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Subject[PATCH V1 11/17] ext4: Let ext4_readdir handle inline data.
Date
From: Tao Ma <boyu.mt@taobao.com>

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
---
fs/ext4/dir.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 101 insertions(+), 0 deletions(-)

diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 6c2199e..8b88cfa 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -27,6 +27,7 @@
#include <linux/slab.h>
#include <linux/rbtree.h>
#include "ext4.h"
+#include "xattr.h"

static unsigned char ext4_filetype_table[] = {
DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
@@ -64,6 +65,9 @@ static unsigned char get_dtype(struct super_block *sb, int filetype)
* 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,
@@ -107,6 +111,100 @@ int __ext4_check_dir_entry(const char *function, unsigned int line,
return 1;
}

+static int ext4_read_inline_dir(struct file *filp,
+ void *dirent, filldir_t filldir)
+{
+ int error = 0;
+ unsigned int offset;
+ 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;
+ void *inline_pos;
+ struct ext4_iloc iloc;
+
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret)
+ return ret;
+
+ sb = inode->i_sb;
+ stored = 0;
+ offset = filp->f_pos & (sb->s_blocksize - 1);
+ inline_pos = ext4_get_inline_data_pos(inode, &iloc);
+ inline_size = ext4_get_max_inline_size(inode);
+
+ ext4_show_inline_dir(inode, iloc.bh, inline_pos, inline_size);
+
+ 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 block
+ * to make sure. */
+ if (filp->f_version != inode->i_version) {
+ for (i = 0; i < inode->i_size && i < offset; ) {
+ de = (struct ext4_dir_entry_2 *)
+ (inline_pos + 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
+ && offset < inline_size) {
+ de = (struct ext4_dir_entry_2 *) (inline_pos + offset);
+ if (ext4_check_dir_entry(inode, filp, de,
+ iloc.bh, inline_pos,
+ 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:
+ brelse(iloc.bh);
+ return ret;
+}
+
static int ext4_readdir(struct file *filp,
void *dirent, filldir_t filldir)
{
@@ -122,6 +220,9 @@ static int ext4_readdir(struct file *filp,

sb = inode->i_sb;

+ if (ext4_has_inline_data(inode))
+ return ext4_read_inline_dir(filp, dirent, filldir);
+
if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
EXT4_FEATURE_COMPAT_DIR_INDEX) &&
((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) ||
--
1.7.0.4


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