796 lines
18 KiB
C
796 lines
18 KiB
C
/*
|
|
* linux/fs/minix/namei.c
|
|
*
|
|
* (C) 1991 Linus Torvalds
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/minix_fs.h>
|
|
#include <linux/kernel.h>
|
|
#include <asm/segment.h>
|
|
|
|
#include <string.h>
|
|
#include <fcntl.h>
|
|
#include <errno.h>
|
|
#include <const.h>
|
|
#include <sys/stat.h>
|
|
|
|
extern int permission(struct inode * inode,int mask);
|
|
extern struct inode * _namei(const char * filename, struct inode * base,
|
|
int follow_links);
|
|
|
|
/*
|
|
* comment out this line if you want names > MINIX_NAME_LEN chars to be
|
|
* truncated. Else they will be disallowed.
|
|
*/
|
|
/* #define NO_TRUNCATE */
|
|
|
|
/*
|
|
* ok, we cannot use strncmp, as the name is not in our data space.
|
|
* Thus we'll have to use minix_match. No big problem. Match also makes
|
|
* some sanity tests.
|
|
*
|
|
* NOTE! unlike strncmp, minix_match returns 1 for success, 0 for failure.
|
|
*/
|
|
static int minix_match(int len,const char * name,struct minix_dir_entry * de)
|
|
{
|
|
register int same __asm__("ax");
|
|
|
|
if (!de || !de->inode || len > MINIX_NAME_LEN)
|
|
return 0;
|
|
/* "" means "." ---> so paths like "/usr/lib//libc.a" work */
|
|
if (!len && (de->name[0]=='.') && (de->name[1]=='\0'))
|
|
return 1;
|
|
if (len < MINIX_NAME_LEN && de->name[len])
|
|
return 0;
|
|
__asm__("cld\n\t"
|
|
"fs ; repe ; cmpsb\n\t"
|
|
"setz %%al"
|
|
:"=a" (same)
|
|
:"0" (0),"S" ((long) name),"D" ((long) de->name),"c" (len)
|
|
:"cx","di","si");
|
|
return same;
|
|
}
|
|
|
|
/*
|
|
* minix_find_entry()
|
|
*
|
|
* finds an entry in the specified directory with the wanted name. It
|
|
* returns the cache buffer in which the entry was found, and the entry
|
|
* itself (as a parameter - res_dir). It does NOT read the inode of the
|
|
* entry - you'll have to do that yourself if you want to.
|
|
*/
|
|
static struct buffer_head * minix_find_entry(struct inode * dir,
|
|
const char * name, int namelen, struct minix_dir_entry ** res_dir)
|
|
{
|
|
int entries;
|
|
int block,i;
|
|
struct buffer_head * bh;
|
|
struct minix_dir_entry * de;
|
|
|
|
*res_dir = NULL;
|
|
if (!dir)
|
|
return NULL;
|
|
#ifdef NO_TRUNCATE
|
|
if (namelen > MINIX_NAME_LEN)
|
|
return NULL;
|
|
#else
|
|
if (namelen > MINIX_NAME_LEN)
|
|
namelen = MINIX_NAME_LEN;
|
|
#endif
|
|
entries = dir->i_size / (sizeof (struct minix_dir_entry));
|
|
if (!(block = dir->i_data[0]))
|
|
return NULL;
|
|
if (!(bh = bread(dir->i_dev,block)))
|
|
return NULL;
|
|
i = 0;
|
|
de = (struct minix_dir_entry *) bh->b_data;
|
|
while (i < entries) {
|
|
if ((char *)de >= BLOCK_SIZE+bh->b_data) {
|
|
brelse(bh);
|
|
bh = NULL;
|
|
if (!(block = bmap(dir,i/MINIX_DIR_ENTRIES_PER_BLOCK)) ||
|
|
!(bh = bread(dir->i_dev,block))) {
|
|
i += MINIX_DIR_ENTRIES_PER_BLOCK;
|
|
continue;
|
|
}
|
|
de = (struct minix_dir_entry *) bh->b_data;
