| /* |
| * Linux/fs/xiafs/namei.c |
| * |
| * Copyright (C) Q. Frank Xia, 1993. |
| * |
| * Based on Linus' minix/namei.c |
| * Copyright (C) Linus Torvalds, 1991, 1992. |
| * |
| * This software may be redistributed per Linux Copyright. |
| */ |
| |
| #include <linux/sched.h> |
| #include <linux/xia_fs.h> |
| #include <linux/kernel.h> |
| #include <linux/string.h> |
| #include <linux/stat.h> |
| #include <linux/fcntl.h> |
| #include <linux/errno.h> |
| #include <asm/segment.h> |
| |
| #include "xiafs_mac.h" |
| |
| #define RNDUP4(x) ((3+(u_long)(x)) & ~3) |
| /* |
| * ok, we cannot use strncmp, as the name is not in our data space. |
| * Thus we'll have to use xiafs_match. No big problem. Match also makes |
| * some sanity tests. |
| * |
| * NOTE! unlike strncmp, xiafs_match returns 1 for success, 0 for failure. |
| */ |
| static int xiafs_match(int len, const char * name, struct xiafs_direct * dep) |
| { |
| int i; |
| |
| if (!dep || !dep->d_ino || len > _XIAFS_NAME_LEN) |
| return 0; |
| /* "" means "." ---> so paths like "/usr/lib//libc.a" work */ |
| if (!len && (dep->d_name[0]=='.') && (dep->d_name[1]=='\0')) |
| return 1; |
| if (len != dep->d_name_len) |
| return 0; |
| for (i=0; i < len; i++) |
| if (*name++ != dep->d_name[i]) |
| return 0; |
| return 1; |
| } |
| |
| /* |
| * xiafs_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 * |
| xiafs_find_entry(struct inode * inode, const char * name, int namelen, |
| struct xiafs_direct ** res_dir, struct xiafs_direct ** res_pre) |
| { |
| int i, zones, pos; |
| struct buffer_head * bh; |
| struct xiafs_direct * dep, * dep_pre; |
| |
| *res_dir = NULL; |
| if (!inode) |
| return NULL; |
| if (namelen > _XIAFS_NAME_LEN) |
| return NULL; |
| |
| if (inode->i_size & (XIAFS_ZSIZE(inode->i_sb) - 1)) { |
| printk("XIA-FS: bad dir size (%s %d)\n", WHERE_ERR); |
| return NULL; |
| } |
| zones=inode->i_size >> XIAFS_ZSIZE_BITS(inode->i_sb); |
| for (i=0; i < zones; i++ ) { |
| bh = xiafs_bread(inode, i, 0); |
| if (!bh) |
| continue; |
| dep_pre=dep=(struct xiafs_direct *)bh->b_data; |
| if (!i && (dep->d_rec_len != 12 || !dep->d_ino || |
| dep->d_name_len != 1 || strcmp(dep->d_name, "."))) { |
| printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR); |
| brelse(bh); |
| return NULL; |
| } |
| pos = 0; |
| while ( pos < XIAFS_ZSIZE(inode->i_sb) ) { |
| if (dep->d_ino > inode->i_sb->u.xiafs_sb.s_ninodes || |
| dep->d_rec_len < 12 || |
| dep->d_rec_len+(char *)dep > bh->b_data+XIAFS_ZSIZE(inode->i_sb) || |
| dep->d_name_len + 8 > dep->d_rec_len || dep->d_name_len <= 0 || |
| dep->d_name[dep->d_name_len] ) { |
| brelse(bh); |
| return NULL; |
| } |
| if (xiafs_match(namelen, name, dep)) { |
| *res_dir=dep; |
| if (res_pre) |
| *res_pre=dep_pre; |
| return bh; |
| } |
| pos += dep->d_rec_len; |
| dep_pre=dep; |
| dep=(struct xiafs_direct *)(bh->b_data + pos); |
| } |
| brelse(bh); |
| if (pos > XIAFS_ZSIZE(inode->i_sb)) { |
| printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR); |
| return NULL; |
| } |
| } |
| return NULL; |
| } |
| |
| int xiafs_lookup(struct inode * dir, const char * name, int len, |
| struct inode ** result) |
| { |
| int ino; |
| struct xiafs_direct * dep; |
