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- #include <linux/fs.h>
- #include <linux/vfs.h>
- #include <linux/slab.h>
- #include <linux/string.h>
- #include <linux/dcache.h>
- #include <linux/xattr.h>
- #include "squashfs_fs.h"
- #include "squashfs_fs_sb.h"
- #include "squashfs_fs_i.h"
- #include "squashfs.h"
- #include "xattr.h"
- static int get_dir_index_using_name(struct super_block *sb,
- u64 *next_block, int *next_offset, u64 index_start,
- int index_offset, int i_count, const char *name,
- int len)
- {
- struct squashfs_sb_info *msblk = sb->s_fs_info;
- int i, length = 0, err;
- unsigned int size;
- struct squashfs_dir_index *index;
- char *str;
- TRACE("Entered get_dir_index_using_name, i_count %d\n", i_count);
- index = kmalloc(sizeof(*index) + SQUASHFS_NAME_LEN * 2 + 2, GFP_KERNEL);
- if (index == NULL) {
- ERROR("Failed to allocate squashfs_dir_index\n");
- goto out;
- }
- str = &index->name[SQUASHFS_NAME_LEN + 1];
- strncpy(str, name, len);
- str[len] = '\0';
- for (i = 0; i < i_count; i++) {
- err = squashfs_read_metadata(sb, index, &index_start,
- &index_offset, sizeof(*index));
- if (err < 0)
- break;
- size = le32_to_cpu(index->size) + 1;
- if (size > SQUASHFS_NAME_LEN)
- break;
- err = squashfs_read_metadata(sb, index->name, &index_start,
- &index_offset, size);
- if (err < 0)
- break;
- index->name[size] = '\0';
- if (strcmp(index->name, str) > 0)
- break;
- length = le32_to_cpu(index->index);
- *next_block = le32_to_cpu(index->start_block) +
- msblk->directory_table;
- }
- *next_offset = (length + *next_offset) % SQUASHFS_METADATA_SIZE;
- kfree(index);
- out:
-
- return length + 3;
- }
- static struct dentry *squashfs_lookup(struct inode *dir, struct dentry *dentry,
- unsigned int flags)
- {
- const unsigned char *name = dentry->d_name.name;
- int len = dentry->d_name.len;
- struct inode *inode = NULL;
- struct squashfs_sb_info *msblk = dir->i_sb->s_fs_info;
- struct squashfs_dir_header dirh;
- struct squashfs_dir_entry *dire;
- u64 block = squashfs_i(dir)->start + msblk->directory_table;
- int offset = squashfs_i(dir)->offset;
- int err, length;
- unsigned int dir_count, size;
- TRACE("Entered squashfs_lookup [%llx:%x]\n", block, offset);
- dire = kmalloc(sizeof(*dire) + SQUASHFS_NAME_LEN + 1, GFP_KERNEL);
- if (dire == NULL) {
- ERROR("Failed to allocate squashfs_dir_entry\n");
- return ERR_PTR(-ENOMEM);
- }
- if (len > SQUASHFS_NAME_LEN) {
- err = -ENAMETOOLONG;
- goto failed;
- }
- length = get_dir_index_using_name(dir->i_sb, &block, &offset,
- squashfs_i(dir)->dir_idx_start,
- squashfs_i(dir)->dir_idx_offset,
- squashfs_i(dir)->dir_idx_cnt, name, len);
- while (length < i_size_read(dir)) {
-
- err = squashfs_read_metadata(dir->i_sb, &dirh, &block,
- &offset, sizeof(dirh));
- if (err < 0)
- goto read_failure;
- length += sizeof(dirh);
- dir_count = le32_to_cpu(dirh.count) + 1;
- if (dir_count > SQUASHFS_DIR_COUNT)
- goto data_error;
- while (dir_count--) {
-
- err = squashfs_read_metadata(dir->i_sb, dire, &block,
- &offset, sizeof(*dire));
- if (err < 0)
- goto read_failure;
- size = le16_to_cpu(dire->size) + 1;
-
- if (size > SQUASHFS_NAME_LEN)
- goto data_error;
- err = squashfs_read_metadata(dir->i_sb, dire->name,
- &block, &offset, size);
- if (err < 0)
- goto read_failure;
- length += sizeof(*dire) + size;
- if (name[0] < dire->name[0])
- goto exit_lookup;
- if (len == size && !strncmp(name, dire->name, len)) {
- unsigned int blk, off, ino_num;
- long long ino;
- blk = le32_to_cpu(dirh.start_block);
- off = le16_to_cpu(dire->offset);
- ino_num = le32_to_cpu(dirh.inode_number) +
- (short) le16_to_cpu(dire->inode_number);
- ino = SQUASHFS_MKINODE(blk, off);
- TRACE("calling squashfs_iget for directory "
- "entry %s, inode %x:%x, %d\n", name,
- blk, off, ino_num);
- inode = squashfs_iget(dir->i_sb, ino, ino_num);
- goto exit_lookup;
- }
- }
- }
- exit_lookup:
- kfree(dire);
- return d_splice_alias(inode, dentry);
- data_error:
- err = -EIO;
- read_failure:
- ERROR("Unable to read directory block [%llx:%x]\n",
- squashfs_i(dir)->start + msblk->directory_table,
- squashfs_i(dir)->offset);
- failed:
- kfree(dire);
- return ERR_PTR(err);
- }
- const struct inode_operations squashfs_dir_inode_ops = {
- .lookup = squashfs_lookup,
- .listxattr = squashfs_listxattr
- };
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