patch-1.3.60 linux/fs/fat/inode.c

• Lines: 543
• Date: Wed Feb 7 09:39:28 1996
• Orig file: v1.3.59/linux/fs/fat/inode.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.59/linux/fs/fat/inode.c linux/fs/fat/inode.c
@@ -0,0 +1,542 @@
+/*
+ *  linux/fs/msdos/inode.c
+ *
+ *  Written 1992,1993 by Werner Almesberger
+ *  VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner
+ */
+
+#define __NO_VERSION__
+#include <linux/module.h>
+
+#include <linux/msdos_fs.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/major.h>
+#include <linux/blkdev.h>
+#include <linux/fs.h>
+#include <linux/stat.h>
+#include <linux/locks.h>
+
+#include "msbuffer.h"
+#include "tables.h"
+
+#include <asm/segment.h>
+
+
+
+void fat_put_inode(struct inode *inode)
+{
+	struct inode *depend;
+	struct super_block *sb;
+
+	if (inode->i_nlink) {
+		if (MSDOS_I(inode)->i_busy) fat_cache_inval_inode(inode);
+		return;
+	}
+	inode->i_size = 0;
+	fat_truncate(inode);
+	depend = MSDOS_I(inode)->i_depend;
+	sb = inode->i_sb;
+	clear_inode(inode);
+	if (depend) {
+		if (MSDOS_I(depend)->i_old != inode) {
+			printk("Invalid link (0x%p): expected 0x%p, got 0x%p\n",
+			    depend, inode, MSDOS_I(depend)->i_old);
+			fat_fs_panic(sb,"...");
+			return;
+		}
+		MSDOS_I(depend)->i_old = NULL;
+		iput(depend);
+	}
+}
+
+
+void fat_put_super(struct super_block *sb)
+{
+	fat_cache_inval_dev(sb->s_dev);
+	set_blocksize (sb->s_dev,BLOCK_SIZE);
+	lock_super(sb);
+	sb->s_dev = 0;
+	unlock_super(sb);
+	MOD_DEC_USE_COUNT;
+	return;
+}
+
+
+static int parse_options(char *options,char *check,char *conversion,uid_t *uid,
+    gid_t *gid,int *umask,int *debug,int *fat,int *quiet,
+	int *blksize, char *dotsOK, char *sys_immutable)
+{
+	char *this_char,*value;
+
+	*check = 'n';
+	*conversion = 'b';
+	*dotsOK = 0;
+	*uid = current->uid;
+	*gid = current->gid;
+	*umask = current->fs->umask;
+	*debug = *fat = *quiet = *sys_immutable = 0;
+	if (!options) return 1;
+	for (this_char = strtok(options,","); this_char; this_char = strtok(NULL,",")) {
+		if ((value = strchr(this_char,'=')) != NULL)
+			*value++ = 0;
+		if (!strcmp(this_char,"check") && value) {
+			if (value[0] && !value[1] && strchr("rns",*value))
+				*check = *value;
+			else if (!strcmp(value,"relaxed")) *check = 'r';
+			else if (!strcmp(value,"normal")) *check = 'n';
+			else if (!strcmp(value,"strict")) *check = 's';
+			else return 0;
+		}
+		else if (!strcmp(this_char,"conv") && value) {
+			if (value[0] && !value[1] && strchr("bta",*value))
+				*conversion = *value;
+			else if (!strcmp(value,"binary")) *conversion = 'b';
+			else if (!strcmp(value,"text")) *conversion = 't';
+			else if (!strcmp(value,"auto")) *conversion = 'a';
+			else return 0;
+		}
+		else if (!strcmp(this_char,"dots")) {
+		  *dotsOK = 1;
+		}
+		else if (!strcmp(this_char,"nodots")) {
+		  *dotsOK = 0;
+		}
+		else if (!strcmp(this_char,"dotsOK") && value) {
+			if (!strcmp(value,"yes")) *dotsOK = 1;
+			else if (!strcmp(value,"no")) *dotsOK = 0;
+			else return 0;
