mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 10:36:42 +07:00
9f2394c9be
This reverts commit 1028b55baf
.
It's broken: it makes ext4 return an error at an invalid point, causing
the readdir wrappers to write the the position of the last successful
directory entry into the position field, which means that the next
readdir will now return that last successful entry _again_.
You can only return fatal errors (that terminate the readdir directory
walk) from within the filesystem readdir functions, the "normal" errors
(that happen when the readdir buffer fills up, for example) happen in
the iterorator where we know the position of the actual failing entry.
I do have a very different patch that does the "signal_pending()"
handling inside the iterator function where it is allowable, but while
that one passes all the sanity checks, I screwed up something like four
times while emailing it out, so I'm not going to commit it today.
So my track record is not good enough, and the stars will have to align
better before that one gets committed. And it would be good to get some
review too, of course, since celestial alignments are always an iffy
debugging model.
IOW, let's just revert the commit that caused the problem for now.
Reported-by: Greg Thelen <gthelen@google.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
656 lines
17 KiB
C
656 lines
17 KiB
C
/*
|
|
* 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 ext4_str fname_crypto_str = {.name = NULL, .len = 0};
|
|
|
|
if (ext4_encrypted_inode(inode)) {
|
|
err = ext4_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 = ext4_fname_crypto_alloc_buffer(inode, EXT4_NAME_LEN,
|
|
&fname_crypto_str);
|
|
if (err < 0)
|
|
return err;
|
|
}
|
|
|
|
offset = ctx->pos & (sb->s_blocksize - 1);
|
|
|
|
while (ctx->pos < inode->i_size) {
|
|
struct ext4_map_blocks map;
|
|
|
|
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 = fname_crypto_str.len;
|
|
|
|
/* Directory is encrypted */
|
|
err = ext4_fname_disk_to_usr(inode,
|
|
NULL, de, &fname_crypto_str);
|
|
fname_crypto_str.len = save_len;
|
|
if (err < 0)
|
|
goto errout;
|
|
if (!dir_emit(ctx,
|
|
fname_crypto_str.name, err,
|
|
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(inode))
|
|
goto done;
|
|
brelse(bh);
|
|
bh = NULL;
|
|
offset = 0;
|
|
}
|
|
done:
|
|
err = 0;
|
|
errout:
|
|
#ifdef CONFIG_EXT4_FS_ENCRYPTION
|
|
ext4_fname_crypto_free_buffer(&fname_crypto_str);
|
|
#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(struct dir_private_info), 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 ext4_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 ext4_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 nlen, 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;
|
|
nlen = EXT4_DIR_REC_LEN(de->name_len);
|
|
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 = 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,
|
|
};
|