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- /*
- * linux/fs/msdos/namei.c
- *
- * Written 1992,1993 by Werner Almesberger
- */
-
- #include <asm/segment.h>
-
- #include <linux/sched.h>
- #include <linux/msdos_fs.h>
- #include <linux/kernel.h>
- #include <linux/errno.h>
- #include <linux/string.h>
- #include <linux/stat.h>
-
- /* MS-DOS "device special files" */
-
- static char *reserved_names[] = {
- "CON ","PRN ","NUL ","AUX ",
- "LPT1 ","LPT2 ","LPT3 ","LPT4 ",
- "COM1 ","COM2 ","COM3 ","COM4 ",
- NULL };
-
-
- /* Characters that are undesirable in an MS-DOS file name */
-
- static char bad_chars[] = "*?<>|\"";
- static char bad_if_strict[] = "+=,; ";
-
-
- /* Formats an MS-DOS file name. Rejects invalid names. */
-
- static int msdos_format_name(char conv,const char *name,int len,char *res,
- int dot_dirs)
- {
- char *walk,**reserved;
- unsigned char c;
- int space;
-
- if (IS_FREE(name)) return -EINVAL;
- if (name[0] == '.' && (len == 1 || (len == 2 && name[1] == '.'))) {
- if (!dot_dirs) return -EEXIST;
- memset(res+1,' ',10);
- while (len--) *res++ = '.';
- return 0;
- }
- space = 1; /* disallow names starting with a dot */
- c = 0;
- for (walk = res; len && walk-res < 8; walk++) {
- c = *name++;
- len--;
- if (conv != 'r' && strchr(bad_chars,c)) return -EINVAL;
- if (conv == 's' && strchr(bad_if_strict,c)) return -EINVAL;
- if (c >= 'A' && c <= 'Z' && conv == 's') return -EINVAL;
- if (c < ' ' || c == ':' || c == '\\') return -EINVAL;
- if (c == '.') break;
- space = c == ' ';
- *walk = c >= 'a' && c <= 'z' ? c-32 : c;
- }
- if (space) return -EINVAL;
- if (conv == 's' && len && c != '.') {
- c = *name++;
- len--;
- if (c != '.') return -EINVAL;
- }
- while (c != '.' && len--) c = *name++;
- if (c == '.') {
- while (walk-res < 8) *walk++ = ' ';
- while (len > 0 && walk-res < MSDOS_NAME) {
- c = *name++;
- len--;
- if (conv != 'r' && strchr(bad_chars,c)) return -EINVAL;
- if (conv == 's' && strchr(bad_if_strict,c))
- return -EINVAL;
- if (c < ' ' || c == ':' || c == '\\' || c == '.')
- return -EINVAL;
- if (c >= 'A' && c <= 'Z' && conv == 's') return -EINVAL;
- space = c == ' ';
- *walk++ = c >= 'a' && c <= 'z' ? c-32 : c;
- }
- if (space) return -EINVAL;
- if (conv == 's' && len) return -EINVAL;
- }
- while (walk-res < MSDOS_NAME) *walk++ = ' ';
- for (reserved = reserved_names; *reserved; reserved++)
- if (!strncmp(res,*reserved,8)) return -EINVAL;
- return 0;
- }
-
-
- /* Locates a directory entry. */
-
- static int msdos_find(struct inode *dir,const char *name,int len,
- struct buffer_head **bh,struct msdos_dir_entry **de,int *ino)
- {
- char msdos_name[MSDOS_NAME];
- int res;
-
- if ((res = msdos_format_name(MSDOS_SB(dir->i_sb)->name_check,name,len,
- msdos_name,1)) < 0) return res;
- return msdos_scan(dir,msdos_name,bh,de,ino);
- }
-
-
- int msdos_lookup(struct inode *dir,const char *name,int len,
- struct inode **result)
- {
- int ino,res;
- struct msdos_dir_entry *de;
- struct buffer_head *bh;
- struct inode *next;
-
- *result = NULL;
- if (!dir) return -ENOENT;
- if (!S_ISDIR(dir->i_mode)) {
- iput(dir);
- return -ENOENT;
- }
- if (len == 1 && name[0] == '.') {
