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Message-Id: <1375436989-18948-10-git-send-email-wenqing.lz@taobao.com> Date: Fri, 2 Aug 2013 17:49:36 +0800 From: Zheng Liu <gnehzuil.liu@...il.com> To: linux-ext4@...r.kernel.org Cc: Theodore Ts'o <tytso@....edu>, Zheng Liu <wenqing.lz@...bao.com> Subject: [PATCH v1 09/22] libext2fs: handle inline data in read/write function From: Zheng Liu <wenqing.lz@...bao.com> Ext2fs_read/write_inline_data functions copy inline_data from/to user's buffer directly. When we want to write some data to a file with inline_data, ext2fs_try_to_write_inline_data is called. In this function, it firstly check the length of data. If the data can be saved in inode, this function will create a new extend attribute to record information of inline_data, and copy all data into this inode. The following commands in debugfs can handle inline_data feature after applying this patch: - dump - cat - rdump - write Signed-off-by: Theodore Ts'o <tytso@....edu> Signed-off-by: Zheng Liu <wenqing.lz@...bao.com> --- lib/ext2fs/ext2_err.et.in | 3 + lib/ext2fs/ext2fs.h | 7 ++ lib/ext2fs/fileio.c | 19 ++++- lib/ext2fs/inline_data.c | 179 ++++++++++++++++++++++++++++++++++++++++++++- 4 files changed, 206 insertions(+), 2 deletions(-) diff --git a/lib/ext2fs/ext2_err.et.in b/lib/ext2fs/ext2_err.et.in index 8a19cab..9252692 100644 --- a/lib/ext2fs/ext2_err.et.in +++ b/lib/ext2fs/ext2_err.et.in @@ -485,4 +485,7 @@ ec EXT2_ET_EXT_ATTR_CURRUPTED, ec EXT2_ET_BAD_EXTRA_SIZE, "Bad inode extra isizevalue" +ec EXT2_ET_INLINE_DATA_NO_SPACE, + "No free space in inline data" + end diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h index 934dbd0..2804748 100644 --- a/lib/ext2fs/ext2fs.h +++ b/lib/ext2fs/ext2fs.h @@ -1359,6 +1359,13 @@ extern errcode_t ext2fs_inline_data_iterate(ext2_filsys fs, extern errcode_t ext2fs_inline_data_create(ext2_filsys fs, struct ext2_inode_large *inode, unsigned int len); +extern errcode_t ext2fs_read_inline_data(ext2_filsys fs, ext2_ino_t ino, + char *buf); +extern errcode_t ext2fs_write_inline_data(ext2_filsys fs, ext2_ino_t ino, + char *buf); +extern errcode_t ext2fs_try_to_write_inline_data(ext2_filsys fs, ext2_ino_t ino, + const void *buf, unsigned int nbytes, + unsigned int *written); /* inode.c */ extern void ext2fs_free_inode_cache(struct ext2_inode_cache *icache); diff --git a/lib/ext2fs/fileio.c b/lib/ext2fs/fileio.c index 1f7002c..89c8ea6 100644 --- a/lib/ext2fs/fileio.c +++ b/lib/ext2fs/fileio.c @@ -163,7 +163,8 @@ static errcode_t sync_buffer_position(ext2_file_t file) b = file->pos / file->fs->blocksize; if (b != file->blockno) { - retval = ext2fs_file_flush(file); + if (!(file->inode.i_flags & EXT4_INLINE_DATA_FL)) + retval = ext2fs_file_flush(file); if (retval) return retval; file->flags &= ~EXT2_FILE_BUF_VALID; @@ -186,6 +187,12 @@ static errcode_t load_buffer(ext2_file_t file, int dontfill) ext2_filsys fs = file->fs; errcode_t retval; + /* We first handle inline_data */ + if (file->inode.i_flags & EXT4_INLINE_DATA_FL) { + retval = ext2fs_read_inline_data(fs, file->ino, file->buf); + return retval; + } + if (!(file->flags & EXT2_FILE_BUF_VALID)) { retval = ext2fs_bmap2(fs, file->ino, &file->inode, BMAP_BUFFER, 0, file->blockno, 0, @@ -280,6 +287,16 @@ errcode_t ext2fs_file_write(ext2_file_t file, const void *buf, if (!(file->flags & EXT2_FILE_WRITE)) return EXT2_ET_FILE_RO; + if (fs->super->s_feature_incompat & EXT4_FEATURE_INCOMPAT_INLINE_DATA) { + retval = ext2fs_try_to_write_inline_data(fs, file->ino, buf, + nbytes, written); + if (!retval) + return retval; + if (retval != EXT2_ET_INLINE_DATA_NO_SPACE) + return retval; + retval = 0; + } + while (nbytes > 0) { retval = sync_buffer_position(file); if (retval) diff --git a/lib/ext2fs/inline_data.c b/lib/ext2fs/inline_data.c index c936e28..5ca95ee 100644 --- a/lib/ext2fs/inline_data.c +++ b/lib/ext2fs/inline_data.c @@ -21,6 +21,8 @@ static void *ext2fs_get_inline_xattr_pos(struct ext2_inode_large *inode, struct inline_data *data); +static unsigned int ext2fs_get_max_inline_size(ext2_filsys fs, + struct ext2_inode_large *inode); static void ext2fs_inline_data_finish_convert(ext2_filsys fs, ext2_ino_t ino, char *target, char *buf, int inline_size); @@ -316,6 +318,74 @@ out: return retval & BLOCK_ERROR ? ctx->errcode : 0; } +errcode_t ext2fs_read_inline_data(ext2_filsys fs, ext2_ino_t ino, char *buf) +{ + struct ext2_inode_large *inode; + struct inline_data data; + errcode_t