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![Linus Torvalds](/assets/img/avatar_default.png)
Pull misc mount API conversions from Al Viro: "Conversions to new API for shmem and friends and for mount_mtd()-using filesystems. As for the rest of the mount API conversions in -next, some of them belong in the individual trees (e.g. binderfs one should definitely go through android folks, after getting redone on top of their changes). I'm going to drop those and send the rest (trivial ones + stuff ACKed by maintainers) in a separate series - by that point they are independent from each other. Some stuff has already migrated into individual trees (NFS conversion, for example, or FUSE stuff, etc.); those presumably will go through the regular merges from corresponding trees." * 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: Make fs_parse() handle fs_param_is_fd-type params better vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API shmem_parse_one(): switch to use of fs_parse() shmem_parse_options(): take handling a single option into a helper shmem_parse_options(): don't bother with mpol in separate variable shmem_parse_options(): use a separate structure to keep the results make shmem_fill_super() static make ramfs_fill_super() static devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single() vfs: Convert squashfs to use the new mount API mtd: Kill mount_mtd() vfs: Convert jffs2 to use the new mount API vfs: Convert cramfs to use the new mount API vfs: Convert romfs to use the new mount API vfs: Add a single-or-reconfig keying to vfs_get_super()
501 lines
13 KiB
C
501 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Squashfs - a compressed read only filesystem for Linux
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*
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* Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
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* Phillip Lougher <phillip@squashfs.org.uk>
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*
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* super.c
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*/
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/*
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* This file implements code to read the superblock, read and initialise
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* in-memory structures at mount time, and all the VFS glue code to register
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* the filesystem.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/fs.h>
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#include <linux/fs_context.h>
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#include <linux/vfs.h>
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#include <linux/slab.h>
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#include <linux/mutex.h>
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#include <linux/pagemap.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/magic.h>
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#include <linux/xattr.h>
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#include "squashfs_fs.h"
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#include "squashfs_fs_sb.h"
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#include "squashfs_fs_i.h"
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#include "squashfs.h"
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#include "decompressor.h"
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#include "xattr.h"
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static struct file_system_type squashfs_fs_type;
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static const struct super_operations squashfs_super_ops;
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static const struct squashfs_decompressor *supported_squashfs_filesystem(
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struct fs_context *fc,
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short major, short minor, short id)
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{
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const struct squashfs_decompressor *decompressor;
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if (major < SQUASHFS_MAJOR) {
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errorf(fc, "Major/Minor mismatch, older Squashfs %d.%d "
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"filesystems are unsupported", major, minor);
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return NULL;
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} else if (major > SQUASHFS_MAJOR || minor > SQUASHFS_MINOR) {
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errorf(fc, "Major/Minor mismatch, trying to mount newer "
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"%d.%d filesystem", major, minor);
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errorf(fc, "Please update your kernel");
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return NULL;
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}
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decompressor = squashfs_lookup_decompressor(id);
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if (!decompressor->supported) {
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errorf(fc, "Filesystem uses \"%s\" compression. This is not supported",
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decompressor->name);
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return NULL;
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}
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return decompressor;
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}
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static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc)
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{
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struct squashfs_sb_info *msblk;
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struct squashfs_super_block *sblk = NULL;
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struct inode *root;
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long long root_inode;
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unsigned short flags;
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unsigned int fragments;
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u64 lookup_table_start, xattr_id_table_start, next_table;
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int err;
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TRACE("Entered squashfs_fill_superblock\n");
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sb->s_fs_info = kzalloc(sizeof(*msblk), GFP_KERNEL);
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if (sb->s_fs_info == NULL) {
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ERROR("Failed to allocate squashfs_sb_info\n");
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return -ENOMEM;
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}
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msblk = sb->s_fs_info;
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msblk->devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE);
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msblk->devblksize_log2 = ffz(~msblk->devblksize);
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mutex_init(&msblk->meta_index_mutex);
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/*
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* msblk->bytes_used is checked in squashfs_read_table to ensure reads
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* are not beyond filesystem end. But as we're using
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* squashfs_read_table here to read the superblock (including the value
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* of bytes_used) we need to set it to an initial sensible dummy value
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*/
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msblk->bytes_used = sizeof(*sblk);
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sblk = squashfs_read_table(sb, SQUASHFS_START, sizeof(*sblk));
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if (IS_ERR(sblk)) {
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errorf(fc, "unable to read squashfs_super_block");
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err = PTR_ERR(sblk);
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sblk = NULL;
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goto failed_mount;
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}
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err = -EINVAL;
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/* Check it is a SQUASHFS superblock */
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sb->s_magic = le32_to_cpu(sblk->s_magic);
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if (sb->s_magic != SQUASHFS_MAGIC) {
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if (!(fc->sb_flags & SB_SILENT))
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errorf(fc, "Can't find a SQUASHFS superblock on %pg",
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sb->s_bdev);
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goto failed_mount;
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}
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/* Check the MAJOR & MINOR versions and lookup compression type */
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msblk->decompressor = supported_squashfs_filesystem(
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fc,
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le16_to_cpu(sblk->s_major),
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le16_to_cpu(sblk->s_minor),
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le16_to_cpu(sblk->compression));
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if (msblk->decompressor == NULL)
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goto failed_mount;
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/* Check the filesystem does not extend beyond the end of the
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block device */
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msblk->bytes_used = le64_to_cpu(sblk->bytes_used);
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if (msblk->bytes_used < 0 || msblk->bytes_used >
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i_size_read(sb->s_bdev->bd_inode))
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goto failed_mount;
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/* Check block size for sanity */
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msblk->block_size = le32_to_cpu(sblk->block_size);
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if (msblk->block_size > SQUASHFS_FILE_MAX_SIZE)
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goto insanity;
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/*
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* Check the system page size is not larger than the filesystem
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* block size (by default 128K). This is currently not supported.