|
|
}
|
|
if (minix_match(namelen,name,de)) {
|
|
*res_dir = de;
|
|
return bh;
|
|
}
|
|
de++;
|
|
i++;
|
|
}
|
|
brelse(bh);
|
|
return NULL;
|
|
}
|
|
|
|
struct inode * minix_follow_link(struct inode * dir, struct inode * inode)
|
|
{
|
|
unsigned short fs;
|
|
struct buffer_head * bh;
|
|
|
|
if (!dir) {
|
|
dir = current->root;
|
|
dir->i_count++;
|
|
}
|
|
if (!inode) {
|
|
iput(dir);
|
|
return NULL;
|
|
}
|
|
if (!S_ISLNK(inode->i_mode)) {
|
|
iput(dir);
|
|
return inode;
|
|
}
|
|
__asm__("mov %%fs,%0":"=r" (fs));
|
|
if ((current->link_count > 5) || !inode->i_data[0] ||
|
|
!(bh = bread(inode->i_dev, inode->i_data[0]))) {
|
|
iput(dir);
|
|
iput(inode);
|
|
return NULL;
|
|
}
|
|
iput(inode);
|
|
__asm__("mov %0,%%fs"::"r" ((unsigned short) 0x10));
|
|
current->link_count++;
|
|
inode = _namei(bh->b_data,dir,1);
|
|
current->link_count--;
|
|
__asm__("mov %0,%%fs"::"r" (fs));
|
|
brelse(bh);
|
|
return inode;
|
|
}
|
|
|
|
int minix_lookup(struct inode * dir,const char * name, int len,
|
|
struct inode ** result)
|
|
{
|
|
int ino;
|
|
struct minix_dir_entry * de;
|
|
struct buffer_head * bh;
|
|
|
|
*result = NULL;
|
|
if (!dir)
|
|
return -ENOENT;
|
|
if (!S_ISDIR(dir->i_mode)) {
|
|
iput(dir);
|
|
return -ENOENT;
|
|
}
|
|
if (!(bh = minix_find_entry(dir,name,len,&de))) {
|
|
iput(dir);
|
|
return -ENOENT;
|
|
}
|
|
ino = de->inode;
|
|
brelse(bh);
|
|
if (!(*result = iget(dir->i_dev,ino))) {
|
|
iput(dir);
|
|
return -EACCES;
|
|
}
|
|
iput(dir);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* minix_add_entry()
|
|
*
|
|
* adds a file entry to the specified directory, using the same
|
|
* semantics as minix_find_entry(). It returns NULL if it failed.
|
|
*
|
|
* NOTE!! The inode part of 'de' is left at 0 - which means you
|
|
* may not sleep between calling this and putting something into
|
|
* the entry, as someone else might have used it while you slept.
|
|
*/
|
|
static struct buffer_head * minix_add_entry(struct inode * dir,
|
|
const char * name, int namelen, struct minix_dir_entry ** res_dir)
|
|
{
|
|
int block,i;
|
|
struct buffer_head * bh;
|
|
struct minix_dir_entry * de;
|
|
|
|
*res_dir = NULL;
|
|
if (!dir)
|
|
return NULL;
|
|
#ifdef NO_TRUNCATE
|
|
if (namelen > MINIX_NAME_LEN)
|
|
return NULL;
|
|
#else
|
|
if (namelen > MINIX_NAME_LEN)
|
|
namelen = MINIX_NAME_LEN;
|
|
#endif
|
|
if (!namelen)
|
|
return NULL;
|
|
if (!(block = dir->i_data[0]))
|
|
return NULL;
|
|
if (!(bh = bread(dir->i_dev,block)))
|
|
return NULL;
|
|
i = 0;
|
|
de = (struct minix_dir_entry *) bh->b_data;
|
|
while (1) {
|
|
if ((char *)de >= BLOCK_SIZE+bh->b_data) {
|
|
brelse(bh);
|
|
bh = NULL;
|
|
block = minix_create_block(dir,i/MINIX_DIR_ENTRIES_PER_BLOCK);
|
|
if (!block)
|
|
return NULL;
|
|
if (!(bh = bread(dir->i_dev,block))) {
|
|
i += MINIX_DIR_ENTRIES_PER_BLOCK;
|
|
continue;
|
|
}
|
|
