original development tree for Linux kernel GTP module; now long in mainline.
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linux-gtp/fs/affs/super.c

575 lines
14 KiB

/*
* linux/fs/affs/inode.c
*
* (c) 1996 Hans-Joachim Widmaier - Rewritten
*
* (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
*
* (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
*
* (C) 1991 Linus Torvalds - minix filesystem
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/statfs.h>
#include <linux/parser.h>
#include <linux/magic.h>
#include <linux/sched.h>
#include "affs.h"
extern struct timezone sys_tz;
static int affs_statfs(struct dentry *dentry, struct kstatfs *buf);
static int affs_remount (struct super_block *sb, int *flags, char *data);
static void
affs_put_super(struct super_block *sb)
{
struct affs_sb_info *sbi = AFFS_SB(sb);
pr_debug("AFFS: put_super()\n");
if (!(sb->s_flags & MS_RDONLY)) {
AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(1);
secs_to_datestamp(get_seconds(),
&AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
affs_fix_checksum(sb, sbi->s_root_bh);
mark_buffer_dirty(sbi->s_root_bh);
}
kfree(sbi->s_prefix);
affs_free_bitmap(sb);
affs_brelse(sbi->s_root_bh);
kfree(sbi);
sb->s_fs_info = NULL;
return;
}
static void
affs_write_super(struct super_block *sb)
{
int clean = 2;
struct affs_sb_info *sbi = AFFS_SB(sb);
if (!(sb->s_flags & MS_RDONLY)) {
// if (sbi->s_bitmap[i].bm_bh) {
// if (buffer_dirty(sbi->s_bitmap[i].bm_bh)) {
// clean = 0;
AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->bm_flag = cpu_to_be32(clean);
secs_to_datestamp(get_seconds(),
&AFFS_ROOT_TAIL(sb, sbi->s_root_bh)->disk_change);
affs_fix_checksum(sb, sbi->s_root_bh);
mark_buffer_dirty(sbi->s_root_bh);
sb->s_dirt = !clean; /* redo until bitmap synced */
} else
sb->s_dirt = 0;
pr_debug("AFFS: write_super() at %lu, clean=%d\n", get_seconds(), clean);
}
static struct kmem_cache * affs_inode_cachep;
static struct inode *affs_alloc_inode(struct super_block *sb)
{
struct affs_inode_info *ei;
ei = (struct affs_inode_info *)kmem_cache_alloc(affs_inode_cachep, GFP_KERNEL);
if (!ei)
return NULL;
ei->vfs_inode.i_version = 1;
return &ei->vfs_inode;
}
static void affs_destroy_inode(struct inode *inode)
{
kmem_cache_free(affs_inode_cachep, AFFS_I(inode));
}
static void init_once(struct kmem_cache *cachep, void *foo)
{
struct affs_inode_info *ei = (struct affs_inode_info *) foo;
init_MUTEX(&ei->i_link_lock);
init_MUTEX(&ei->i_ext_lock);
inode_init_once(&ei->vfs_inode);
}
static int init_inodecache(void)
{
affs_inode_cachep = kmem_cache_create("affs_inode_cache",
sizeof(struct affs_inode_info),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
init_once);
if (affs_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
static void destroy_inodecache(void)
{
kmem_cache_destroy(affs_inode_cachep);
}
static const struct super_operations affs_sops = {
.alloc_inode = affs_alloc_inode,
.destroy_inode = affs_destroy_inode,
.write_inode = affs_write_inode,
.put_inode = affs_put_inode,
.drop_inode = affs_drop_inode,
.delete_inode = affs_delete_inode,
.clear_inode = affs_clear_inode,
.put_super = affs_put_super,
.write_super = affs_write_super,
.statfs = affs_statfs,
.remount_fs = affs_remount,
};
enum {
Opt_bs, Opt_mode, Opt_mufs, Opt_prefix, Opt_protect,
Opt_reserved, Opt_root, Opt_setgid, Opt_setuid,
Opt_verbose, Opt_volume, Opt_ignore, Opt_err,
};
static match_table_t tokens = {
{Opt_bs, "bs=%u"},