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*/
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if (PAGE_SIZE > msblk->block_size) {
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errorf(fc, "Page size > filesystem block size (%d). This is "
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"currently not supported!", msblk->block_size);
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goto failed_mount;
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}
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/* Check block log for sanity */
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msblk->block_log = le16_to_cpu(sblk->block_log);
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if (msblk->block_log > SQUASHFS_FILE_MAX_LOG)
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goto failed_mount;
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/* Check that block_size and block_log match */
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if (msblk->block_size != (1 << msblk->block_log))
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goto insanity;
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/* Check the root inode for sanity */
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root_inode = le64_to_cpu(sblk->root_inode);
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if (SQUASHFS_INODE_OFFSET(root_inode) > SQUASHFS_METADATA_SIZE)
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goto insanity;
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msblk->inode_table = le64_to_cpu(sblk->inode_table_start);
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msblk->directory_table = le64_to_cpu(sblk->directory_table_start);
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msblk->inodes = le32_to_cpu(sblk->inodes);
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msblk->fragments = le32_to_cpu(sblk->fragments);
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flags = le16_to_cpu(sblk->flags);
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TRACE("Found valid superblock on %pg\n", sb->s_bdev);
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TRACE("Inodes are %scompressed\n", SQUASHFS_UNCOMPRESSED_INODES(flags)
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? "un" : "");
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TRACE("Data is %scompressed\n", SQUASHFS_UNCOMPRESSED_DATA(flags)
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? "un" : "");
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TRACE("Filesystem size %lld bytes\n", msblk->bytes_used);
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TRACE("Block size %d\n", msblk->block_size);
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TRACE("Number of inodes %d\n", msblk->inodes);
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TRACE("Number of fragments %d\n", msblk->fragments);
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TRACE("Number of ids %d\n", le16_to_cpu(sblk->no_ids));
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TRACE("sblk->inode_table_start %llx\n", msblk->inode_table);
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TRACE("sblk->directory_table_start %llx\n", msblk->directory_table);
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TRACE("sblk->fragment_table_start %llx\n",
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(u64) le64_to_cpu(sblk->fragment_table_start));
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TRACE("sblk->id_table_start %llx\n",
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(u64) le64_to_cpu(sblk->id_table_start));
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sb->s_maxbytes = MAX_LFS_FILESIZE;
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sb->s_time_min = 0;
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sb->s_time_max = U32_MAX;
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sb->s_flags |= SB_RDONLY;
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sb->s_op = &squashfs_super_ops;
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err = -ENOMEM;
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msblk->block_cache = squashfs_cache_init("metadata",
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SQUASHFS_CACHED_BLKS, SQUASHFS_METADATA_SIZE);
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if (msblk->block_cache == NULL)
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goto failed_mount;
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/* Allocate read_page block */
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msblk->read_page = squashfs_cache_init("data",
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squashfs_max_decompressors(), msblk->block_size);
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if (msblk->read_page == NULL) {
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errorf(fc, "Failed to allocate read_page block");
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goto failed_mount;
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}
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msblk->stream = squashfs_decompressor_setup(sb, flags);
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if (IS_ERR(msblk->stream)) {
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err = PTR_ERR(msblk->stream);
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msblk->stream = NULL;
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goto insanity;
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}
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/* Handle xattrs */
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sb->s_xattr = squashfs_xattr_handlers;
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xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start);
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if (xattr_id_table_start == SQUASHFS_INVALID_BLK) {
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next_table = msblk->bytes_used;
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goto allocate_id_index_table;
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}
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/* Allocate and read xattr id lookup table */
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msblk->xattr_id_table = squashfs_read_xattr_id_table(sb,
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xattr_id_table_start, &msblk->xattr_table, &msblk->xattr_ids);
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if (IS_ERR(msblk->xattr_id_table)) {
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errorf(fc, "unable to read xattr id index table");
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err = PTR_ERR(msblk->xattr_id_table);
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msblk->xattr_id_table = NULL;
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if (err != -ENOTSUPP)
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goto failed_mount;
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}
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next_table = msblk->xattr_table;
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allocate_id_index_table:
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/* Allocate and read id index table */
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msblk->id_table = squashfs_read_id_index_table(sb,
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le64_to_cpu(sblk->id_table_start), next_table,
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le16_to_cpu(sblk->no_ids));
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if (IS_ERR(msblk->id_table)) {
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errorf(fc, "unable to read id index table");
