From: Marco Stornelli <marco.storne...@gmail.com>
Super block operations.
Signed-off-by: Marco Stornelli <marco.storne...@gmail.com>
---
diff --git a/fs/pramfs/super.c b/fs/pramfs/super.c
new file mode 100644
index 0000000..0157b35
--- /dev/null
+++ b/fs/pramfs/super.c
@@ -0,0 +1,940 @@
+/*
+ * BRIEF DESCRIPTION
+ *
+ * Super block operations.
+ *
+ * Copyright 2009-2010 Marco Stornelli <marco.storne...@gmail.com>
+ * Copyright 2003 Sony Corporation
+ * Copyright 2003 Matsushita Electric Industrial Co., Ltd.
+ * 2003-2004 (c) MontaVista Software, Inc. , Steve Longerbeam
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/blkdev.h>
+#include <linux/parser.h>
+#include <linux/vfs.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/seq_file.h>
+#include <linux/mount.h>
+#include <linux/mm.h>
+#include <linux/ctype.h>
+#include <linux/bitops.h>
+#include <linux/magic.h>
+#include <linux/exportfs.h>
+#include <linux/random.h>
+#include "xattr.h"
+#include "pram.h"
+
+static struct super_operations pram_sops;
+static const struct export_operations pram_export_ops;
+static struct kmem_cache *pram_inode_cachep;
+
+#ifdef CONFIG_PRAMFS_TEST
+static void *first_pram_super;
+
+struct pram_super_block *get_pram_super(void)
+{
+ return (struct pram_super_block *)first_pram_super;
+}
+EXPORT_SYMBOL(get_pram_super);
+#endif
+
+void pram_error_mng(struct super_block * sb, const char * fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ printk(KERN_ERR "pramfs error: ");
+ vprintk(fmt, args);
+ printk("\n");
+ va_end(args);
+
+ if (test_opt(sb, ERRORS_PANIC))
+ panic("pramfs: panic from previous error\n");
+ if (test_opt(sb, ERRORS_RO)) {
+ printk(KERN_CRIT "pramfs error: remounting filesystem
read-only");
+ sb->s_flags |= MS_RDONLY;
+ }
+}
+
+static void pram_set_blocksize(struct super_block *sb, unsigned long size)
+{
+ int bits;
+
+ /*
+ * We've already validated the user input and the value here must be
+ * between PRAM_MAX_BLOCK_SIZE and PRAM_MIN_BLOCK_SIZE
+ * and it must be a power of 2.
+ */
+ bits = fls(size) - 1;
+ sb->s_blocksize_bits = bits;
+ sb->s_blocksize = (1<<bits);
+}
+
+static inline void *pram_ioremap(phys_addr_t phys_addr, ssize_t size, bool
protect)
+{
+ void *retval;
+
+ /*
+ * NOTE: Userland may not map this resource, we will mark the region so
+ * /dev/mem and the sysfs MMIO access will not be allowed. This
+ * restriction depends on STRICT_DEVMEM option. If this option is
+ * disabled or not available we mark the region only as busy.
