^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * Compressed rom filesystem for Linux.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * Copyright (C) 1999 Linus Torvalds.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * This file is released under the GPL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * These are the VFS interfaces to the compressed rom filesystem.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * The actual compression is based on zlib, see the other files.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/file.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/pagemap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/pfn_t.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/ramfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <linux/blkdev.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <linux/mtd/mtd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/mtd/super.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <linux/fs_context.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include <linux/vfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include <linux/mutex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #include <uapi/linux/cramfs_fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #include "internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) * cramfs super-block data in memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) struct cramfs_sb_info {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) unsigned long magic;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) unsigned long size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) unsigned long blocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) unsigned long files;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) void *linear_virt_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) resource_size_t linear_phys_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) size_t mtd_point_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) static inline struct cramfs_sb_info *CRAMFS_SB(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) return sb->s_fs_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) static const struct super_operations cramfs_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) static const struct inode_operations cramfs_dir_inode_operations;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) static const struct file_operations cramfs_directory_operations;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) static const struct file_operations cramfs_physmem_fops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) static const struct address_space_operations cramfs_aops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) static DEFINE_MUTEX(read_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) /* These macros may change in future, to provide better st_ino semantics. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) #define OFFSET(x) ((x)->i_ino)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) static unsigned long cramino(const struct cramfs_inode *cino, unsigned int offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) if (!cino->offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) return offset + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) if (!cino->size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) return offset + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) * The file mode test fixes buggy mkcramfs implementations where
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) * cramfs_inode->offset is set to a non zero value for entries
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) * which did not contain data, like devices node and fifos.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) switch (cino->mode & S_IFMT) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) case S_IFREG:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) case S_IFDIR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) case S_IFLNK:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) return cino->offset << 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) return offset + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) static struct inode *get_cramfs_inode(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) const struct cramfs_inode *cramfs_inode, unsigned int offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) struct inode *inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) static struct timespec64 zerotime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) inode = iget_locked(sb, cramino(cramfs_inode, offset));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) if (!inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) return ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) if (!(inode->i_state & I_NEW))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) return inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) switch (cramfs_inode->mode & S_IFMT) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) case S_IFREG:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) inode->i_fop = &generic_ro_fops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) inode->i_data.a_ops = &cramfs_aops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) if (IS_ENABLED(CONFIG_CRAMFS_MTD) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) CRAMFS_SB(sb)->flags & CRAMFS_FLAG_EXT_BLOCK_POINTERS &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) CRAMFS_SB(sb)->linear_phys_addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) inode->i_fop = &cramfs_physmem_fops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) case S_IFDIR:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) inode->i_op = &cramfs_dir_inode_operations;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) inode->i_fop = &cramfs_directory_operations;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) case S_IFLNK:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) inode->i_op = &page_symlink_inode_operations;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) inode_nohighmem(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) inode->i_data.a_ops = &cramfs_aops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) init_special_inode(inode, cramfs_inode->mode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) old_decode_dev(cramfs_inode->size));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) inode->i_mode = cramfs_inode->mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) i_uid_write(inode, cramfs_inode->uid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) i_gid_write(inode, cramfs_inode->gid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) /* if the lower 2 bits are zero, the inode contains data */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) if (!(inode->i_ino & 3)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) inode->i_size = cramfs_inode->size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) inode->i_blocks = (cramfs_inode->size - 1) / 512 + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) /* Struct copy intentional */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) inode->i_mtime = inode->i_atime = inode->i_ctime = zerotime;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) /* inode->i_nlink is left 1 - arguably wrong for directories,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) but it's the best we can do without reading the directory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) contents. 1 yields the right result in GNU find, even
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) without -noleaf option. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) unlock_new_inode(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) return inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) * We have our own block cache: don't fill up the buffer cache
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) * with the rom-image, because the way the filesystem is set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) * up the accesses should be fairly regular and cached in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) * page cache and dentry tree anyway..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) * This also acts as a way to guarantee contiguous areas of up to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) * BLKS_PER_BUF*PAGE_SIZE, so that the caller doesn't need to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) * worry about end-of-buffer issues even when decompressing a full