- *result = dir;
- return 0;
- }
- if (len == 2 && name[0] == '.' && name[1] == '.') {
- ino = msdos_parent_ino(dir,0);
- iput(dir);
- if (ino < 0) return ino;
- if (!(*result = iget(dir->i_sb,ino))) return -EACCES;
- return 0;
- }
- if ((res = msdos_find(dir,name,len,&bh,&de,&ino)) < 0) {
- iput(dir);
- return res;
- }
- if (bh) brelse(bh);
- /* printk("lookup: ino=%d\n",ino); */
- if (!(*result = iget(dir->i_sb,ino))) {
- iput(dir);
- return -EACCES;
- }
- if (MSDOS_I(*result)->i_busy) { /* mkdir in progress */
- iput(*result);
- iput(dir);
- return -ENOENT;
- }
- while (MSDOS_I(*result)->i_old) {
- next = MSDOS_I(*result)->i_old;
- iput(*result);
- if (!(*result = iget(next->i_sb,next->i_ino))) {
- fs_panic(dir->i_sb,"msdos_lookup: Can't happen");
- iput(dir);
- return -ENOENT;
- }
- }
- iput(dir);
- return 0;
- }
-
-
- /* Creates a directory entry (name is already formatted). */
-
- static int msdos_create_entry(struct inode *dir,char *name,int is_dir,
- struct inode **result)
- {
- struct buffer_head *bh;
- struct msdos_dir_entry *de;
- int res,ino;
-
- if ((res = msdos_scan(dir,NULL,&bh,&de,&ino)) < 0) {
- if (res != -ENOENT) return res;
- if (dir->i_ino == MSDOS_ROOT_INO) return -ENOSPC;
- if ((res = msdos_add_cluster(dir)) < 0) return res;
- if ((res = msdos_scan(dir,NULL,&bh,&de,&ino)) < 0) return res;
- }
- /*
- * XXX all times should be set by caller upon successful completion.
- */
- dir->i_ctime = dir->i_mtime = CURRENT_TIME;
- dir->i_dirt = 1;
- memcpy(de->name,name,MSDOS_NAME);
- de->attr = is_dir ? ATTR_DIR : ATTR_ARCH;
- de->start = 0;
- date_unix2dos(dir->i_mtime,&de->time,&de->date);
- de->size = 0;
- bh->b_dirt = 1;
- if ((*result = iget(dir->i_sb,ino)) != NULL)
- msdos_read_inode(*result);
- brelse(bh);
- if (!*result) return -EIO;
- (*result)->i_mtime = (*result)->i_atime = (*result)->i_ctime =
- CURRENT_TIME;
- (*result)->i_dirt = 1;
- return 0;
- }
-
-
- int msdos_create(struct inode *dir,const char *name,int len,int mode,
- struct inode **result)
- {
- struct buffer_head *bh;
- struct msdos_dir_entry *de;
- char msdos_name[MSDOS_NAME];
- int ino,res;
-
- if (!dir) return -ENOENT;
- if ((res = msdos_format_name(MSDOS_SB(dir->i_sb)->name_check,name,len,
- msdos_name,0)) < 0) {
- iput(dir);
- return res;
- }
- lock_creation();
- if (msdos_scan(dir,msdos_name,&bh,&de,&ino) >= 0) {
- unlock_creation();
- brelse(bh);
- iput(dir);
- return -EEXIST;
- }
- res = msdos_create_entry(dir,msdos_name,S_ISDIR(mode),result);
- unlock_creation();
- iput(dir);
- return res;
- }
-
-
- #ifdef DEBUG
-
- static void dump_fat(struct super_block *sb,int start)
- {
- printk("[");
- while (start) {
- printk("%d ",start);
- start = fat_access(sb,start,-1);
- if (!start) {
- printk("ERROR");
- break;
- }
- if (start == -1) break;
- }
- printk("]\n");
- }
-
- #endif
-
-
- int msdos_mkdir(struct inode *dir,const char *name,int len,int mode)
- {
- struct buffer_head *bh;
- struct msdos_dir_entry *de;
- struct inode *inode,*dot;
- char msdos_name[MSDOS_NAME];
- int ino,res;
-
- if ((res = msdos_format_name(MSDOS_SB(dir->i_sb)->name_check,name,len,
- msdos_name,0)) < 0) {
- iput(dir);
- return res;
- }