de = (struct minix_dir_entry *) bh->b_data;
|
|
}
|
|
if (i*sizeof(struct minix_dir_entry) >= dir->i_size) {
|
|
de->inode=0;
|
|
dir->i_size = (i+1)*sizeof(struct minix_dir_entry);
|
|
dir->i_dirt = 1;
|
|
dir->i_ctime = CURRENT_TIME;
|
|
}
|
|
if (!de->inode) {
|
|
dir->i_mtime = CURRENT_TIME;
|
|
for (i=0; i < MINIX_NAME_LEN ; i++)
|
|
de->name[i]=(i<namelen)?get_fs_byte(name+i):0;
|
|
bh->b_dirt = 1;
|
|
*res_dir = de;
|
|
return bh;
|
|
}
|
|
de++;
|
|
i++;
|
|
}
|
|
brelse(bh);
|
|
return NULL;
|
|
}
|
|
|
|
int minix_create(struct inode * dir,const char * name, int len, int mode,
|
|
struct inode ** result)
|
|
{
|
|
struct inode * inode;
|
|
struct buffer_head * bh;
|
|
struct minix_dir_entry * de;
|
|
|
|
*result = NULL;
|
|
if (!dir)
|
|
return -ENOENT;
|
|
inode = minix_new_inode(dir->i_dev);
|
|
if (!inode) {
|
|
iput(dir);
|
|
return -ENOSPC;
|
|
}
|
|
inode->i_mode = mode;
|
|
inode->i_dirt = 1;
|
|
bh = minix_add_entry(dir,name,len,&de);
|
|
if (!bh) {
|
|
inode->i_nlink--;
|
|
iput(inode);
|
|
iput(dir);
|
|
return -ENOSPC;
|
|
}
|
|
de->inode = inode->i_ino;
|
|
bh->b_dirt = 1;
|
|
brelse(bh);
|
|
iput(dir);
|
|
*result = inode;
|
|
return 0;
|
|
}
|
|
|
|
int minix_mknod(struct inode * dir, const char * name, int len, int mode, int rdev)
|
|
{
|
|
struct inode * inode;
|
|
struct buffer_head * bh;
|
|
struct minix_dir_entry * de;
|
|
|
|
if (!dir)
|
|
return -ENOENT;
|
|
bh = minix_find_entry(dir,name,len,&de);
|
|
if (bh) {
|
|
brelse(bh);
|
|
iput(dir);
|
|
return -EEXIST;
|
|
}
|
|
inode = minix_new_inode(dir->i_dev);
|
|
if (!inode) {
|
|
iput(dir);
|
|
return -ENOSPC;
|
|
}
|
|
inode->i_uid = current->euid;
|
|
inode->i_mode = mode;
|
|
if (S_ISBLK(mode) || S_ISCHR(mode))
|
|
inode->i_rdev = rdev;
|
|
inode->i_mtime = inode->i_atime = CURRENT_TIME;
|
|
inode->i_dirt = 1;
|
|
bh = minix_add_entry(dir,name,len,&de);
|
|
if (!bh) {
|
|
inode->i_nlink--;
|
|
iput(inode);
|
|
iput(dir);
|
|
return -ENOSPC;
|
|
}
|
|
de->inode = inode->i_ino;
|
|
bh->b_dirt = 1;
|
|
brelse(bh);
|
|
iput(dir);
|
|
iput(inode);
|
|
return 0;
|
|
}
|
|
|
|
int minix_mkdir(struct inode * dir, const char * name, int len, int mode)
|
|
{
|
|
struct inode * inode;
|
|
struct buffer_head * bh, *dir_block;
|
|
struct minix_dir_entry * de;
|
|
|
|
bh = minix_find_entry(dir,name,len,&de);
|
|
if (bh) {
|
|
brelse(bh);
|
|
iput(dir);
|
|
return -EEXIST;
|
|
}
|
|
inode = minix_new_inode(dir->i_dev);
|
|
if (!inode) {
|
|
iput(dir);
|
|
return -ENOSPC;
|
|
}
|
|
inode->i_size = 32;
|
|
inode->i_dirt = 1;
|
|
inode->i_mtime = inode->i_atime = CURRENT_TIME;
|
|
if (!(inode->i_data[0] = minix_new_block(inode->i_dev))) {
|
|
iput(dir);
|
|
inode->i_nlink--;
|
|
iput(inode);
|
|
return -ENOSPC;
|
|
}
|
|
inode->i_dirt = 1;
|
|
if (!(dir_block = bread(inode->i_dev,inode->i_data[0]))) {
|
|
iput(dir);
|
|
inode->i_nlink--;
|
|
iput(inode);