| struct buffer_head * bh; |
| |
| *result = NULL; |
| if (!dir) |
| return -ENOENT; |
| if (!S_ISDIR(dir->i_mode)) { |
| iput(dir); |
| return -ENOENT; |
| } |
| if (!(bh = xiafs_find_entry(dir, name, len, &dep, NULL))) { |
| iput(dir); |
| return -ENOENT; |
| } |
| ino = dep->d_ino; |
| brelse(bh); |
| if (!(*result = iget(dir->i_sb, ino))) { |
| iput(dir); |
| return -EACCES; |
| } |
| iput(dir); |
| return 0; |
| } |
| |
| /* |
| * xiafs_add_entry() |
| * |
| * adds a file entry to the specified directory, using the same |
| * semantics as xiafs_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 * xiafs_add_entry(struct inode * dir, |
| const char * name, int namelen, struct xiafs_direct ** res_dir, |
| struct xiafs_direct ** res_pre) |
| { |
| int i, pos, offset; |
| struct buffer_head * bh; |
| struct xiafs_direct * de, * de_pre; |
| |
| *res_dir = NULL; |
| if (!dir || !namelen || namelen > _XIAFS_NAME_LEN) |
| return NULL; |
| |
| if (dir->i_size & (XIAFS_ZSIZE(dir->i_sb) - 1)) { |
| printk("XIA-FS: bad dir size (%s %d)\n", WHERE_ERR); |
| return NULL; |
| } |
| pos=0; |
| for ( ; ; ) { |
| bh = xiafs_bread(dir, pos >> XIAFS_ZSIZE_BITS(dir->i_sb), pos ? 1:0); |
| if (!bh) |
| return NULL; |
| de_pre=de=(struct xiafs_direct *)bh->b_data; |
| if (!pos) { |
| if (de->d_rec_len != 12 || !de->d_ino || de->d_name_len != 1 || |
| strcmp(de->d_name, ".")) { |
| printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR); |
| brelse(bh); |
| return NULL; |
| } |
| offset = 12; |
| de_pre=de=(struct xiafs_direct *)(bh->b_data+12); |
| } else |
| offset = 0; |
| while (offset < XIAFS_ZSIZE(dir->i_sb)) { |
| if (pos >= dir->i_size) { |
| de->d_ino=0; |
| de->d_name_len=0; |
| de->d_name[0]=0; |
| de->d_rec_len=XIAFS_ZSIZE(dir->i_sb); |
| dir->i_size += XIAFS_ZSIZE(dir->i_sb); |
| dir->i_dirt = 1; |
| } else { |
| if (de->d_ino > dir->i_sb->u.xiafs_sb.s_ninodes || |
| de->d_rec_len < 12 || |
| (char *)de+de->d_rec_len > bh->b_data+XIAFS_ZSIZE(dir->i_sb) || |
| de->d_name_len + 8 > de->d_rec_len || |
| de->d_name[de->d_name_len]) { |
| printk("XIA-FS: bad directory entry (%s %d)\n", WHERE_ERR); |
| brelse(bh); |
| return NULL; |
| } |
| if (de->d_ino && |
| RNDUP4(de->d_name_len)+RNDUP4(namelen)+16<=de->d_rec_len) { |
| i=RNDUP4(de->d_name_len)+8; |
| de_pre=de; |
| de=(struct xiafs_direct *)(i+(u_char *)de_pre); |
| de->d_ino=0; |
| de->d_rec_len=de_pre->d_rec_len-i; |
| de_pre->d_rec_len=i; |
| } |
| } |
| if (!de->d_ino && RNDUP4(namelen)+8 <= de->d_rec_len) { |
| dir->i_atime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
| dir->i_dirt = 1; |
| memcpy(de->d_name, name, namelen); |
| de->d_name[namelen]=0; |
| de->d_name_len=namelen; |
| bh->b_dirt = 1; |
| *res_dir = de; |
| if (res_pre) |
| *res_pre = de_pre; |
| return bh; |
| } |
| offset+=de->d_rec_len; |
| de_pre=de; |
| de=(struct xiafs_direct *)(bh->b_data+offset); |
| } |
| brelse(bh); |
| if (offset > XIAFS_ZSIZE(dir->i_sb)) { |
| printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR); |
| return NULL; |
| } |
| pos+=XIAFS_ZSIZE(dir->i_sb); |
| } |
| return NULL; |
| } |
| |
| int xiafs_create(struct inode * dir, const char * name, int len, int mode, |