{Opt_mode, "mode=%o"},
{Opt_mufs, "mufs"},
{Opt_prefix, "prefix=%s"},
{Opt_protect, "protect"},
{Opt_reserved, "reserved=%u"},
{Opt_root, "root=%u"},
{Opt_setgid, "setgid=%u"},
{Opt_setuid, "setuid=%u"},
{Opt_verbose, "verbose"},
{Opt_volume, "volume=%s"},
{Opt_ignore, "grpquota"},
{Opt_ignore, "noquota"},
{Opt_ignore, "quota"},
{Opt_ignore, "usrquota"},
{Opt_err, NULL},
};
static int
parse_options(char *options, uid_t *uid, gid_t *gid, int *mode, int *reserved, s32 *root,
int *blocksize, char **prefix, char *volume, unsigned long *mount_opts)
{
char *p;
substring_t args[MAX_OPT_ARGS];
/* Fill in defaults */
*uid = current->uid;
*gid = current->gid;
*reserved = 2;
*root = -1;
*blocksize = -1;
volume[0] = ':';
volume[1] = 0;
*mount_opts = 0;
if (!options)
return 1;
while ((p = strsep(&options, ",")) != NULL) {
int token, n, option;
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case Opt_bs:
if (match_int(&args[0], &n))
return -EINVAL;
if (n != 512 && n != 1024 && n != 2048
&& n != 4096) {
printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
return 0;
}
*blocksize = n;
break;
case Opt_mode:
if (match_octal(&args[0], &option))
return 1;
*mode = option & 0777;
*mount_opts |= SF_SETMODE;
break;
case Opt_mufs:
*mount_opts |= SF_MUFS;
break;
case Opt_prefix:
/* Free any previous prefix */
kfree(*prefix);
*prefix = NULL;
*prefix = match_strdup(&args[0]);
if (!*prefix)
return 0;
*mount_opts |= SF_PREFIX;
break;
case Opt_protect:
*mount_opts |= SF_IMMUTABLE;
break;
case Opt_reserved:
if (match_int(&args[0], reserved))
return 1;
break;
case Opt_root:
if (match_int(&args[0], root))
return 1;
break;
case Opt_setgid:
if (match_int(&args[0], &option))
return 1;
*gid = option;
*mount_opts |= SF_SETGID;
break;
case Opt_setuid:
if (match_int(&args[0], &option))
return -EINVAL;
*uid = option;
*mount_opts |= SF_SETUID;
break;
case Opt_verbose:
*mount_opts |= SF_VERBOSE;
break;
case Opt_volume: {
char *vol = match_strdup(&args[0]);
strlcpy(volume, vol, 32);
kfree(vol);
break;
}
case Opt_ignore:
/* Silently ignore the quota options */
break;
default:
printk("AFFS: Unrecognized mount option \"%s\" "
"or missing value\n", p);
return 0;
}
}
return 1;
}
/* This function definitely needs to be split up. Some fine day I'll
* hopefully have the guts to do so. Until then: sorry for the mess.
*/
static int affs_fill_super(struct super_block *sb, void *data, int silent)
{
struct affs_sb_info *sbi;
struct buffer_head *root_bh = NULL;
struct buffer_head *boot_bh;
struct inode *root_inode = NULL;
s32 root_block;
int size, blocksize;
u32 chksum;
int num_bm;
int i, j;
s32 key;
uid_t uid;
gid_t gid;
int reserved;
unsigned long mount_flags;
int tmp_flags; /* fix remount prototype... */
u8 sig[4];
int ret = -EINVAL;
pr_debug("AFFS: read_super(%s)\n",data ? (const char *)data : "no options");
sb->s_magic = AFFS_SUPER_MAGIC;
sb->s_op = &affs_sops;
sb->s_flags |= MS_NODIRATIME;
sbi = kzalloc(sizeof(struct affs_sb_info), GFP_KERNEL);
if (!sbi)
return -ENOMEM;
sb->s_fs_info = sbi;
init_MUTEX(&sbi->s_bmlock);
if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
&blocksize,&sbi->s_prefix,
sbi->s_volume, &mount_flags)) {
printk(KERN_ERR "AFFS: Error parsing options\n");
return -EINVAL;
}
/* N.B. after this point s_prefix must be released */
sbi->s_flags = mount_flags;
sbi->s_mode = i;
sbi->s_uid = uid;
sbi->s_gid = gid;
sbi->s_reserved= reserved;
/* Get the size of the device in 512-byte blocks.
