by Tao Ma

[permalink] [raw]

Subject: [PATCH V6 12/23] ext4: Let ext4_readdir handle inline data.

From: Tao Ma <[email protected]>

For "." and "..", we just call filldir by ourselves
instead of iterating the real dir entry.

Signed-off-by: Tao Ma <[email protected]>
---
fs/ext4/dir.c | 25 +++++-----
fs/ext4/ext4.h | 12 +++++
fs/ext4/inline.c | 136 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/ext4/xattr.h | 9 ++++
4 files changed, 169 insertions(+), 13 deletions(-)

diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 7c9d08b..b8d877f 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -27,23 +27,11 @@
#include <linux/slab.h>
#include <linux/rbtree.h>
#include "ext4.h"
-
-static unsigned char ext4_filetype_table[] = {
- DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
-};
+#include "xattr.h"

static int ext4_dx_readdir(struct file *filp,
void *dirent, filldir_t filldir);

-static unsigned char get_dtype(struct super_block *sb, int filetype)
-{
- if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
- (filetype >= EXT4_FT_MAX))
- return DT_UNKNOWN;
-
- return (ext4_filetype_table[filetype]);
-}
-
/**
* Check if the given dir-inode refers to an htree-indexed directory
* (or a directory which chould potentially get coverted to use htree
@@ -68,6 +56,9 @@ static int is_dx_dir(struct inode *inode)
* 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,
@@ -124,6 +115,14 @@ static int ext4_readdir(struct file *filp,
int ret = 0;
int dir_has_error = 0;

+ if (ext4_has_inline_data(inode)) {
+ int has_inline_data = 1;
+ ret = ext4_read_inline_dir(filp, dirent, filldir,
+ &has_inline_data);
+ if (has_inline_data)
+ return ret;
+ }
+
if (is_dx_dir(inode)) {
err = ext4_dx_readdir(filp, dirent, filldir);
if (err != ERR_BAD_DX_DIR) {
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index dd31b05..c7cd07e 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1957,6 +1957,18 @@ static inline void ext4_update_dx_flag(struct inode *inode)
EXT4_FEATURE_COMPAT_DIR_INDEX))
ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
}
+static unsigned char ext4_filetype_table[] = {
+ DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
+};
+
+static inline unsigned char get_dtype(struct super_block *sb, int filetype)
+{
+ if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) ||
+ (filetype >= EXT4_FT_MAX))
+ return DT_UNKNOWN;
+
+ return ext4_filetype_table[filetype];
+}

/* fsync.c */
extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 5a17543..8270265 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -1282,6 +1282,142 @@ 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.
diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
index 6fecf7b..7162662 100644
--- a/fs/ext4/xattr.h
+++ b/fs/ext4/xattr.h
@@ -168,6 +168,9 @@ extern int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
extern int ext4_try_create_inline_dir(handle_t *handle,
struct inode *parent,
struct inode *inode);
+extern int ext4_read_inline_dir(struct file *filp,
+ void *dirent, filldir_t filldir,
+ int *has_inline_data);
# else /* CONFIG_EXT4_FS_XATTR */

static inline int
@@ -345,6 +348,12 @@ static inline int ext4_try_create_inline_dir(handle_t *handle,
{
return 0;
}
+static inline int ext4_read_inline_dir(struct file *filp,
+ void *dirent, filldir_t filldir,
+ int *has_inline_data)
+{
+ return 0;
+}
# endif /* CONFIG_EXT4_FS_XATTR */

#ifdef CONFIG_EXT4_FS_SECURITY
--
1.7.1