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) * page cache.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) * Note: This is all optimized away at compile time when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) * CONFIG_CRAMFS_BLOCKDEV=n.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) #define READ_BUFFERS (2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) /* NEXT_BUFFER(): Loop over [0..(READ_BUFFERS-1)]. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) #define NEXT_BUFFER(_ix) ((_ix) ^ 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) * BLKS_PER_BUF_SHIFT should be at least 2 to allow for "compressed"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) * data that takes up more space than the original and with unlucky
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) * alignment.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) #define BLKS_PER_BUF_SHIFT (2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) #define BLKS_PER_BUF (1 << BLKS_PER_BUF_SHIFT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) #define BUFFER_SIZE (BLKS_PER_BUF*PAGE_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) static unsigned char read_buffers[READ_BUFFERS][BUFFER_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) static unsigned buffer_blocknr[READ_BUFFERS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) static struct super_block *buffer_dev[READ_BUFFERS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) static int next_buffer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) * Populate our block cache and return a pointer to it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) unsigned int len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) struct page *pages[BLKS_PER_BUF];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) unsigned i, blocknr, buffer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) unsigned long devsize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) char *data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) if (!len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) blocknr = offset >> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) offset &= PAGE_SIZE - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) /* Check if an existing buffer already has the data.. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) for (i = 0; i < READ_BUFFERS; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) unsigned int blk_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) if (buffer_dev[i] != sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) if (blocknr < buffer_blocknr[i])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) blk_offset = (blocknr - buffer_blocknr[i]) << PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) blk_offset += offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) if (blk_offset > BUFFER_SIZE ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) blk_offset + len > BUFFER_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) return read_buffers[i] + blk_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) devsize = mapping->host->i_size >> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) /* Ok, read in BLKS_PER_BUF pages completely first. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) for (i = 0; i < BLKS_PER_BUF; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) struct page *page = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) if (blocknr + i < devsize) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) page = read_mapping_page(mapping, blocknr + i, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) /* synchronous error? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) if (IS_ERR(page))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) page = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) pages[i] = page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) for (i = 0; i < BLKS_PER_BUF; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) struct page *page = pages[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) if (page) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) wait_on_page_locked(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) if (!PageUptodate(page)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) /* asynchronous error */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) pages[i] = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) buffer = next_buffer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) next_buffer = NEXT_BUFFER(buffer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) buffer_blocknr[buffer] = blocknr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) buffer_dev[buffer] = sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) data = read_buffers[buffer];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) for (i = 0; i < BLKS_PER_BUF; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) struct page *page = pages[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) if (page) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) memcpy(data, kmap(page), PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) kunmap(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) memset(data, 0, PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) data += PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) return read_buffers[buffer] + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) * Return a pointer to the linearly addressed cramfs image in memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) static void *cramfs_direct_read(struct super_block *sb, unsigned int offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) unsigned int len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) if (!len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) if (len > sbi->size || offset > sbi->size - len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) return page_address(ZERO_PAGE(0));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) return sbi->linear_virt_addr + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) * Returns a pointer to a buffer containing at least LEN bytes of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) * filesystem starting at byte offset OFFSET into the filesystem.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) static void *cramfs_read(struct super_block *sb, unsigned int offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) unsigned int len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) if (IS_ENABLED(CONFIG_CRAMFS_MTD) && sbi->linear_virt_addr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) return cramfs_direct_read(sb, offset, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) else if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) return cramfs_blkdev_read(sb, offset, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) * For a mapping to be possible, we need a range of uncompressed and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) * contiguous blocks. Return the offset for the first block and number of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) * valid blocks for which that is true, or zero otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) static u32 cramfs_get_block_range(struct inode *inode, u32 pgoff, u32 *pages)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) struct cramfs_sb_info *sbi = CRAMFS_SB(inode->i_sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) u32 *blockptrs, first_block_addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) * We can dereference memory directly here as this code may be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) * reached only when there is a direct filesystem image mapping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) * available in memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) blockptrs = (u32 *)(sbi->linear_virt_addr + OFFSET(inode) + pgoff * 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) first_block_addr = blockptrs[0] & ~CRAMFS_BLK_FLAGS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) i = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) u32 block_off = i * (PAGE_SIZE >> CRAMFS_BLK_DIRECT_PTR_SHIFT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) u32 expect = (first_block_addr + block_off) |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) CRAMFS_BLK_FLAG_DIRECT_PTR |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) CRAMFS_BLK_FLAG_UNCOMPRESSED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) if (blockptrs[i] != expect) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) pr_debug("range: block %d/%d got %#x expects %#x\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) pgoff+i, pgoff + *pages - 1,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) blockptrs[i], expect);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) if (i == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) } while (++i < *pages);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) *pages = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) return first_block_addr << CRAMFS_BLK_DIRECT_PTR_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) #ifdef CONFIG_MMU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) * Return true if the last page of a file in the filesystem image contains