+		}
+		else if (!strcmp(this_char,"uid")) {
+			if (!value || !*value)
+				return 0;
+			*uid = simple_strtoul(value,&value,0);
+			if (*value)
+				return 0;
+		}
+		else if (!strcmp(this_char,"gid")) {
+			if (!value || !*value)
+				return 0;
+			*gid = simple_strtoul(value,&value,0);
+			if (*value)
+				return 0;
+		}
+		else if (!strcmp(this_char,"umask")) {
+			if (!value || !*value)
+				return 0;
+			*umask = simple_strtoul(value,&value,8);
+			if (*value)
+				return 0;
+		}
+		else if (!strcmp(this_char,"debug")) {
+			if (value) return 0;
+			*debug = 1;
+		}
+		else if (!strcmp(this_char,"fat")) {
+			if (!value || !*value)
+				return 0;
+			*fat = simple_strtoul(value,&value,0);
+			if (*value || (*fat != 12 && *fat != 16))
+				return 0;
+		}
+		else if (!strcmp(this_char,"quiet")) {
+			if (value) return 0;
+			*quiet = 1;
+		}
+		else if (!strcmp(this_char,"blocksize")) {
+			*blksize = simple_strtoul(value,&value,0);
+			if (*value)
+				return 0;
+			if (*blksize != 512 && *blksize != 1024){
+				printk ("MSDOS FS: Invalid blocksize (512 or 1024)\n");
+			}
+		}
+		else if (!strcmp(this_char,"sys_immutable")) {
+			if (value)
+				return 0;
+			*sys_immutable = 1;
+		}
+		else return 1;
+	}
+	return 1;
+}
+
+
+/* Read the super block of an MS-DOS FS. */
+
+struct super_block *fat_read_super(struct super_block *sb,void *data, int silent)
+{
+	struct buffer_head *bh;
+	struct msdos_boot_sector *b;
+	int data_sectors,logical_sector_size,sector_mult,fat_clusters=0;
+	int debug,error,fat,quiet;
+	char check,conversion,dotsOK,sys_immutable;
+	uid_t uid;
+	gid_t gid;
+	int umask;
+	int blksize = 512;
+
+	MOD_INC_USE_COUNT;
+	if (hardsect_size[MAJOR(sb->s_dev)] != NULL){
+		blksize = hardsect_size[MAJOR(sb->s_dev)][MINOR(sb->s_dev)];
+		if (blksize != 512){
+			printk ("MSDOS: Hardware sector size is %d\n",blksize);
+		}
+	}
+	if (!parse_options((char *) data,&check,&conversion,&uid,&gid,&umask,
+	    &debug,&fat,&quiet,&blksize,&dotsOK,&sys_immutable)
+		|| (blksize != 512 && blksize != 1024)) {
+		sb->s_dev = 0;
+		MOD_DEC_USE_COUNT;
+		return NULL;
+	}
+	cache_init();
+	lock_super(sb);
+	/* The first read is always 1024 bytes */
+	sb->s_blocksize = 1024;
+	set_blocksize(sb->s_dev, 1024);
+	bh = bread(sb->s_dev, 0, 1024);
+	unlock_super(sb);
+	if (bh == NULL || !fat_is_uptodate(sb,bh)) {
+		brelse (bh);
+		sb->s_dev = 0;
+		printk("FAT bread failed\n");
+		MOD_DEC_USE_COUNT;
+		return NULL;
+	}
+	b = (struct msdos_boot_sector *) bh->b_data;
+	set_blocksize(sb->s_dev, blksize);
+/*
+ * The DOS3 partition size limit is *not* 32M as many people think.  
+ * Instead, it is 64K sectors (with the usual sector size being
+ * 512 bytes, leading to a 32M limit).
+ * 
+ * DOS 3 partition managers got around this problem by faking a 
+ * larger sector size, ie treating multiple physical sectors as 
+ * a single logical sector.
+ * 
+ * We can accommodate this scheme by adjusting our cluster size,
+ * fat_start, and data_start by an appropriate value.