+ */
+ retval = request_mem_region_exclusive(phys_addr, size, "pramfs");
+ if (!retval)
+ goto fail;
+
+ retval = ioremap_nocache(phys_addr, size);
+
+ if (retval && protect)
+ pram_writeable(retval, size, 0);
+fail:
+ return retval;
+}
+
+static loff_t pram_max_size(int bits)
+{
+ loff_t res;
+ res = (1ULL << (3*bits - 6)) - 1;
+
+ if (res > MAX_LFS_FILESIZE)
+ res = MAX_LFS_FILESIZE;
+
+ pram_info("max file size %llu bytes\n", res);
+ return res;
+}
+
+enum {
+ Opt_addr, Opt_bpi, Opt_size,
+ Opt_num_inodes, Opt_mode, Opt_uid,
+ Opt_gid, Opt_blocksize, Opt_user_xattr,
+ Opt_nouser_xattr, Opt_noprotect,
+ Opt_acl, Opt_noacl, Opt_xip,
+ Opt_err_cont, Opt_err_panic, Opt_err_ro,
+ Opt_err
+};
+
+static const match_table_t tokens = {
+ {Opt_bpi, "physaddr=%x"},
+ {Opt_bpi, "bpi=%u"},
+ {Opt_size, "init=%s"},
+ {Opt_num_inodes, "N=%u"},
+ {Opt_mode, "mode=%o"},
+ {Opt_uid, "uid=%u"},
+ {Opt_gid, "gid=%u"},
+ {Opt_blocksize, "bs=%s"},
+ {Opt_user_xattr, "user_xattr"},
+ {Opt_user_xattr, "nouser_xattr"},
+ {Opt_noprotect, "noprotect"},
+ {Opt_acl, "acl"},
+ {Opt_acl, "noacl"},
+ {Opt_xip, "xip"},
+ {Opt_err_cont, "errors=continue"},
+ {Opt_err_panic, "errors=panic"},
+ {Opt_err_ro, "errors=remount-ro"},
+ {Opt_err, NULL},
+};
+
+static phys_addr_t get_phys_addr(void **data)
+{
+ phys_addr_t phys_addr;
+ char *options = (char *) *data;
+
+ if (!options || strncmp(options, "physaddr=", 9) != 0)
+ return (phys_addr_t)ULLONG_MAX;
+ options += 9;
+ phys_addr = (phys_addr_t)simple_strtoull(options, &options, 0);
+ if (*options && *options != ',') {
+ printk(KERN_ERR "Invalid phys addr specification: %s\n",
+ (char *) *data);
+ return (phys_addr_t)ULLONG_MAX;
+ }
+ if (phys_addr & (PAGE_SIZE - 1)) {
+ printk(KERN_ERR "physical address 0x%16llx for pramfs isn't "
+ "aligned to a page boundary\n",
+ (u64)phys_addr);
+ return (phys_addr_t)ULLONG_MAX;
+ }
+ if (*options == ',')
+ options++;
+ *data = (void *) options;
+ return phys_addr;
+}
+
+static int pram_parse_options(char *options, struct pram_sb_info *sbi, bool
remount)
+{
+ char *p, *rest;
+ substring_t args[MAX_OPT_ARGS];
+ int option;
+
+ if (!options)
+ return 0;
+
+ while ((p = strsep(&options, ",")) != NULL) {
+ int token;
+ if (!*p)
+ continue;
+
+ token = match_token(p, tokens, args);
+ switch (token) {
+ case Opt_addr:
+ if (remount)
+ goto bad_opt;
+ /* physaddr managed in get_phys_addr() */
+ break;
+ case Opt_bpi:
+ if (remount)
+ goto bad_opt;
+ if (match_int(&args[0], &option))
+ goto bad_val;
+ sbi->bpi = option;
+ break;
+ case Opt_uid:
+ if (remount)
+ goto bad_opt;
+ if (match_int(&args[0], &option))
+ goto bad_val;
+ sbi->uid = option;
+ break;
+ case Opt_gid:
+ if (match_int(&args[0], &option))
+ goto bad_val;
+ sbi->gid = option;
+ break;
+ case Opt_mode:
+ if (match_octal(&args[0], &option))
+ goto bad_val;
+ sbi->mode = option & 01777U;
+ break;
+ case Opt_size:
+ if (remount)
+ goto bad_opt;
+ /* memparse() will accept a K/M/G without a digit */
+ if (!isdigit(*args[0].from))
+ goto bad_val;
+ sbi->initsize = memparse(args[0].from, &rest);
+ break;
+ case Opt_num_inodes:
+ if (remount)
+ goto bad_opt;
+ if (match_int(&args[0], &option))
+ goto bad_val;
+ sbi->num_inodes = option;
+ break;