- lock_creation();
- if (msdos_scan(dir,msdos_name,&bh,&de,&ino) >= 0) {
- unlock_creation();
- brelse(bh);
- iput(dir);
- return -EEXIST;
- }
- if ((res = msdos_create_entry(dir,msdos_name,1,&inode)) < 0) {
- unlock_creation();
- iput(dir);
- return res;
- }
- dir->i_nlink++;
- inode->i_nlink = 2; /* no need to mark them dirty */
- MSDOS_I(inode)->i_busy = 1; /* prevent lookups */
- if ((res = msdos_add_cluster(inode)) < 0) goto mkdir_error;
- if ((res = msdos_create_entry(inode,MSDOS_DOT,1,&dot)) < 0)
- goto mkdir_error;
- dot->i_size = inode->i_size; /* doesn't grow in the 2nd create_entry */
- MSDOS_I(dot)->i_start = MSDOS_I(inode)->i_start;
- dot->i_nlink = inode->i_nlink;
- dot->i_dirt = 1;
- iput(dot);
- if ((res = msdos_create_entry(inode,MSDOS_DOTDOT,1,&dot)) < 0)
- goto mkdir_error;
- unlock_creation();
- dot->i_size = dir->i_size;
- MSDOS_I(dot)->i_start = MSDOS_I(dir)->i_start;
- dot->i_nlink = dir->i_nlink;
- dot->i_dirt = 1;
- MSDOS_I(inode)->i_busy = 0;
- iput(dot);
- iput(inode);
- iput(dir);
- return 0;
- mkdir_error:
- iput(inode);
- if (msdos_rmdir(dir,name,len) < 0)
- fs_panic(dir->i_sb,"rmdir in mkdir failed");
- unlock_creation();
- return res;
- }
-
-
- static int msdos_empty(struct inode *dir)
- {
- off_t pos;
- struct buffer_head *bh;
- struct msdos_dir_entry *de;
-
- if (dir->i_count > 1)
- return -EBUSY;
- if (MSDOS_I(dir)->i_start) { /* may be zero in mkdir */
- pos = 0;
- bh = NULL;
- while (msdos_get_entry(dir,&pos,&bh,&de) > -1)
- if (!IS_FREE(de->name) && strncmp(de->name,MSDOS_DOT,
- MSDOS_NAME) && strncmp(de->name,MSDOS_DOTDOT,
- MSDOS_NAME)) {
- brelse(bh);
- return -ENOTEMPTY;
- }
- if (bh)
- brelse(bh);
- }
- return 0;
- }
-
-
- int msdos_rmdir(struct inode *dir,const char *name,int len)
- {
- int res,ino;
- struct buffer_head *bh;
- struct msdos_dir_entry *de;
- struct inode *inode;
-
- bh = NULL;
- inode = NULL;
- res = -EPERM;
- if (name[0] == '.' && (len == 1 || (len == 2 && name[1] == '.')))
- goto rmdir_done;
- if ((res = msdos_find(dir,name,len,&bh,&de,&ino)) < 0) goto rmdir_done;
- res = -ENOENT;
- if (!(inode = iget(dir->i_sb,ino))) goto rmdir_done;
- res = -ENOTDIR;
- if (!S_ISDIR(inode->i_mode)) goto rmdir_done;
- res = -EBUSY;
- if (dir->i_dev != inode->i_dev || dir == inode) goto rmdir_done;
- res = msdos_empty(inode);
- if (res)
- goto rmdir_done;
- inode->i_nlink = 0;
- inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
- dir->i_nlink--;
- inode->i_dirt = dir->i_dirt = 1;
- de->name[0] = DELETED_FLAG;
- bh->b_dirt = 1;
- res = 0;
- rmdir_done:
- brelse(bh);
- iput(dir);
- iput(inode);
- return res;
- }
-
-
- int msdos_unlink(struct inode *dir,const char *name,int len)
- {
- int res,ino;
- struct buffer_head *bh;
- struct msdos_dir_entry *de;
- struct inode *inode;
-
- bh = NULL;
- inode = NULL;
- if ((res = msdos_find(dir,name,len,&bh,&de,&ino)) < 0)
- goto unlink_done;
- if (!(inode = iget(dir->i_sb,ino))) {
- res = -ENOENT;
- goto unlink_done;
- }
- if (!S_ISREG(inode->i_mode)) {
- res = -EPERM;
- goto unlink_done;
- }
- inode->i_nlink = 0;
- inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
- MSDOS_I(inode)->i_busy = 1;