+ *
+ * (by Drew Eckhardt)
+ */
+
+#define ROUND_TO_MULTIPLE(n,m) ((n) && (m) ? (n)+(m)-1-((n)-1)%(m) : 0)
+    /* don't divide by zero */
+
+	logical_sector_size = CF_LE_W(*(unsigned short *) &b->sector_size);
+	sector_mult = logical_sector_size >> SECTOR_BITS;
+	MSDOS_SB(sb)->cluster_size = b->cluster_size*sector_mult;
+	MSDOS_SB(sb)->fats = b->fats;
+	MSDOS_SB(sb)->fat_start = CF_LE_W(b->reserved)*sector_mult;
+	MSDOS_SB(sb)->fat_length = CF_LE_W(b->fat_length)*sector_mult;
+	MSDOS_SB(sb)->dir_start = (CF_LE_W(b->reserved)+b->fats*CF_LE_W(
+	    b->fat_length))*sector_mult;
+	MSDOS_SB(sb)->dir_entries = CF_LE_W(*((unsigned short *) &b->dir_entries
+	    ));
+	MSDOS_SB(sb)->data_start = MSDOS_SB(sb)->dir_start+ROUND_TO_MULTIPLE((
+	    MSDOS_SB(sb)->dir_entries << MSDOS_DIR_BITS) >> SECTOR_BITS,
+	    sector_mult);
+	data_sectors = (CF_LE_W(*((unsigned short *) &b->sectors)) ?
+	    CF_LE_W(*((unsigned short *) &b->sectors)) :
+	    CF_LE_L(b->total_sect))*sector_mult-MSDOS_SB(sb)->data_start;
+	error = !b->cluster_size || !sector_mult;
+	if (!error) {
+		MSDOS_SB(sb)->clusters = b->cluster_size ? data_sectors/
+		    b->cluster_size/sector_mult : 0;
+		MSDOS_SB(sb)->fat_bits = fat ? fat : MSDOS_SB(sb)->clusters >
+		    MSDOS_FAT12 ? 16 : 12;
+		fat_clusters = MSDOS_SB(sb)->fat_length*SECTOR_SIZE*8/
+		    MSDOS_SB(sb)->fat_bits;
+		error = !MSDOS_SB(sb)->fats || (MSDOS_SB(sb)->dir_entries &
+		    (MSDOS_DPS-1)) || MSDOS_SB(sb)->clusters+2 > fat_clusters+
+		    MSDOS_MAX_EXTRA || (logical_sector_size & (SECTOR_SIZE-1))
+		    || !b->secs_track || !b->heads;
+	}
+	brelse(bh);
+	/*
+		This must be done after the brelse because the bh is a dummy
+		allocated by fat_bread (see buffer.c)
+	*/
+	sb->s_blocksize = blksize;	/* Using this small block size solve the */
+				/* the misfit with buffer cache and cluster */
+				/* because cluster (DOS) are often aligned */
+				/* on odd sector */
+	sb->s_blocksize_bits = blksize == 512 ? 9 : 10;
+	if (error || debug) {
+		/* The MSDOS_CAN_BMAP is obsolete, but left just to remember */
+		printk("[MS-DOS FS Rel. 12,FAT %d,check=%c,conv=%c,"
+		    "uid=%d,gid=%d,umask=%03o%s]\n",MSDOS_SB(sb)->fat_bits,check,
+		    conversion,uid,gid,umask,MSDOS_CAN_BMAP(MSDOS_SB(sb)) ?