|
|
return -ERROR;
|
|
}
|
|
de = (struct minix_dir_entry *) dir_block->b_data;
|
|
de->inode=inode->i_ino;
|
|
strcpy(de->name,".");
|
|
de++;
|
|
de->inode = dir->i_ino;
|
|
strcpy(de->name,"..");
|
|
inode->i_nlink = 2;
|
|
dir_block->b_dirt = 1;
|
|
brelse(dir_block);
|
|
inode->i_mode = I_DIRECTORY | (mode & 0777 & ~current->umask);
|
|
inode->i_dirt = 1;
|
|
bh = minix_add_entry(dir,name,len,&de);
|
|
if (!bh) {
|
|
iput(dir);
|
|
inode->i_nlink=0;
|
|
iput(inode);
|
|
return -ENOSPC;
|
|
}
|
|
de->inode = inode->i_ino;
|
|
bh->b_dirt = 1;
|
|
dir->i_nlink++;
|
|
dir->i_dirt = 1;
|
|
iput(dir);
|
|
iput(inode);
|
|
brelse(bh);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* routine to check that the specified directory is empty (for rmdir)
|
|
*/
|
|
static int empty_dir(struct inode * inode)
|
|
{
|
|
int nr,block;
|
|
int len;
|
|
struct buffer_head * bh;
|
|
struct minix_dir_entry * de;
|
|
|
|
len = inode->i_size / sizeof (struct minix_dir_entry);
|
|
if (len<2 || !inode->i_data[0] ||
|
|
!(bh=bread(inode->i_dev,inode->i_data[0]))) {
|
|
printk("warning - bad directory on dev %04x\n",inode->i_dev);
|
|
return 0;
|
|
}
|
|
de = (struct minix_dir_entry *) bh->b_data;
|
|
if (de[0].inode != inode->i_ino || !de[1].inode ||
|
|
strcmp(".",de[0].name) || strcmp("..",de[1].name)) {
|
|
printk("warning - bad directory on dev %04x\n",inode->i_dev);
|
|
return 0;
|
|
}
|
|
nr = 2;
|
|
de += 2;
|
|
while (nr<len) {
|
|
if ((void *) de >= (void *) (bh->b_data+BLOCK_SIZE)) {
|
|
brelse(bh);
|
|
block=bmap(inode,nr/MINIX_DIR_ENTRIES_PER_BLOCK);
|
|
if (!block) {
|
|
nr += MINIX_DIR_ENTRIES_PER_BLOCK;
|
|
continue;
|
|
}
|
|
if (!(bh=bread(inode->i_dev,block)))
|
|
return 0;
|
|
de = (struct minix_dir_entry *) bh->b_data;
|
|
}
|
|
if (de->inode) {
|
|
brelse(bh);
|
|
return 0;
|
|
}
|
|
de++;
|
|
nr++;
|
|
}
|
|
brelse(bh);
|
|
return 1;
|
|
}
|
|
|
|
int minix_rmdir(struct inode * dir, const char * name, int len)
|
|
{
|
|
int retval;
|
|
struct inode * inode;
|
|
struct buffer_head * bh;
|
|
struct minix_dir_entry * de;
|
|
|
|
inode = NULL;
|
|
bh = minix_find_entry(dir,name,len,&de);
|
|
retval = -ENOENT;
|
|
if (!bh)
|
|
goto end_rmdir;
|
|
retval = -EPERM;
|
|
if (!(inode = iget(dir->i_dev, de->inode)))
|
|
goto end_rmdir;
|
|
if ((dir->i_mode & S_ISVTX) && current->euid &&
|
|
inode->i_uid != current->euid)
|
|
goto end_rmdir;
|
|
if (inode->i_dev != dir->i_dev)
|
|
goto end_rmdir;
|
|
if (inode == dir) /* we may not delete ".", but "../dir" is ok */
|
|
goto end_rmdir;
|
|
if (!S_ISDIR(inode->i_mode)) {
|
|
retval = -ENOTDIR;
|
|
goto end_rmdir;
|
|
}
|
|
if (!empty_dir(inode)) {
|
|
retval = -ENOTEMPTY;
|
|
goto end_rmdir;
|
|
}
|
|
if (inode->i_count > 1) {
|
|
retval = -EBUSY;
|
|
goto end_rmdir;
|
|
}
|
|
if (inode->i_nlink != 2)
|
|
printk("empty directory has nlink!=2 (%d)\n",inode->i_nlink);
|
|