+ case Opt_blocksize:
+ if (remount)
+ goto bad_opt;
+ /* memparse() will accept a K/M/G without a digit */
+ if (!isdigit(*args[0].from))
+ goto bad_val;
+ sbi->blocksize = memparse(args[0].from, &rest);
+ if (sbi->blocksize < PRAM_MIN_BLOCK_SIZE ||
+ sbi->blocksize > PRAM_MAX_BLOCK_SIZE ||
+ !is_power_of_2(sbi->blocksize))
+ goto bad_val;
+ break;
+ case Opt_err_panic:
+ clear_opt(sbi->s_mount_opt, ERRORS_CONT);
+ clear_opt(sbi->s_mount_opt, ERRORS_RO);
+ set_opt(sbi->s_mount_opt, ERRORS_PANIC);
+ break;
+ case Opt_err_ro:
+ clear_opt(sbi->s_mount_opt, ERRORS_CONT);
+ clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
+ set_opt(sbi->s_mount_opt, ERRORS_RO);
+ break;
+ case Opt_err_cont:
+ clear_opt(sbi->s_mount_opt, ERRORS_RO);
+ clear_opt(sbi->s_mount_opt, ERRORS_PANIC);
+ set_opt(sbi->s_mount_opt, ERRORS_CONT);
+ break;
+ case Opt_noprotect:
+#ifdef CONFIG_PRAMFS_WRITE_PROTECT
+ if (remount)
+ goto bad_opt;
+ clear_opt(sbi->s_mount_opt, PROTECT);
+#endif
+ break;
+#ifdef CONFIG_PRAMFS_XATTR
+ case Opt_user_xattr:
+ set_opt(sbi->s_mount_opt, XATTR_USER);
+ break;
+ case Opt_nouser_xattr:
+ clear_opt(sbi->s_mount_opt, XATTR_USER);
+ break;
+#else
+ case Opt_user_xattr:
+ case Opt_nouser_xattr:
+ pram_info("(no)user_xattr options not supported\n");
+ break;
+#endif
+#ifdef CONFIG_PRAMFS_POSIX_ACL
+ case Opt_acl:
+ set_opt(sbi->s_mount_opt, POSIX_ACL);
+ break;
+ case Opt_noacl:
+ clear_opt(sbi->s_mount_opt, POSIX_ACL);
+ break;
+#else
+ case Opt_acl:
+ case Opt_noacl:
+ pram_info("(no)acl options not supported\n");
+ break;
+#endif
+ case Opt_xip:
+#ifdef CONFIG_PRAMFS_XIP
+ if (remount)
+ goto bad_opt;
+ set_opt(sbi->s_mount_opt, XIP);
+ break;
+#else
+ pram_info("xip option not supported\n");
+ break;
+#endif
+ default: {
+ goto bad_opt;
+ }
+ }
+ }
+
+ return 0;
+
+bad_val:
+ printk(KERN_ERR "Bad value '%s' for mount option '%s'\n", args[0].from,
p);
+ return -EINVAL;
+bad_opt:
+ printk(KERN_ERR "Bad mount option: \"%s\"\n", p);
+ return -EINVAL;
+}
+
+static struct pram_inode *pram_init(struct super_block *sb, unsigned long size)
+{
+ unsigned long bpi, num_inodes, bitmap_size, blocksize, num_blocks;
+ u64 bitmap_start;
+ struct pram_inode *root_i;
+ struct pram_super_block *super;
+ struct pram_sb_info *sbi = (struct pram_sb_info *)sb->s_fs_info;
+
+ pram_info("creating an empty pramfs of size %lu\n", size);
+ if (pram_is_protected(sb))
+ sbi->virt_addr = pram_ioremap(sbi->phys_addr, size, 1);
+ else
+ sbi->virt_addr = pram_ioremap(sbi->phys_addr, size, 0);
+
+ if (!sbi->virt_addr) {
+ printk(KERN_ERR "ioremap of the pramfs image failed\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+#ifdef CONFIG_PRAMFS_TEST
+ if (!first_pram_super)
+ first_pram_super = sbi->virt_addr;
+#endif
+
+ if (!sbi->blocksize)
+ blocksize = PRAM_DEF_BLOCK_SIZE;
+ else
+ blocksize = sbi->blocksize;
+
+ pram_set_blocksize(sb, blocksize);
+ blocksize = sb->s_blocksize;
+
+ if (sbi->blocksize && sbi->blocksize != blocksize)
+ sbi->blocksize = blocksize;
+
+ if (size < blocksize) {
+ printk(KERN_ERR "size smaller then block size\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (!sbi->bpi)
+ /*
+ * default is that 5% of the filesystem is
+ * devoted to the inode table
+ */