| struct inode ** result) |
| { |
| struct inode * inode; |
| struct buffer_head * bh; |
| struct xiafs_direct * de; |
| |
| *result = NULL; |
| if (!dir) |
| return -ENOENT; |
| inode = xiafs_new_inode(dir); |
| if (!inode) { |
| iput(dir); |
| return -ENOSPC; |
| } |
| inode->i_op = &xiafs_file_inode_operations; |
| inode->i_mode = mode; |
| inode->i_dirt = 1; |
| bh = xiafs_add_entry(dir, name, len, &de, NULL); |
| if (!bh) { |
| inode->i_nlink--; |
| inode->i_dirt = 1; |
| iput(inode); |
| iput(dir); |
| return -ENOSPC; |
| } |
| de->d_ino = inode->i_ino; |
| bh->b_dirt = 1; |
| brelse(bh); |
| iput(dir); |
| *result = inode; |
| return 0; |
| } |
| |
| int xiafs_mknod(struct inode *dir, const char *name, int len, int mode, int rdev) |
| { |
| struct inode * inode; |
| struct buffer_head * bh; |
| struct xiafs_direct * de; |
| |
| if (!dir) |
| return -ENOENT; |
| bh = xiafs_find_entry(dir,name,len,&de, NULL); |
| if (bh) { |
| brelse(bh); |
| iput(dir); |
| return -EEXIST; |
| } |
| inode = xiafs_new_inode(dir); |
| if (!inode) { |
| iput(dir); |
| return -ENOSPC; |
| } |
| inode->i_uid = current->euid; |
| inode->i_mode = mode; |
| inode->i_op = NULL; |
| if (S_ISREG(inode->i_mode)) |
| inode->i_op = &xiafs_file_inode_operations; |
| else if (S_ISDIR(inode->i_mode)) { |
| inode->i_op = &xiafs_dir_inode_operations; |
| if (dir->i_mode & S_ISGID) |
| inode->i_mode |= S_ISGID; |
| } |
| else if (S_ISLNK(inode->i_mode)) |
| inode->i_op = &xiafs_symlink_inode_operations; |
| else if (S_ISCHR(inode->i_mode)) |
| inode->i_op = &chrdev_inode_operations; |
| else if (S_ISBLK(inode->i_mode)) |
| inode->i_op = &blkdev_inode_operations; |
| else if (S_ISFIFO(inode->i_mode)) |
| init_fifo(inode); |
| if (S_ISBLK(mode) || S_ISCHR(mode)) |
| inode->i_rdev = rdev; |
| inode->i_atime = inode->i_ctime = inode->i_atime = CURRENT_TIME; |
| inode->i_dirt = 1; |
| bh = xiafs_add_entry(dir, name, len, &de, NULL); |
| if (!bh) { |
| inode->i_nlink--; |
| inode->i_dirt = 1; |
| iput(inode); |
| iput(dir); |
| return -ENOSPC; |
| } |
| de->d_ino = inode->i_ino; |
| bh->b_dirt = 1; |
| brelse(bh); |
| iput(dir); |
| iput(inode); |
| return 0; |
| } |
| |
| int xiafs_mkdir(struct inode * dir, const char * name, int len, int mode) |
| { |
| struct inode * inode; |
| struct buffer_head * bh, *dir_block; |
| struct xiafs_direct * de; |
| |
| bh = xiafs_find_entry(dir,name,len,&de, NULL); |
| if (bh) { |
| brelse(bh); |
| iput(dir); |
| return -EEXIST; |
| } |
| if (dir->i_nlink > 64000) { |
| iput(dir); |
| return -EMLINK; |
| } |
| inode = xiafs_new_inode(dir); |
| if (!inode) { |
| iput(dir); |
| return -ENOSPC; |
| } |
| inode->i_op = &xiafs_dir_inode_operations; |
| inode->i_size = XIAFS_ZSIZE(dir->i_sb); |
| inode->i_atime = inode->i_ctime = inode->i_mtime = CURRENT_TIME; |
| dir_block = xiafs_bread(inode,0,1); |
| if (!dir_block) { |
| iput(dir); |
| inode->i_nlink--; |
| inode->i_dirt = 1; |
| iput(inode); |
| return -ENOSPC; |
| } |
| de = (struct xiafs_direct *) dir_block->b_data; |
| de->d_ino=inode->i_ino; |
| strcpy(de->d_name,"."); |
| de->d_name_len=1; |
| de->d_rec_len=12; |
| de =(struct xiafs_direct *)(12 + dir_block->b_data); |
| de->d_ino = dir->i_ino; |