+		    ",bmap" : "");
+		printk("[me=0x%x,cs=%d,#f=%d,fs=%d,fl=%d,ds=%d,de=%d,data=%d,"
+		    "se=%d,ts=%ld,ls=%d]\n",b->media,MSDOS_SB(sb)->cluster_size,
+		    MSDOS_SB(sb)->fats,MSDOS_SB(sb)->fat_start,MSDOS_SB(sb)->
+		    fat_length,MSDOS_SB(sb)->dir_start,MSDOS_SB(sb)->dir_entries,
+		    MSDOS_SB(sb)->data_start,CF_LE_W(*(unsigned short *) &b->
+		    sectors),(unsigned long)b->total_sect,logical_sector_size);
+		printk ("Transaction block size = %d\n",blksize);
+	}
+	if (MSDOS_SB(sb)->clusters+2 > fat_clusters)
+		MSDOS_SB(sb)->clusters = fat_clusters-2;
+	if (error) {
+		if (!silent)
+			printk("VFS: Can't find a valid MSDOS filesystem on dev "
+			       "%s.\n", kdevname(sb->s_dev));
+		sb->s_dev = 0;
+		MOD_DEC_USE_COUNT;
+		return NULL;
+	}
+	sb->s_magic = MSDOS_SUPER_MAGIC;
+	MSDOS_SB(sb)->name_check = check;
+	MSDOS_SB(sb)->conversion = conversion;
+	/* set up enough so that it can read an inode */
+	MSDOS_SB(sb)->fs_uid = uid;
+	MSDOS_SB(sb)->fs_gid = gid;
+	MSDOS_SB(sb)->fs_umask = umask;
+	MSDOS_SB(sb)->quiet = quiet;
+	MSDOS_SB(sb)->dotsOK = dotsOK;
+	MSDOS_SB(sb)->sys_immutable = sys_immutable;
+	MSDOS_SB(sb)->vfat = 0;   /* vfat_read_super sets this */
+	MSDOS_SB(sb)->umsdos = 0; /* umsdos_read_super will set this */
+	MSDOS_SB(sb)->free_clusters = -1; /* don't know yet */
+	MSDOS_SB(sb)->fat_wait = NULL;
+	MSDOS_SB(sb)->fat_lock = 0;
+	MSDOS_SB(sb)->prev_free = 0;
+	if (!(sb->s_mounted = iget(sb,MSDOS_ROOT_INO))) {
+		sb->s_dev = 0;
+		printk("get root inode failed\n");
+		MOD_DEC_USE_COUNT;
+		return NULL;
+	}
+	return sb;
+}
+
+
+void fat_statfs(struct super_block *sb,struct statfs *buf, int bufsiz)
+{
+	int free,nr;
+	struct statfs tmp;
+
+	lock_fat(sb);
+	if (MSDOS_SB(sb)->free_clusters != -1)
+		free = MSDOS_SB(sb)->free_clusters;
+	else {
+		free = 0;
+		for (nr = 2; nr < MSDOS_SB(sb)->clusters+2; nr++)
+			if (!fat_access(sb,nr,-1)) free++;
+		MSDOS_SB(sb)->free_clusters = free;
+	}
+	unlock_fat(sb);
+	tmp.f_type = sb->s_magic;
+	tmp.f_bsize = MSDOS_SB(sb)->cluster_size*SECTOR_SIZE;
+	tmp.f_blocks = MSDOS_SB(sb)->clusters;
+	tmp.f_bfree = free;
+	tmp.f_bavail = free;
+	tmp.f_files = 0;
+	tmp.f_ffree = 0;
+	tmp.f_namelen = 12;
+	memcpy_tofs(buf, &tmp, bufsiz);
+}
+
+
+int fat_bmap(struct inode *inode,int block)
+{
+	struct msdos_sb_info *sb;
+	int cluster,offset;
+
+	sb = MSDOS_SB(inode->i_sb);
+	if (inode->i_ino == MSDOS_ROOT_INO) {
+		return sb->dir_start + block;
+	}
+	cluster = block/sb->cluster_size;
+	offset = block % sb->cluster_size;
+	if (!(cluster = get_cluster(inode,cluster))) return 0;
+	return (cluster-2)*sb->cluster_size+sb->data_start+offset;
+}
+
+
+void fat_read_inode(struct inode *inode, struct inode_operations *fs_dir_inode_ops)
+{
+	struct super_block *sb = inode->i_sb;
+	struct buffer_head *bh;
+	struct msdos_dir_entry *raw_entry;