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err = PTR_ERR(msblk->id_table);
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msblk->id_table = NULL;
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goto failed_mount;
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}
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next_table = le64_to_cpu(msblk->id_table[0]);
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/* Handle inode lookup table */
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lookup_table_start = le64_to_cpu(sblk->lookup_table_start);
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if (lookup_table_start == SQUASHFS_INVALID_BLK)
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goto handle_fragments;
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/* Allocate and read inode lookup table */
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msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb,
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lookup_table_start, next_table, msblk->inodes);
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if (IS_ERR(msblk->inode_lookup_table)) {
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errorf(fc, "unable to read inode lookup table");
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err = PTR_ERR(msblk->inode_lookup_table);
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msblk->inode_lookup_table = NULL;
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goto failed_mount;
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}
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next_table = le64_to_cpu(msblk->inode_lookup_table[0]);
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sb->s_export_op = &squashfs_export_ops;
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handle_fragments:
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fragments = msblk->fragments;
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if (fragments == 0)
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goto check_directory_table;
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msblk->fragment_cache = squashfs_cache_init("fragment",
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SQUASHFS_CACHED_FRAGMENTS, msblk->block_size);
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if (msblk->fragment_cache == NULL) {
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err = -ENOMEM;
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goto failed_mount;
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}
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/* Allocate and read fragment index table */
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msblk->fragment_index = squashfs_read_fragment_index_table(sb,
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le64_to_cpu(sblk->fragment_table_start), next_table, fragments);
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if (IS_ERR(msblk->fragment_index)) {
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errorf(fc, "unable to read fragment index table");
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err = PTR_ERR(msblk->fragment_index);
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msblk->fragment_index = NULL;
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goto failed_mount;
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}
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next_table = le64_to_cpu(msblk->fragment_index[0]);
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check_directory_table:
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/* Sanity check directory_table */
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if (msblk->directory_table > next_table) {
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err = -EINVAL;
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goto insanity;
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}
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/* Sanity check inode_table */
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if (msblk->inode_table >= msblk->directory_table) {
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err = -EINVAL;
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goto insanity;
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}
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/* allocate root */
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root = new_inode(sb);
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if (!root) {
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err = -ENOMEM;
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goto failed_mount;
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}
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err = squashfs_read_inode(root, root_inode);
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if (err) {
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make_bad_inode(root);
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iput(root);
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goto failed_mount;
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}
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insert_inode_hash(root);
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sb->s_root = d_make_root(root);
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if (sb->s_root == NULL) {
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ERROR("Root inode create failed\n");
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err = -ENOMEM;
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goto failed_mount;
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}
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TRACE("Leaving squashfs_fill_super\n");
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kfree(sblk);
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return 0;
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insanity:
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errorf(fc, "squashfs image failed sanity check");
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failed_mount:
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squashfs_cache_delete(msblk->block_cache);
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squashfs_cache_delete(msblk->fragment_cache);
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squashfs_cache_delete(msblk->read_page);
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squashfs_decompressor_destroy(msblk);
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kfree(msblk->inode_lookup_table);
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kfree(msblk->fragment_index);
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kfree(msblk->id_table);
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kfree(msblk->xattr_id_table);
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kfree(sb->s_fs_info);
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sb->s_fs_info = NULL;
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kfree(sblk);
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return err;
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}
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static int squashfs_get_tree(struct fs_context *fc)
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{
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return get_tree_bdev(fc, squashfs_fill_super);
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}
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static int squashfs_reconfigure(struct fs_context *fc)
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{
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sync_filesystem(fc->root->d_sb);
