patch-1.3.60 linux/fs/msdos/misc.c

• Lines: 554
• Date: Thu Jan 1 02:00:00 1970
• Orig file: v1.3.59/linux/fs/msdos/misc.c
• Orig date: Sat Nov 11 17:41:33 1995

diff -u --recursive --new-file v1.3.59/linux/fs/msdos/misc.c linux/fs/msdos/misc.c
@@ -1,553 +0,0 @@
-/*
- *  linux/fs/msdos/misc.c
- *
- *  Written 1992,1993 by Werner Almesberger
- */
-
-#include <linux/fs.h>
-#include <linux/msdos_fs.h>
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/string.h>
-#include <linux/stat.h>
-
-#include "msbuffer.h"
-
-#define PRINTK(x)
-#define Printk(x)	printk x
-
-/* Well-known binary file extensions - of course there are many more */
-
-static char bin_extensions[] =
-  "EXE" "COM" "BIN" "APP" "SYS" "DRV" "OVL" "OVR" "OBJ" "LIB" "DLL" "PIF" /* program code */
-  "ARC" "ZIP" "LHA" "LZH" "ZOO" "TAR" "Z  " "ARJ"	/* common archivers */
-  "TZ " "TAZ" "TZP" "TPZ"		/* abbreviations of tar.Z and tar.zip */
-  "GZ " "TGZ" "DEB"			/* .gz, .tar.gz and Debian packages   */
-  "GIF" "BMP" "TIF" "GL " "JPG" "PCX"	/* graphics */
-  "TFM" "VF " "GF " "PK " "PXL" "DVI";	/* TeX */
-
-
-/*
- * fs_panic reports a severe file system problem and sets the file system
- * read-only. The file system can be made writable again by remounting it.
- */
-
-void fs_panic(struct super_block *s,const char *msg)
-{
-	int not_ro;
-
-	not_ro = !(s->s_flags & MS_RDONLY);
-	if (not_ro) s->s_flags |= MS_RDONLY;
-	printk("Filesystem panic (dev %s, ", kdevname(s->s_dev));
-	printk("mounted on %s:%ld)\n  %s\n", /* note: kdevname returns & static char[] */
-	       kdevname(s->s_covered->i_dev), s->s_covered->i_ino, msg);
-	if (not_ro)
-		printk("  File system has been set read-only\n");
-}
-
-
-/*
- * is_binary selects optional text conversion based on the conversion mode and
- * the extension part of the file name.
- */
-
-int is_binary(char conversion,char *extension)
-{
-	char *walk;
-
-	switch (conversion) {
-		case 'b':
-			return 1;
-		case 't':
-			return 0;
-		case 'a':
-			for (walk = bin_extensions; *walk; walk += 3)
-				if (!strncmp(extension,walk,3)) return 1;
-			return 0;
-		default:
-			printk("Invalid conversion mode - defaulting to "
-			    "binary.\n");
-			return 1;
-	}
-}
-
-
-/* File creation lock. This is system-wide to avoid deadlocks in rename. */
-/* (rename might deadlock before detecting cross-FS moves.) */
-
-static struct wait_queue *creation_wait = NULL;
-static creation_lock = 0;
-
-
-void lock_creation(void)
-{
-	while (creation_lock) sleep_on(&creation_wait);
-	creation_lock = 1;
-}
-
-
-void unlock_creation(void)
-{
-	creation_lock = 0;
-	wake_up(&creation_wait);
-}
-
-
-void lock_fat(struct super_block *sb)
-{
-	while (MSDOS_SB(sb)->fat_lock) sleep_on(&MSDOS_SB(sb)->fat_wait);
-	MSDOS_SB(sb)->fat_lock = 1;
-}
-
-
-void unlock_fat(struct super_block *sb)
-{
-	MSDOS_SB(sb)->fat_lock = 0;
-	wake_up(&MSDOS_SB(sb)->fat_wait);
-}
-
-
-/*
- * msdos_add_cluster tries to allocate a new cluster and adds it to the file
- * represented by inode. The cluster is zero-initialized.