+	int nr;
+
+/* printk("read inode %d\n",inode->i_ino); */
+	MSDOS_I(inode)->i_busy = 0;
+	MSDOS_I(inode)->i_depend = MSDOS_I(inode)->i_old = NULL;
+	MSDOS_I(inode)->i_binary = 1;
+	inode->i_uid = MSDOS_SB(inode->i_sb)->fs_uid;
+	inode->i_gid = MSDOS_SB(inode->i_sb)->fs_gid;
+	if (inode->i_ino == MSDOS_ROOT_INO) {
+		inode->i_mode = (S_IRWXUGO & ~MSDOS_SB(inode->i_sb)->fs_umask) |
+		    S_IFDIR;
+		inode->i_op = fs_dir_inode_ops;
+		inode->i_nlink = fat_subdirs(inode)+2;
+		    /* subdirs (neither . nor ..) plus . and "self" */
+		inode->i_size = MSDOS_SB(inode->i_sb)->dir_entries*
+		    sizeof(struct msdos_dir_entry);
+		inode->i_blksize = MSDOS_SB(inode->i_sb)->cluster_size*
+		    SECTOR_SIZE;
+		inode->i_blocks = (inode->i_size+inode->i_blksize-1)/
+		    inode->i_blksize*MSDOS_SB(inode->i_sb)->cluster_size;
+		MSDOS_I(inode)->i_start = 0;
+		MSDOS_I(inode)->i_attrs = 0;
+		inode->i_mtime = inode->i_atime = inode->i_ctime = 0;
+		return;
+	}
+	if (!(bh = bread(inode->i_dev,inode->i_ino >> MSDOS_DPB_BITS,
+	    SECTOR_SIZE))) {
+		printk("dev = %s, ino = %ld\n",
+		       kdevname(inode->i_dev), inode->i_ino);
+		panic("fat_read_inode: unable to read i-node block");
+	}
+	raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
+	    [inode->i_ino & (MSDOS_DPB-1)];
+	if ((raw_entry->attr & ATTR_DIR) && !IS_FREE(raw_entry->name)) {
+		inode->i_mode = MSDOS_MKMODE(raw_entry->attr,S_IRWXUGO &
+		    ~MSDOS_SB(inode->i_sb)->fs_umask) | S_IFDIR;
+		inode->i_op = fs_dir_inode_ops;
+
+		MSDOS_I(inode)->i_start = CF_LE_W(raw_entry->start);
+		inode->i_nlink = fat_subdirs(inode);
+		    /* includes .., compensating for "self" */
+#ifdef DEBUG
+		if (!inode->i_nlink) {
+			printk("directory %d: i_nlink == 0\n",inode->i_ino);
+			inode->i_nlink = 1;
+		}
+#endif
+		inode->i_size = 0;
+		if ((nr = CF_LE_W(raw_entry->start)) != 0)
+			while (nr != -1) {
+				inode->i_size += SECTOR_SIZE*MSDOS_SB(inode->
+				    i_sb)->cluster_size;
+				if (!(nr = fat_access(inode->i_sb,nr,-1))) {
+					printk("Directory %ld: bad FAT\n",
+					    inode->i_ino);
+					break;
+				}
+			}
+	} else { /* not a directory */
+		inode->i_mode = MSDOS_MKMODE(raw_entry->attr,
+		    (IS_NOEXEC(inode) ? S_IRUGO|S_IWUGO : S_IRWXUGO)
+		    & ~MSDOS_SB(inode->i_sb)->fs_umask) | S_IFREG;
+		inode->i_op = (sb->s_blocksize == 1024)
+			? &fat_file_inode_operations_1024
+			: &fat_file_inode_operations;
+		MSDOS_I(inode)->i_start = CF_LE_W(raw_entry->start);
+		inode->i_nlink = 1;
+		inode->i_size = CF_LE_L(raw_entry->size);
+	}
+	if(raw_entry->attr & ATTR_SYS)
+		if (MSDOS_I(inode)->sys_immutable)
+			inode->i_flags |= S_IMMUTABLE;
+	MSDOS_I(inode)->i_binary = is_binary(MSDOS_SB(inode->i_sb)->conversion,
+	    raw_entry->ext);
+	MSDOS_I(inode)->i_attrs = raw_entry->attr & ATTR_UNUSED;
+	/* this is as close to the truth as we can get ... */