+ bpi = 20 * PRAM_INODE_SIZE;
+ else
+ bpi = sbi->bpi;
+
+ if (!sbi->num_inodes)
+ num_inodes = size / bpi;
+ else
+ num_inodes = sbi->num_inodes;
+
+ /*
+ * up num_inodes such that the end of the inode table
+ * (and start of bitmap) is on a block boundary
+ */
+ bitmap_start = (PRAM_SB_SIZE*2) + (num_inodes<<PRAM_INODE_BITS);
+ if (bitmap_start & (blocksize - 1))
+ bitmap_start = (bitmap_start + blocksize) &
+ ~(blocksize-1);
+ num_inodes = (bitmap_start - (PRAM_SB_SIZE*2)) >> PRAM_INODE_BITS;
+
+ if (sbi->num_inodes && num_inodes != sbi->num_inodes)
+ sbi->num_inodes = num_inodes;
+
+ num_blocks = (size - bitmap_start) >> sb->s_blocksize_bits;
+
+ if (!num_blocks) {
+ printk(KERN_ERR "num blocks equals to zero\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* calc the data blocks in-use bitmap size in bytes */
+ if (num_blocks & 7)
+ bitmap_size = ((num_blocks + 8) & ~7) >> 3;
+ else
+ bitmap_size = num_blocks >> 3;
+ /* round it up to the nearest blocksize boundary */
+ if (bitmap_size & (blocksize - 1))
+ bitmap_size = (bitmap_size + blocksize) & ~(blocksize-1);
+
+ pram_info("blocksize %lu, num inodes %lu, num blocks %lu\n",
+ blocksize, num_inodes, num_blocks);
+ pram_dbg("bitmap start 0x%08x, bitmap size %lu\n",
+ (unsigned int)bitmap_start, bitmap_size);
+ pram_dbg("max name length %d\n", (unsigned int)PRAM_NAME_LEN);
+
+ super = pram_get_super(sb);
+ pram_memunlock_range(sb, super, bitmap_start + bitmap_size);
+
+ /* clear out super-block and inode table */
+ memset(super, 0, bitmap_start);
+ super->s_size = cpu_to_be64(size);
+ super->s_blocksize = cpu_to_be32(blocksize);
+ super->s_inodes_count = cpu_to_be32(num_inodes);
+ super->s_blocks_count = cpu_to_be32(num_blocks);
+ super->s_free_inodes_count = cpu_to_be32(num_inodes - 1);
+ super->s_bitmap_blocks = cpu_to_be32(bitmap_size >>
sb->s_blocksize_bits);
+ super->s_free_blocks_count = cpu_to_be32(num_blocks -
be32_to_cpu(super->s_bitmap_blocks));
+ super->s_free_inode_hint = cpu_to_be32(1);
+ super->s_bitmap_start = cpu_to_be64(bitmap_start);
+ super->s_magic = cpu_to_be16(PRAM_SUPER_MAGIC);
+ pram_sync_super(super);
+
+ root_i = pram_get_inode(sb, PRAM_ROOT_INO);
+
+ root_i->i_mode = cpu_to_be32(sbi->mode);
+ root_i->i_mode = cpu_to_be16(root_i->i_mode | S_IFDIR);
+ root_i->i_uid = cpu_to_be32(sbi->uid);
+ root_i->i_gid = cpu_to_be32(sbi->gid);
+ root_i->i_links_count = cpu_to_be16(2);
+ root_i->i_d.d_parent = cpu_to_be64(PRAM_ROOT_INO);
+ pram_sync_inode(root_i);
+
+ pram_init_bitmap(sb);
+
+ pram_memlock_range(sb, super, bitmap_start + bitmap_size);
+
+ return root_i;
+}
+
+static inline void set_default_opts(struct pram_sb_info *sbi)
+{
+ set_opt(sbi->s_mount_opt, PROTECT);
+ set_opt(sbi->s_mount_opt, ERRORS_CONT);
+}
+
+static int pram_fill_super(struct super_block *sb, void *data, int silent)
+{
+ struct pram_super_block *super, *super_redund;
+ struct pram_inode *root_pi;
+ struct pram_sb_info *sbi = NULL;
+ struct inode *root_i = NULL;
+ u64 root_offset;
+ unsigned long blocksize, initsize = 0;
+ u32 random = 0;
+ int retval = -EINVAL;
+
+ BUILD_BUG_ON(sizeof(struct pram_super_block) > PRAM_SB_SIZE);
+ BUILD_BUG_ON(sizeof(struct pram_inode) > PRAM_INODE_SIZE);
+