- */
-
-int msdos_add_cluster(struct inode *inode)
-{
-	struct super_block *sb = inode->i_sb;
-	int count,nr,limit,last,curr,sector,last_sector,file_cluster;
-	struct buffer_head *bh;
-	int cluster_size = MSDOS_SB(inode->i_sb)->cluster_size;
-
-	if (inode->i_ino == MSDOS_ROOT_INO) return -ENOSPC;
-	if (!MSDOS_SB(inode->i_sb)->free_clusters) return -ENOSPC;
-	lock_fat(inode->i_sb);
-	limit = MSDOS_SB(inode->i_sb)->clusters;
-	nr = limit; /* to keep GCC happy */
-	for (count = 0; count < limit; count++) {
-		nr = ((count+MSDOS_SB(inode->i_sb)->prev_free) % limit)+2;
-		if (fat_access(inode->i_sb,nr,-1) == 0) break;
-	}
-	PRINTK (("cnt = %d --",count));
-#ifdef DEBUG
-printk("free cluster: %d\n",nr);
-#endif
-	MSDOS_SB(inode->i_sb)->prev_free = (count+MSDOS_SB(inode->i_sb)->
-	    prev_free+1) % limit;
-	if (count >= limit) {
-		MSDOS_SB(inode->i_sb)->free_clusters = 0;
-		unlock_fat(inode->i_sb);
-		return -ENOSPC;
-	}
-	fat_access(inode->i_sb,nr,MSDOS_SB(inode->i_sb)->fat_bits == 12 ?
-	    0xff8 : 0xfff8);
-	if (MSDOS_SB(inode->i_sb)->free_clusters != -1)
-		MSDOS_SB(inode->i_sb)->free_clusters--;
-	unlock_fat(inode->i_sb);
-#ifdef DEBUG
-printk("set to %x\n",fat_access(inode->i_sb,nr,-1));
-#endif
-	last = 0;
-	/* We must locate the last cluster of the file to add this
-	   new one (nr) to the end of the link list (the FAT).
-	   
-	   Here file_cluster will be the number of the last cluster of the
-	   file (before we add nr).
-	   
-	   last is the corresponding cluster number on the disk. We will
-	   use last to plug the nr cluster. We will use file_cluster to
-	   update the cache.
-	*/
-	file_cluster = 0;
-	if ((curr = MSDOS_I(inode)->i_start) != 0) {
-		cache_lookup(inode,INT_MAX,&last,&curr);
-		file_cluster = last;
-		while (curr && curr != -1){
-			PRINTK (("."));
-			file_cluster++;
-			if (!(curr = fat_access(inode->i_sb,
-			    last = curr,-1))) {
-				fs_panic(inode->i_sb,"File without EOF");
-				return -ENOSPC;
-			}
-		}
-		PRINTK ((" --  "));
-	}
-#ifdef DEBUG
-printk("last = %d\n",last);
-#endif
-	if (last) fat_access(inode->i_sb,last,nr);
-	else {
-		MSDOS_I(inode)->i_start = nr;
-		inode->i_dirt = 1;
-	}
-#ifdef DEBUG
-if (last) printk("next set to %d\n",fat_access(inode->i_sb,last,-1));
-#endif
-	sector = MSDOS_SB(inode->i_sb)->data_start+(nr-2)*cluster_size;
-	last_sector = sector + cluster_size;
-	for ( ; sector < last_sector; sector++) {
-		#ifdef DEBUG
-			printk("zeroing sector %d\n",sector);
-		#endif
-		if (!(bh = getblk(inode->i_dev,sector,SECTOR_SIZE)))
-			printk("getblk failed\n");
-		else {
-			memset(bh->b_data,0,SECTOR_SIZE);
-			msdos_set_uptodate(sb,bh,1);
-			mark_buffer_dirty(bh, 1);
-			brelse(bh);
-		}
-	}
-	if (file_cluster != inode->i_blocks/cluster_size){
-		printk ("file_cluster badly computed!!! %d <> %ld\n"
-			,file_cluster,inode->i_blocks/cluster_size);
-	}else{
-		cache_add(inode,file_cluster,nr);
-	}
-	inode->i_blocks += cluster_size;
-	if (S_ISDIR(inode->i_mode)) {
-		if (inode->i_size & (SECTOR_SIZE-1)) {
-			fs_panic(inode->i_sb,"Odd directory size");
-			inode->i_size = (inode->i_size+SECTOR_SIZE) &
-			    ~(SECTOR_SIZE-1);
-		}
-		inode->i_size += SECTOR_SIZE*cluster_size;
-#ifdef DEBUG
-printk("size is %d now (%x)\n",inode->i_size,inode);
-#endif
-		inode->i_dirt = 1;
