@@ -1,6 +1,5 @@
config CRAMFS
tristate "Compressed ROM file system support (cramfs) (OBSOLETE)"
- depends on BLOCK
select ZLIB_INFLATE
help
Saying Y here includes support for CramFs (Compressed ROM File
@@ -20,3 +19,31 @@ config CRAMFS
in terms of performance and features.
If unsure, say N.
+
+config CRAMFS_BLOCKDEV
+ bool "Support CramFs image over a regular block device" if EXPERT
+ depends on CRAMFS && BLOCK
+ default y
+ help
+ This option allows the CramFs driver to load data from a regular
+ block device such a disk partition or a ramdisk.
+
+config CRAMFS_PHYSMEM
+ bool "Support CramFs image directly mapped in physical memory"
+ depends on CRAMFS
+ default y if !CRAMFS_BLOCKDEV
+ help
+ This option allows the CramFs driver to load data directly from
+ a linear adressed memory range (usually non volatile memory
+ like flash) instead of going through the block device layer.
+ This saves some memory since no intermediate buffering is
+ necessary.
+
+ The filesystem type for this feature is "cramfs_physmem".
+ The location of the CramFs image in memory is board
+ dependent. Therefore, if you say Y, you must know the proper
+ physical address where to store the CramFs image and specify
+ it using the physaddr=0x******** mount option (for example:
+ "mount -t cramfs_physmem -o physaddr=0x100000 none /mnt").
+
+ If unsure, say N.
@@ -24,6 +24,7 @@
#include <linux/mutex.h>
#include <uapi/linux/cramfs_fs.h>
#include <linux/uaccess.h>
+#include <linux/io.h>
#include "internal.h"
@@ -36,6 +37,8 @@ struct cramfs_sb_info {
unsigned long blocks;
unsigned long files;
unsigned long flags;
+ void *linear_virt_addr;
+ phys_addr_t linear_phys_addr;
};
static inline struct cramfs_sb_info *CRAMFS_SB(struct super_block *sb)
@@ -140,6 +143,9 @@ static struct inode *get_cramfs_inode(struct super_block *sb,
* BLKS_PER_BUF*PAGE_SIZE, so that the caller doesn't need to
* worry about end-of-buffer issues even when decompressing a full
* page cache.
+ *
+ * Note: This is all optimized away at compile time when
+ * CONFIG_CRAMFS_BLOCKDEV=n.
*/
#define READ_BUFFERS (2)
/* NEXT_BUFFER(): Loop over [0..(READ_BUFFERS-1)]. */
@@ -160,10 +166,10 @@ static struct super_block *buffer_dev[READ_BUFFERS];
static int next_buffer;
/*
- * Returns a pointer to a buffer containing at least LEN bytes of
- * filesystem starting at byte offset OFFSET into the filesystem.
+ * Populate our block cache and return a pointer from it.
*/
-static void *cramfs_read(struct super_block *sb, unsigned int offset, unsigned int len)
+static void *cramfs_blkdev_read(struct super_block *sb, unsigned int offset,
+ unsigned int len)
{
struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
struct page *pages[BLKS_PER_BUF];
@@ -239,7 +245,39 @@ static void *cramfs_read(struct super_block *sb, unsigned int offset, unsigned i
return read_buffers[buffer] + offset;
}
-static void cramfs_kill_sb(struct super_block *sb)
+/*
+ * Return a pointer to the linearly addressed cramfs image in memory.
+ */
+static void *cramfs_direct_read(struct super_block *sb, unsigned int offset,
+ unsigned int len)
+{
+ struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
+
+ if (!len)
+ return NULL;
+ if (len > sbi->size || offset > sbi->size - len)
+ return page_address(ZERO_PAGE(0));
+ return sbi->linear_virt_addr + offset;
+}
+
+/*
+ * Returns a pointer to a buffer containing at least LEN bytes of
+ * filesystem starting at byte offset OFFSET into the filesystem.