+ sbi = kzalloc(sizeof(struct pram_sb_info), GFP_KERNEL);
+ if (!sbi)
+ return -ENOMEM;
+ sb->s_fs_info = sbi;
+
+ set_default_opts(sbi);
+
+#ifdef CONFIG_PRAMFS_XATTR
+ spin_lock_init(&sbi->desc_tree_lock);
+ sbi->desc_tree.rb_node = NULL;
+#endif
+
+ sbi->phys_addr = get_phys_addr(&data);
+ if (sbi->phys_addr == (phys_addr_t)ULLONG_MAX)
+ goto out;
+
+ get_random_bytes(&random, sizeof(u32));
+ atomic_set(&sbi->next_generation, random);
+
+ /* Init with default values */
+ sbi->mode = (S_IRWXUGO | S_ISVTX);
+ sbi->uid = current_fsuid();
+ sbi->gid = current_fsgid();
+
+ if (pram_parse_options(data, sbi, 0))
+ goto out;
+
+ if (test_opt(sb, XIP) && test_opt(sb, PROTECT)) {
+ printk(KERN_ERR "xip and protect options both enabled\n");
+ goto out;
+ }
+
+ if (test_opt(sb, XIP) && sbi->blocksize != PAGE_SIZE) {
+ printk(KERN_ERR "blocksize not equal to page size and xip
enabled\n");
+ goto out;
+ }
+
+ initsize = sbi->initsize;
+
+ /* Init a new pramfs instance */
+ if (initsize) {
+ root_pi = pram_init(sb, initsize);
+
+ if (IS_ERR(root_pi))
+ goto out;
+
+ super = pram_get_super(sb);
+
+ goto setup_sb;
+ }
+
+ pram_dbg("checking physical address 0x%016llx for pramfs image\n",
+ (u64)sbi->phys_addr);
+
+ /* Map only one page for now. Will remap it when fs size is known. */
+ initsize = PAGE_SIZE;
+ if (pram_is_protected(sb))
+ sbi->virt_addr = pram_ioremap(sbi->phys_addr, initsize, 1);
+ else
+ sbi->virt_addr = pram_ioremap(sbi->phys_addr, initsize, 0);
+ if (!sbi->virt_addr) {
+ printk(KERN_ERR "ioremap of the pramfs image failed\n");
+ goto out;
+ }
+
+ super = pram_get_super(sb);
+ super_redund = pram_get_redund_super(sb);
+
+ /* Do sanity checks on the superblock */
+ if (be16_to_cpu(super->s_magic) != PRAM_SUPER_MAGIC) {
+ if (be16_to_cpu(super_redund->s_magic) != PRAM_SUPER_MAGIC) {
+ if (!silent)
+ printk(KERN_ERR "Can't find a valid pramfs "
+ "partition\n");
+ goto out;
+ } else {
+ pram_warn("Error in super block: try to repair it with "
+ "the redundant copy");
+ /* Try to auto-recover the super block */
+ memcpy(super, super_redund, PRAM_SB_SIZE);
+ }
+ }
+
+ /* Read the superblock */
+ if (pram_calc_checksum((u8 *)super, PRAM_SB_SIZE)) {
+ if (pram_calc_checksum((u8 *)super_redund, PRAM_SB_SIZE)) {
+ printk(KERN_ERR "checksum error in super block\n");
+ goto out;
+ } else {
+ pram_warn("Error in super block: try to repair it with "
+ "the redundant copy");
+ /* Try to auto-recover the super block */
+ memcpy(super, super_redund, PRAM_SB_SIZE);
+ }
+ }
+
+ blocksize = be32_to_cpu(super->s_blocksize);
+ pram_set_blocksize(sb, blocksize);
+
+ initsize = be64_to_cpu(super->s_size);
+ pram_info("pramfs image appears to be %lu KB in size\n", initsize>>10);
+ pram_info("blocksize %lu\n", blocksize);
+
+ /* Read the root inode */
+ root_pi = pram_get_inode(sb, PRAM_ROOT_INO);
+
+ /* Check that the root inode is in a sane state */
+ if (pram_calc_checksum((u8 *)root_pi, PRAM_INODE_SIZE)) {
+ printk(KERN_ERR "checksum error in root inode!\n");
+ goto out;
+ }
+
+ if (be64_to_cpu(root_pi->i_d.d_next)) {
+ printk(KERN_ERR "root->next not NULL??!!\n");
+ goto out;
+ }
+
+ if (!S_ISDIR(be16_to_cpu(root_pi->i_mode))) {
+ printk(KERN_ERR "root is not a directory!\n");
+ goto out;
+ }
+
