linux/fs/ext4/dir.c
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

664 lines
17 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/ext4/dir.c
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* from
*
* linux/fs/minix/dir.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* ext4 directory handling functions
*
* Big-endian to little-endian byte-swapping/bitmaps by
* David S. Miller (davem@caip.rutgers.edu), 1995
*
* Hash Tree Directory indexing (c) 2001 Daniel Phillips
*
*/
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/slab.h>
#include "ext4.h"
#include "xattr.h"
static int ext4_dx_readdir(struct file *, struct dir_context *);
/**
* Check if the given dir-inode refers to an htree-indexed directory
* (or a directory which could potentially get converted to use htree
* indexing).
*
* Return 1 if it is a dx dir, 0 if not
*/
static int is_dx_dir(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
if (ext4_has_feature_dir_index(inode->i_sb) &&
((ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) ||
((inode->i_size >> sb->s_blocksize_bits) == 1) ||
ext4_has_inline_data(inode)))
return 1;
return 0;
}
/*
* 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,
struct ext4_dir_entry_2 *de,
struct buffer_head *bh, char *buf, int size,
unsigned int offset)
{
const char *error_msg = NULL;
const int rlen = ext4_rec_len_from_disk(de->rec_len,
dir->i_sb->s_blocksize);
if (unlikely(rlen < EXT4_DIR_REC_LEN(1)))
error_msg = "rec_len is smaller than minimal";
else if (unlikely(rlen % 4 != 0))
error_msg = "rec_len % 4 != 0";
else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len)))
error_msg = "rec_len is too small for name_len";
else if (unlikely(((char *) de - buf) + rlen > size))
error_msg = "directory entry across range";
else if (unlikely(le32_to_cpu(de->inode) >
le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count)))
error_msg = "inode out of bounds";
else
return 0;
if (filp)
ext4_error_file(filp, function, line, bh->b_blocknr,
"bad entry in directory: %s - offset=%u(%u), "
"inode=%u, rec_len=%d, name_len=%d",
error_msg, (unsigned) (offset % size),
offset, le32_to_cpu(de->inode),
rlen, de->name_len);
else
ext4_error_inode(dir, function, line, bh->b_blocknr,
"bad entry in directory: %s - offset=%u(%u), "
"inode=%u, rec_len=%d, name_len=%d",
error_msg, (unsigned) (offset % size),
offset, le32_to_cpu(de->inode),
rlen, de->name_len);
return 1;
}
static int ext4_readdir(struct file *file, struct dir_context *ctx)
{
unsigned int offset;
int i;
struct ext4_dir_entry_2 *de;
int err;
struct inode *inode = file_inode(file);
struct super_block *sb = inode->i_sb;
struct buffer_head *bh = NULL;
int dir_has_error = 0;
struct fscrypt_str fstr = FSTR_INIT(NULL, 0);
if (ext4_encrypted_inode(inode)) {
err = fscrypt_get_encryption_info(inode);
if (err && err != -ENOKEY)
return err;
}
if (is_dx_dir(inode)) {
err = ext4_dx_readdir(file, ctx);
if (err != ERR_BAD_DX_DIR) {
return err;
}
/*
* We don't set the inode dirty flag since it's not
* critical that it get flushed back to the disk.
