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authorTao Ma <boyu.mt@taobao.com>2012-12-10 14:05:59 -0500
committerTheodore Ts'o <tytso@mit.edu>2012-12-10 14:05:59 -0500
commit65d165d9366dbf783d0102177006d47c8859ba31 (patch)
tree39a1699951de4aafad0a81a77d3b20de38925ee9 /fs/ext4/inline.c
parent3c47d54170b6a678875566b1b8d6dcf57904e49b (diff)
downloadop-kernel-dev-65d165d9366dbf783d0102177006d47c8859ba31.zip
op-kernel-dev-65d165d9366dbf783d0102177006d47c8859ba31.tar.gz
ext4: let ext4_readdir handle inline data
For "." and "..", we just call filldir by ourselves instead of iterating the real dir entry. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/inline.c')
-rw-r--r--fs/ext4/inline.c136
1 files changed, 136 insertions, 0 deletions
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index bf73228..4715041 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -1288,6 +1288,142 @@ out:
return ret;
}
+int ext4_read_inline_dir(struct file *filp,
+ void *dirent, filldir_t filldir,
+ int *has_inline_data)
+{
+ int error = 0;
+ unsigned int offset, parent_ino;
+ 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 = 0;
+ struct ext4_iloc iloc;
+ void *dir_buf = NULL;
+
+ ret = ext4_get_inode_loc(inode, &iloc);
+ if (ret)
+ return ret;
+
+ down_read(&EXT4_I(inode)->xattr_sem);
+ if (!ext4_has_inline_data(inode)) {
+ up_read(&EXT4_I(inode)->xattr_sem);
+ *has_inline_data = 0;
+ goto out;
+ }
+
+ inline_size = ext4_get_inline_size(inode);
+ dir_buf = kmalloc(inline_size, GFP_NOFS);
+ if (!dir_buf) {
+ ret = -ENOMEM;
+ up_read(&EXT4_I(inode)->xattr_sem);
+ goto out;
+ }
+
+ ret = ext4_read_inline_data(inode, dir_buf, inline_size, &iloc);
+ up_read(&EXT4_I(inode)->xattr_sem);
+ if (ret < 0)
+ goto out;
+
+ sb = inode->i_sb;
+ stored = 0;
+ parent_ino = le32_to_cpu(((struct ext4_dir_entry_2 *)dir_buf)->inode);
+
+ 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 inline
+ * dir to make sure.
+ */
+ if (filp->f_version != inode->i_version) {
+ for (i = 0;
+ i < inode->i_size && i < offset;) {
+ if (!i) {
+ /* skip "." and ".." if needed. */
+ i += EXT4_INLINE_DOTDOT_SIZE;
+ continue;
+ }
+ de = (struct ext4_dir_entry_2 *)
+ (dir_buf + 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) {
+ if (filp->f_pos == 0) {
+ error = filldir(dirent, ".", 1, 0, inode->i_ino,
+ DT_DIR);
+ if (error)
+ break;
+ stored++;
+
+ error = filldir(dirent, "..", 2, 0, parent_ino,
+ DT_DIR);
+ if (error)
+ break;
+ stored++;
+
+ filp->f_pos = offset = EXT4_INLINE_DOTDOT_SIZE;
+ continue;
+ }
+
+ de = (struct ext4_dir_entry_2 *)(dir_buf + offset);
+ if (ext4_check_dir_entry(inode, filp, de,
+ iloc.bh, dir_buf,
+ 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:
+ kfree(dir_buf);
+ brelse(iloc.bh);
+ return ret;
+}
+
/*
* Try to create the inline data for the new dir.
* If it succeeds, return 0, otherwise return the error.
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