diff options
Diffstat (limited to 'fs/qnx4/namei.c')
| -rw-r--r-- | fs/qnx4/namei.c | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/fs/qnx4/namei.c b/fs/qnx4/namei.c new file mode 100644 index 0000000..4af4951 --- /dev/null +++ b/fs/qnx4/namei.c @@ -0,0 +1,249 @@ +/* + * QNX4 file system, Linux implementation. + * + * Version : 0.2.1 + * + * Using parts of the xiafs filesystem. + * + * History : + * + * 01-06-1998 by Richard Frowijn : first release. + * 21-06-1998 by Frank Denis : dcache support, fixed error codes. + * 04-07-1998 by Frank Denis : first step for rmdir/unlink. + */ + +#include <linux/config.h> +#include <linux/time.h> +#include <linux/fs.h> +#include <linux/qnx4_fs.h> +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/stat.h> +#include <linux/fcntl.h> +#include <linux/errno.h> +#include <linux/smp_lock.h> +#include <linux/buffer_head.h> + + +/* + * check if the filename is correct. For some obscure reason, qnx writes a + * new file twice in the directory entry, first with all possible options at 0 + * and for a second time the way it is, they want us not to access the qnx + * filesystem when whe are using linux. + */ +static int qnx4_match(int len, const char *name, + struct buffer_head *bh, unsigned long *offset) +{ + struct qnx4_inode_entry *de; + int namelen, thislen; + + if (bh == NULL) { + printk("qnx4: matching unassigned buffer !\n"); + return 0; + } + de = (struct qnx4_inode_entry *) (bh->b_data + *offset); + *offset += QNX4_DIR_ENTRY_SIZE; + if ((de->di_status & QNX4_FILE_LINK) != 0) { + namelen = QNX4_NAME_MAX; + } else { + namelen = QNX4_SHORT_NAME_MAX; + } + /* "" means "." ---> so paths like "/usr/lib//libc.a" work */ + if (!len && (de->di_fname[0] == '.') && (de->di_fname[1] == '\0')) { + return 1; + } + thislen = strlen( de->di_fname ); + if ( thislen > namelen ) + thislen = namelen; + if (len != thislen) { + return 0; + } + if (strncmp(name, de->di_fname, len) == 0) { + if ((de->di_status & (QNX4_FILE_USED|QNX4_FILE_LINK)) != 0) { + return 1; + } + } + return 0; +} + +static struct buffer_head *qnx4_find_entry(int len, struct inode *dir, + const char *name, struct qnx4_inode_entry **res_dir, int *ino) +{ + unsigned long block, offset, blkofs; + struct buffer_head *bh; + + *res_dir = NULL; + if (!dir->i_sb) { + printk("qnx4: no superblock on dir.\n"); + return NULL; + } + bh = NULL; + block = offset = blkofs = 0; + while (blkofs * QNX4_BLOCK_SIZE + offset < dir->i_size) { + if (!bh) { + bh = qnx4_bread(dir, blkofs, 0); + if (!bh) { + blkofs++; + continue; + } + } + *res_dir = (struct qnx4_inode_entry *) (bh->b_data + offset); + if (qnx4_match(len, name, bh, &offset)) { + block = qnx4_block_map( dir, blkofs ); + *ino = block * QNX4_INODES_PER_BLOCK + + (offset / QNX4_DIR_ENTRY_SIZE) - 1; + return bh; + } + if (offset < bh->b_size) { + continue; + } + brelse(bh); + bh = NULL; + offset = 0; + blkofs++; + } + brelse(bh); + *res_dir = NULL; + return NULL; +} + +struct dentry * qnx4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) +{ + int ino; + struct qnx4_inode_entry *de; + struct qnx4_link_info *lnk; + struct buffer_head *bh; + const char *name = dentry->d_name.name; + int len = dentry->d_name.len; + struct inode *foundinode = NULL; + + lock_kernel(); + if (!