*/
ext4_clear_inode_flag(file_inode(file),
EXT4_INODE_INDEX);
}
if (ext4_has_inline_data(inode)) {
int has_inline_data = 1;
err = ext4_read_inline_dir(file, ctx,
&has_inline_data);
if (has_inline_data)
return err;
}
if (ext4_encrypted_inode(inode)) {
err = fscrypt_fname_alloc_buffer(inode, EXT4_NAME_LEN, &fstr);
if (err < 0)
return err;
}
offset = ctx->pos & (sb->s_blocksize - 1);
while (ctx->pos < inode->i_size) {
struct ext4_map_blocks map;
if (fatal_signal_pending(current)) {
err = -ERESTARTSYS;
goto errout;
}
cond_resched();
map.m_lblk = ctx->pos >> EXT4_BLOCK_SIZE_BITS(sb);
map.m_len = 1;
err = ext4_map_blocks(NULL, inode, &map, 0);
if (err > 0) {
pgoff_t index = map.m_pblk >>
(PAGE_SHIFT - inode->i_blkbits);
if (!ra_has_index(&file->f_ra, index))
page_cache_sync_readahead(
sb->s_bdev->bd_inode->i_mapping,
&file->f_ra, file,
index, 1);
file->f_ra.prev_pos = (loff_t)index << PAGE_SHIFT;
bh = ext4_bread(NULL, inode, map.m_lblk, 0);
if (IS_ERR(bh)) {
err = PTR_ERR(bh);
bh = NULL;
goto errout;
}
}
if (!bh) {
if (!dir_has_error) {
EXT4_ERROR_FILE(file, 0,
"directory contains a "
"hole at offset %llu",
(unsigned long long) ctx->pos);
dir_has_error = 1;
}
/* corrupt size? Maybe no more blocks to read */
if (ctx->pos > inode->i_blocks << 9)
break;
ctx->pos += sb->s_blocksize - offset;
continue;
}
/* Check the checksum */
if (!buffer_verified(bh) &&
!ext4_dirent_csum_verify(inode,
(struct ext4_dir_entry *)bh->b_data)) {
EXT4_ERROR_FILE(file, 0, "directory fails checksum "
"at offset %llu",
(unsigned long long)ctx->pos);
ctx->pos += sb->s_blocksize - offset;
brelse(bh);
bh = NULL;
continue;
}
set_buffer_verified(bh);
/* If the dir block 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 (file->f_version != inode->i_version) {
for (i = 0; i < sb->s_blocksize && i < offset; ) {
de = (struct ext4_dir_entry_2 *)
(bh->b_data + 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,
sb->s_blocksize) < EXT4_DIR_REC_LEN(1))
break;
i += ext4_rec_len_from_disk(de->rec_len,
sb->s_blocksize);
}
offset = i;
ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1))
| offset;
file->f_version = inode->i_version;
}
while (ctx->pos < inode->i_size
&& offset < sb->s_blocksize) {
de = (struct ext4_dir_entry_2 *) (bh->b_data + offset);
if (ext4_check_dir_entry(inode, file, de, bh,
bh->b_data, bh->b_size,
offset)) {
/*
* On error, skip to the next block
*/
ctx->pos = (ctx->pos |
(sb->s_blocksize - 1)) + 1;
break;
}
offset += ext4_rec_len_from_disk(de->rec_len,
sb->s_blocksize);
if (le32_to_cpu(de->inode)) {
if (!ext4_encrypted_inode(inode)) {
if (!dir_emit(ctx, de->name,
de->name_len,
le32_to_cpu(de->inode),
get_dtype(sb, de->file_type)))
goto done;
} else {
int save_len = fstr.len;
struct fscrypt_str de_name =
FSTR_INIT(de->name,
de->name_len);
/* Directory is encrypted */
err = fscrypt_fname_disk_to_usr(inode,
0, 0, &de_name, &fstr);
de_name = fstr;
fstr.len = save_len;
if (err)
goto errout;
if (!dir_emit(ctx,
de_name.name, de_name.len,
le32_to_cpu(de->inode),
get_dtype(sb, de->file_type)))
goto done;
}
}
ctx->pos += ext4_rec_len_from_disk(de->rec_len,
sb->s_blocksize);
}
if ((ctx->pos < inode->i_size) && !dir_relax_shared(inode))
goto done;
brelse(bh);
bh = NULL;
offset = 0;
}
done:
err = 0;
errout:
#ifdef CONFIG_EXT4_FS_ENCRYPTION
fscrypt_fname_free_buffer(&fstr);
#endif
brelse(bh);
return err;
}
static inline int is_32bit_api(void)
{
#ifdef CONFIG_COMPAT
return in_compat_syscall();
#else
return (BITS_PER_LONG == 32);
#endif
}
/*
* These functions convert from the major/minor hash to an f_pos
* value for dx directories
*
* Upper layer (for example NFS) should specify FMODE_32BITHASH or
* FMODE_64BITHASH explicitly. On the other hand, we allow ext4 to be mounted
* directly on both 32-bit and 64-bit nodes, under such case, neither
* FMODE_32BITHASH nor FMODE_64BITHASH is specified.