+ root_offset = be64_to_cpu(root_pi->i_type.dir.head);
+ if (root_offset == 0)
+ pram_dbg("empty filesystem\n");
+
+ /* Remap the whole filesystem now */
+ if (pram_is_protected(sb))
+ pram_writeable(sbi->virt_addr, PAGE_SIZE, 1);
+ iounmap(sbi->virt_addr);
+ release_mem_region(sbi->phys_addr, PAGE_SIZE);
+ if (pram_is_protected(sb))
+ sbi->virt_addr = pram_ioremap(sbi->phys_addr, initsize, 1);
+ else
+ sbi->virt_addr = pram_ioremap(sbi->phys_addr, initsize, 0);
+ if (!sbi->virt_addr) {
+ printk(KERN_ERR "ioremap of the pramfs image failed\n");
+ goto out;
+ }
+ super = pram_get_super(sb);
+
+#ifdef CONFIG_PRAMFS_TEST
+ if (!first_pram_super)
+ first_pram_super = sbi->virt_addr;
+#endif
+
+ /* Set it all up.. */
+ setup_sb:
+ sb->s_magic = be16_to_cpu(super->s_magic);
+ sb->s_op = &pram_sops;
+ sb->s_maxbytes = pram_max_size(sb->s_blocksize_bits);
+ sb->s_time_gran = 1;
+ sb->s_export_op = &pram_export_ops;
+ sb->s_xattr = pram_xattr_handlers;
+#ifdef CONFIG_PRAMFS_POSIX_ACL
+ sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+ (sbi->s_mount_opt & PRAM_MOUNT_POSIX_ACL) ?
+ MS_POSIXACL : 0;
+#endif
+ root_i = pram_iget(sb, PRAM_ROOT_INO);
+ if (IS_ERR(root_i)) {
+ retval = PTR_ERR(root_i);
+ goto out;
+ }
+
+ sb->s_root = d_alloc_root(root_i);
+ if (!sb->s_root) {
+ iput(root_i);
+ printk(KERN_ERR "get pramfs root inode failed\n");
+ retval = -ENOMEM;
+ goto out;
+ }
+
+ retval = 0;
+ return retval;
+ out:
+ if (sbi->virt_addr) {
+ if (pram_is_protected(sb))
+ pram_writeable(sbi->virt_addr, initsize, 1);
+ iounmap(sbi->virt_addr);
+ release_mem_region(sbi->phys_addr, initsize);
+ }
+
+ kfree(sbi);
+ return retval;
+}
+
+int pram_statfs(struct dentry *d, struct kstatfs *buf)
+{
+ struct super_block *sb = d->d_sb;
+ struct pram_super_block *ps = pram_get_super(sb);
+
+ buf->f_type = PRAM_SUPER_MAGIC;
+ buf->f_bsize = sb->s_blocksize;
+ buf->f_blocks = be32_to_cpu(ps->s_blocks_count);
+ buf->f_bfree = buf->f_bavail = pram_count_free_blocks(sb);
+ buf->f_files = be32_to_cpu(ps->s_inodes_count);
+ buf->f_ffree = be32_to_cpu(ps->s_free_inodes_count);
+ buf->f_namelen = PRAM_NAME_LEN;
+ return 0;
+}
+
+static int pram_show_options(struct seq_file *seq, struct vfsmount *vfs)
+{
+ struct pram_sb_info *sbi = (struct pram_sb_info
*)vfs->mnt_sb->s_fs_info;
+
+ seq_printf(seq, ",physaddr=0x%016llx", (u64)sbi->phys_addr);
+ if (sbi->initsize)
+ seq_printf(seq, ",init=%luk", sbi->initsize >> 10);
+ if (sbi->blocksize)
+ seq_printf(seq, ",bs=%lu", sbi->blocksize);
+ if (sbi->bpi)
+ seq_printf(seq, ",bpi=%lu", sbi->bpi);
+ if (sbi->num_inodes)
+ seq_printf(seq, ",N=%lu", sbi->num_inodes);
+ if (sbi->mode != (S_IRWXUGO | S_ISVTX))
+ seq_printf(seq, ",mode=%03o", sbi->mode);
+ if (sbi->uid != 0)
+ seq_printf(seq, ",uid=%u", sbi->uid);
+ if (sbi->gid != 0)
+ seq_printf(seq, ",gid=%u", sbi->gid);
+ if (test_opt(vfs->mnt_sb, ERRORS_RO))
+ seq_puts(seq, ",errors=remount-ro");
+ if (test_opt(vfs->mnt_sb, ERRORS_PANIC))
+ seq_puts(seq, ",errors=panic");
+#ifdef CONFIG_PRAMFS_WRITE_PROTECT
+ /* memory protection enabled by default */
+ if (!test_opt(vfs->mnt_sb, PROTECT))
+ seq_puts(seq, ",noprotect");
+#else
+ /*
+ * If it's not compiled say to the user that there
+ * isn't the protection.