| strcpy(de->d_name,".."); |
| de->d_name_len=2; |
| de->d_rec_len=XIAFS_ZSIZE(dir->i_sb)-12; |
| inode->i_nlink = 2; |
| dir_block->b_dirt = 1; |
| brelse(dir_block); |
| inode->i_mode = S_IFDIR | (mode & 0777 & ~current->umask); |
| if (dir->i_mode & S_ISGID) |
| inode->i_mode |= S_ISGID; |
| inode->i_dirt = 1; |
| bh = xiafs_add_entry(dir, name, len, &de, NULL); |
| if (!bh) { |
| iput(dir); |
| inode->i_nlink=0; |
| iput(inode); |
| return -ENOSPC; |
| } |
| de->d_ino = 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 i, zones, offset; |
| struct buffer_head * bh; |
| struct xiafs_direct * de; |
| |
| if (inode->i_size & (XIAFS_ZSIZE(inode->i_sb)-1) ) { |
| printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR); |
| return 1; |
| } |
| |
| zones=inode->i_size >> XIAFS_ZSIZE_BITS(inode->i_sb); |
| for (i=0; i < zones; i++) { |
| bh = xiafs_bread(inode, i, 0); |
| if (!i) { |
| if (!bh) { |
| printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR); |
| return 1; |
| } |
| de=(struct xiafs_direct *)bh->b_data; |
| if (de->d_ino != inode->i_ino || strcmp(".", de->d_name) || |
| de->d_rec_len != 12 ) { |
| printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR); |
| brelse(bh); |
| return 1; |
| } |
| de=(struct xiafs_direct *)(12 + bh->b_data); |
| if (!de->d_ino || strcmp("..", de->d_name)) { |
| printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR); |
| brelse(bh); |
| return 1; |
| } |
| offset=de->d_rec_len+12; |
| } |
| else |
| offset = 0; |
| if (!bh) |
| continue; |
| while (offset < XIAFS_ZSIZE(inode->i_sb)) { |
| de=(struct xiafs_direct *)(bh->b_data+offset); |
| if (de->d_ino > inode->i_sb->u.xiafs_sb.s_ninodes || |
| de->d_rec_len < 12 || |
| (char *)de+de->d_rec_len > bh->b_data+XIAFS_ZSIZE(inode->i_sb) || |
| de->d_name_len + 8 > de->d_rec_len || |
| de->d_name[de->d_name_len]) { |
| printk("XIA-FS: bad directory (%s %d)\n", WHERE_ERR); |
| brelse(bh); |
| return 1; |
| } |
| if (de->d_ino) { |
| brelse(bh); |
| return 0; |
| } |
| offset+=de->d_rec_len; |
| } |
| brelse(bh); |
| } |
| return 1; |
| } |
| |
| static void xiafs_rm_entry(struct xiafs_direct *de, struct xiafs_direct * de_pre) |
| { |
| if (de==de_pre) { |
| de->d_ino=0; |
| return; |
| } |
| while (de_pre->d_rec_len+(u_char *)de_pre < (u_char *)de) { |
| if (de_pre->d_rec_len < 12) { |
| printk("XIA-FS: bad directory entry (%s %d)\n", WHERE_ERR); |
| return; |
| } |
| de_pre=(struct xiafs_direct *)(de_pre->d_rec_len+(u_char *)de_pre); |
| } |
| if (de_pre->d_rec_len+(u_char *)de_pre > (u_char *)de) { |
| printk("XIA-FS: bad directory entry (%s %d)\n", WHERE_ERR); |
| return; |
| } |
| de_pre->d_rec_len+=de->d_rec_len; |
| } |
| |
| int xiafs_rmdir(struct inode * dir, const char * name, int len) |
| { |
| int retval; |
| struct inode * inode; |
| struct buffer_head * bh; |
| struct xiafs_direct * de, * de_pre; |
| |
| inode = NULL; |
| bh = xiafs_find_entry(dir, name, len, &de, &de_pre); |
| retval = -ENOENT; |
| if (!bh) |
| goto end_rmdir; |
| retval = -EPERM; |
| if (!(inode = iget(dir->i_sb, de->d_ino))) |
| 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("XIA-FS: empty directory has nlink!=2 (%s %d)\n", WHERE_ERR); |