*/
static inline loff_t hash2pos(struct file *filp, __u32 major, __u32 minor)
{
if ((filp->f_mode & FMODE_32BITHASH) ||
(!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
return major >> 1;
else
return ((__u64)(major >> 1) << 32) | (__u64)minor;
}
static inline __u32 pos2maj_hash(struct file *filp, loff_t pos)
{
if ((filp->f_mode & FMODE_32BITHASH) ||
(!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
return (pos << 1) & 0xffffffff;
else
return ((pos >> 32) << 1) & 0xffffffff;
}
static inline __u32 pos2min_hash(struct file *filp, loff_t pos)
{
if ((filp->f_mode & FMODE_32BITHASH) ||
(!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
return 0;
else
return pos & 0xffffffff;
}
/*
* Return 32- or 64-bit end-of-file for dx directories
*/
static inline loff_t ext4_get_htree_eof(struct file *filp)
{
if ((filp->f_mode & FMODE_32BITHASH) ||
(!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
return EXT4_HTREE_EOF_32BIT;
else
return EXT4_HTREE_EOF_64BIT;
}
/*
* ext4_dir_llseek() calls generic_file_llseek_size to handle htree
* directories, where the "offset" is in terms of the filename hash
* value instead of the byte offset.
*
* Because we may return a 64-bit hash that is well beyond offset limits,
* we need to pass the max hash as the maximum allowable offset in
* the htree directory case.
*
* For non-htree, ext4_llseek already chooses the proper max offset.
*/
static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence)
{
struct inode *inode = file->f_mapping->host;
int dx_dir = is_dx_dir(inode);
loff_t htree_max = ext4_get_htree_eof(file);
if (likely(dx_dir))
return generic_file_llseek_size(file, offset, whence,
htree_max, htree_max);
else
return ext4_llseek(file, offset, whence);
}
/*
* This structure holds the nodes of the red-black tree used to store
* the directory entry in hash order.
*/
struct fname {
__u32 hash;
__u32 minor_hash;
struct rb_node rb_hash;
struct fname *next;
__u32 inode;
__u8 name_len;
__u8 file_type;
char name[0];
};
/*
* This functoin implements a non-recursive way of freeing all of the
* nodes in the red-black tree.
*/
static void free_rb_tree_fname(struct rb_root *root)
{
struct fname *fname, *next;
rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash)
while (fname) {
struct fname *old = fname;
fname = fname->next;
kfree(old);
}
*root = RB_ROOT;
}
static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp,
loff_t pos)
{
struct dir_private_info *p;
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p)
return NULL;
p->curr_hash = pos2maj_hash(filp, pos);
p->curr_minor_hash = pos2min_hash(filp, pos);
return p;
}
void ext4_htree_free_dir_info(struct dir_private_info *p)
{
free_rb_tree_fname(&p->root);
kfree(p);
}
/*
* Given a directory entry, enter it into the fname rb tree.
*
* When filename encryption is enabled, the dirent will hold the
* encrypted filename, while the htree will hold decrypted filename.
* The decrypted filename is passed in via ent_name. parameter.
*/
int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
__u32 minor_hash,
struct ext4_dir_entry_2 *dirent,
struct fscrypt_str *ent_name)
{
struct rb_node **p, *parent = NULL;
struct fname *fname, *new_fn;
struct dir_private_info *info;
int len;
info = dir_file->private_data;
p = &info->root.rb_node;
/* Create and allocate the fname structure */
len = sizeof(struct fname) + ent_name->len + 1;
new_fn = kzalloc(len, GFP_KERNEL);
if (!new_fn)
return -ENOMEM;
new_fn->hash = hash;
new_fn->minor_hash = minor_hash;
new_fn->inode = le32_to_cpu(dirent->inode);
new_fn->name_len = ent_name->len;
new_fn->file_type = dirent->file_type;
memcpy(new_fn->name, ent_name->name, ent_name->len);
new_fn->name[ent_name->len] = 0;
while (*p) {
parent = *p;
fname = rb_entry(parent, struct fname, rb_hash);
/*
* If the hash and minor hash match up, then we put
* them on a linked list. This rarely happens...
*/
if ((new_fn->hash == fname->hash) &&
(new_fn->minor_hash == fname->minor_hash)) {
new_fn->next = fname->next;
fname->next = new_fn;
return 0;
}
if (new_fn->hash < fname->hash)
p = &(*p)->rb_left;
else if (new_fn->hash > fname->hash)
p = &(*p)->rb_right;
else if (new_fn->minor_hash < fname->minor_hash)
p = &(*p)->rb_left;
else /* if (new_fn->minor_hash > fname->minor_hash) */
p = &(*p)->rb_right;
}
rb_link_node(&new_fn->rb_hash, parent, p);
rb_insert_color(&new_fn->rb_hash, &info->root);
return 0;
}
/*
* This is a helper function for ext4_dx_readdir. It calls filldir
* for all entres on the fname linked list. (Normally there is only
* one entry on the linked list, unless there are 62 bit hash collisions.)