+ */
+ seq_puts(seq, ",noprotect");
+#endif
+
+#ifdef CONFIG_PRAMFS_XATTR
+ /* user xattr not enabled by default */
+ if (test_opt(vfs->mnt_sb, XATTR_USER))
+ seq_puts(seq, ",user_xattr");
+#endif
+
+#ifdef CONFIG_PRAMFS_POSIX_ACL
+ /* acl not enabled by default */
+ if (test_opt(vfs->mnt_sb, POSIX_ACL))
+ seq_puts(seq, ",acl");
+#endif
+
+#ifdef CONFIG_PRAMFS_XIP
+ /* xip not enabled by default */
+ if (test_opt(vfs->mnt_sb, XIP))
+ seq_puts(seq, ",xip");
+#endif
+
+ return 0;
+}
+
+int pram_remount(struct super_block *sb, int *mntflags, char *data)
+{
+ unsigned long old_sb_flags;
+ unsigned long old_mount_opt;
+ struct pram_super_block *ps;
+ struct pram_sb_info *sbi = (struct pram_sb_info *)sb->s_fs_info;
+ int ret = -EINVAL;
+
+ /* Store the old options */
+ old_sb_flags = sb->s_flags;
+ old_mount_opt = sbi->s_mount_opt;
+
+ if (pram_parse_options(data, sbi, 1))
+ goto restore_opt;
+
+ sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
+ ((sbi->s_mount_opt & PRAM_MOUNT_POSIX_ACL) ? MS_POSIXACL : 0);
+
+ if ((*mntflags & MS_RDONLY) != (sb->s_flags & MS_RDONLY)) {
+ ps = pram_get_super(sb);
+ pram_memunlock_super(sb, ps);
+ ps->s_mtime = cpu_to_be32(get_seconds()); /* update mount time
*/
+ pram_memlock_super(sb, ps);
+ }
+
+ ret = 0;
+ return ret;
+
+ restore_opt:
+ sb->s_flags = old_sb_flags;
+ sbi->s_mount_opt = old_mount_opt;
+ return ret;
+}
+
+void pram_put_super(struct super_block *sb)
+{
+ struct pram_sb_info *sbi = (struct pram_sb_info *)sb->s_fs_info;
+ struct pram_super_block *ps = pram_get_super(sb);
+ u64 size = be64_to_cpu(ps->s_size);
+
+#ifdef CONFIG_PRAMFS_TEST
+ if (first_pram_super == sbi->virt_addr)
+ first_pram_super = NULL;
+#endif
+
+ pram_xattr_put_super(sb);
+ /* It's unmount time, so unmap the pramfs memory */
+ if (sbi->virt_addr) {
+ if (pram_is_protected(sb))
+ pram_writeable(sbi->virt_addr, size, 1);
+ iounmap(sbi->virt_addr);
+ sbi->virt_addr = NULL;
+ release_mem_region(sbi->phys_addr, size);
+ }
+
+ sb->s_fs_info = NULL;
+ kfree(sbi);
+}
+
+static struct inode *pram_alloc_inode(struct super_block *sb)
+{
+ struct pram_inode_vfs *vi = (struct pram_inode_vfs *)
+ kmem_cache_alloc(pram_inode_cachep, GFP_KERNEL);
+ if (!vi)
+ return NULL;
+ vi->vfs_inode.i_version = 1;
+ return &vi->vfs_inode;
+}
+
+static void pram_destroy_inode(struct inode *inode)
+{
+ kmem_cache_free(pram_inode_cachep, PRAM_I(inode));
+}
+
+static void init_once(void *foo)
+{
+ struct pram_inode_vfs *vi = (struct pram_inode_vfs *) foo;
+
+#ifdef CONFIG_PRAMFS_XATTR
+ init_rwsem(&vi->xattr_sem);
+#endif
+ mutex_init(&vi->truncate_mutex);
+ mutex_init(&vi->i_meta_mutex);
+ inode_init_once(&vi->vfs_inode);
+}
+
+static int __init init_inodecache(void)
+{
+ pram_inode_cachep = kmem_cache_create("pram_inode_cache",
+ sizeof(struct pram_inode_vfs),
+ 0, (SLAB_RECLAIM_ACCOUNT|
+ SLAB_MEM_SPREAD),
+ init_once);
+ if (pram_inode_cachep == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
+static void destroy_inodecache(void)
+{
+ kmem_cache_destroy(pram_inode_cachep);
+}
+
+/*
+ * the super block writes are all done "on the fly", so the
+ * super block is never in a "dirty" state, so there's no need
+ * for write_super.
