patch-2.1.71 linux/fs/affs/super.c

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diff -u --recursive --new-file v2.1.70/linux/fs/affs/super.c linux/fs/affs/super.c
@@ -0,0 +1,691 @@
+/*
+ *  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 ISO9660 filesystem.
+ *
+ *  (C) 1991  Linus Torvalds - minix filesystem
+ */
+
+#define DEBUG 0
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/malloc.h>
+#include <linux/stat.h>
+#include <linux/sched.h>
+#include <linux/affs_fs.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/locks.h>
+#include <linux/errno.h>
+#include <linux/genhd.h>
+#include <linux/amigaffs.h>
+#include <linux/major.h>
+#include <linux/blkdev.h>
+#include <linux/init.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+
+extern int *blk_size[];
+extern struct timezone sys_tz;
+
+#define MIN(a,b) (((a)<(b))?(a):(b))
+
+static int affs_statfs(struct super_block *sb, struct statfs *buf, int bufsiz);
+static int affs_remount (struct super_block *sb, int *flags, char *data);
+
+static void
+affs_put_super(struct super_block *sb)
+{
+	int	 i;
+
+	pr_debug("affs_put_super()\n");
+
+	lock_super(sb);
+	for (i = 0; i < sb->u.affs_sb.s_bm_count; i++)
+		affs_brelse(sb->u.affs_sb.s_bitmap[i].bm_bh);
+	if (!(sb->s_flags & MS_RDONLY)) {
+		ROOT_END_S(sb->u.affs_sb.s_root_bh->b_data,sb)->bm_flag = be32_to_cpu(1);
+		secs_to_datestamp(CURRENT_TIME,
+				  &ROOT_END_S(sb->u.affs_sb.s_root_bh->b_data,sb)->disk_altered);
+		affs_fix_checksum(sb->s_blocksize,sb->u.affs_sb.s_root_bh->b_data,5);
+		mark_buffer_dirty(sb->u.affs_sb.s_root_bh,1);
+	}
+
+	if (sb->u.affs_sb.s_prefix)
+		kfree(sb->u.affs_sb.s_prefix);
+	kfree(sb->u.affs_sb.s_bitmap);
+	affs_brelse(sb->u.affs_sb.s_root_bh);
+
+	/* I'm not happy with this. It would be better to save the previous
+	 * value of this devices blksize_size[][] in the super block and
+	 * restore it here, but with the affs superblock being quite large
+	 * already ...
+	 */
+	set_blocksize(sb->s_dev,BLOCK_SIZE);
+
+	sb->s_dev = 0;
+	unlock_super(sb);
+	MOD_DEC_USE_COUNT;
+	return;
+}
+
+static void
+affs_write_super(struct super_block *sb)
+{
+	int	 i, clean = 2;
+
+	if (!(sb->s_flags & MS_RDONLY)) {
+		lock_super(sb);
+		for (i = 0, clean = 1; i < sb->u.affs_sb.s_bm_count; i++) {
+			if (sb->u.affs_sb.s_bitmap[i].bm_bh) {
+				if (buffer_dirty(sb->u.affs_sb.s_bitmap[i].bm_bh)) {
+					clean = 0;
+					break;
+				}
+			}
+		}
+		unlock_super(sb);
+		ROOT_END_S(sb->u.affs_sb.s_root_bh->b_data,sb)->bm_flag = be32_to_cpu(clean);
+		secs_to_datestamp(CURRENT_TIME,
+				  &ROOT_END_S(sb->u.affs_sb.s_root_bh->b_data,sb)->disk_altered);
+		affs_fix_checksum(sb->s_blocksize,sb->u.affs_sb.s_root_bh->b_data,5);
+		mark_buffer_dirty(sb->u.affs_sb.s_root_bh,1);
+		sb->s_dirt = !clean;	/* redo until bitmap synced */
+	} else
+		sb->s_dirt = 0;
+
+	pr_debug("AFFS: write_super() at %d, clean=%d\n",CURRENT_TIME,clean);
+}
+
+static struct super_operations affs_sops = {
+	affs_read_inode,
+	affs_write_inode,
+	affs_put_inode,
+	affs_delete_inode,
+	affs_notify_change,
+	affs_put_super,
+	affs_write_super,
+	affs_statfs,
+	affs_remount
+};
+