de->inode = 0;
|
|
bh->b_dirt = 1;
|
|
inode->i_nlink=0;
|
|
inode->i_dirt=1;
|
|
dir->i_nlink--;
|
|
dir->i_ctime = dir->i_mtime = CURRENT_TIME;
|
|
dir->i_dirt=1;
|
|
retval = 0;
|
|
end_rmdir:
|
|
iput(dir);
|
|
iput(inode);
|
|
brelse(bh);
|
|
return retval;
|
|
}
|
|
|
|
int minix_unlink(struct inode * dir, const char * name, int len)
|
|
{
|
|
int retval;
|
|
struct inode * inode;
|
|
struct buffer_head * bh;
|
|
struct minix_dir_entry * de;
|
|
|
|
retval = -ENOENT;
|
|
inode = NULL;
|
|
bh = minix_find_entry(dir,name,len,&de);
|
|
if (!bh)
|
|
goto end_unlink;
|
|
if (!(inode = iget(dir->i_dev, de->inode)))
|
|
goto end_unlink;
|
|
retval = -EPERM;
|
|
if ((dir->i_mode & S_ISVTX) && !suser() &&
|
|
current->euid != inode->i_uid &&
|
|
current->euid != dir->i_uid)
|
|
goto end_unlink;
|
|
if (S_ISDIR(inode->i_mode))
|
|
goto end_unlink;
|
|
if (!inode->i_nlink) {
|
|
printk("Deleting nonexistent file (%04x:%d), %d\n",
|
|
inode->i_dev,inode->i_ino,inode->i_nlink);
|
|
inode->i_nlink=1;
|
|
}
|
|
de->inode = 0;
|
|
bh->b_dirt = 1;
|
|
inode->i_nlink--;
|
|
inode->i_dirt = 1;
|
|
inode->i_ctime = CURRENT_TIME;
|
|
retval = 0;
|
|
end_unlink:
|
|
brelse(bh);
|
|
iput(inode);
|
|
iput(dir);
|
|
return retval;
|
|
}
|
|
|
|
int minix_symlink(struct inode * dir, const char * name, int len, const char * symname)
|
|
{
|
|
struct minix_dir_entry * de;
|
|
struct inode * inode = NULL;
|
|
struct buffer_head * bh = NULL, * name_block = NULL;
|
|
int i;
|
|
char c;
|
|
|
|
if (!(inode = minix_new_inode(dir->i_dev))) {
|
|
iput(dir);
|
|
return -ENOSPC;
|
|
}
|
|
inode->i_mode = S_IFLNK | 0777;
|
|
inode->i_dirt = 1;
|
|
if (!(inode->i_data[0] = minix_new_block(inode->i_dev))) {
|
|
iput(dir);
|
|
inode->i_nlink--;
|
|
iput(inode);
|
|
return -ENOSPC;
|
|
}
|
|
inode->i_dirt = 1;
|
|
if (!(name_block = bread(inode->i_dev,inode->i_data[0]))) {
|
|
iput(dir);
|
|
inode->i_nlink--;
|
|
iput(inode);
|
|
return -ERROR;
|
|
}
|
|
i = 0;
|
|
while (i < 1023 && (c=get_fs_byte(symname++)))
|
|
name_block->b_data[i++] = c;
|
|
name_block->b_data[i] = 0;
|
|
name_block->b_dirt = 1;
|
|
brelse(name_block);
|
|
inode->i_size = i;
|
|
inode->i_dirt = 1;
|
|
bh = minix_find_entry(dir,name,len,&de);
|
|
if (bh) {
|
|
inode->i_nlink--;
|
|
iput(inode);
|
|
brelse(bh);
|
|
iput(dir);
|
|
return -EEXIST;
|
|
}
|
|
bh = minix_add_entry(dir,name,len,&de);
|
|
if (!bh) {
|
|
inode->i_nlink--;
|
|
iput(inode);
|
|
iput(dir);
|
|
return -ENOSPC;
|
|
}
|
|
de->inode = inode->i_ino;
|
|
bh->b_dirt = 1;
|
|
brelse(bh);
|
|
iput(dir);
|
|
iput(inode);
|
|
return 0;
|
|
}
|
|
|
|
int minix_link(struct inode * oldinode, struct inode * dir, const char * name, int len)
|
|
{
|
|
struct minix_dir_entry * de;
|
|
struct buffer_head * bh;
|
|
|
|
if (S_ISDIR(oldinode->i_mode)) {
|
|
iput(oldinode);
|
|
iput(dir);
|
|
return -EPERM;
|
|
}
|
|
