ext2fs_process_dir_block(), and given that
> ext2fs_inline-data_dir_iterate() is a non-public function, it makes
> the code simpler and more maintable to call ext2fs_process_dir_block()
> directly. I think we would be better having a
> ext2fs_process_dir_buffer() function, instead of complicating the
> ext2fs_process_dir_block() interface, but that's a cleanup that we can
> do in a different commit.
>
> Here are the diffs that I had to apply to make everything be
> consistent. It was a pretty significant change, so I'd appreciate a
> second pair of eyes to sanity check what I changed. This diff is
> versus the state of the tree after applying your PATCH v3 11/30 diff.
>
> - Ted
>
> diff --git a/lib/ext2fs/dir_iterate.c b/lib/ext2fs/dir_iterate.c
> index 6bdfae5..8afccbe 100644
> --- a/lib/ext2fs/dir_iterate.c
> +++ b/lib/ext2fs/dir_iterate.c
> @@ -129,9 +129,7 @@ errcode_t ext2fs_dir_iterate2(ext2_filsys fs,
> ext2fs_free_mem(&ctx.buf);
> if (retval == EXT2_ET_INLINE_DATA_CANT_ITERATE) {
> ctx.flags |= DIRENT_FLAG_INCLUDE_INLINE_DATA;
> - retval = ext2fs_inline_data_dir_iterate(fs, dir,
> - ext2fs_process_dir_block,
> - &ctx);
> + (void) ext2fs_inline_data_dir_iterate(fs, dir, &ctx);
> }
> if (retval)
> return retval;
Hmm. In order to get into ext2fs_inline_data_dir_iterate(), it has to be the
case that retval == EXT2_ET_INLINE_DATA_CANT_ITERATE. But then we immediately
return that error code, which means that anything interesting in ctx.errcode
will be lost. I /think/ you want to set retval = 0 in that if clause?
> diff --git a/lib/ext2fs/ext2fsP.h b/lib/ext2fs/ext2fsP.h
> index d910f42..b2afd15 100644
> --- a/lib/ext2fs/ext2fsP.h
> +++ b/lib/ext2fs/ext2fsP.h
> @@ -88,15 +88,9 @@ extern int ext2fs_process_dir_block(ext2_filsys fs,
> int ref_offset,
> void *priv_data);
>
> -extern errcode_t ext2fs_inline_data_dir_iterate(ext2_filsys fs,
> - ext2_ino_t ino,
> - int (*func)(ext2_filsys fs,
> - blk64_t *blocknr,
> - e2_blkcnt_t blockcnt,
> - blk64_t ref_blk,
> - int ref_offset,
> - void *priv_data),
> - void *priv_data);
> +extern int ext2fs_inline_data_dir_iterate(ext2_filsys fs,
> + ext2_ino_t ino,
> + void *priv_data);
>
> /* Generic numeric progress meter */
>
> diff --git a/lib/ext2fs/inline_data.c b/lib/ext2fs/inline_data.c
> index b768b9a..db1bc03 100644
> --- a/lib/ext2fs/inline_data.c
> +++ b/lib/ext2fs/inline_data.c
> @@ -78,36 +78,32 @@ err:
> }
>
>
> -errcode_t ext2fs_inline_data_dir_iterate(ext2_filsys fs,
> - ext2_ino_t ino,
> - int (*func)(ext2_filsys fs,
> - blk64_t *blocknr,
> - e2_blkcnt_t blockcnt,
> - blk64_t ref_blk,
> - int ref_offset,
> - void *priv_data),
> - void *priv_data)
> +int ext2fs_inline_data_dir_iterate(ext2_filsys fs, ext2_ino_t ino,
> + void *priv_data)
> {
> struct dir_context *ctx;
> struct ext2_inode inode;
> struct ext2_dir_entry dirent;
> struct ext2_inline_data data;
> - errcode_t retval = 0;
> + int ret = BLOCK_ABORT;
> e2_blkcnt_t blockcnt = 0;
>
> ctx = (struct dir_context *)priv_data;
>
> - retval = ext2fs_read_inode(fs, ino, &inode);
> - if (retval)
> + ctx->errcode = ext2fs_read_inode(fs, ino, &inode);
> + if (ctx->errcode)
> goto out;
>
> - if (!(inode.i_flags & EXT4_INLINE_DATA_FL))
> - return EXT2_ET_NO_INLINE_DATA;
> + if (!(inode.i_flags & EXT4_INLINE_DATA_FL)) {
> + ctx->errcode = EXT2_ET_NO_INLINE_DATA;
> + goto out;
> + }
>
> if (!LINUX_S_ISDIR(inode.i_mode)) {
> - retval = EXT2_ET_NO_DIRECTORY;
> + ctx->errcode = EXT2_ET_NO_DIRECTORY;
> goto out;
> }
> + ret = 0;
>
> /* we first check '.' and '..' dir */
> dirent.inode = ino;
> @@ -117,8 +113,8 @@ errcode_t ext2fs_inline_data_dir_iterate(ext2_filsys fs,
> dirent.name[1] = '\0';
> ctx->buf = (char *)&dirent;
> ext2fs_get_rec_len(fs, &dirent, &ctx->buflen);
> - retval |= (*func)(fs, 0, blockcnt++, 0, 0, priv_data);
> - if (retval & BLOCK_ABORT)