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) * some other data that doesn't belong to that file. It is assumed that the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) * last block is CRAMFS_BLK_FLAG_DIRECT_PTR | CRAMFS_BLK_FLAG_UNCOMPRESSED
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) * (verified by cramfs_get_block_range() and directly accessible in memory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) static bool cramfs_last_page_is_shared(struct inode *inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) struct cramfs_sb_info *sbi = CRAMFS_SB(inode->i_sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) u32 partial, last_page, blockaddr, *blockptrs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) char *tail_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) partial = offset_in_page(inode->i_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) if (!partial)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) last_page = inode->i_size >> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) blockptrs = (u32 *)(sbi->linear_virt_addr + OFFSET(inode));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) blockaddr = blockptrs[last_page] & ~CRAMFS_BLK_FLAGS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) blockaddr <<= CRAMFS_BLK_DIRECT_PTR_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) tail_data = sbi->linear_virt_addr + blockaddr + partial;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) return memchr_inv(tail_data, 0, PAGE_SIZE - partial) ? true : false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) static int cramfs_physmem_mmap(struct file *file, struct vm_area_struct *vma)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) struct inode *inode = file_inode(file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) struct cramfs_sb_info *sbi = CRAMFS_SB(inode->i_sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) unsigned int pages, max_pages, offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) unsigned long address, pgoff = vma->vm_pgoff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) char *bailout_reason;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) ret = generic_file_readonly_mmap(file, vma);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) * Now try to pre-populate ptes for this vma with a direct
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) * mapping avoiding memory allocation when possible.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) /* Could COW work here? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) bailout_reason = "vma is writable";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) if (vma->vm_flags & VM_WRITE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) goto bailout;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) max_pages = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) bailout_reason = "beyond file limit";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) if (pgoff >= max_pages)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) goto bailout;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) pages = min(vma_pages(vma), max_pages - pgoff);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) offset = cramfs_get_block_range(inode, pgoff, &pages);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) bailout_reason = "unsuitable block layout";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) if (!offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) goto bailout;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) address = sbi->linear_phys_addr + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) bailout_reason = "data is not page aligned";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) if (!PAGE_ALIGNED(address))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) goto bailout;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) /* Don't map the last page if it contains some other data */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) if (pgoff + pages == max_pages && cramfs_last_page_is_shared(inode)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) pr_debug("mmap: %s: last page is shared\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) file_dentry(file)->d_name.name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) pages--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) if (!pages) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) bailout_reason = "no suitable block remaining";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) goto bailout;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) if (pages == vma_pages(vma)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) * The entire vma is mappable. remap_pfn_range() will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) * make it distinguishable from a non-direct mapping
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) * in /proc/<pid>/maps by substituting the file offset
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) * with the actual physical address.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) ret = remap_pfn_range(vma, vma->vm_start, address >> PAGE_SHIFT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) pages * PAGE_SIZE, vma->vm_page_prot);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) * Let's create a mixed map if we can't map it all.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) * The normal paging machinery will take care of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) * unpopulated ptes via cramfs_readpage().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) vma->vm_flags |= VM_MIXEDMAP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) for (i = 0; i < pages && !ret; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) vm_fault_t vmf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) unsigned long off = i * PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) pfn_t pfn = phys_to_pfn_t(address + off, PFN_DEV);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) vmf = vmf_insert_mixed(vma, vma->vm_start + off, pfn);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) if (vmf & VM_FAULT_ERROR)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) ret = vm_fault_to_errno(vmf, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) if (!ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) pr_debug("mapped %s[%lu] at 0x%08lx (%u/%lu pages) "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) "to vma 0x%08lx, page_prot 0x%llx\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) file_dentry(file)->d_name.name, pgoff,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) address, pages, vma_pages(vma), vma->vm_start,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) (unsigned long long)pgprot_val(vma->vm_page_prot));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) bailout:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) pr_debug("%s[%lu]: direct mmap impossible: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) file_dentry(file)->d_name.name, pgoff, bailout_reason);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) /* Didn't manage any direct map, but normal paging is still possible */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) #else /* CONFIG_MMU */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) static int cramfs_physmem_mmap(struct file *file, struct vm_area_struct *vma)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -ENOSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) static unsigned long cramfs_physmem_get_unmapped_area(struct file *file,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) unsigned long addr, unsigned long len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) unsigned long pgoff, unsigned long flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) struct inode *inode = file_inode(file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) struct super_block *sb = inode->i_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) unsigned int pages, block_pages, max_pages, offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) pages = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) max_pages = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) if (pgoff >= max_pages || pages > max_pages - pgoff)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) block_pages = pages;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) offset = cramfs_get_block_range(inode, pgoff, &block_pages);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) if (!offset || block_pages != pages)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) return -ENOSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) addr = sbi->linear_phys_addr + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) pr_debug("get_unmapped for %s ofs %#lx siz %lu at 0x%08lx\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) file_dentry(file)->d_name.name, pgoff*PAGE_SIZE, len, addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) return addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) static unsigned int cramfs_physmem_mmap_capabilities(struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT |
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) NOMMU_MAP_READ | NOMMU_MAP_EXEC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) #endif /* CONFIG_MMU */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) static const struct file_operations cramfs_physmem_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) .llseek = generic_file_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) .read_iter = generic_file_read_iter,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) .splice_read = generic_file_splice_read,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) .mmap = cramfs_physmem_mmap,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) #ifndef CONFIG_MMU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) .get_unmapped_area = cramfs_physmem_get_unmapped_area,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) .mmap_capabilities = cramfs_physmem_mmap_capabilities,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) static void cramfs_kill_sb(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) if (IS_ENABLED(CONFIG_CRAMFS_MTD) && sb->s_mtd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) if (sbi && sbi->mtd_point_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) mtd_unpoint(sb->s_mtd, 0, sbi->mtd_point_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) kill_mtd_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) } else if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV) && sb->s_bdev) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) kill_block_super(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) kfree(sbi);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) static int cramfs_reconfigure(struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) sync_filesystem(fc->root->d_sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) fc->sb_flags |= SB_RDONLY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) static int cramfs_read_super(struct super_block *sb, struct fs_context *fc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) struct cramfs_super *super)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) unsigned long root_offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) bool silent = fc->sb_flags & SB_SILENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) /* We don't know the real size yet */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) sbi->size = PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) /* Read the first block and get the superblock from it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) mutex_lock(&read_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) memcpy(super, cramfs_read(sb, 0, sizeof(*super)), sizeof(*super));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) mutex_unlock(&read_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) /* Do sanity checks on the superblock */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) if (super->magic != CRAMFS_MAGIC) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) /* check for wrong endianness */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) if (super->magic == CRAMFS_MAGIC_WEND) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) if (!silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) errorfc(fc, "wrong endianness");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) /* check at 512 byte offset */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) mutex_lock(&read_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) memcpy(super,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) cramfs_read(sb, 512, sizeof(*super)),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) sizeof(*super));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) mutex_unlock(&read_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) if (super->magic != CRAMFS_MAGIC) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) if (super->magic == CRAMFS_MAGIC_WEND && !silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) errorfc(fc, "wrong endianness");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) else if (!silent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) errorfc(fc, "wrong magic");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) /* get feature flags first */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) if (super->flags & ~CRAMFS_SUPPORTED_FLAGS) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) errorfc(fc, "unsupported filesystem features");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) /* Check that the root inode is in a sane state */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) if (!S_ISDIR(super->root.mode)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) errorfc(fc, "root is not a directory");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) /* correct strange, hard-coded permissions of mkcramfs */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) super->root.mode |= 0555;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) root_offset = super->root.offset << 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) if (super->flags & CRAMFS_FLAG_FSID_VERSION_2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) sbi->size = super->size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) sbi->blocks = super->fsid.blocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) sbi->files = super->fsid.files;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) sbi->size = 1<<28;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) sbi->blocks = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) sbi->files = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) sbi->magic = super->magic;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) sbi->flags = super->flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) if (root_offset == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) infofc(fc, "empty filesystem");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) else if (!(super->flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) ((root_offset != sizeof(struct cramfs_super)) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) (root_offset != 512 + sizeof(struct cramfs_super))))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) errorfc(fc, "bad root offset %lu", root_offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) static int cramfs_finalize_super(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) struct cramfs_inode *cramfs_root)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) struct inode *root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) /* Set it all up.. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) sb->s_flags |= SB_RDONLY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) sb->s_time_min = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) sb->s_time_max = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) sb->s_op = &cramfs_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) root = get_cramfs_inode(sb, cramfs_root, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) if (IS_ERR(root))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) return PTR_ERR(root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) sb->s_root = d_make_root(root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) if (!sb->s_root)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) static int cramfs_blkdev_fill_super(struct super_block *sb, struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) struct cramfs_sb_info *sbi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) struct cramfs_super super;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) int i, err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) sbi = kzalloc(sizeof(struct cramfs_sb_info), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) if (!sbi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) sb->s_fs_info = sbi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) /* Invalidate the read buffers on mount: think disk change.. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) for (i = 0; i < READ_BUFFERS; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) buffer_blocknr[i] = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) err = cramfs_read_super(sb, fc, &super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) return cramfs_finalize_super(sb, &super.root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) static int cramfs_mtd_fill_super(struct super_block *sb, struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) struct cramfs_sb_info *sbi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) struct cramfs_super super;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) sbi = kzalloc(sizeof(struct cramfs_sb_info), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) if (!sbi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) sb->s_fs_info = sbi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) /* Map only one page for now. Will remap it when fs size is known. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) err = mtd_point(sb->s_mtd, 0, PAGE_SIZE, &sbi->mtd_point_size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) &sbi->linear_virt_addr, &sbi->linear_phys_addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) if (err || sbi->mtd_point_size != PAGE_SIZE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) pr_err("unable to get direct memory access to mtd:%s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) sb->s_mtd->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) return err ? : -ENODATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) pr_info("checking physical address %pap for linear cramfs image\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) &sbi->linear_phys_addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) err = cramfs_read_super(sb, fc, &super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) /* Remap the whole filesystem now */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) pr_info("linear cramfs image on mtd:%s appears to be %lu KB in size\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) sb->s_mtd->name, sbi->size/1024);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) mtd_unpoint(sb->s_mtd, 0, PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) err = mtd_point(sb->s_mtd, 0, sbi->size, &sbi->mtd_point_size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) &sbi->linear_virt_addr, &sbi->linear_phys_addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) if (err || sbi->mtd_point_size != sbi->size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) pr_err("unable to get direct memory access to mtd:%s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) sb->s_mtd->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) return err ? : -ENODATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) return cramfs_finalize_super(sb, &super.root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) static int cramfs_statfs(struct dentry *dentry, struct kstatfs *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) struct super_block *sb = dentry->d_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) u64 id = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) if (sb->s_bdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) id = huge_encode_dev(sb->s_bdev->bd_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) else if (sb->s_dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) id = huge_encode_dev(sb->s_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) buf->f_type = CRAMFS_MAGIC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) buf->f_bsize = PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) buf->f_blocks = CRAMFS_SB(sb)->blocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) buf->f_bfree = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) buf->f_bavail = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) buf->f_files = CRAMFS_SB(sb)->files;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) buf->f_ffree = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) buf->f_fsid = u64_to_fsid(id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) buf->f_namelen = CRAMFS_MAXPATHLEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) * Read a cramfs directory entry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) static int cramfs_readdir(struct file *file, struct dir_context *ctx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) struct inode *inode = file_inode(file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) struct super_block *sb = inode->i_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) char *buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) unsigned int offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) /* Offset within the thing. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) if (ctx->pos >= inode->i_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) offset = ctx->pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) /* Directory entries are always 4-byte aligned */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) if (offset & 3)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) buf = kmalloc(CRAMFS_MAXPATHLEN, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) if (!buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) while (offset < inode->i_size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) struct cramfs_inode *de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) unsigned long nextoffset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) char *name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) ino_t ino;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) umode_t mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) int namelen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) mutex_lock(&read_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) de = cramfs_read(sb, OFFSET(inode) + offset, sizeof(*de)+CRAMFS_MAXPATHLEN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) name = (char *)(de+1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) * Namelengths on disk are shifted by two
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) * and the name padded out to 4-byte boundaries
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) * with zeroes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) namelen = de->namelen << 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) memcpy(buf, name, namelen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) ino = cramino(de, OFFSET(inode) + offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) mode = de->mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) mutex_unlock(&read_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) nextoffset = offset + sizeof(*de) + namelen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) if (!namelen) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) kfree(buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) if (buf[namelen-1])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) namelen--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) if (!dir_emit(ctx, buf, namelen, ino, mode >> 12))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) ctx->pos = offset = nextoffset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) kfree(buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762) * Lookup and fill in the inode data..