-	}
-	return 0;
-}
-
-
-/* Linear day numbers of the respective 1sts in non-leap years. */
-
-static int day_n[] = { 0,31,59,90,120,151,181,212,243,273,304,334,0,0,0,0 };
-		  /* JanFebMarApr May Jun Jul Aug Sep Oct Nov Dec */
-
-
-extern struct timezone sys_tz;
-
-
-/* Convert a MS-DOS time/date pair to a UNIX date (seconds since 1 1 70). */
-
-int date_dos2unix(unsigned short time,unsigned short date)
-{
-	int month,year,secs;
-
-	month = ((date >> 5) & 15)-1;
-	year = date >> 9;
-	secs = (time & 31)*2+60*((time >> 5) & 63)+(time >> 11)*3600+86400*
-	    ((date & 31)-1+day_n[month]+(year/4)+year*365-((year & 3) == 0 &&
-	    month < 2 ? 1 : 0)+3653);
-			/* days since 1.1.70 plus 80's leap day */
-	secs += sys_tz.tz_minuteswest*60;
-	return secs;
-}
-
-
-/* Convert linear UNIX date to a MS-DOS time/date pair. */
-
-void date_unix2dos(int unix_date,unsigned short *time,
-    unsigned short *date)
-{
-	int day,year,nl_day,month;
-
-	unix_date -= sys_tz.tz_minuteswest*60;
-	*time = (unix_date % 60)/2+(((unix_date/60) % 60) << 5)+
-	    (((unix_date/3600) % 24) << 11);
-	day = unix_date/86400-3652;
-	year = day/365;
-	if ((year+3)/4+365*year > day) year--;
-	day -= (year+3)/4+365*year;
-	if (day == 59 && !(year & 3)) {
-		nl_day = day;
-		month = 2;
-	}
-	else {
-		nl_day = (year & 3) || day <= 59 ? day : day-1;
-		for (month = 0; month < 12; month++)
-			if (day_n[month] > nl_day) break;
-	}
-	*date = nl_day-day_n[month-1]+1+(month << 5)+(year << 9);
-}
-
-
-/* Returns the inode number of the directory entry at offset pos. If bh is
-   non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
-   returned in bh. */
-
-int msdos_get_entry(struct inode *dir, loff_t *pos,struct buffer_head **bh,
-    struct msdos_dir_entry **de)
-{
-	struct super_block *sb = dir->i_sb;
-	int sector,offset;
-
-	while (1) {
-		offset = *pos;
-		PRINTK (("get_entry offset %d\n",offset));
-		if ((sector = msdos_smap(dir,offset >> SECTOR_BITS)) == -1)
-			return -1;
-		PRINTK (("get_entry sector %d %p\n",sector,*bh));
-		if (!sector)
-			return -1; /* beyond EOF */
-		*pos += sizeof(struct msdos_dir_entry);
-		if (*bh)
-			brelse(*bh);
-		PRINTK (("get_entry sector apres brelse\n"));
-		if (!(*bh = bread(dir->i_dev,sector,SECTOR_SIZE))) {
-			printk("Directory sread (sector %d) failed\n",sector);
-			continue;
-		}
-		PRINTK (("get_entry apres sread\n"));
-		*de = (struct msdos_dir_entry *) ((*bh)->b_data+(offset &
-		    (SECTOR_SIZE-1)));
-		return (sector << MSDOS_DPS_BITS)+((offset & (SECTOR_SIZE-1)) >>
-		    MSDOS_DIR_BITS);
-	}
-}
-
-
-/*
- * Now an ugly part: this set of directory scan routines works on clusters
- * rather than on inodes and sectors. They are necessary to locate the '..'
- * directory "inode". raw_scan_sector operates in four modes:
- *
- * name     number   ino      action
- * -------- -------- -------- -------------------------------------------------
- * non-NULL -        X        Find an entry with that name
- * NULL     non-NULL non-NULL Find an entry whose data starts at *number
- * NULL     non-NULL NULL     Count subdirectories in *number. (*)
- * NULL     NULL     non-NULL Find an empty entry
- *
- * (*) The return code should be ignored. It DOES NOT indicate success or
- *     failure. *number has to be initialized to zero.