(bh = qnx4_find_entry(len, dir, name, &de, &ino))) + goto out; + /* The entry is linked, let's get the real info */ + if ((de->di_status & QNX4_FILE_LINK) == QNX4_FILE_LINK) { + lnk = (struct qnx4_link_info *) de; + ino = (le32_to_cpu(lnk->dl_inode_blk) - 1) * + QNX4_INODES_PER_BLOCK + + lnk->dl_inode_ndx; + } + brelse(bh); + + if ((foundinode = iget(dir->i_sb, ino)) == NULL) { + unlock_kernel(); + QNX4DEBUG(("qnx4: lookup->iget -> NULL\n")); + return ERR_PTR(-EACCES); + } +out: + unlock_kernel(); + d_add(dentry, foundinode); + + return NULL; +} + +#ifdef CONFIG_QNX4FS_RW +int qnx4_create(struct inode *dir, struct dentry *dentry, int mode, + struct nameidata *nd) +{ + QNX4DEBUG(("qnx4: qnx4_create\n")); + if (dir == NULL) { + return -ENOENT; + } + return -ENOSPC; +} + +int qnx4_rmdir(struct inode *dir, struct dentry *dentry) +{ + struct buffer_head *bh; + struct qnx4_inode_entry *de; + struct inode *inode; + int retval; + int ino; + + QNX4DEBUG(("qnx4: qnx4_rmdir [%s]\n", dentry->d_name.name)); + lock_kernel(); + bh = qnx4_find_entry(dentry->d_name.len, dir, dentry->d_name.name, + &de, &ino); + if (bh == NULL) { + unlock_kernel(); + return -ENOENT; + } + inode = dentry->d_inode; + if (inode->i_ino != ino) { + retval = -EIO; + goto end_rmdir; + } +#if 0 + if (!empty_dir(inode)) { + retval = -ENOTEMPTY; + goto end_rmdir; + } +#endif + if (inode->i_nlink != 2) { + QNX4DEBUG(("empty directory has nlink!=2 (%d)\n", inode->i_nlink)); + } + QNX4DEBUG(("qnx4: deleting directory\n")); + de->di_status = 0; + memset(de->di_fname, 0, sizeof de->di_fname); + de->di_mode = 0; + mark_buffer_dirty(bh); + inode->i_nlink = 0; + mark_inode_dirty(inode); + inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC; + dir->i_nlink--; + mark_inode_dirty(dir); + retval = 0; + + end_rmdir: + brelse(bh); + + unlock_kernel(); + return retval; +} + +int qnx4_unlink(struct inode *dir, struct dentry *dentry) +{ + struct buffer_head *bh; + struct qnx4_inode_entry *de; + struct inode *inode; + int retval; + int ino; + + QNX4DEBUG(("qnx4: qnx4_unlink [%s]\n", dentry->d_name.name)); + lock_kernel(); + bh = qnx4_find_entry(dentry->d_name.len, dir, dentry->d_name.name, + &de, &ino); + if (bh == NULL) { + unlock_kernel(); + return -ENOENT; + } + inode = dentry->d_inode; + if (inode->i_ino != ino) { + retval = -EIO; + goto end_unlink; + } + retval = -EPERM; + if (!inode->i_nlink) { + QNX4DEBUG(("Deleting nonexistent file (%s:%lu), %d\n", + inode->i_sb->s_id, + inode->i_ino, inode->i_nlink)); + inode->i_nlink = 1; + } + de->di_status = 0; + memset(de->di_fname, 0, sizeof de->di_fname); + de->di_mode = 0; + mark_buffer_dirty(bh); + dir->i_ctime = dir->i_mtime = CURRENT_TIME_SEC; + mark_inode_dirty(dir); + inode->i_nlink--; + inode->i_ctime = dir->i_ctime; + mark_inode_dirty(inode); + retval = 0; + +end_unlink: + unlock_kernel(); + brelse(bh); + + return retval; +} +#endif |