*/
static int call_filldir(struct file *file, struct dir_context *ctx,
struct fname *fname)
{
struct dir_private_info *info = file->private_data;
struct inode *inode = file_inode(file);
struct super_block *sb = inode->i_sb;
if (!fname) {
ext4_msg(sb, KERN_ERR, "%s:%d: inode #%lu: comm %s: "
"called with null fname?!?", __func__, __LINE__,
inode->i_ino, current->comm);
return 0;
}
ctx->pos = hash2pos(file, fname->hash, fname->minor_hash);
while (fname) {
if (!dir_emit(ctx, fname->name,
fname->name_len,
fname->inode,
get_dtype(sb, fname->file_type))) {
info->extra_fname = fname;
return 1;
}
fname = fname->next;
}
return 0;
}
static int ext4_dx_readdir(struct file *file, struct dir_context *ctx)
{
struct dir_private_info *info = file->private_data;
struct inode *inode = file_inode(file);
struct fname *fname;
int ret;
if (!info) {
info = ext4_htree_create_dir_info(file, ctx->pos);
if (!info)
return -ENOMEM;
file->private_data = info;
}
if (ctx->pos == ext4_get_htree_eof(file))
return 0; /* EOF */
/* Some one has messed with f_pos; reset the world */
if (info->last_pos != ctx->pos) {
free_rb_tree_fname(&info->root);
info->curr_node = NULL;
info->extra_fname = NULL;
info->curr_hash = pos2maj_hash(file, ctx->pos);
info->curr_minor_hash = pos2min_hash(file, ctx->pos);
}
/*
* If there are any leftover names on the hash collision
* chain, return them first.
*/
if (info->extra_fname) {
if (call_filldir(file, ctx, info->extra_fname))
goto finished;
info->extra_fname = NULL;
goto next_node;
} else if (!info->curr_node)
info->curr_node = rb_first(&info->root);
while (1) {
/*
* Fill the rbtree if we have no more entries,
* or the inode has changed since we last read in the
* cached entries.
*/
if ((!info->curr_node) ||
(file->f_version != inode->i_version)) {
info->curr_node = NULL;
free_rb_tree_fname(&info->root);
file->f_version = inode->i_version;
ret = ext4_htree_fill_tree(file, info->curr_hash,
info->curr_minor_hash,
&info->next_hash);
if (ret < 0)
return ret;
if (ret == 0) {
ctx->pos = ext4_get_htree_eof(file);
break;
}
info->curr_node = rb_first(&info->root);
}
fname = rb_entry(info->curr_node, struct fname, rb_hash);
info->curr_hash = fname->hash;
info->curr_minor_hash = fname->minor_hash;
if (call_filldir(file, ctx, fname))
break;
next_node:
info->curr_node = rb_next(info->curr_node);
if (info->curr_node) {
fname = rb_entry(info->curr_node, struct fname,
rb_hash);
info->curr_hash = fname->hash;
info->curr_minor_hash = fname->minor_hash;
} else {
if (info->next_hash == ~0) {
ctx->pos = ext4_get_htree_eof(file);
break;
}
info->curr_hash = info->next_hash;
info->curr_minor_hash = 0;
}
}
finished:
info->last_pos = ctx->pos;
return 0;
}
static int ext4_dir_open(struct inode * inode, struct file * filp)
{
if (ext4_encrypted_inode(inode))
return fscrypt_get_encryption_info(inode) ? -EACCES : 0;
return 0;
}
static int ext4_release_dir(struct inode *inode, struct file *filp)
{
if (filp->private_data)
ext4_htree_free_dir_info(filp->private_data);
return 0;
}
int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf,
int buf_size)
{
struct ext4_dir_entry_2 *de;
int rlen;
unsigned int offset = 0;
char *top;
de = (struct ext4_dir_entry_2 *)buf;
top = buf + buf_size;
while ((char *) de < top) {
if (ext4_check_dir_entry(dir, NULL, de, bh,
buf, buf_size, offset))
return -EFSCORRUPTED;
rlen = ext4_rec_len_from_disk(de->rec_len, buf_size);
de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
offset += rlen;
}
if ((char *) de > top)
return -EFSCORRUPTED;
return 0;
}
const struct file_operations ext4_dir_operations = {
.llseek = ext4_dir_llseek,
.read = generic_read_dir,
.iterate_shared = ext4_readdir,
.unlocked_ioctl = ext4_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = ext4_compat_ioctl,
#endif
.fsync = ext4_sync_file,
.open = ext4_dir_open,
.release = ext4_release_dir,
};