+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	*this_char, *value;
+	int	 f;
+
+	/* 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;
+	for (this_char = strtok(options,","); this_char; this_char = strtok(NULL,",")) {
+		f = 0;
+		if ((value = strchr(this_char,'=')) != NULL)
+			*value++ = 0;
+		if (!strcmp(this_char,"protect")) {
+			if (value) {
+				printk("AFFS: Option protect does not take an argument\n");
+				return 0;
+			}
+			*mount_opts |= SF_IMMUTABLE;
+		} else if (!strcmp(this_char,"verbose")) {
+			if (value) {
+				printk("AFFS: Option verbose does not take an argument\n");
+				return 0;
+			}
+			*mount_opts |= SF_VERBOSE;
+		} else if ((f = !strcmp(this_char,"setuid")) || !strcmp(this_char,"setgid")) {
+			if (value) {
+				if (!*value) {
+					printk("AFFS: Argument for set[ug]id option missing\n");
+					return 0;
+				} else {
+					(f ? *uid : *gid) = simple_strtoul(value,&value,0);
+					if (*value) {
+						printk("AFFS: Bad set[ug]id argument\n");
+						return 0;
+					}
+					*mount_opts |= f ? SF_SETUID : SF_SETGID;
+				}
+			}
+		} else if (!strcmp(this_char,"prefix")) {
+			if (!value || !*value) {
+				printk("AFFS: The prefix option requires an argument\n");
+				return 0;
+			}
+			if (*prefix)		/* Free any previous prefix */
+				kfree(*prefix);
+			*prefix = kmalloc(strlen(value) + 1,GFP_KERNEL);
+			if (!*prefix)
+				return 0;
+			strcpy(*prefix,value);
+			*mount_opts |= SF_PREFIX;
+		} else if (!strcmp(this_char,"volume")) {
+			if (!value || !*value) {
+				printk("AFFS: The volume option requires an argument\n");
+				return 0;
+			}
+			if (strlen(value) > 30)
+				value[30] = 0;
+			strncpy(volume,value,30);
+		} else if (!strcmp(this_char,"mode")) {
+			if (!value || !*value) {
+				printk("AFFS: The mode option requires an argument\n");
+				return 0;
+			}
+			*mode = simple_strtoul(value,&value,8) & 0777;
+			if (*value)
+				return 0;
+			*mount_opts |= SF_SETMODE;
+		} else if (!strcmp(this_char,"reserved")) {
+			if (!value || !*value) {
+				printk("AFFS: The reserved option requires an argument\n");
+				return 0;
+			}
+			*reserved = simple_strtoul(value,&value,0);
+			if (*value)
+				return 0;
+		} else if (!strcmp(this_char,"root")) {
+			if (!value || !*value) {
+				printk("AFFS: The root option requires an argument\n");
+				return 0;
+			}
+			*root = simple_strtoul(value,&value,0);
+			if (*value)
+				return 0;
+		} else if (!strcmp(this_char,"bs")) {
+			if (!value || !*value) {
+				printk("AFFS: The bs option requires an argument\n");
+				return 0;
+			}
+			*blocksize = simple_strtoul(value,&value,0);
+			if (*value)
+				return 0;
+			if (*blocksize != 512 && *blocksize != 1024 && *blocksize != 2048
+			    && *blocksize != 4096) {
+				printk ("AFFS: Invalid blocksize (512, 1024, 2048, 4096 allowed)\n");
+				return 0;
+			}
+		} else if (!strcmp (this_char, "grpquota")
+			 || !strcmp (this_char, "noquota")
+			 || !strcmp (this_char, "quota")
+			 || !strcmp (this_char, "usrquota"))
+			 /* Silently ignore the quota options */
+			;
+		else {
+			printk("AFFS: Unrecognized mount option %s\n", this_char);