bh = minix_find_entry(dir,name,len,&de);
|
|
if (bh) {
|
|
brelse(bh);
|
|
iput(dir);
|
|
iput(oldinode);
|
|
return -EEXIST;
|
|
}
|
|
bh = minix_add_entry(dir,name,len,&de);
|
|
if (!bh) {
|
|
iput(dir);
|
|
iput(oldinode);
|
|
return -ENOSPC;
|
|
}
|
|
de->inode = oldinode->i_ino;
|
|
bh->b_dirt = 1;
|
|
brelse(bh);
|
|
iput(dir);
|
|
oldinode->i_nlink++;
|
|
oldinode->i_ctime = CURRENT_TIME;
|
|
oldinode->i_dirt = 1;
|
|
iput(oldinode);
|
|
return 0;
|
|
}
|
|
|
|
static int subdir(struct inode * new, struct inode * old)
|
|
{
|
|
unsigned short fs;
|
|
int ino;
|
|
int result;
|
|
|
|
__asm__("mov %%fs,%0":"=r" (fs));
|
|
__asm__("mov %0,%%fs"::"r" ((unsigned short) 0x10));
|
|
new->i_count++;
|
|
result = 0;
|
|
for (;;) {
|
|
if (new == old) {
|
|
result = 1;
|
|
break;
|
|
}
|
|
if (new->i_dev != old->i_dev)
|
|
break;
|
|
ino = new->i_ino;
|
|
if (minix_lookup(new,"..",2,&new))
|
|
break;
|
|
if (new->i_ino == ino)
|
|
break;
|
|
}
|
|
iput(new);
|
|
__asm__("mov %0,%%fs"::"r" (fs));
|
|
return result;
|
|
}
|
|
|
|
#define PARENT_INO(buffer) \
|
|
(((struct minix_dir_entry *) (buffer))[1].inode)
|
|
|
|
#define PARENT_NAME(buffer) \
|
|
(((struct minix_dir_entry *) (buffer))[1].name)
|
|
|
|
/*
|
|
* rename uses retrying to avoid race-conditions: at least they should be minimal.
|
|
* it tries to allocate all the blocks, then sanity-checks, and if the sanity-
|
|
* checks fail, it tries to restart itself again. Very practical - no changes
|
|
* are done until we know everything works ok.. and then all the changes can be
|
|
* done in one fell swoop when we have claimed all the buffers needed.
|
|
*
|
|
* Anybody can rename anything with this: the permission checks are left to the
|
|
* higher-level routines.
|
|
*/
|
|
static int do_minix_rename(struct inode * old_dir, const char * old_name, int old_len,
|
|
struct inode * new_dir, const char * new_name, int new_len)
|
|
{
|
|
struct inode * old_inode, * new_inode;
|
|
struct buffer_head * old_bh, * new_bh, * dir_bh;
|
|
struct minix_dir_entry * old_de, * new_de;
|
|
int retval;
|
|
|
|
goto start_up;
|
|
try_again:
|
|
brelse(old_bh);
|
|
brelse(new_bh);
|
|
brelse(dir_bh);
|
|
iput(old_inode);
|
|
iput(new_inode);
|
|
current->counter = 0;
|
|
schedule();
|
|
start_up:
|
|
old_inode = new_inode = NULL;
|
|
old_bh = new_bh = dir_bh = NULL;
|
|
old_bh = minix_find_entry(old_dir,old_name,old_len,&old_de);
|
|
retval = -ENOENT;
|
|
if (!old_bh)
|
|
goto end_rename;
|
|
old_inode = iget(old_dir->i_dev, old_de->inode);
|
|
if (!old_inode)
|
|
goto end_rename;
|
|
new_bh = minix_find_entry(new_dir,new_name,new_len,&new_de);
|
|
if (new_bh) {
|
|
new_inode = iget(new_dir->i_dev, new_de->inode);
|
|
if (!new_inode) {
|
|
brelse(new_bh);
|
|
new_bh = NULL;
|
|
}
|
|
}
|
|
if (new_inode == old_inode) {
|
|
retval = 0;
|
|
goto end_rename;
|
|
}
|
|
if (S_ISDIR(old_inode->i_mode)) {
|