| xiafs_rm_entry(de, de_pre); |
| bh->b_dirt = 1; |
| inode->i_nlink=0; |
| inode->i_dirt=1; |
| dir->i_nlink--; |
| dir->i_atime = 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 xiafs_unlink(struct inode * dir, const char * name, int len) |
| { |
| int retval; |
| struct inode * inode; |
| struct buffer_head * bh; |
| struct xiafs_direct * de, * de_pre; |
| |
| repeat: |
| retval = -ENOENT; |
| inode = NULL; |
| bh = xiafs_find_entry(dir, name, len, &de, &de_pre); |
| if (!bh) |
| goto end_unlink; |
| if (!(inode = iget(dir->i_sb, de->d_ino))) |
| goto end_unlink; |
| if (de->d_ino != inode->i_ino) { |
| iput(inode); |
| brelse(bh); |
| current->counter = 0; |
| schedule(); |
| goto repeat; |
| } |
| 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("XIA-FS: Deleting nonexistent file (%s %d)\n", WHERE_ERR); |
| inode->i_nlink=1; |
| } |
| xiafs_rm_entry(de, de_pre); |
| bh->b_dirt = 1; |
| dir->i_atime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; |
| dir->i_dirt = 1; |
| inode->i_nlink--; |
| inode->i_dirt = 1; |
| retval = 0; |
| end_unlink: |
| brelse(bh); |
| iput(inode); |
| iput(dir); |
| return retval; |
| } |
| |
| int xiafs_symlink(struct inode * dir, const char * name, |
| int len, const char * symname) |
| { |
| struct xiafs_direct * de; |
| struct inode * inode = NULL; |
| struct buffer_head * bh = NULL, * name_block = NULL; |
| int i; |
| char c; |
| |
| bh = xiafs_find_entry(dir,name,len, &de, NULL); |
| if (bh) { |
| brelse(bh); |
| iput(dir); |
| return -EEXIST; |
| } |
| if (!(inode = xiafs_new_inode(dir))) { |
| iput(dir); |
| return -ENOSPC; |
| } |
| inode->i_mode = S_IFLNK | 0777; |
| inode->i_op = &xiafs_symlink_inode_operations; |
| name_block = xiafs_bread(inode,0,1); |
| if (!name_block) { |
| iput(dir); |
| inode->i_nlink--; |
| inode->i_dirt = 1; |
| iput(inode); |
| return -ENOSPC; |
| } |
| for (i = 0; i < BLOCK_SIZE-1 && (c=*symname++); i++) |
| 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 = xiafs_add_entry(dir, name, len, &de, NULL); |
| if (!bh) { |
| inode->i_nlink--; |
| inode->i_dirt = 1; |
| iput(inode); |
| iput(dir); |
| return -ENOSPC; |
| } |
| de->d_ino = inode->i_ino; |
| bh->b_dirt = 1; |
| brelse(bh); |
| iput(dir); |
| iput(inode); |
| return 0; |
| } |
| |
| int xiafs_link(struct inode * oldinode, struct inode * dir, |
| const char * name, int len) |
| { |
| struct xiafs_direct * de; |
| struct buffer_head * bh; |
| |
| if (S_ISDIR(oldinode->i_mode)) { |
| iput(oldinode); |
| iput(dir); |
| return -EPERM; |
| } |
| if (oldinode->i_nlink > 64000) { |
| iput(oldinode); |
| iput(dir); |
| return -EMLINK; |
| } |
| bh = xiafs_find_entry(dir, name, len, &de, NULL); |
| if (bh) { |
| brelse(bh); |
| iput(dir); |
| iput(oldinode); |
| return -EEXIST; |
| } |
| bh = xiafs_add_entry(dir, name, len, &de, NULL); |
| if (!bh) { |
| iput(dir); |
| iput(oldinode); |
| return -ENOSPC; |
| } |
| de->d_ino = oldinode->i_ino; |
| bh->b_dirt = 1; |
| brelse(bh); |
| iput(dir); |
| oldinode->i_nlink++; |
| oldinode->i_atime = oldinode->i_ctime = CURRENT_TIME; |
| oldinode->i_dirt = 1; |
| iput(oldinode); |
| return 0; |
| } |
| |
| static int subdir(struct inode * new_inode, struct inode * old_inode) |