+			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 struct super_block *
+affs_read_super(struct super_block *s,void *data, int silent)
+{
+	struct buffer_head	*bh = NULL;
+	struct buffer_head	*bb;
+	struct inode		*root_inode;
+	kdev_t			 dev = s->s_dev;
+	s32			 root_block;
+	int			 size;
+	u32			 chksum;
+	u32			*bm;
+	s32			 ptype, stype;
+	int			 mapidx;
+	int			 num_bm;
+	int			 i, j;
+	s32			 key;
+	int			 blocksize;
+	uid_t			 uid;
+	gid_t			 gid;
+	int			 reserved;
+	int			 az_no;
+	int			 bmalt = 0;
+	unsigned long		 mount_flags;
+	unsigned long		 offset;
+
+	pr_debug("affs_read_super(%s)\n",data ? (const char *)data : "no options");
+
+	MOD_INC_USE_COUNT;
+
+	s->u.affs_sb.s_prefix = NULL;
+	if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,
+	    &blocksize,&s->u.affs_sb.s_prefix,s->u.affs_sb.s_volume,&mount_flags)) {
+		s->s_dev = 0;
+		printk(KERN_ERR "AFFS: Error parsing options\n");
+		MOD_DEC_USE_COUNT;
+		return NULL;
+	}
+	lock_super(s);
+
+	/* 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 = blksize_size[MAJOR(dev)][MINOR(dev)];
+	size = (size ? size : BLOCK_SIZE) / 512 * blk_size[MAJOR(dev)][MINOR(dev)];
+
+	s->u.affs_sb.s_bitmap  = NULL;
+	s->u.affs_sb.s_root_bh = NULL;
+	s->u.affs_sb.s_flags   = mount_flags;
+	s->u.affs_sb.s_mode    = i;
+	s->u.affs_sb.s_uid     = uid;
+	s->u.affs_sb.s_gid     = gid;
+
+	if (size == 0) {
+		s->s_dev = 0;
+		unlock_super(s);
+		printk(KERN_ERR "AFFS: Could not determine device size\n");
+		goto out;
+	}
+	s->u.affs_sb.s_partition_size = size;
+	s->u.affs_sb.s_reserved       = reserved;
+
+	/* Try to find root block. Its location depends on the block size. */
+
+	s->u.affs_sb.s_hashsize = 0;
+	if (blocksize > 0) {
+		i = blocksize;
+		j = blocksize;
+	} else {
+		i = 512;
+		j = 4096;
+	}
+	for (blocksize = i, key = 0; blocksize <= j; blocksize <<= 1, size >>= 1) {
+		if (root_block < 0)
+			s->u.affs_sb.s_root_block = (reserved + size - 1) / 2;
+		else
+			s->u.affs_sb.s_root_block = root_block;
+		set_blocksize(dev,blocksize);
+
+		/* 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 bs=%d bytes, root at %u, "
+				 "size=%d blocks, %d reserved\n",kdevname(dev),blocksize,
+				 s->u.affs_sb.s_root_block + num_bm,size,reserved);
+			bh = affs_bread(dev,s->u.affs_sb.s_root_block + num_bm,blocksize);
+			if (!bh) {
+				printk(KERN_ERR "AFFS: Cannot read root block\n");
+				goto out;
+			}
+			if (!affs_checksum_block(blocksize,bh->b_data,&ptype,&stype) &&
+			    ptype == T_SHORT && stype == ST_ROOT) {
+				s->s_blocksize             = blocksize;
+				s->u.affs_sb.s_hashsize    = blocksize / 4 - 56;
+				s->u.affs_sb.s_root_block += num_bm;
+				key                        = 1;
+				break;
+			}
+		}
+		if (key)
+			break;
+		affs_brelse(bh);
+		bh = NULL;
+	}
+	if (!key) {
+		affs_brelse(bh);
+		if (!silent)
+			printk(KERN_ERR "AFFS: Cannot find a valid root block on device %s\n",
+				kdevname(dev));
+		goto out;
+	}
+	root_block = s->u.affs_sb.s_root_block;
+
+	s->u.affs_sb.s_partition_size   = size;
+	s->s_blocksize_bits             = blocksize == 512 ? 9 :
+					  blocksize == 1024 ? 10 :
+					  blocksize == 2048 ? 11 : 12;
+