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) static struct dentry *cramfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) unsigned int offset = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767) struct inode *inode = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) int sorted;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) mutex_lock(&read_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) sorted = CRAMFS_SB(dir->i_sb)->flags & CRAMFS_FLAG_SORTED_DIRS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) while (offset < dir->i_size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) struct cramfs_inode *de;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) char *name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775) int namelen, retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) int dir_off = OFFSET(dir) + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) de = cramfs_read(dir->i_sb, dir_off, sizeof(*de)+CRAMFS_MAXPATHLEN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) name = (char *)(de+1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781) /* Try to take advantage of sorted directories */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) if (sorted && (dentry->d_name.name[0] < name[0]))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) namelen = de->namelen << 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786) offset += sizeof(*de) + namelen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) /* Quick check that the name is roughly the right length */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) if (((dentry->d_name.len + 3) & ~3) != namelen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793) if (!namelen) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) inode = ERR_PTR(-EIO);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) if (name[namelen-1])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) namelen--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) if (namelen != dentry->d_name.len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803) retval = memcmp(dentry->d_name.name, name, namelen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804) if (retval > 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) if (!retval) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) inode = get_cramfs_inode(dir->i_sb, de, dir_off);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) /* else (retval < 0) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811) if (sorted)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815) mutex_unlock(&read_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816) return d_splice_alias(inode, dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) static int cramfs_readpage(struct file *file, struct page *page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) struct inode *inode = page->mapping->host;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822) u32 maxblock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823) int bytes_filled;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824) void *pgdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826) maxblock = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827) bytes_filled = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828) pgdata = kmap(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830) if (page->index < maxblock) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 831) struct super_block *sb = inode->i_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 832) u32 blkptr_offset = OFFSET(inode) + page->index * 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 833) u32 block_ptr, block_start, block_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) bool uncompressed, direct;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836) mutex_lock(&read_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837) block_ptr = *(u32 *) cramfs_read(sb, blkptr_offset, 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838) uncompressed = (block_ptr & CRAMFS_BLK_FLAG_UNCOMPRESSED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) direct = (block_ptr & CRAMFS_BLK_FLAG_DIRECT_PTR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) block_ptr &= ~CRAMFS_BLK_FLAGS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842) if (direct) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844) * The block pointer is an absolute start pointer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845) * shifted by 2 bits. The size is included in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846) * first 2 bytes of the data block when compressed,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847) * or PAGE_SIZE otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849) block_start = block_ptr << CRAMFS_BLK_DIRECT_PTR_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850) if (uncompressed) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851) block_len = PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852) /* if last block: cap to file length */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853) if (page->index == maxblock - 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854) block_len =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855) offset_in_page(inode->i_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857) block_len = *(u16 *)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) cramfs_read(sb, block_start, 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859) block_start += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863) * The block pointer indicates one past the end of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) * the current block (start of next block). If this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865) * is the first block then it starts where the block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866) * pointer table ends, otherwise its start comes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 867) * from the previous block's pointer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 868) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 869) block_start = OFFSET(inode) + maxblock * 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 870) if (page->index)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 871) block_start = *(u32 *)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 872) cramfs_read(sb, blkptr_offset - 4, 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 873) /* Beware... previous ptr might be a direct ptr */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 874) if (unlikely(block_start & CRAMFS_BLK_FLAG_DIRECT_PTR)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 875) /* See comments on earlier code. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 876) u32 prev_start = block_start;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 877) block_start = prev_start & ~CRAMFS_BLK_FLAGS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 878) block_start <<= CRAMFS_BLK_DIRECT_PTR_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 879) if (prev_start & CRAMFS_BLK_FLAG_UNCOMPRESSED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 880) block_start += PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 881) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 882) block_len = *(u16 *)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 883) cramfs_read(sb, block_start, 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 884) block_start += 2 + block_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 885) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 886) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 887) block_start &= ~CRAMFS_BLK_FLAGS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 888) block_len = block_ptr - block_start;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 889) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 890)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 891) if (block_len == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 892) ; /* hole */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 893) else if (unlikely(block_len > 2*PAGE_SIZE ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 894) (uncompressed && block_len > PAGE_SIZE))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 895) mutex_unlock(&read_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 896) pr_err("bad data blocksize %u\n", block_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 897) goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 898) } else