+ */
+static void *cramfs_read(struct super_block *sb, unsigned int offset,
+ unsigned int len)
+{
+ struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
+
+ if (IS_ENABLED(CONFIG_CRAMFS_PHYSMEM) && sbi->linear_virt_addr)
+ return cramfs_direct_read(sb, offset, len);
+ else if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV))
+ return cramfs_blkdev_read(sb, offset, len);
+ else
+ return NULL;
+}
+
+static void cramfs_blkdev_kill_sb(struct super_block *sb)
{
struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
@@ -247,6 +285,16 @@ static void cramfs_kill_sb(struct super_block *sb)
kfree(sbi);
}
+static void cramfs_physmem_kill_sb(struct super_block *sb)
+{
+ struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
+
+ if (sbi->linear_virt_addr)
+ memunmap(sbi->linear_virt_addr);
+ kill_anon_super(sb);
+ kfree(sbi);
+}
+
static int cramfs_remount(struct super_block *sb, int *flags, char *data)
{
sync_filesystem(sb);
@@ -254,34 +302,24 @@ static int cramfs_remount(struct super_block *sb, int *flags, char *data)
return 0;
}
-static int cramfs_fill_super(struct super_block *sb, void *data, int silent)
+static int cramfs_read_super(struct super_block *sb,
+ struct cramfs_super *super, int silent)
{
- int i;
- struct cramfs_super super;
+ struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
unsigned long root_offset;
- struct cramfs_sb_info *sbi;
- struct inode *root;
-
- sb->s_flags |= MS_RDONLY;
-
- sbi = kzalloc(sizeof(struct cramfs_sb_info), GFP_KERNEL);
- if (!sbi)
- return -ENOMEM;
- sb->s_fs_info = sbi;
- /* Invalidate the read buffers on mount: think disk change.. */
- mutex_lock(&read_mutex);
- for (i = 0; i < READ_BUFFERS; i++)
- buffer_blocknr[i] = -1;
+ /* We don't know the real size yet */
+ sbi->size = PAGE_SIZE;
/* Read the first block and get the superblock from it */
- memcpy(&super, cramfs_read(sb, 0, sizeof(super)), sizeof(super));
+ mutex_lock(&read_mutex);
+ memcpy(super, cramfs_read(sb, 0, sizeof(*super)), sizeof(*super));
mutex_unlock(&read_mutex);
/* Do sanity checks on the superblock */
- if (super.magic != CRAMFS_MAGIC) {
+ if (super->magic != CRAMFS_MAGIC) {
/* check for wrong endianness */
- if (super.magic == CRAMFS_MAGIC_WEND) {
+ if (super->magic == CRAMFS_MAGIC_WEND) {
if (!silent)
pr_err("wrong endianness\n");
return -EINVAL;
@@ -289,10 +327,12 @@ static int cramfs_fill_super(struct super_block *sb, void *data, int silent)
/* check at 512 byte offset */
mutex_lock(&read_mutex);
- memcpy(&super, cramfs_read(sb, 512, sizeof(super)), sizeof(super));
+ memcpy(super,
+ cramfs_read(sb, 512, sizeof(*super)),
+ sizeof(*super));
mutex_unlock(&read_mutex);
- if (super.magic != CRAMFS_MAGIC) {
- if (super.magic == CRAMFS_MAGIC_WEND && !silent)
+ if (super->magic != CRAMFS_MAGIC) {
+ if (super->magic == CRAMFS_MAGIC_WEND && !silent)
pr_err("wrong endianness\n");
else if (!silent)
pr_err("wrong magic\n");
@@ -301,34 +341,34 @@ static int cramfs_fill_super(struct super_block *sb, void *data, int silent)
}
/* get feature flags first */
- if (super.flags & ~CRAMFS_SUPPORTED_FLAGS) {
+ if (super->flags & ~CRAMFS_SUPPORTED_FLAGS) {
pr_err("unsupported filesystem features\n");
return -EINVAL;
}
/* Check that the root inode is in a sane state */
- if (!S_ISDIR(super.root.mode)) {
+ if (!S_ISDIR(super->root.mode)) {
pr_err("root is not a directory\n");