+	/* Find out which kind of FS we have */
+	bb = affs_bread(dev,0,s->s_blocksize);
+	if (bb) {
+		chksum = be32_to_cpu(*(u32 *)bb->b_data);
+
+		/* 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) && !(s->s_flags & MS_RDONLY)) {
+			printk(KERN_NOTICE "AFFS: Dircache FS - mounting %s read only\n",
+				kdevname(dev));
+			s->s_flags |= MS_RDONLY;
+			s->u.affs_sb.s_flags |= SF_READONLY;
+		}
+		switch (chksum) {
+			case MUFS_FS:
+			case MUFS_INTLFFS:
+				s->u.affs_sb.s_flags |= SF_MUFS;
+				/* fall thru */
+			case FS_INTLFFS:
+				s->u.affs_sb.s_flags |= SF_INTL;
+				break;
+			case MUFS_DCFFS:
+			case MUFS_FFS:
+				s->u.affs_sb.s_flags |= SF_MUFS;
+				break;
+			case FS_DCFFS:
+			case FS_FFS:
+				break;
+			case MUFS_OFS:
+				s->u.affs_sb.s_flags |= SF_MUFS;
+				/* fall thru */
+			case FS_OFS:
+				s->u.affs_sb.s_flags |= SF_OFS;
+				break;
+			case MUFS_DCOFS:
+			case MUFS_INTLOFS:
+				s->u.affs_sb.s_flags |= SF_MUFS;
+			case FS_DCOFS:
+			case FS_INTLOFS:
+				s->u.affs_sb.s_flags |= SF_INTL | SF_OFS;
+				break;
+			default:
+				printk(KERN_ERR "AFFS: Unknown filesystem on device %s: %08X\n",
+					kdevname(dev),chksum);
+				affs_brelse(bb);
+				goto out;
+		}
+		affs_brelse(bb);
+	} else {
+		printk(KERN_ERR "AFFS: Cannot read boot block\n");
+		goto out;
+	}
+	if (mount_flags & SF_VERBOSE) {
+		chksum = cpu_to_be32(chksum);
+		printk(KERN_NOTICE "AFFS: Mounting volume \"%*s\": Type=%.3s\\%c, Blocksize=%d\n",
+			GET_END_PTR(struct root_end,bh->b_data,blocksize)->disk_name[0],
+			&GET_END_PTR(struct root_end,bh->b_data,blocksize)->disk_name[1],
+			(char *)&chksum,((char *)&chksum)[3] + '0',blocksize);
+	}
+
+	s->s_magic  = AFFS_SUPER_MAGIC;
+	s->s_flags |= MS_NODEV | MS_NOSUID;
+
+	/* Keep super block in cache */
+	if (!(s->u.affs_sb.s_root_bh = affs_bread(dev,root_block,s->s_blocksize))) {
+		printk(KERN_ERR "AFFS: Cannot read root block\n");
+		goto out;
+	}
+
+	/* Allocate space for bitmaps, zones and others */
+
+	size   = s->u.affs_sb.s_partition_size - reserved;
+	num_bm = (size + s->s_blocksize * 8 - 32 - 1) / (s->s_blocksize * 8 - 32);
+	az_no  = (size + AFFS_ZONE_SIZE - 1) / (AFFS_ZONE_SIZE - 32);
+	ptype  = num_bm * sizeof(struct affs_bm_info) +
+		 az_no * sizeof(struct affs_alloc_zone) +
+		 MAX_ZONES * sizeof(struct affs_zone);
+	pr_debug("num_bm=%d, az_no=%d, sum=%d\n",num_bm,az_no,ptype);
+	if (!(s->u.affs_sb.s_bitmap = kmalloc(ptype,GFP_KERNEL))) {
+		printk(KERN_ERR "AFFS: Not enough memory\n");
+		goto out;
+	}
+	memset(s->u.affs_sb.s_bitmap,0,ptype);
+
+	s->u.affs_sb.s_zones   = (struct affs_zone *)&s->u.affs_sb.s_bitmap[num_bm];
+	s->u.affs_sb.s_alloc   = (struct affs_alloc_zone *)&s->u.affs_sb.s_zones[MAX_ZONES];
+	s->u.affs_sb.s_num_az  = az_no;
+
+	mapidx = 0;
+
+	if (ROOT_END_S(bh->b_data,s)->bm_flag == 0) {
+		if (!(s->s_flags & MS_RDONLY)) {
+			printk(KERN_NOTICE "AFFS: Bitmap invalid - mounting %s read only\n",
+				kdevname(dev));
+			s->s_flags |= MS_RDONLY;
+		}
+		affs_brelse(bh);
+		bh = NULL;
+		goto nobitmap;
+	}
+
+	/* The following section is ugly, I know. Especially because of the
+	 * reuse of some variables that are not named properly.
