diff options
Diffstat (limited to 'fs/xiafs/namei.c')
| -rw-r--r-- | fs/xiafs/namei.c | 848 |
1 files changed, 848 insertions, 0 deletions
diff --git a/fs/xiafs/namei.c b/fs/xiafs/namei.c new file mode 100644 index 000000000..0532b1754 --- /dev/null +++ b/fs/xiafs/namei.c @@ -0,0 +1,848 @@ +/* + * 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) { + /* + * 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->d_name, name, namelen); + de->d_name[namelen]=0; + de->d_name_len=namelen; + mark_buffer_dirty(bh, 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; + mark_buffer_dirty(bh, 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->fsuid; + 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; + mark_buffer_dirty(bh, 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; + mark_buffer_dirty(dir_block, 1); + brelse(dir_block); + inode->i_mode = S_IFDIR | (mode & S_IRWXUGO & ~current->fs->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; + mark_buffer_dirty(bh, 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) && !fsuser() && + current->fsuid != inode->i_uid && + current->fsuid != dir->i_uid) + 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); + mark_buffer_dirty(bh, 1); + inode->i_nlink=0; + inode->i_dirt=1; + dir->i_nlink--; + inode->i_ctime = 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; + retval = -EPERM; + if (S_ISDIR(inode->i_mode)) + goto end_unlink; + if (de->d_ino != inode->i_ino) { + iput(inode); + brelse(bh); + current->counter = 0; + schedule(); + goto repeat; + } + if ((dir->i_mode & S_ISVTX) && !fsuser() && + current->fsuid != inode->i_uid && + current->fsuid != dir->i_uid) + 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); + mark_buffer_dirty(bh, 1); + inode->i_ctime = 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 | S_IRWXUGO; + 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; + mark_buffer_dirty(name_block, 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; + mark_buffer_dirty(bh, 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; + mark_buffer_dirty(bh, 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_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, 0); /* don't cross mnt-points */ + if (!old_inode) + goto end_rename; + retval = -EPERM; + if ((old_dir->i_mode & S_ISVTX) && + current->fsuid != old_inode->i_uid && + current->fsuid != old_dir->i_uid && !fsuser()) + 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, 0); + 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->fsuid != new_inode->i_uid && + current->fsuid != new_dir->i_uid && !fsuser()) + 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; + } + mark_buffer_dirty(old_bh, 1); + mark_buffer_dirty(new_bh, 1); + if (dir_bh) { + PARENT_INO(dir_bh->b_data) = new_dir->i_ino; + mark_buffer_dirty(dir_bh, 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; +} |