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fc->sb_flags |= SB_RDONLY;
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return 0;
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}
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static const struct fs_context_operations squashfs_context_ops = {
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.get_tree = squashfs_get_tree,
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.reconfigure = squashfs_reconfigure,
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};
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static int squashfs_init_fs_context(struct fs_context *fc)
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{
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fc->ops = &squashfs_context_ops;
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return 0;
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}
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static int squashfs_statfs(struct dentry *dentry, struct kstatfs *buf)
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{
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struct squashfs_sb_info *msblk = dentry->d_sb->s_fs_info;
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u64 id = huge_encode_dev(dentry->d_sb->s_bdev->bd_dev);
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TRACE("Entered squashfs_statfs\n");
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buf->f_type = SQUASHFS_MAGIC;
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buf->f_bsize = msblk->block_size;
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buf->f_blocks = ((msblk->bytes_used - 1) >> msblk->block_log) + 1;
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buf->f_bfree = buf->f_bavail = 0;
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buf->f_files = msblk->inodes;
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buf->f_ffree = 0;
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buf->f_namelen = SQUASHFS_NAME_LEN;
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buf->f_fsid.val[0] = (u32)id;
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buf->f_fsid.val[1] = (u32)(id >> 32);
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return 0;
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}
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static void squashfs_put_super(struct super_block *sb)
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{
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if (sb->s_fs_info) {
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struct squashfs_sb_info *sbi = sb->s_fs_info;
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squashfs_cache_delete(sbi->block_cache);
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squashfs_cache_delete(sbi->fragment_cache);
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squashfs_cache_delete(sbi->read_page);
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squashfs_decompressor_destroy(sbi);
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kfree(sbi->id_table);
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kfree(sbi->fragment_index);
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kfree(sbi->meta_index);
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kfree(sbi->inode_lookup_table);
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kfree(sbi->xattr_id_table);
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kfree(sb->s_fs_info);
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sb->s_fs_info = NULL;
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}
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}
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static struct kmem_cache *squashfs_inode_cachep;
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static void init_once(void *foo)
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{
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struct squashfs_inode_info *ei = foo;
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inode_init_once(&ei->vfs_inode);
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}
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static int __init init_inodecache(void)
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{
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squashfs_inode_cachep = kmem_cache_create("squashfs_inode_cache",
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sizeof(struct squashfs_inode_info), 0,
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SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|SLAB_ACCOUNT,
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init_once);
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return squashfs_inode_cachep ? 0 : -ENOMEM;
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}
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static void destroy_inodecache(void)
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{
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/*
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* Make sure all delayed rcu free inodes are flushed before we
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* destroy cache.
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*/
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rcu_barrier();
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kmem_cache_destroy(squashfs_inode_cachep);
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}
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static int __init init_squashfs_fs(void)
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{
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int err = init_inodecache();
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if (err)
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return err;
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err = register_filesystem(&squashfs_fs_type);
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if (err) {
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destroy_inodecache();
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return err;
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}
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pr_info("version 4.0 (2009/01/31) Phillip Lougher\n");
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return 0;
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}
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static void __exit exit_squashfs_fs(void)
|
|
{
|
|
unregister_filesystem(&squashfs_fs_type);
|
|
destroy_inodecache();
|
|
}
|
|
|
|
|
|
static struct inode *squashfs_alloc_inode(struct super_block *sb)
|
|
{
|
|
struct squashfs_inode_info *ei =
|
|
kmem_cache_alloc(squashfs_inode_cachep, GFP_KERNEL);
|
|
|
|
return ei ? &ei->vfs_inode : NULL;
|
|
}
|
|
|
|
|
|
static void squashfs_free_inode(struct inode *inode)
|
|
{
|
|
kmem_cache_free(squashfs_inode_cachep, squashfs_i(inode));
|
|
}
|
|
|
|
static struct file_system_type squashfs_fs_type = {
|
|
.owner = THIS_MODULE,
|
|
.name = "squashfs",
|
|
.init_fs_context = squashfs_init_fs_context,
|
|
.kill_sb = kill_block_super,
|
|
.fs_flags = FS_REQUIRES_DEV
|
|
};
|
|
MODULE_ALIAS_FS("squashfs");
|
|
|
|
static const struct super_operations squashfs_super_ops = {
|
|
.alloc_inode = squashfs_alloc_inode,
|
|
.free_inode = squashfs_free_inode,
|
|
.statfs = squashfs_statfs,
|
|
.put_super = squashfs_put_super,
|
|
};
|
|
|
|
module_init(init_squashfs_fs);
|
|
module_exit(exit_squashfs_fs);
|
|
MODULE_DESCRIPTION("squashfs 4.0, a compressed read-only filesystem");
|
|
MODULE_AUTHOR("Phillip Lougher <phillip@squashfs.org.uk>");
|
|
MODULE_LICENSE("GPL");
|