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

• Lines: 282
• Date: Wed Feb 7 09:39:27 1996
• Orig file: v1.3.59/linux/fs/fat/dir.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.59/linux/fs/fat/dir.c linux/fs/fat/dir.c
@@ -0,0 +1,281 @@
+/*
+ *  linux/fs/msdos/dir.c
+ *  MS-DOS directory handling functions
+ *
+ *  Written 1992,1993 by Werner Almesberger
+ *
+ *  Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
+ *
+ *  VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner
+ */
+
+#include <linux/fs.h>
+#include <linux/msdos_fs.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/stat.h>
+#include <linux/string.h>
+#include <linux/ioctl.h>
+
+#include <asm/segment.h>
+
+#include "msbuffer.h"
+#include "tables.h"
+
+
+#define PRINTK(X)
+
+static int fat_dir_read(struct inode * inode,struct file * filp, char * buf,int count)
+{
+	return -EISDIR;
+}
+
+struct file_operations fat_dir_operations = {
+	NULL,			/* lseek - default */
+	fat_dir_read,		/* read */
+	NULL,			/* write - bad */
+	fat_readdir,		/* readdir */
+	NULL,			/* select - default */
+	fat_dir_ioctl,		/* ioctl - default */
+	NULL,			/* mmap */
+	NULL,			/* no special open code */
+	NULL,			/* no special release code */
+	file_fsync		/* fsync */
+};
+
+
+int fat_dir_ioctl(struct inode * inode, struct file * filp,
+		  unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+#if 0
+	/*
+	 * We want to provide an interface for Samba to be able
+	 * to get the short filename for a given long filename.
+	 * We should be able to accomplish by modifying fat_readdir
+	 * slightly.
+	 */
+	case VFAT_LONGNAME_TO_SHORT:
+#endif
+	default:
+		return -EINVAL;
+	}
+}
+
+int fat_readdir(
+	struct inode *inode,
+	struct file *filp,
+	void *dirent,
+	filldir_t filldir)
+{
+	struct super_block *sb = inode->i_sb;
+	int ino,i,i2,last;
+	char c;
+	struct buffer_head *bh;
+	struct msdos_dir_entry *de;
+	unsigned long oldpos = filp->f_pos;
+	int is_long;
+	char longname[256];
+	unsigned char long_len = 0; /* Make compiler warning go away */
+	unsigned char alias_checksum = 0; /* Make compiler warning go away */
+
+
+	if (!inode || !S_ISDIR(inode->i_mode))
+		return -EBADF;
+/* Fake . and .. for the root directory. */
+	if (inode->i_ino == MSDOS_ROOT_INO) {
+		while (oldpos < 2) {
+			if (filldir(dirent, "..", oldpos+1, oldpos, MSDOS_ROOT_INO) < 0)
+				return 0;
+			oldpos++;
+			filp->f_pos++;
+		}
+		if (oldpos == 2)
+			filp->f_pos = 0;
+	}
+	if (filp->f_pos & (sizeof(struct msdos_dir_entry)-1))
+		return -ENOENT;
+
+ 	bh = NULL;
+	longname[0] = '\0';
+	is_long = 0;
+	ino = fat_get_entry(inode,&filp->f_pos,&bh,&de);
+	while (ino > -1) {
+		/* Should we warn about finding extended entries on fs
+		 * mounted non-vfat ? Deleting or renaming files will cause
+		 * corruption, as extended entries are not updated.