+ */
+static struct super_operations pram_sops = {
+ .alloc_inode = pram_alloc_inode,
+ .destroy_inode = pram_destroy_inode,
+ .write_inode = pram_write_inode,
+ .dirty_inode = pram_dirty_inode,
+ .evict_inode = pram_evict_inode,
+ .put_super = pram_put_super,
+ .statfs = pram_statfs,
+ .remount_fs = pram_remount,
+ .show_options = pram_show_options,
+};
+
+static struct dentry *pram_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+{
+ return mount_nodev(fs_type, flags, data, pram_fill_super);
+}
+
+static struct file_system_type pram_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "pramfs",
+ .mount = pram_mount,
+ .kill_sb = kill_anon_super,
+};
+
+static struct inode *pram_nfs_get_inode(struct super_block *sb,
+ u64 ino, u32 generation)
+{
+ struct pram_super_block *ps = pram_get_super(sb);
+ struct inode *inode;
+
+ if (ino < PRAM_ROOT_INO)
+ return ERR_PTR(-ESTALE);
+ if (((ino - PRAM_ROOT_INO) >> PRAM_INODE_BITS) >
be32_to_cpu(ps->s_inodes_count))
+ return ERR_PTR(-ESTALE);
+
+ inode = pram_iget(sb, ino);
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
+ if (generation && inode->i_generation != generation) {
+ /* we didn't find the right inode.. */
+ iput(inode);
+ return ERR_PTR(-ESTALE);
+ }
+ return inode;
+}
+
+static struct dentry *
+pram_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
+ int fh_type)
+{
+ return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+ pram_nfs_get_inode);
+}
+
+static struct dentry *
+pram_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len,
+ int fh_type)
+{
+ return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+ pram_nfs_get_inode);
+}
+
+static const struct export_operations pram_export_ops = {
+ .fh_to_dentry = pram_fh_to_dentry,
+ .fh_to_parent = pram_fh_to_parent,
+ .get_parent = pram_get_parent,
+};
+
+static int __init init_pram_fs(void)
+{
+ int rc = 0;
+
+ rc = init_pram_xattr();
+ if (rc)
+ return rc;
+
+ rc = init_inodecache();
+ if (rc)
+ goto out1;
+
+ rc = bdi_init(&pram_backing_dev_info);
+ if (rc)
+ goto out2;
+
+ rc = register_filesystem(&pram_fs_type);
+ if (rc)
+ goto out3;
+
+ return 0;
+
+out3:
+ bdi_destroy(&pram_backing_dev_info);
+out2:
+ destroy_inodecache();
+out1:
+ exit_pram_xattr();
+ return rc;
+}
+
+static void __exit exit_pram_fs(void)
+{
+ unregister_filesystem(&pram_fs_type);
+ bdi_destroy(&pram_backing_dev_info);
+ destroy_inodecache();
+ exit_pram_xattr();
+}
+
+MODULE_AUTHOR("Marco Stornelli <marco.storne...@gmail.com>");
+MODULE_DESCRIPTION("Protected/Persistent RAM Filesystem");
+MODULE_LICENSE("GPL");
+
+module_init(init_pram_fs)
+module_exit(exit_pram_fs)
--
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