if (uncompressed) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 899) memcpy(pgdata,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 900) cramfs_read(sb, block_start, block_len),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 901) block_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 902) bytes_filled = block_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 903) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 904) bytes_filled = cramfs_uncompress_block(pgdata,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 905) PAGE_SIZE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 906) cramfs_read(sb, block_start, block_len),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 907) block_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 908) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 909) mutex_unlock(&read_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 910) if (unlikely(bytes_filled < 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 911) goto err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 912) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 913)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 914) memset(pgdata + bytes_filled, 0, PAGE_SIZE - bytes_filled);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 915) flush_dcache_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 916) kunmap(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 917) SetPageUptodate(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 918) unlock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 919) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 920)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 921) err:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 922) kunmap(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 923) ClearPageUptodate(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 924) SetPageError(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 925) unlock_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 926) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 927) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 928)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 929) static const struct address_space_operations cramfs_aops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 930) .readpage = cramfs_readpage
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 931) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 932)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 933) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 934) * Our operations:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 935) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 936)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 937) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 938) * A directory can only readdir
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 939) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 940) static const struct file_operations cramfs_directory_operations = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 941) .llseek = generic_file_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 942) .read = generic_read_dir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 943) .iterate_shared = cramfs_readdir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 944) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 945)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 946) static const struct inode_operations cramfs_dir_inode_operations = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 947) .lookup = cramfs_lookup,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 948) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 949)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 950) static const struct super_operations cramfs_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 951) .statfs = cramfs_statfs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 952) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 953)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 954) static int cramfs_get_tree(struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 955) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 956) int ret = -ENOPROTOOPT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 957)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 958) if (IS_ENABLED(CONFIG_CRAMFS_MTD)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 959) ret = get_tree_mtd(fc, cramfs_mtd_fill_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 960) if (!ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 961) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 962) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 963) if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 964) ret = get_tree_bdev(fc, cramfs_blkdev_fill_super);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 965) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 966) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 967)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 968) static const struct fs_context_operations cramfs_context_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 969) .get_tree = cramfs_get_tree,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 970) .reconfigure = cramfs_reconfigure,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 971) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 972)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 973) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 974) * Set up the filesystem mount context.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 975) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 976) static int cramfs_init_fs_context(struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 977) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 978) fc->ops = &cramfs_context_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 979) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 980) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 981)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 982) static struct file_system_type cramfs_fs_type = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 983) .owner = THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 984) .name = "cramfs",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 985) .init_fs_context = cramfs_init_fs_context,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 986) .kill_sb = cramfs_kill_sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 987) .fs_flags = FS_REQUIRES_DEV,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 988) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 989) MODULE_ALIAS_FS("cramfs");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 990)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 991) static int __init init_cramfs_fs(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 992) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 993) int rv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 994)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 995) rv = cramfs_uncompress_init();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 996) if (rv < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 997) return rv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 998) rv = register_filesystem(&cramfs_fs_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 999) if (rv < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1000) cramfs_uncompress_exit();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1001) return rv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1002) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1003)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1004) static void __exit exit_cramfs_fs(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1005) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1006) cramfs_uncompress_exit();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1007) unregister_filesystem(&cramfs_fs_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1008) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1009)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1010) module_init(init_cramfs_fs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1011) module_exit(exit_cramfs_fs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1012) MODULE_LICENSE("GPL");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1013) MODULE_IMPORT_NS(ANDROID_GKI_VFS_EXPORT_ONLY);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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