+	 */
+
+	key    = root_block;
+	ptype  = s->s_blocksize / 4 - 49;
+	stype  = ptype + 25;
+	offset = s->u.affs_sb.s_reserved;
+	az_no  = 0;
+	while (bh) {
+		bm = (u32 *)bh->b_data;
+		for (i = ptype; i < stype && bm[i]; i++, mapidx++) {
+			if (mapidx >= num_bm) {
+				printk(KERN_ERR "AFFS: Extraneous bitmap pointer - "
+					       "mounting %s read only.\n",kdevname(dev));
+				s->s_flags |= MS_RDONLY;
+				s->u.affs_sb.s_flags |= SF_READONLY;
+				continue;
+			}
+			bb = affs_bread(s->s_dev,be32_to_cpu(bm[i]),s->s_blocksize);
+			if (bb) {
+				if (affs_checksum_block(s->s_blocksize,bb->b_data,NULL,NULL) &&
+				    !(s->s_flags & MS_RDONLY)) {
+					printk(KERN_WARNING "AFFS: Bitmap (%d,key=%lu) invalid - "
+					       "mounting %s read only.\n",mapidx,be32_to_cpu(bm[i]),
+						kdevname(dev));
+					s->s_flags |= MS_RDONLY;
+					s->u.affs_sb.s_flags |= SF_READONLY;
+				}
+				/* Mark unused bits in the last word as allocated */
+				if (size <= s->s_blocksize * 8 - 32) {	/* last bitmap */
+					ptype = size / 32 + 1;		/* word number */
+					key   = size & 0x1F;		/* used bits */
+					if (key && !(s->s_flags & MS_RDONLY)) {
+						chksum = cpu_to_be32(0x7FFFFFFF >> (31 - key));
+						((u32 *)bb->b_data)[ptype] &= chksum;
+						affs_fix_checksum(s->s_blocksize,bb->b_data,0);
+						mark_buffer_dirty(bb,1);
+						bmalt = 1;
+					}
+					ptype = (size + 31) & ~0x1F;
+					size  = 0;
+					s->u.affs_sb.s_flags |= SF_BM_VALID;
+				} else {
+					ptype = s->s_blocksize * 8 - 32;
+					size -= ptype;
+				}
+				s->u.affs_sb.s_bitmap[mapidx].bm_firstblk = offset;
+				s->u.affs_sb.s_bitmap[mapidx].bm_bh       = NULL;
+				s->u.affs_sb.s_bitmap[mapidx].bm_key      = be32_to_cpu(bm[i]);
+				s->u.affs_sb.s_bitmap[mapidx].bm_count    = 0;
+				offset += ptype;
+
+				for (j = 0; ptype > 0; j++, az_no++, ptype -= key) {
+					key = MIN(ptype,AFFS_ZONE_SIZE);	/* size in bits */
+					s->u.affs_sb.s_alloc[az_no].az_size = key / 32;
+					s->u.affs_sb.s_alloc[az_no].az_free =
+						affs_count_free_bits(key / 8,bb->b_data +
+								     j * (AFFS_ZONE_SIZE / 8) + 4);
+				}
+				affs_brelse(bb);
+			} else {
+				printk(KERN_ERR "AFFS: Cannot read bitmap\n");
+				goto out;
+			}
+		}
+		key   = be32_to_cpu(bm[stype]);		/* Next block of bitmap pointers	*/
+		ptype = 0;
+		stype = s->s_blocksize / 4 - 1;
+		affs_brelse(bh);
+		if (key) {
+			if (!(bh = affs_bread(s->s_dev,key,s->s_blocksize))) {
+				printk(KERN_ERR "AFFS: Cannot read bitmap extension\n");
+				goto out;
+			}
+		} else
+			bh = NULL;
+	}
+	if (mapidx < num_bm) {
+		printk(KERN_ERR "AFFS: Got only %d bitmap blocks, expected %d\n",mapidx,num_bm);
+		goto out;
+	}
+nobitmap:
+	s->u.affs_sb.s_bm_count = num_bm;
+
+	/* set up enough so that it can read an inode */
+
+	s->s_dev   = dev;
+	s->s_op    = &affs_sops;
+	s->s_dirt  = 1;
+	root_inode = iget(s,root_block);
+	s->s_root  = d_alloc_root(root_inode,NULL);
+	unlock_super(s);
+
+	if (!(s->s_root)) {
+		s->s_dev = 0;
+		affs_brelse(s->u.affs_sb.s_root_bh);
+		printk(KERN_ERR "AFFS: get root inode failed\n");
+		MOD_DEC_USE_COUNT;
+		return NULL;
+	}
+
+	/* Record date of last change if the bitmap was truncated and
+	 * create data zones if the volume is writable.
