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Message-Id: <1348286469-31690-10-git-send-email-wenqing.lz@taobao.com>
Date: Sat, 22 Sep 2012 12:00:57 +0800
From: Zheng Liu <gnehzuil.liu@...il.com>
To: linux-ext4@...r.kernel.org
Cc: tytso@....edu, Zheng Liu <wenqing.lz@...bao.com>
Subject: [PATCH 09/21 v5] 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 innode, 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: 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 | 170 +++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 198 insertions(+), 1 deletions(-)
diff --git a/lib/ext2fs/ext2_err.et.in b/lib/ext2fs/ext2_err.et.in
index 537d840..17de695 100644
--- a/lib/ext2fs/ext2_err.et.in
+++ b/lib/ext2fs/ext2_err.et.in
@@ -476,6 +476,9 @@ ec EXT2_ET_UNKNOWN_CSUM,
ec EXT2_ET_MMP_CSUM_INVALID,
"MMP block checksum does not match MMP block"
+ec EXT2_ET_INLINE_DATA_NO_SPACE,
+ "No free space in inline data"
+
ec EXT2_ET_BAD_EXTRA_SIZE,
"Bad inode extra isizevalue"
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 779eca5..801e2dd 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -1347,6 +1347,13 @@ extern errcode_t ext2fs_inline_data_mkdir(ext2_filsys fs, ext2_ino_t parent,
ext2_ino_t ino, const char *name);
extern errcode_t ext2fs_convert_inline_data(ext2_filsys fs, ext2_ino_t ino,
void *priv_data);
+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 errcode_t ext2fs_flush_icache(ext2_filsys fs);
diff --git a/lib/ext2fs/fileio.c b/lib/ext2fs/fileio.c
index 1f7002c..d751666 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 (!ext2fs_inode_has_inline_data(file->fs, file->ino))
+ 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 ef7b216..a847b68 100644
--- a/lib/ext2fs/inline_data.c
+++ b/lib/ext2fs/inline_data.c
@@ -24,6 +24,7 @@ static int ext2fs_iget_extra_inode(ext2_filsys fs, struct ext2_inode_large *inod
struct inline_data *data);
static void *ext2fs_get_inline_xattr_pos(struct ext2_inode_large *inode,
struct inline_data *data);
+static 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, void *buf,
int inline_size);
@@ -314,6 +315,73 @@ 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;
+ 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_iget_extra_inode(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;
+ 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_iget_extra_inode(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_convert_inline_data(ext2_filsys fs,
ext2_ino_t ino,
void *priv_data)
@@ -519,3 +587,105 @@ out:
ext2fs_free_mem(&inode);
return retval;
}
+
+static 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;
+ int free, 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 = ext2fs_le16_to_cpu(entry->e_value_offs);
+ if (offs < min_offs)
+ min_offs = offs;
+ }
+ }
+ free = min_offs -
+ ((void *)entry - (void *)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_iget_extra_inode(fs, inode, &data);
+ if (retval && retval != EXT2_ET_BAD_EXT_ATTR_MAGIC)
+ return 0;
+
+ if (data.inline_off) {
+ entry = (struct ext2_ext_attr_entry *)
+ ((void *)inode + data.inline_off);
+ free += ext2fs_le32_to_cpu(entry->e_value_size);
+ goto out;
+ }
+
+ free -= EXT2_EXT_ATTR_LEN(strlen(EXT4_EXT_ATTR_SYSTEM_DATA));
+
+ if (free > EXT2_EXT_ATTR_ROUND)
+ free = EXT2_EXT_ATTR_SIZE(free - EXT2_EXT_ATTR_ROUND);
+ else
+ free = 0;
+
+out:
+ return free + 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;
+ 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_create_inline_data(fs, inode, nbytes);
+ if (retval)
+ goto out;
+
+ retval = ext2fs_iget_extra_inode(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),
+ 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));
+
+out:
+ ext2fs_free_mem(&inode);
+ return retval;
+}
--
1.7.4.1
--
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