- *
- * - = not used, X = a value is returned unless NULL
- *
- * If res_bh is non-NULL, the buffer is not deallocated but returned to the
- * caller on success. res_de is set accordingly.
- *
- * If cont is non-zero, raw_found continues with the entry after the one
- * res_bh/res_de point to.
- */
-
-
-#define RSS_NAME /* search for name */ \
-    done = !strncmp(data[entry].name,name,MSDOS_NAME) && \
-     !(data[entry].attr & ATTR_VOLUME);
-
-#define RSS_START /* search for start cluster */ \
-    done = !IS_FREE(data[entry].name) && CF_LE_W(data[entry].start) == *number;
-
-#define RSS_FREE /* search for free entry */ \
-    { \
-	done = IS_FREE(data[entry].name); \
-	if (done) { \
-	    inode = iget(sb,sector*MSDOS_DPS+entry); \
-	    if (inode) { \
-	    /* Directory slots of busy deleted files aren't available yet. */ \
-		done = !MSDOS_I(inode)->i_busy; \
-		iput(inode); \
-	    } \
-	} \
-    }
-
-#define RSS_COUNT /* count subdirectories */ \
-    { \
-	done = 0; \
-	if (!IS_FREE(data[entry].name) && (data[entry].attr & ATTR_DIR)) \
-	    (*number)++; \
-    }
-
-static int raw_scan_sector(struct super_block *sb,int sector,const char *name,
-    int *number,int *ino,struct buffer_head **res_bh,
-    struct msdos_dir_entry **res_de,char scantype)
-{
-	struct buffer_head *bh;
-	struct msdos_dir_entry *data;
-	struct inode *inode;
-	int entry,start,done;
-
-	if (!(bh = bread(sb->s_dev,sector,SECTOR_SIZE))) return -EIO;
-	data = (struct msdos_dir_entry *) bh->b_data;
-	for (entry = 0; entry < MSDOS_DPS; entry++) {
-/* RSS_COUNT:  if (data[entry].name == name) done=true else done=false. */
-		if (name) {
-			RSS_NAME
-			if (done && scantype) {   /* scantype != SCAN_ANY */
-				done = (data[entry].attr & ATTR_HIDDEN)
-					? (scantype==SCAN_HID)
-					: (scantype==SCAN_NOTHID);
-			}
-		} else {
-			if (!ino) RSS_COUNT
-			else {
-				if (number) RSS_START
-				else RSS_FREE
-			}
-		}
-		if (done) {
-			if (ino) *ino = sector*MSDOS_DPS+entry;
-			start = CF_LE_W(data[entry].start);
-			if (!res_bh) brelse(bh);
-			else {
-				*res_bh = bh;
-				*res_de = &data[entry];
-			}
-			return start;
-		}
-	}
-	brelse(bh);
-	return -ENOENT;
-}
-
-
-/*
- * raw_scan_root performs raw_scan_sector on the root directory until the
- * requested entry is found or the end of the directory is reached.
- */
-
-static int raw_scan_root(struct super_block *sb,const char *name,int *number,int *ino,
-    struct buffer_head **res_bh,struct msdos_dir_entry **res_de,char scantype)
-{
-	int count,cluster;
-
-	for (count = 0; count < MSDOS_SB(sb)->dir_entries/MSDOS_DPS; count++) {
-		if ((cluster = raw_scan_sector(sb,MSDOS_SB(sb)->dir_start+count,
-		    name,number,ino,res_bh,res_de,scantype)) >= 0) return cluster;
-	}
-	return -ENOENT;
-}
-
-
-/*
- * raw_scan_nonroot performs raw_scan_sector on a non-root directory until the
- * requested entry is found or the end of the directory is reached.