return -EINVAL;
}
/* correct strange, hard-coded permissions of mkcramfs */
- super.root.mode |= (S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH);
+ super->root.mode |= 0555;
- root_offset = super.root.offset << 2;
- if (super.flags & CRAMFS_FLAG_FSID_VERSION_2) {
- sbi->size = super.size;
- sbi->blocks = super.fsid.blocks;
- sbi->files = super.fsid.files;
+ root_offset = super->root.offset << 2;
+ if (super->flags & CRAMFS_FLAG_FSID_VERSION_2) {
+ sbi->size = super->size;
+ sbi->blocks = super->fsid.blocks;
+ sbi->files = super->fsid.files;
} else {
sbi->size = 1<<28;
sbi->blocks = 0;
sbi->files = 0;
}
- sbi->magic = super.magic;
- sbi->flags = super.flags;
+ sbi->magic = super->magic;
+ sbi->flags = super->flags;
if (root_offset == 0)
pr_info("empty filesystem");
- else if (!(super.flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET) &&
+ else if (!(super->flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET) &&
((root_offset != sizeof(struct cramfs_super)) &&
(root_offset != 512 + sizeof(struct cramfs_super))))
{
@@ -336,9 +376,18 @@ static int cramfs_fill_super(struct super_block *sb, void *data, int silent)
return -EINVAL;
}
+ return 0;
+}
+
+static int cramfs_finalize_super(struct super_block *sb,
+ struct cramfs_inode *cramfs_root)
+{
+ struct inode *root;
+
/* Set it all up.. */
+ sb->s_flags |= MS_RDONLY;
sb->s_op = &cramfs_ops;
- root = get_cramfs_inode(sb, &super.root, 0);
+ root = get_cramfs_inode(sb, cramfs_root, 0);
if (IS_ERR(root))
return PTR_ERR(root);
sb->s_root = d_make_root(root);
@@ -347,6 +396,95 @@ static int cramfs_fill_super(struct super_block *sb, void *data, int silent)
return 0;
}
+static int cramfs_blkdev_fill_super(struct super_block *sb, void *data,
+ int silent)
+{
+ struct cramfs_sb_info *sbi;
+ struct cramfs_super super;
+ int i, err;
+
+ sbi = kzalloc(sizeof(struct cramfs_sb_info), GFP_KERNEL);
+ if (!sbi)
+ return -ENOMEM;
+ sb->s_fs_info = sbi;
+
+ /* Invalidate the read buffers on mount: think disk change.. */
+ for (i = 0; i < READ_BUFFERS; i++)
+ buffer_blocknr[i] = -1;
+
+ err = cramfs_read_super(sb, &super, silent);
+ if (err)
+ return err;
+ return cramfs_finalize_super(sb, &super.root);
+}
+
+static int cramfs_physmem_fill_super(struct super_block *sb, void *data,
+ int silent)
+{
+ struct cramfs_sb_info *sbi;
+ struct cramfs_super super;
+ char *p;
+ int err;
+
+ sbi = kzalloc(sizeof(struct cramfs_sb_info), GFP_KERNEL);
+ if (!sbi)
+ return -ENOMEM;
+ sb->s_fs_info = sbi;
+
+ /*
+ * The physical location of the cramfs image is specified as
+ * a mount parameter. This parameter is mandatory for obvious
+ * reasons. Some validation is made on the phys address but this
+ * is not exhaustive and we count on the fact that someone using
+ * this feature is supposed to know what he/she's doing.
+ */
+ if (!data || !(p = strstr((char *)data, "physaddr="))) {
+ pr_err("unknown physical address for linear cramfs image\n");
+ return -EINVAL;
+ }
+ sbi->linear_phys_addr = memparse(p + 9, NULL);
+ if (!sbi->linear_phys_addr) {
+ pr_err("bad value for cramfs image physical address\n");
+ return -EINVAL;
+ }
+ if (!PAGE_ALIGNED(sbi->linear_phys_addr)) {
+ pr_err("physical address %pap isn't page aligned\n",
+ &sbi->linear_phys_addr);
+ return -EINVAL;
+ }
+
+ /*
+ * Map only one page for now. Will remap it when fs size is known.