+		 */
+		if (!MSDOS_SB(sb)->vfat && 
+		    !MSDOS_SB(sb)->umsdos &&  /* umsdos is safe for us */
+		    !IS_RDONLY(inode) && 
+		    (de->attr == ATTR_EXT) &&
+		    !MSDOS_SB(sb)->quiet) {
+			printk("MSDOS-fs warning: vfat directory entry found on fs mounted non-vfat (device %s)\n",
+			       kdevname(sb->s_dev));
+		}
+
+		/* Check for long filename entry */
+		if (MSDOS_SB(sb)->vfat && (de->name[0] == (__s8) DELETED_FLAG)) {
+			is_long = 0;
+			oldpos = filp->f_pos;
+		} else if (MSDOS_SB(sb)->vfat && de->attr ==  ATTR_EXT) {
+			int get_new_entry;
+			struct msdos_dir_slot *ds;
+			unsigned char page, pg_off, ascii;
+			unsigned char *uni_page;
+			unsigned char offset;
+			unsigned char id;
+			unsigned char slot;
+			unsigned char slots = 0;
+			int i;
+
+			offset = 0;
+			ds = (struct msdos_dir_slot *) de;
+			id = ds->id;
+			if (id & 0x40) {
+				slots = id & ~0x40;
+				is_long = 1;
+				alias_checksum = ds->alias_checksum;
+			}
+
+			get_new_entry = 1;
+			slot = slots;
+			while (slot > 0) {
+				PRINTK(("1. get_new_entry: %d\n", get_new_entry));
+				if (ds->attr !=  ATTR_EXT) {
+					is_long = 0;
+					get_new_entry = 0;
+					break;
+				}
+				if ((ds->id & ~0x40) != slot) {
+					is_long = 0;
+					break;
+				}
+				if (ds->alias_checksum != alias_checksum) {
+					is_long = 0;
+					break;
+				}
+				slot--;
+				offset = slot * 13;
+				PRINTK(("2. get_new_entry: %d\n", get_new_entry));
+				for (i = 0; i < 10; i += 2) {
+					pg_off = ds->name0_4[i];
+					page = ds->name0_4[i+1];
+					if (pg_off == 0 && page == 0) {
+						goto found_end;
+					}
+					uni_page = fat_uni2asc_pg[page];
+					ascii = uni_page[pg_off];
+					longname[offset++] = ascii ? ascii : '?';
+				}
+				for (i = 0; i < 12; i += 2) {
+					pg_off = ds->name5_10[i];
+					page = ds->name5_10[i+1];
+					if (pg_off == 0 && page == 0) {
+						goto found_end;
+					}
+					uni_page = fat_uni2asc_pg[page];
+					ascii = uni_page[pg_off];
+					longname[offset++] = ascii ? ascii : '?';
+				}
+				for (i = 0; i < 4; i += 2) {
+					pg_off = ds->name11_12[i];
+					page = ds->name11_12[i+1];
+					if (pg_off == 0 && page == 0) {
+						goto found_end;
+					}
+					uni_page = fat_uni2asc_pg[page];
+					ascii = uni_page[pg_off];
+					longname[offset++] = ascii ? ascii : '?';
+				}
+				found_end:
+				PRINTK(("3. get_new_entry: %d\n", get_new_entry));
+				if (ds->id & 0x40) {
+					longname[offset] = '\0';
+					long_len = offset;
+				}
+				if (slot > 0) {
+					ino = fat_get_entry(inode,&filp->f_pos,&bh,&de);
+					PRINTK(("4. get_new_entry: %d\n", get_new_entry));
+					if (ino == -1) {
+						is_long = 0;
+						get_new_entry = 0;
+						break;
+					}
+					ds = (struct msdos_dir_slot *) de;
+				}
+				PRINTK(("5. get_new_entry: %d\n", get_new_entry));
+			}
+			PRINTK(("Long filename: %s, get_new_entry: %d\n", longname, get_new_entry));
+		} else if (!IS_FREE(de->name) && !(de->attr & ATTR_VOLUME)) {
+			char bufname[13];
+			char *ptname = bufname;
+			int dotoffset = 0;
+
+			if (is_long) {
+				unsigned char sum;
+
+				for (sum = i = 0; i < 11; i++) {
+					sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + de->name[i];
+				}
+
+				if (sum != alias_checksum) {
+					PRINTK(("Checksums don't match %d != %d\n", sum, alias_checksum));
+					is_long = 0;
+				}
+			}
+
+			if ((de->attr & ATTR_HIDDEN) && MSDOS_SB(sb)->dotsOK) {
+				bufname[0] = '.';
+				dotoffset = 1;
+				ptname = bufname+1;
+			}
+			for (i = last = 0; i < 8; i++) {
+				if (!(c = de->name[i])) break;
+				if (c >= 'A' && c <= 'Z') c += 32;
+				/* see namei.c, msdos_format_name */
+				if (c == 0x05) c = 0xE5;
+				if (c != ' ')
+					last = i+1;
+				ptname[i] = c;
+			}
+			i = last;
+			ptname[i] = '.';
+			i++;
+			for (i2 = 0; i2 < 3; i2++) {
+				if (!(c = de->ext[i2])) break;
+				if (c >= 'A' && c <= 'Z') c += 32;
+				if (c != ' ')
+					last = i+1;
+				ptname[i] = c;
+				i++;
+			}
+			if ((i = last) != 0) {
+				if (!strcmp(de->name,MSDOS_DOT))
+					ino = inode->i_ino;
+				else if (!strcmp(de->name,MSDOS_DOTDOT))
+					ino = fat_parent_ino(inode,0);
+
+				if (!is_long) {
+					if (filldir(dirent, bufname, i+dotoffset, oldpos, ino) < 0) {
+						filp->f_pos = oldpos;
+						break;
+					}
+				} else {
+					if (filldir(dirent, longname, long_len, oldpos, ino) < 0) {
+						filp->f_pos = oldpos;
+						break;
+					}
+				}
+				oldpos = filp->f_pos;
+			}
+			is_long = 0;
+		} else {
+			is_long = 0;
+			oldpos = filp->f_pos;
+		}
+		ino = fat_get_entry(inode,&filp->f_pos,&bh,&de);	
+	}
+	if (bh) brelse(bh);
+	return 0;
+}