- inode->i_dirt = dir->i_dirt = 1;
- de->name[0] = DELETED_FLAG;
- bh->b_dirt = 1;
- unlink_done:
- brelse(bh);
- iput(inode);
- iput(dir);
- return res;
- }
-
-
- static int rename_same_dir(struct inode *old_dir,char *old_name,
- struct inode *new_dir,char *new_name,struct buffer_head *old_bh,
- struct msdos_dir_entry *old_de,int old_ino)
- {
- struct buffer_head *new_bh;
- struct msdos_dir_entry *new_de;
- struct inode *new_inode,*old_inode;
- int new_ino,exists,error;
-
- if (!strncmp(old_name,new_name,MSDOS_NAME)) return 0;
- exists = msdos_scan(new_dir,new_name,&new_bh,&new_de,&new_ino) >= 0;
- if (*(unsigned char *) old_de->name == DELETED_FLAG) {
- if (exists) brelse(new_bh);
- return -ENOENT;
- }
- if (exists) {
- if (!(new_inode = iget(new_dir->i_sb,new_ino))) {
- brelse(new_bh);
- return -EIO;
- }
- error = S_ISDIR(new_inode->i_mode) ? (old_de->attr & ATTR_DIR) ?
- msdos_empty(new_inode) : -EPERM : (old_de->attr & ATTR_DIR)
- ? -EPERM : 0;
- if (error) {
- iput(new_inode);
- brelse(new_bh);
- return error;
- }
- if (S_ISDIR(new_inode->i_mode)) {
- new_dir->i_nlink--;
- new_dir->i_dirt = 1;
- }
- new_inode->i_nlink = 0;
- MSDOS_I(new_inode)->i_busy = 1;
- new_inode->i_dirt = 1;
- new_de->name[0] = DELETED_FLAG;
- new_bh->b_dirt = 1;
- iput(new_inode);
- brelse(new_bh);
- }
- memcpy(old_de->name,new_name,MSDOS_NAME);
- old_bh->b_dirt = 1;
- if (MSDOS_SB(old_dir->i_sb)->conversion == 'a') /* update binary info */
- if ((old_inode = iget(old_dir->i_sb,old_ino)) != NULL) {
- msdos_read_inode(old_inode);
- iput(old_inode);
- }
- return 0;
- }
-
-
- static int rename_diff_dir(struct inode *old_dir,char *old_name,
- struct inode *new_dir,char *new_name,struct buffer_head *old_bh,
- struct msdos_dir_entry *old_de,int old_ino)
- {
- struct buffer_head *new_bh,*free_bh,*dotdot_bh;
- struct msdos_dir_entry *new_de,*free_de,*dotdot_de;
- struct inode *old_inode,*new_inode,*free_inode,*dotdot_inode,*walk;
- int new_ino,free_ino,dotdot_ino;
- int error,exists,ino;
-
- if (old_dir->i_dev != new_dir->i_dev) return -EINVAL;
- if (old_ino == new_dir->i_ino) return -EINVAL;
- if (!(walk = iget(new_dir->i_sb,new_dir->i_ino))) return -EIO;
- while (walk->i_ino != MSDOS_ROOT_INO) {
- ino = msdos_parent_ino(walk,1);
- iput(walk);
- if (ino < 0) return ino;
- if (ino == old_ino) return -EINVAL;
- if (!(walk = iget(new_dir->i_sb,ino))) return -EIO;
- }
- iput(walk);
- while ((error = msdos_scan(new_dir,NULL,&free_bh,&free_de,&free_ino)) <
- 0) {
- if (error != -ENOENT) return error;
- error = msdos_add_cluster(new_dir);
- if (error) return error;
- }
- exists = msdos_scan(new_dir,new_name,&new_bh,&new_de,&new_ino) >= 0;
- if (!(old_inode = iget(old_dir->i_sb,old_ino))) {
- brelse(free_bh);
- if (exists) brelse(new_bh);
- return -EIO;
- }
- if (*(unsigned char *) old_de->name == DELETED_FLAG) {
- iput(old_inode);
- brelse(free_bh);
- if (exists) brelse(new_bh);
- return -ENOENT;
- }
- new_inode = NULL; /* to make GCC happy */
- if (exists) {
- if (!(new_inode = iget(new_dir->i_sb,new_ino))) {
- iput(old_inode);
- brelse(new_bh);
- return -EIO;
- }
- error = S_ISDIR(new_inode->i_mode) ? (old_de->attr & ATTR_DIR) ?