* If we later see that the partition uses bigger
* blocks, we will have to change it.
*/
size = sb->s_bdev->bd_inode->i_size >> 9;
pr_debug("AFFS: initial blocksize=%d, #blocks=%d\n", 512, size);
affs_set_blocksize(sb, PAGE_SIZE);
/* Try to find root block. Its location depends on the block size. */
i = 512;
j = 4096;
if (blocksize > 0) {
i = j = blocksize;
size = size / (blocksize / 512);
}
for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
sbi->s_root_block = root_block;
if (root_block < 0)
sbi->s_root_block = (reserved + size - 1) / 2;
pr_debug("AFFS: setting blocksize to %d\n", blocksize);
affs_set_blocksize(sb, blocksize);
sbi->s_partition_size = size;
/* The root block location that was calculated above is not
* correct if the partition size is an odd number of 512-
* byte blocks, which will be rounded down to a number of
* 1024-byte blocks, and if there were an even number of
* reserved blocks. Ideally, all partition checkers should
* report the real number of blocks of the real blocksize,
* but since this just cannot be done, we have to try to
* find the root block anyways. In the above case, it is one
* block behind the calculated one. So we check this one, too.
*/
for (num_bm = 0; num_bm < 2; num_bm++) {
pr_debug("AFFS: Dev %s, trying root=%u, bs=%d, "
"size=%d, reserved=%d\n",
sb->s_id,
sbi->s_root_block + num_bm,
blocksize, size, reserved);
root_bh = affs_bread(sb, sbi->s_root_block + num_bm);
if (!root_bh)
continue;
if (!affs_checksum_block(sb, root_bh) &&
be32_to_cpu(AFFS_ROOT_HEAD(root_bh)->ptype) == T_SHORT &&
be32_to_cpu(AFFS_ROOT_TAIL(sb, root_bh)->stype) == ST_ROOT) {
sbi->s_hashsize = blocksize / 4 - 56;
sbi->s_root_block += num_bm;
key = 1;
goto got_root;
}
affs_brelse(root_bh);
root_bh = NULL;
}
}
if (!silent)
printk(KERN_ERR "AFFS: No valid root block on device %s\n",
sb->s_id);
goto out_error;
/* N.B. after this point bh must be released */
got_root:
root_block = sbi->s_root_block;
/* Find out which kind of FS we have */
boot_bh = sb_bread(sb, 0);
if (!boot_bh) {
printk(KERN_ERR "AFFS: Cannot read boot block\n");
goto out_error;
}
memcpy(sig, boot_bh->b_data, 4);
brelse(boot_bh);
chksum = be32_to_cpu(*(__be32 *)sig);
/* Dircache filesystems are compatible with non-dircache ones
* when reading. As long as they aren't supported, writing is
* not recommended.
*/
if ((chksum == FS_DCFFS || chksum == MUFS_DCFFS || chksum == FS_DCOFS
|| chksum == MUFS_DCOFS) && !(sb->s_flags & MS_RDONLY)) {
printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
sb->s_id);
sb->s_flags |= MS_RDONLY;
}
switch (chksum) {
case MUFS_FS:
case MUFS_INTLFFS:
case MUFS_DCFFS:
sbi->s_flags |= SF_MUFS;
/* fall thru */
case FS_INTLFFS:
case FS_DCFFS:
sbi->s_flags |= SF_INTL;
break;
case MUFS_FFS:
sbi->s_flags |= SF_MUFS;
break;
case FS_FFS:
break;
case MUFS_OFS:
sbi->s_flags |= SF_MUFS;
/* fall thru */
case FS_OFS:
sbi->s_flags |= SF_OFS;
sb->s_flags |= MS_NOEXEC;
break;
case MUFS_DCOFS:
case MUFS_INTLOFS:
sbi->s_flags |= SF_MUFS;
case FS_DCOFS:
case FS_INTLOFS:
sbi->s_flags |= SF_INTL | SF_OFS;
sb->s_flags |= MS_NOEXEC;
break;
default:
printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
sb->s_id, chksum);
goto out_error;
}
if (mount_flags & SF_VERBOSE) {
u8 len = AFFS_ROOT_TAIL(sb, root_bh)->disk_name[0];