| { |
| int ino; |
| int result; |
| |
| new_inode->i_count++; |
| result = 0; |
| for (;;) { |
| if (new_inode == old_inode) { |
| result = 1; |
| break; |
| } |
| if (new_inode->i_dev != old_inode->i_dev) |
| break; |
| ino = new_inode->i_ino; |
| if (xiafs_lookup(new_inode,"..",2,&new_inode)) |
| break; |
| if (new_inode->i_ino == ino) |
| break; |
| } |
| iput(new_inode); |
| return result; |
| } |
| |
| #define PARENT_INO(buffer) \ |
| (((struct xiafs_direct *) ((u_char *)(buffer) + 12))->d_ino) |
| |
| /* |
| * rename uses retry 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_xiafs_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 xiafs_direct * old_de, * old_de_pre, * new_de, * new_de_pre; |
| int retval; |
| |
| try_again: |
| old_inode = new_inode = NULL; |
| old_bh = new_bh = dir_bh = NULL; |
| old_bh = xiafs_find_entry(old_dir, old_name, old_len, &old_de, &old_de_pre); |
| retval = -ENOENT; |
| if (!old_bh) |
| goto end_rename; |
| old_inode = iget(old_dir->i_sb, old_de->d_ino); |
| if (!old_inode) |
| goto end_rename; |
| retval = -EPERM; |
| if ((old_dir->i_mode & S_ISVTX) && |
| current->euid != old_inode->i_uid && |
| current->euid != old_dir->i_uid && !suser()) |
| goto end_rename; |
| new_bh = xiafs_find_entry(new_dir, new_name, new_len, &new_de, NULL); |
| if (new_bh) { |
| new_inode = iget(new_dir->i_sb, new_de->d_ino); |
| if (!new_inode) { |
| brelse(new_bh); |
| new_bh = NULL; |
| } |
| } |
| if (new_inode == old_inode) { |
| retval = 0; |
| goto end_rename; |
| } |
| if (new_inode && S_ISDIR(new_inode->i_mode)) { |
| retval = -EEXIST; |
| goto end_rename; |
| } |
| retval = -EPERM; |
| if (new_inode && (new_dir->i_mode & S_ISVTX) && |
| current->euid != new_inode->i_uid && |
| current->euid != new_dir->i_uid && !suser()) |
| 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; |
| dir_bh = xiafs_bread(old_inode,0,0); |
| if (!dir_bh) |
| goto end_rename; |
| if (PARENT_INO(dir_bh->b_data) != old_dir->i_ino) |
| goto end_rename; |
| retval = -EMLINK; |
| if (new_dir->i_nlink > 64000) |
| goto end_rename; |
| } |
| if (!new_bh) |
| new_bh = xiafs_add_entry(new_dir, new_name, new_len, &new_de, &new_de_pre); |
| retval = -ENOSPC; |
| if (!new_bh) |
| goto end_rename; |
| /* sanity checking */ |
| if ( (new_inode && (new_de->d_ino != new_inode->i_ino)) |
| || (new_de->d_ino && !new_inode) |
| || (old_de->d_ino != old_inode->i_ino)) { |
| xiafs_rm_entry(new_de, new_de_pre); |
| brelse(old_bh); |
| brelse(new_bh); |
| brelse(dir_bh); |
| iput(old_inode); |
| iput(new_inode); |
| current->counter=0; |
| schedule(); |
| goto try_again; |
| } |
| xiafs_rm_entry(old_de, old_de_pre); |
| new_de->d_ino = old_inode->i_ino; |
| if (new_inode) { |
| new_inode->i_nlink--; |
| new_inode->i_dirt = 1; |
| } |
| 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 xiafs_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 wait_queue * wait = NULL; |
| static int lock = 0; |
| int result; |
| |
| while (lock) |
| sleep_on(&wait); |
| lock = 1; |
| result = do_xiafs_rename(old_dir, old_name, old_len, |
| new_dir, new_name, new_len); |
| lock = 0; |
| wake_up(&wait); |
| return result; |
| } |
| |
| |
| |
| |
| |