+ * Although we'll only read from it, we want the CPU cache to
+ * kick in for the higher throughput it provides, hence MEMREMAP_WB.
+ */
+ pr_info("checking physical address %pap for linear cramfs image\n",
+ &sbi->linear_phys_addr);
+ sbi->linear_virt_addr = memremap(sbi->linear_phys_addr, PAGE_SIZE,
+ MEMREMAP_WB);
+ if (!sbi->linear_virt_addr) {
+ pr_err("memremap of the linear cramfs image failed\n");
+ return -ENOMEM;
+ }
+
+ err = cramfs_read_super(sb, &super, silent);
+ if (err)
+ return err;
+
+ /* Remap the whole filesystem now */
+ pr_info("linear cramfs image appears to be %lu KB in size\n",
+ sbi->size/1024);
+ memunmap(sbi->linear_virt_addr);
+ sbi->linear_virt_addr = memremap(sbi->linear_phys_addr, sbi->size,
+ MEMREMAP_WB);
+ if (!sbi->linear_virt_addr) {
+ pr_err("ioremap of the linear cramfs image failed\n");
+ return -ENOMEM;
+ }
+
+ return cramfs_finalize_super(sb, &super.root);
+}
+
static int cramfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
@@ -573,38 +711,68 @@ static const struct super_operations cramfs_ops = {
.statfs = cramfs_statfs,
};
-static struct dentry *cramfs_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data)
+static struct dentry *cramfs_blkdev_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return mount_bdev(fs_type, flags, dev_name, data,
+ cramfs_blkdev_fill_super);
+}
+
+static struct dentry *cramfs_physmem_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
{
- return mount_bdev(fs_type, flags, dev_name, data, cramfs_fill_super);
+ return mount_nodev(fs_type, flags, data, cramfs_physmem_fill_super);
}
static struct file_system_type cramfs_fs_type = {
.owner = THIS_MODULE,
.name = "cramfs",
- .mount = cramfs_mount,
- .kill_sb = cramfs_kill_sb,
+ .mount = cramfs_blkdev_mount,
+ .kill_sb = cramfs_blkdev_kill_sb,
.fs_flags = FS_REQUIRES_DEV,
};
+
+static struct file_system_type cramfs_physmem_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "cramfs_physmem",
+ .mount = cramfs_physmem_mount,
+ .kill_sb = cramfs_physmem_kill_sb,
+};
+
+#ifdef CONFIG_CRAMFS_BLOCKDEV
MODULE_ALIAS_FS("cramfs");
+#endif
+#ifdef CONFIG_CRAMFS_PHYSMEM
+MODULE_ALIAS_FS("cramfs_physmem");
+#endif
static int __init init_cramfs_fs(void)
{
int rv;
- rv = cramfs_uncompress_init();
- if (rv < 0)
- return rv;
- rv = register_filesystem(&cramfs_fs_type);
- if (rv < 0)
- cramfs_uncompress_exit();
- return rv;
+ if ((rv = cramfs_uncompress_init()) < 0)
+ goto err0;
+ if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV) &&
+ (rv = register_filesystem(&cramfs_fs_type)) < 0)
+ goto err1;
+ if (IS_ENABLED(CONFIG_CRAMFS_PHYSMEM) &&
+ (rv = register_filesystem(&cramfs_physmem_fs_type)) < 0)
+ goto err2;
+ return 0;
+
+err2: if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV))
+ unregister_filesystem(&cramfs_fs_type);
+err1: cramfs_uncompress_exit();
+err0: return rv;
}
static void __exit exit_cramfs_fs(void)
{
cramfs_uncompress_exit();
- unregister_filesystem(&cramfs_fs_type);
+ if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV))
+ unregister_filesystem(&cramfs_fs_type);
+ if (IS_ENABLED(CONFIG_CRAMFS_PHYSMEM))
+ unregister_filesystem(&cramfs_physmem_fs_type);
}
module_init(init_cramfs_fs)