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![Linus Torvalds](/assets/img/avatar_default.png)
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
627 lines
17 KiB
C
627 lines
17 KiB
C
/*
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* linux/fs/ufs/ufs_dir.c
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*
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* Copyright (C) 1996
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* Adrian Rodriguez (adrian@franklins-tower.rutgers.edu)
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* Laboratory for Computer Science Research Computing Facility
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* Rutgers, The State University of New Jersey
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*
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* swab support by Francois-Rene Rideau <fare@tunes.org> 19970406
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*
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* 4.4BSD (FreeBSD) support added on February 1st 1998 by
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* Niels Kristian Bech Jensen <nkbj@image.dk> partially based
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* on code by Martin von Loewis <martin@mira.isdn.cs.tu-berlin.de>.
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*/
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#include <linux/time.h>
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#include <linux/fs.h>
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#include <linux/ufs_fs.h>
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#include <linux/smp_lock.h>
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#include <linux/buffer_head.h>
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#include <linux/sched.h>
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#include "swab.h"
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#include "util.h"
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#undef UFS_DIR_DEBUG
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#ifdef UFS_DIR_DEBUG
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#define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x;
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#else
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#define UFSD(x)
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#endif
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static int
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ufs_check_dir_entry (const char *, struct inode *, struct ufs_dir_entry *,
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struct buffer_head *, unsigned long);
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/*
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* NOTE! unlike strncmp, ufs_match returns 1 for success, 0 for failure.
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*
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* len <= UFS_MAXNAMLEN and de != NULL are guaranteed by caller.
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*/
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static inline int ufs_match(struct super_block *sb, int len,
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const char * const name, struct ufs_dir_entry * de)
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{
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if (len != ufs_get_de_namlen(sb, de))
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return 0;
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if (!de->d_ino)
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return 0;
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return !memcmp(name, de->d_name, len);
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}
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/*
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* This is blatantly stolen from ext2fs
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*/
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static int
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ufs_readdir (struct file * filp, void * dirent, filldir_t filldir)
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{
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struct inode *inode = filp->f_dentry->d_inode;
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int error = 0;
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unsigned long offset, lblk;
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int i, stored;
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struct buffer_head * bh;
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struct ufs_dir_entry * de;
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struct super_block * sb;
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int de_reclen;
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unsigned flags;
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u64 blk= 0L;
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lock_kernel();
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sb = inode->i_sb;
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flags = UFS_SB(sb)->s_flags;
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UFSD(("ENTER, ino %lu f_pos %lu\n", inode->i_ino, (unsigned long) filp->f_pos))
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stored = 0;
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bh = NULL;
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offset = filp->f_pos & (sb->s_blocksize - 1);
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while (!error && !stored && filp->f_pos < inode->i_size) {
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lblk = (filp->f_pos) >> sb->s_blocksize_bits;
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blk = ufs_frag_map(inode, lblk);
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if (!blk || !(bh = sb_bread(sb, blk))) {
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/* XXX - error - skip to the next block */
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printk("ufs_readdir: "
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"dir inode %lu has a hole at offset %lu\n",
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inode->i_ino, (unsigned long int)filp->f_pos);
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filp->f_pos += sb->s_blocksize - offset;
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continue;
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}
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revalidate:
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/* If the dir block has changed since the last call to
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* readdir(2), then we might be pointing to an invalid
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* dirent right now. Scan from the start of the block
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* to make sure. */
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if (filp->f_version != inode->i_version) {
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for (i = 0; i < sb->s_blocksize && i < offset; ) {
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de = (struct ufs_dir_entry *)(bh->b_data + i);
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/* It's too expensive to do a full
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* dirent test each time round this
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* loop, but we do have to test at
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* least that it is non-zero. A
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* failure will be detected in the
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* dirent test below. */
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de_reclen = fs16_to_cpu(sb, de->d_reclen);
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if (de_reclen < 1)
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break;
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i += de_reclen;
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}
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offset = i;
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filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
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| offset;