|
retval = -EEXIST;
|
|
if (new_bh)
|
|
goto end_rename;
|
|
retval = -EACCES;
|
|
if (!permission(old_inode, MAY_WRITE))
|
|
goto end_rename;
|
|
retval = -EINVAL;
|
|
if (subdir(new_dir, old_inode))
|
|
goto end_rename;
|
|
retval = -EIO;
|
|
if (!old_inode->i_data[0])
|
|
goto end_rename;
|
|
if (!(dir_bh = bread(old_inode->i_dev, old_inode->i_data[0])))
|
|
goto end_rename;
|
|
if (PARENT_INO(dir_bh->b_data) != old_dir->i_ino)
|
|
goto end_rename;
|
|
}
|
|
if (!new_bh)
|
|
new_bh = minix_add_entry(new_dir,new_name,new_len,&new_de);
|
|
retval = -ENOSPC;
|
|
if (!new_bh)
|
|
goto end_rename;
|
|
/* sanity checking before doing the rename - avoid races */
|
|
if (new_inode && (new_de->inode != new_inode->i_ino))
|
|
goto try_again;
|
|
if (new_de->inode && !new_inode)
|
|
goto try_again;
|
|
if (old_de->inode != old_inode->i_ino)
|
|
goto try_again;
|
|
/* ok, that's it */
|
|
old_de->inode = 0;
|
|
new_de->inode = old_inode->i_ino;
|
|
if (new_inode)
|
|
new_inode->i_nlink--;
|
|
old_bh->b_dirt = 1;
|
|
new_bh->b_dirt = 1;
|
|
if (dir_bh) {
|
|
PARENT_INO(dir_bh->b_data) = new_dir->i_ino;
|
|
dir_bh->b_dirt = 1;
|
|
old_dir->i_nlink--;
|
|
new_dir->i_nlink++;
|
|
old_dir->i_dirt = 1;
|
|
new_dir->i_dirt = 1;
|
|
}
|
|
retval = 0;
|
|
end_rename:
|
|
brelse(dir_bh);
|
|
brelse(old_bh);
|
|
brelse(new_bh);
|
|
iput(old_inode);
|
|
iput(new_inode);
|
|
iput(old_dir);
|
|
iput(new_dir);
|
|
return retval;
|
|
}
|
|
|
|
/*
|
|
* Ok, rename also locks out other renames, as they can change the parent of
|
|
* a directory, and we don't want any races. Other races are checked for by
|
|
* "do_rename()", which restarts if there are inconsistencies.
|
|
*
|
|
* Note that there is no race between different filesystems: it's only within
|
|
* the same device that races occur: many renames can happen at once, as long
|
|
* as they are on different partitions.
|
|
*/
|
|
int minix_rename(struct inode * old_dir, const char * old_name, int old_len,
|
|
struct inode * new_dir, const char * new_name, int new_len)
|
|
{
|
|
static struct task_struct * wait = NULL;
|
|
static int lock = 0;
|
|
int result;
|
|
|
|
while (lock)
|
|
sleep_on(&wait);
|
|
lock = 1;
|
|
result = do_minix_rename(old_dir, old_name, old_len,
|
|
new_dir, new_name, new_len);
|
|
lock = 0;
|
|
wake_up(&wait);
|
|
return result;
|
|
}
|
|
|
|
int minix_readlink(struct inode * inode, char * buffer, int buflen)
|
|
{
|
|
struct buffer_head * bh;
|
|
int i;
|
|
char c;
|
|
|
|
if (!S_ISLNK(inode->i_mode)) {
|
|
iput(inode);
|
|
return -EINVAL;
|
|
}
|
|
if (buflen > 1023)
|
|
buflen = 1023;
|
|
if (inode->i_data[0])
|
|
bh = bread(inode->i_dev, inode->i_data[0]);
|
|
else
|
|
bh = NULL;
|
|
iput(inode);
|
|
if (!bh)
|
|
return 0;
|
|
i = 0;
|
|
while (i<buflen && (c = bh->b_data[i])) {
|
|
i++;
|
|
put_fs_byte(c,buffer++);
|
|
}
|
|
brelse(bh);
|
|
return i;
|
|
}
|