+	 */
+
+	if (!(s->s_flags & MS_RDONLY)) {
+		if (bmalt) {
+			secs_to_datestamp(CURRENT_TIME,&ROOT_END(
+				s->u.affs_sb.s_root_bh->b_data,root_inode)->disk_altered);
+			affs_fix_checksum(s->s_blocksize,s->u.affs_sb.s_root_bh->b_data,5);
+			mark_buffer_dirty(s->u.affs_sb.s_root_bh,1);
+		}
+		affs_make_zones(s);
+	}
+
+	pr_debug("AFFS: s_flags=%lX\n",s->s_flags);
+	return s;
+
+ out: /* Kick out for various error conditions */
+	affs_brelse (bh);
+	affs_brelse(s->u.affs_sb.s_root_bh);
+	if (s->u.affs_sb.s_bitmap)
+		kfree(s->u.affs_sb.s_bitmap);
+	set_blocksize(dev,BLOCK_SIZE);
+	s->s_dev = 0;
+	unlock_super(s);
+	MOD_DEC_USE_COUNT;
+	return NULL;
+}
+
+static int
+affs_remount(struct super_block *sb, int *flags, char *data)
+{
+	int			 blocksize;
+	uid_t			 uid;
+	gid_t			 gid;
+	int			 mode;
+	int			 reserved;
+	int			 root_block;
+	unsigned long		 mount_flags;
+	unsigned long		 read_only = sb->u.affs_sb.s_flags & SF_READONLY;
+
+	pr_debug("AFFS: remount(flags=0x%x,opts=\"%s\")\n",*flags,data);
+
+	if (!parse_options(data,&uid,&gid,&mode,&reserved,&root_block,
+	    &blocksize,&sb->u.affs_sb.s_prefix,sb->u.affs_sb.s_volume,&mount_flags))
+		return -EINVAL;
+	sb->u.affs_sb.s_flags = mount_flags | read_only;
+	sb->u.affs_sb.s_mode  = mode;
+	sb->u.affs_sb.s_uid   = uid;
+	sb->u.affs_sb.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);
+		sb->s_flags |= MS_RDONLY;
+	} else if (!(sb->u.affs_sb.s_flags & SF_READONLY)) {
+		sb->s_flags &= ~MS_RDONLY;
+		affs_make_zones(sb);
+	} else {
+		affs_warning(sb,"remount","Cannot remount fs read/write because of errors");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int
+affs_statfs(struct super_block *sb, struct statfs *buf, int bufsiz)
+{
+	int		 free;
+	struct statfs	 tmp;
+
+	pr_debug("AFFS: statfs() partsize=%d, reserved=%d\n",sb->u.affs_sb.s_partition_size,
+	     sb->u.affs_sb.s_reserved);
+
+	free          = affs_count_free_blocks(sb);
+	tmp.f_type    = AFFS_SUPER_MAGIC;
+	tmp.f_bsize   = sb->s_blocksize;
+	tmp.f_blocks  = sb->u.affs_sb.s_partition_size - sb->u.affs_sb.s_reserved;
+	tmp.f_bfree   = free;
+	tmp.f_bavail  = free;
+	tmp.f_files   = 0;
+	tmp.f_ffree   = 0;
+	return copy_to_user(buf,&tmp,bufsiz) ? -EFAULT : 0;
+}
+
+static struct file_system_type affs_fs_type = {
+	"affs",
+	FS_REQUIRES_DEV,
+	affs_read_super,
+	NULL
+};
+
+__initfunc(int init_affs_fs(void))
+{
+	return register_filesystem(&affs_fs_type);
+}
+
+#ifdef MODULE
+EXPORT_NO_SYMBOLS;
+
+int
+init_module(void)
+{
+	return register_filesystem(&affs_fs_type);
+}
+
+void
+cleanup_module(void)
+{
+	unregister_filesystem(&affs_fs_type);
+}
+
+#endif

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TCL-scripts by Sam Shen, slshen@lbl.gov