- */
-
-static int raw_scan_nonroot(struct super_block *sb,int start,const char *name,
-    int *number,int *ino,struct buffer_head **res_bh,struct msdos_dir_entry
-    **res_de,char scantype)
-{
-	int count,cluster;
-
-#ifdef DEBUG
-	printk("raw_scan_nonroot: start=%d\n",start);
-#endif
-	do {
-		for (count = 0; count < MSDOS_SB(sb)->cluster_size; count++) {
-			if ((cluster = raw_scan_sector(sb,(start-2)*
-			    MSDOS_SB(sb)->cluster_size+MSDOS_SB(sb)->data_start+
-			    count,name,number,ino,res_bh,res_de,scantype)) >= 0)
-				return cluster;
-		}
-		if (!(start = fat_access(sb,start,-1))) {
-			fs_panic(sb,"FAT error");
-			break;
-		}
-#ifdef DEBUG
-	printk("next start: %d\n",start);
-#endif
-	}
-	while (start != -1);
-	return -ENOENT;
-}
-
-
-/*
- * raw_scan performs raw_scan_sector on any sector.
- *
- * NOTE: raw_scan must not be used on a directory that is is the process of
- *       being created.
- */
-
-static int raw_scan(struct super_block *sb, int start, const char *name,
-    int *number, int *ino, struct buffer_head **res_bh,
-    struct msdos_dir_entry **res_de, char scantype)
-{
-	if (start) return raw_scan_nonroot
-		(sb,start,name,number,ino,res_bh,res_de,scantype);
-	else return raw_scan_root
-		(sb,name,number,ino,res_bh,res_de,scantype);
-}
-
-
-/*
- * msdos_parent_ino returns the inode number of the parent directory of dir.
- * File creation has to be deferred while msdos_parent_ino is running to
- * prevent renames.
- */
-
-int msdos_parent_ino(struct inode *dir,int locked)
-{
-	static int zero = 0;
-	int error,curr,prev,nr;
-
-	if (!S_ISDIR(dir->i_mode)) panic("Non-directory fed to m_p_i");
-	if (dir->i_ino == MSDOS_ROOT_INO) return dir->i_ino;
-	if (!locked) lock_creation(); /* prevent renames */
-	if ((curr = raw_scan(dir->i_sb,MSDOS_I(dir)->i_start,MSDOS_DOTDOT,
-	    &zero,NULL,NULL,NULL,SCAN_ANY)) < 0) {
-		if (!locked) unlock_creation();
-		return curr;
-	}
-	if (!curr) nr = MSDOS_ROOT_INO;
-	else {
-		if ((prev = raw_scan(dir->i_sb,curr,MSDOS_DOTDOT,&zero,NULL,
-		    NULL,NULL,SCAN_ANY)) < 0) {
-			if (!locked) unlock_creation();
-			return prev;
-		}
-		if ((error = raw_scan(dir->i_sb,prev,NULL,&curr,&nr,NULL,
-		    NULL,SCAN_ANY)) < 0) {
-			if (!locked) unlock_creation();
-			return error;
-		}
-	}
-	if (!locked) unlock_creation();
-	return nr;
-}
-
-
-/*
- * msdos_subdirs counts the number of sub-directories of dir. It can be run
- * on directories being created.
- */
-
-int msdos_subdirs(struct inode *dir)
-{
-	int count;
-
-	count = 0;
-	if (dir->i_ino == MSDOS_ROOT_INO)
-		(void) raw_scan_root(dir->i_sb,NULL,&count,NULL,NULL,NULL,SCAN_ANY);
-	else {
-		if (!MSDOS_I(dir)->i_start) return 0; /* in mkdir */
-		else (void) raw_scan_nonroot(dir->i_sb,MSDOS_I(dir)->i_start,
-		    NULL,&count,NULL,NULL,NULL,SCAN_ANY);
-	}
-	return count;
-}
-
-
-/*
- * Scans a directory for a given file (name points to its formatted name) or
- * for an empty directory slot (name is NULL). Returns an error code or zero.
- */
-
-int msdos_scan(struct inode *dir,const char *name,struct buffer_head **res_bh,
-    struct msdos_dir_entry **res_de,int *ino, char scantype)
-{
-	int res;
-
-	res = (name)
-		? raw_scan(dir->i_sb,MSDOS_I(dir)->i_start,
-		    name, NULL, ino, res_bh, res_de, scantype)
-		: raw_scan(dir->i_sb,MSDOS_I(dir)->i_start,
-		    NULL, NULL, ino, res_bh, res_de, scantype);
-	return res<0 ? res : 0;
-}