+	inode->i_blksize = MSDOS_SB(inode->i_sb)->cluster_size*SECTOR_SIZE;
+	inode->i_blocks = (inode->i_size+inode->i_blksize-1)/
+	    inode->i_blksize*MSDOS_SB(inode->i_sb)->cluster_size;
+	inode->i_mtime = inode->i_atime =
+	    date_dos2unix(CF_LE_W(raw_entry->time),CF_LE_W(raw_entry->date));
+	inode->i_ctime =
+		MSDOS_SB(inode->i_sb)->vfat
+		? date_dos2unix(CF_LE_W(raw_entry->ctime),CF_LE_W(raw_entry->cdate))
+		: inode->i_mtime;
+	brelse(bh);
+}
+
+
+void fat_write_inode(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+	struct buffer_head *bh;
+	struct msdos_dir_entry *raw_entry;
+
+	inode->i_dirt = 0;
+	if (inode->i_ino == MSDOS_ROOT_INO || !inode->i_nlink) return;
+	if (!(bh = bread(inode->i_dev,inode->i_ino >> MSDOS_DPB_BITS,
+	    SECTOR_SIZE))) {
+		printk("dev = %s, ino = %ld\n",
+		       kdevname(inode->i_dev), inode->i_ino);
+		panic("msdos_write_inode: unable to read i-node block");
+	}
+	raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
+	    [inode->i_ino & (MSDOS_DPB-1)];
+	if (S_ISDIR(inode->i_mode)) {
+		raw_entry->attr = ATTR_DIR;
+		raw_entry->size = 0;
+	}
+	else {
+		raw_entry->attr = ATTR_NONE;
+		raw_entry->size = CT_LE_L(inode->i_size);
+	}
+	raw_entry->attr |= MSDOS_MKATTR(inode->i_mode) |
+	    MSDOS_I(inode)->i_attrs;
+	raw_entry->start = CT_LE_L(MSDOS_I(inode)->i_start);
+	fat_date_unix2dos(inode->i_mtime,&raw_entry->time,&raw_entry->date);
+	raw_entry->time = CT_LE_W(raw_entry->time);
+	raw_entry->date = CT_LE_W(raw_entry->date);
+	if (MSDOS_SB(sb)->vfat) {
+		fat_date_unix2dos(inode->i_ctime,&raw_entry->ctime,&raw_entry->cdate);
+		raw_entry->ctime = CT_LE_W(raw_entry->ctime);
+		raw_entry->cdate = CT_LE_W(raw_entry->cdate);
+	}
+	mark_buffer_dirty(bh, 1);
+	brelse(bh);
+}
+
+
+int fat_notify_change(struct inode * inode,struct iattr * attr)
+{
+	int error;
+
+	error = inode_change_ok(inode, attr);
+	if (error)
+		return error;
+
+	if (((attr->ia_valid & ATTR_UID) && 
+	     (attr->ia_uid != MSDOS_SB(inode->i_sb)->fs_uid)) ||
+	    ((attr->ia_valid & ATTR_GID) && 
+	     (attr->ia_gid != MSDOS_SB(inode->i_sb)->fs_gid)) ||
+	    ((attr->ia_valid & ATTR_MODE) &&
+	     (attr->ia_mode & ~MSDOS_VALID_MODE)))
+		error = -EPERM;
+
+	if (error)
+		return MSDOS_SB(inode->i_sb)->quiet ? 0 : error;
+
+	inode_setattr(inode, attr);
+
+	if (IS_NOEXEC(inode) && !S_ISDIR(inode->i_mode))
+		inode->i_mode &= S_IFMT | S_IRUGO | S_IWUGO;
+	else
+		inode->i_mode |= S_IXUGO;
+
+	inode->i_mode = ((inode->i_mode & S_IFMT) | ((((inode->i_mode & S_IRWXU
+	    & ~MSDOS_SB(inode->i_sb)->fs_umask) | S_IRUSR) >> 6)*S_IXUGO)) &
+	    ~MSDOS_SB(inode->i_sb)->fs_umask;
+	return 0;
+}
+
+
+#ifdef MODULE
+int init_module(void)
+{
+	return init_fat_fs();
+}
+
+
+void cleanup_module(void)
+{
+	/* Nothing to be done, really! */
+	return;
+}
+#endif
+