retval = 0; + unsigned int inline_size; + + 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 err; + + retval = ext2fs_inline_data_find(fs, inode, &data); + if (retval) + goto err; + + inline_size = data.inline_size; + + memcpy(buf, (void *)inode->i_block, EXT4_MIN_INLINE_DATA_SIZE); + if (inline_size > EXT4_MIN_INLINE_DATA_SIZE) + memcpy(buf + EXT4_MIN_INLINE_DATA_SIZE, + ext2fs_get_inline_xattr_pos(inode, &data), + inline_size - EXT4_MIN_INLINE_DATA_SIZE); + +err: + ext2fs_free_mem(&inode); + return retval; +} + +errcode_t ext2fs_write_inline_data(ext2_filsys fs, ext2_ino_t ino, char *buf) +{ + struct ext2_inode_large *inode; + struct inline_data data; + errcode_t retval = 0; + unsigned int inline_size; + + 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 err; + + retval = ext2fs_inline_data_find(fs, inode, &data); + if (retval) + goto err; + + inline_size = data.inline_size; + + memcpy((void *)inode->i_block, buf, EXT4_MIN_INLINE_DATA_SIZE); + if (inline_size > EXT4_MIN_INLINE_DATA_SIZE) + memcpy(ext2fs_get_inline_xattr_pos(inode, &data), + buf + EXT4_MIN_INLINE_DATA_SIZE, + inline_size - EXT4_MIN_INLINE_DATA_SIZE); + + retval = ext2fs_write_inode_full(fs, ino, (void *)inode, + EXT2_INODE_SIZE(fs->super)); +err: + ext2fs_free_mem(&inode); + return retval; +} + errcode_t ext2fs_inline_data_convert(ext2_filsys fs, ext2_ino_t ino, void *priv_data) @@ -430,6 +500,114 @@ out: return retval; } +static unsigned int ext2fs_get_max_inline_size(ext2_filsys fs, + struct ext2_inode_large *inode) +{ + struct ext2_ext_attr_entry *entry; + struct ext2_ext_attr_ibody_header *header; + struct inline_data data; + errcode_t retval = 0; + size_t freesize, min_offs; + + min_offs = EXT2_INODE_SIZE(fs->super) - + EXT2_GOOD_OLD_INODE_SIZE - + inode->i_extra_isize - + sizeof(struct ext2_ext_attr_ibody_header); + + header = IHDR(inode); + entry = IFIRST(header); + + for (; !EXT2_EXT_IS_LAST_ENTRY(entry); + entry = EXT2_EXT_ATTR_NEXT(entry)) { + if (!entry->e_value_block && entry->e_value_size) { + size_t offs = entry->e_value_offs; + if (offs < min_offs) + min_offs = offs; + } + } + freesize = min_offs - + ((char *)entry - (char *)IFIRST(header)) - sizeof(__u32); + + /* + * We try to get inline data offset, but maybe it doesn't be + * created. So we ignore this error. + */ + retval = ext2fs_inline_data_find(fs, inode, &data); + if (retval && retval != EXT2_ET_BAD_EXT_ATTR_MAGIC) + return 0; + + if (data.inline_off) { + entry = (struct ext2_ext_attr_entry *) + ((char *)inode + data.inline_off); + freesize += entry->e_value_size; + goto out; + } + + freesize -= EXT2_EXT_ATTR_LEN(strlen(EXT4_EXT_ATTR_SYSTEM_DATA)); + + if (freesize > EXT2_EXT_ATTR_ROUND) + freesize = EXT2_EXT_ATTR_SIZE(freesize - EXT2_EXT_ATTR_ROUND); + else + freesize = 0; + +out: + return freesize + EXT4_MIN_INLINE_DATA_SIZE; +} + +errcode_t ext2fs_try_to_write_inline_data(ext2_filsys fs, ext2_ino_t ino, + const void *buf, unsigned int nbytes, + unsigned int *written) +{ + struct ext2_inode_large *inode; + struct inline_data data; + errcode_t retval = 0; + unsigned int inline_size = 0; + + 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 (nbytes > ext2fs_get_max_inline_size(fs, inode)) { + retval = EXT2_ET_INLINE_DATA_NO_SPACE; + goto out; + } + + retval = ext2fs_inline_data_create(fs, inode, nbytes); + if (retval) + goto out; + + retval = ext2fs_inline_data_find(fs, inode, &data); + if (retval) + goto out; + + inline_size = data.inline_size; + + memcpy((void *)inode->i_block, buf, EXT4_MIN_INLINE_DATA_SIZE); + if (inline_size > EXT4_MIN_INLINE_DATA_SIZE) + memcpy(ext2fs_get_inline_xattr_pos(inode, &data), + (const char *) buf + EXT4_MIN_INLINE_DATA_SIZE, + inline_size - EXT4_MIN_INLINE_DATA_SIZE); + + inode->i_flags &= ~EXT4_EXTENTS_FL; + inode->i_flags |= EXT4_INLINE_DATA_FL; + + retval = ext2fs_write_inode_full(fs, ino, (void *)inode, + EXT2_INODE_SIZE(fs->super)); + + if (!retval) + *written = nbytes; + else + *written = 0; + +out: + ext2fs_free_mem(&inode); + return retval; +} + errcode_t ext2fs_inline_data_create(ext2_filsys fs, struct ext2_inode_large *inode, unsigned int len) @@ -442,7 +620,6 @@ errcode_t ext2fs_inline_data_create(ext2_filsys fs, .name_index = EXT4_EXT_ATTR_INDEX_SYSTEM, .name = EXT4_EXT_ATTR_SYSTEM_DATA, }; - void *buf; errcode_t retval; if (len > EXT4_MIN_INLINE_DATA_SIZE) { -- 1.7.9.7 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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