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filp->f_version = inode->i_version;
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}
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while (!error && filp->f_pos < inode->i_size
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&& offset < sb->s_blocksize) {
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de = (struct ufs_dir_entry *) (bh->b_data + offset);
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/* XXX - put in a real ufs_check_dir_entry() */
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if ((de->d_reclen == 0) || (ufs_get_de_namlen(sb, de) == 0)) {
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filp->f_pos = (filp->f_pos &
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(sb->s_blocksize - 1)) +
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sb->s_blocksize;
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brelse(bh);
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unlock_kernel();
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return stored;
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}
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if (!ufs_check_dir_entry ("ufs_readdir", inode, de,
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bh, offset)) {
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/* On error, skip the f_pos to the
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next block. */
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filp->f_pos = (filp->f_pos |
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(sb->s_blocksize - 1)) +
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1;
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brelse (bh);
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unlock_kernel();
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return stored;
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}
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offset += fs16_to_cpu(sb, de->d_reclen);
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if (de->d_ino) {
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/* We might block in the next section
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* if the data destination is
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* currently swapped out. So, use a
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* version stamp to detect whether or
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* not the directory has been modified
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* during the copy operation. */
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unsigned long version = filp->f_version;
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unsigned char d_type = DT_UNKNOWN;
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UFSD(("filldir(%s,%u)\n", de->d_name,
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fs32_to_cpu(sb, de->d_ino)))
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UFSD(("namlen %u\n", ufs_get_de_namlen(sb, de)))
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if ((flags & UFS_DE_MASK) == UFS_DE_44BSD)
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d_type = de->d_u.d_44.d_type;
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error = filldir(dirent, de->d_name,
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ufs_get_de_namlen(sb, de), filp->f_pos,
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fs32_to_cpu(sb, de->d_ino), d_type);
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if (error)
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break;
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if (version != filp->f_version)
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goto revalidate;
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stored ++;
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}
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filp->f_pos += fs16_to_cpu(sb, de->d_reclen);
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}
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offset = 0;
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brelse (bh);
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}
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unlock_kernel();
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return 0;
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}
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/*
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* define how far ahead to read directories while searching them.
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*/
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#define NAMEI_RA_CHUNKS 2
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#define NAMEI_RA_BLOCKS 4
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#define NAMEI_RA_SIZE (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
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#define NAMEI_RA_INDEX(c,b) (((c) * NAMEI_RA_BLOCKS) + (b))
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/*
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* ufs_find_entry()
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*
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* finds an entry in the specified directory with the wanted name. It
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* returns the cache buffer in which the entry was found, and the entry
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* itself (as a parameter - res_bh). It does NOT read the inode of the
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* entry - you'll have to do that yourself if you want to.
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*/
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struct ufs_dir_entry * ufs_find_entry (struct dentry *dentry,
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struct buffer_head ** res_bh)
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{
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struct super_block * sb;
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struct buffer_head * bh_use[NAMEI_RA_SIZE];
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struct buffer_head * bh_read[NAMEI_RA_SIZE];
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unsigned long offset;
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int block, toread, i, err;
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struct inode *dir = dentry->d_parent->d_inode;
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const char *name = dentry->d_name.name;
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int namelen = dentry->d_name.len;
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UFSD(("ENTER, dir_ino %lu, name %s, namlen %u\n", dir->i_ino, name, namelen))
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*res_bh = NULL;
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sb = dir->i_sb;
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if (namelen > UFS_MAXNAMLEN)
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return NULL;
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memset (bh_use, 0, sizeof (bh_use));
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toread = 0;
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for (block = 0; block < NAMEI_RA_SIZE; ++block) {
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struct buffer_head * bh;
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if ((block << sb->s_blocksize_bits) >= dir->i_size)
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break;
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bh = ufs_getfrag (dir, block, 0, &err);
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bh_use[block] = bh;
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if (bh && !buffer_uptodate(bh))
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bh_read[toread++] = bh;
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}
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for (block = 0, offset = 0; offset < dir->i_size; block++) {
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struct buffer_head * bh;
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struct ufs_dir_entry * de;
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char * dlimit;