printk(KERN_NOTICE "AFFS: Mounting volume \"%.*s\": Type=%.3s\\%c, Blocksize=%d\n",
len > 31 ? 31 : len,
AFFS_ROOT_TAIL(sb, root_bh)->disk_name + 1,
sig, sig[3] + '0', blocksize);
}
sb->s_flags |= MS_NODEV | MS_NOSUID;
sbi->s_data_blksize = sb->s_blocksize;
if (sbi->s_flags & SF_OFS)
sbi->s_data_blksize -= 24;
/* Keep super block in cache */
sbi->s_root_bh = root_bh;
/* N.B. after this point s_root_bh must be released */
tmp_flags = sb->s_flags;
if (affs_init_bitmap(sb, &tmp_flags))
goto out_error;
sb->s_flags = tmp_flags;
/* set up enough so that it can read an inode */
root_inode = affs_iget(sb, root_block);
if (IS_ERR(root_inode)) {
ret = PTR_ERR(root_inode);
goto out_error_noinode;
}
sb->s_root = d_alloc_root(root_inode);
if (!sb->s_root) {
printk(KERN_ERR "AFFS: Get root inode failed\n");
goto out_error;
}
sb->s_root->d_op = &affs_dentry_operations;
pr_debug("AFFS: s_flags=%lX\n",sb->s_flags);
return 0;
/*
* Begin the cascaded cleanup ...
*/
out_error:
if (root_inode)
iput(root_inode);
out_error_noinode:
kfree(sbi->s_bitmap);
affs_brelse(root_bh);
kfree(sbi->s_prefix);
kfree(sbi);
sb->s_fs_info = NULL;
return ret;
}
static int
affs_remount(struct super_block *sb, int *flags, char *data)
{
struct affs_sb_info *sbi = AFFS_SB(sb);
int blocksize;
uid_t uid;
gid_t gid;
int mode;
int reserved;
int root_block;
unsigned long mount_flags;
int res = 0;
pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
*flags |= MS_NODIRATIME;
if (!parse_options(data,&uid,&gid,&mode,&reserved,&root_block,
&blocksize,&sbi->s_prefix,sbi->s_volume,&mount_flags))
return -EINVAL;
sbi->s_flags = mount_flags;
sbi->s_mode = mode;
sbi->s_uid = uid;
sbi->s_gid = gid;
if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
return 0;
if (*flags & MS_RDONLY) {
sb->s_dirt = 1;
while (sb->s_dirt)
affs_write_super(sb);
affs_free_bitmap(sb);
} else
res = affs_init_bitmap(sb, flags);
return res;
}
static int
affs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
int free;
pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",AFFS_SB(sb)->s_partition_size,
AFFS_SB(sb)->s_reserved);
free = affs_count_free_blocks(sb);
buf->f_type = AFFS_SUPER_MAGIC;
buf->f_bsize = sb->s_blocksize;
buf->f_blocks = AFFS_SB(sb)->s_partition_size - AFFS_SB(sb)->s_reserved;
buf->f_bfree = free;
buf->f_bavail = free;
return 0;
}
[PATCH] VFS: Permit filesystem to override root dentry on mount Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
17 years ago
static int affs_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
{
[PATCH] VFS: Permit filesystem to override root dentry on mount Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
17 years ago
return get_sb_bdev(fs_type, flags, dev_name, data, affs_fill_super,
mnt);
}
static struct file_system_type affs_fs_type = {
.owner = THIS_MODULE,
.name = "affs",
.get_sb = affs_get_sb,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
static int __init init_affs_fs(void)
{
int err = init_inodecache();
if (err)
goto out1;
err = register_filesystem(&affs_fs_type);
if (err)
goto out;
return 0;
out:
destroy_inodecache();
out1:
return err;
}
static void __exit exit_affs_fs(void)
{
unregister_filesystem(&affs_fs_type);
destroy_inodecache();
}
MODULE_DESCRIPTION("Amiga filesystem support for Linux");
MODULE_LICENSE("GPL");
module_init(init_affs_fs)
module_exit(exit_affs_fs)