- msdos_empty(new_inode) : -EPERM : (old_de->attr & ATTR_DIR)
- ? -EPERM : 0;
- if (error) {
- iput(new_inode);
- iput(old_inode);
- brelse(new_bh);
- return error;
- }
- new_inode->i_nlink = 0;
- MSDOS_I(new_inode)->i_busy = 1;
- new_inode->i_dirt = 1;
- new_de->name[0] = DELETED_FLAG;
- new_bh->b_dirt = 1;
- }
- memcpy(free_de,old_de,sizeof(struct msdos_dir_entry));
- memcpy(free_de->name,new_name,MSDOS_NAME);
- if (!(free_inode = iget(new_dir->i_sb,free_ino))) {
- free_de->name[0] = DELETED_FLAG;
- /* Don't mark free_bh as dirty. Both states are supposed to be equivalent. */
- brelse(free_bh);
- if (exists) {
- iput(new_inode);
- brelse(new_bh);
- }
- return -EIO;
- }
- if (exists && S_ISDIR(new_inode->i_mode)) {
- new_dir->i_nlink--;
- new_dir->i_dirt = 1;
- }
- msdos_read_inode(free_inode);
- MSDOS_I(old_inode)->i_busy = 1;
- cache_inval_inode(old_inode);
- old_inode->i_dirt = 1;
- old_de->name[0] = DELETED_FLAG;
- old_bh->b_dirt = 1;
- free_bh->b_dirt = 1;
- if (!exists) iput(free_inode);
- else {
- MSDOS_I(new_inode)->i_depend = free_inode;
- MSDOS_I(free_inode)->i_old = new_inode;
- /* free_inode is put when putting new_inode */
- iput(new_inode);
- brelse(new_bh);
- }
- if (S_ISDIR(old_inode->i_mode)) {
- if ((error = msdos_scan(old_inode,MSDOS_DOTDOT,&dotdot_bh,
- &dotdot_de,&dotdot_ino)) < 0) goto rename_done;
- if (!(dotdot_inode = iget(old_inode->i_sb,dotdot_ino))) {
- brelse(dotdot_bh);
- error = -EIO;
- goto rename_done;
- }
- dotdot_de->start = MSDOS_I(dotdot_inode)->i_start =
- MSDOS_I(new_dir)->i_start;
- dotdot_inode->i_dirt = 1;
- dotdot_bh->b_dirt = 1;
- old_dir->i_nlink--;
- new_dir->i_nlink++;
- /* no need to mark them dirty */
- dotdot_inode->i_nlink = new_dir->i_nlink;
- iput(dotdot_inode);
- brelse(dotdot_bh);
- }
- error = 0;
- rename_done:
- brelse(free_bh);
- iput(old_inode);
- return error;
- }
-
-
- int msdos_rename(struct inode *old_dir,const char *old_name,int old_len,
- struct inode *new_dir,const char *new_name,int new_len)
- {
- char old_msdos_name[MSDOS_NAME],new_msdos_name[MSDOS_NAME];
- struct buffer_head *old_bh;
- struct msdos_dir_entry *old_de;
- int old_ino,error;
-
- if ((error = msdos_format_name(MSDOS_SB(old_dir->i_sb)->name_check,
- old_name,old_len,old_msdos_name,1)) < 0) goto rename_done;
- if ((error = msdos_format_name(MSDOS_SB(new_dir->i_sb)->name_check,
- new_name,new_len,new_msdos_name,0)) < 0) goto rename_done;
- if ((error = msdos_scan(old_dir,old_msdos_name,&old_bh,&old_de,
- &old_ino)) < 0) goto rename_done;
- lock_creation();
- if (old_dir == new_dir)
- error = rename_same_dir(old_dir,old_msdos_name,new_dir,
- new_msdos_name,old_bh,old_de,old_ino);
- else error = rename_diff_dir(old_dir,old_msdos_name,new_dir,
- new_msdos_name,old_bh,old_de,old_ino);
- unlock_creation();
- brelse(old_bh);
- rename_done:
- iput(old_dir);
- iput(new_dir);
- return error;
- }
-