> + ret |= ext2fs_process_dir_block(fs, 0, blockcnt++, 0, 0, priv_data);
> + if (ret & BLOCK_ABORT)
> goto out;
>
> dirent.inode = ext2fs_le32_to_cpu(inode.i_block[0]);
> @@ -129,8 +125,8 @@ errcode_t ext2fs_inline_data_dir_iterate(ext2_filsys fs,
> dirent.name[2] = '\0';
> ctx->buf = (char *)&dirent;
> ext2fs_get_rec_len(fs, &dirent, &ctx->buflen);
> - retval |= (*func)(fs, 0, blockcnt++, 0, 0, priv_data);
> - if (retval & BLOCK_INLINE_DATA_CHANGED) {
> + ret |= ext2fs_process_dir_block(fs, 0, blockcnt++, 0, 0, priv_data);
> + if (ret & BLOCK_INLINE_DATA_CHANGED) {
> errcode_t err;
>
> inode.i_block[0] = ext2fs_cpu_to_le32(dirent.inode);
> @@ -138,62 +134,68 @@ errcode_t ext2fs_inline_data_dir_iterate(ext2_filsys fs,
> if (err)
> goto out;
> }
> - if (retval & BLOCK_ABORT)
> + if (ret & BLOCK_ABORT)
> goto out;
>
> ctx->buf = (char *)inode.i_block + EXT4_INLINE_DATA_DOTDOT_SIZE;
> ctx->buflen = EXT4_MIN_INLINE_DATA_SIZE - EXT4_INLINE_DATA_DOTDOT_SIZE;
> #ifdef WORDS_BIGENDIAN
> - retval = ext2fs_dirent_swab_in2(fs, ctx->buf, ctx->buflen, 0);
> - if (retval)
> + ctx->errcode = ext2fs_dirent_swab_in2(fs, ctx->buf, ctx->buflen, 0);
> + if (ctx->errcode) {
> + ret |= BLOCK_ABORT;
> goto out;
> + }
> #endif
> - retval |= (*func)(fs, 0, blockcnt++, 0, 0, priv_data);
> - if (retval & BLOCK_INLINE_DATA_CHANGED) {
> - errcode_t err;
> -
> + ret |= ext2fs_process_dir_block(fs, 0, blockcnt++, 0, 0, priv_data);
> + if (ret & BLOCK_INLINE_DATA_CHANGED) {
Was BLOCK_INLINE_DATA_CHANGED ever cleared from retval? As written, I /think/
that writing either dot or dotdot entries will result in the EA being written
too, even if nothing changes there.
Guess I'll have a look at the other patches too.
--D
> #ifdef WORDS_BIGENDIAN
> - err = ext2fs_dirent_swab_out2(fs, ctx->buf, ctx->buflen, 0);
> - if (err)
> + ctx->errcode = ext2fs_dirent_swab_out2(fs, ctx->buf,
> + ctx->buflen, 0);
> + if (ctx->errcode) {
> + ret |= BLOCK_ABORT;
> goto out;
> + }
> #endif
> - err = ext2fs_write_inode(fs, ino, &inode);
> - if (err)
> - goto out;
> + ctx->errcode = ext2fs_write_inode(fs, ino, &inode);
> + if (ctx->errcode)
> + ret |= BLOCK_ABORT;
> }
> - if (retval & BLOCK_ABORT)
> + if (ret & BLOCK_ABORT)
> goto out;
>
> data.fs = fs;
> data.ino = ino;
> - retval = ext2fs_inline_data_ea_get(&data);
> - if (retval)
> + ctx->errcode = ext2fs_inline_data_ea_get(&data);
> + if (ctx->errcode) {
> + ret |= BLOCK_ABORT;
> goto out;
> + }
> if (data.ea_size <= 0)
> goto out;
>
> ctx->buf = data.ea_data;
> ctx->buflen = data.ea_size;
> #ifdef WORDS_BIGENDIAN
> - retval = ext2fs_dirent_swab_in2(fs, ctx->buf, ctx->buflen, 0);
> - if (retval)
> + ctx.errcode = ext2fs_dirent_swab_in2(fs, ctx->buf, ctx->buflen, 0);
> + if (ctx.errcode) {
> + ret |= BLOCK_ABORT;
> goto out;
> + }
> #endif
>
> - retval |= (*func)(fs, 0, blockcnt++, 0, 0, priv_data);
> - if (retval & BLOCK_INLINE_DATA_CHANGED) {
> - errcode_t err;
> -
> + ret |= ext2fs_process_dir_block(fs, 0, blockcnt++, 0, 0, priv_data);
> + if (ret & BLOCK_INLINE_DATA_CHANGED) {
> #ifdef WORDS_BIGENDIAN
> - err = ext2fs_dirent_swab_out2(fs, ctx->buf, ctx->buflen, 0);
> - if (err) {
> - retval = err;
> + ctx->errcode = ext2fs_dirent_swab_out2(fs, ctx->buf,
> + ctx->buflen, 0);
> + if (ctx->errcode) {
> + ret |= BLOCK_ABORT;
> goto out1;
> }
> #endif
> - err = ext2fs_inline_data_ea_set(&data);
> - if (err)
> - retval = err;
> + ctx->errcode = ext2fs_inline_data_ea_set(&data);
> + if (ctx->errcode)
> + ret |= BLOCK_ABORT;
> }
>
> out1:
> @@ -201,6 +203,6 @@ out1:
> ctx->buf = 0;
>
> out:
> - retval &= ~(BLOCK_ABORT | BLOCK_INLINE_DATA_CHANGED);
> - return retval & BLOCK_ERROR ? ctx->errcode : retval;
> + ret &= ~(BLOCK_ABORT | BLOCK_INLINE_DATA_CHANGED);
> + return ret;
> }
> --
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