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if ((block % NAMEI_RA_BLOCKS) == 0 && toread) {
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ll_rw_block (READ, toread, bh_read);
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toread = 0;
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}
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bh = bh_use[block % NAMEI_RA_SIZE];
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if (!bh) {
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ufs_error (sb, "ufs_find_entry",
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"directory #%lu contains a hole at offset %lu",
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dir->i_ino, offset);
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offset += sb->s_blocksize;
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continue;
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}
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wait_on_buffer (bh);
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if (!buffer_uptodate(bh)) {
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/*
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* read error: all bets are off
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*/
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break;
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}
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de = (struct ufs_dir_entry *) bh->b_data;
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dlimit = bh->b_data + sb->s_blocksize;
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while ((char *) de < dlimit && offset < dir->i_size) {
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/* this code is executed quadratically often */
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/* do minimal checking by hand */
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int de_len;
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if ((char *) de + namelen <= dlimit &&
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ufs_match(sb, namelen, name, de)) {
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/* found a match -
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just to be sure, do a full check */
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if (!ufs_check_dir_entry("ufs_find_entry",
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dir, de, bh, offset))
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goto failed;
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for (i = 0; i < NAMEI_RA_SIZE; ++i) {
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if (bh_use[i] != bh)
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brelse (bh_use[i]);
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}
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*res_bh = bh;
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return de;
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}
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/* prevent looping on a bad block */
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de_len = fs16_to_cpu(sb, de->d_reclen);
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if (de_len <= 0)
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goto failed;
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offset += de_len;
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de = (struct ufs_dir_entry *) ((char *) de + de_len);
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}
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brelse (bh);
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if (((block + NAMEI_RA_SIZE) << sb->s_blocksize_bits ) >=
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dir->i_size)
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bh = NULL;
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else
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bh = ufs_getfrag (dir, block + NAMEI_RA_SIZE, 0, &err);
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bh_use[block % NAMEI_RA_SIZE] = bh;
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if (bh && !buffer_uptodate(bh))
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bh_read[toread++] = bh;
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}
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failed:
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for (i = 0; i < NAMEI_RA_SIZE; ++i) brelse (bh_use[i]);
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UFSD(("EXIT\n"))
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return NULL;
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}
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static int
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ufs_check_dir_entry (const char *function, struct inode *dir,
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struct ufs_dir_entry *de, struct buffer_head *bh,
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unsigned long offset)
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{
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struct super_block *sb = dir->i_sb;
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const char *error_msg = NULL;
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int rlen = fs16_to_cpu(sb, de->d_reclen);
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if (rlen < UFS_DIR_REC_LEN(1))
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error_msg = "reclen is smaller than minimal";
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else if (rlen % 4 != 0)
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error_msg = "reclen % 4 != 0";
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else if (rlen < UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)))
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error_msg = "reclen is too small for namlen";
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else if (((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize)
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error_msg = "directory entry across blocks";
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else if (fs32_to_cpu(sb, de->d_ino) > (UFS_SB(sb)->s_uspi->s_ipg *
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UFS_SB(sb)->s_uspi->s_ncg))
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error_msg = "inode out of bounds";
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if (error_msg != NULL)
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ufs_error (sb, function, "bad entry in directory #%lu, size %Lu: %s - "
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"offset=%lu, inode=%lu, reclen=%d, namlen=%d",
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dir->i_ino, dir->i_size, error_msg, offset,
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(unsigned long)fs32_to_cpu(sb, de->d_ino),
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rlen, ufs_get_de_namlen(sb, de));
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return (error_msg == NULL ? 1 : 0);
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}
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struct ufs_dir_entry *ufs_dotdot(struct inode *dir, struct buffer_head **p)
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{
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int err;
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struct buffer_head *bh = ufs_bread (dir, 0, 0, &err);
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struct ufs_dir_entry *res = NULL;
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if (bh) {
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res = (struct ufs_dir_entry *) bh->b_data;
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res = (struct ufs_dir_entry *)((char *)res +
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fs16_to_cpu(dir->i_sb, res->d_reclen));
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}
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*p = bh;
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return res;
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}
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ino_t ufs_inode_by_name(struct inode * dir, struct dentry *dentry)
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{
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ino_t res = 0;
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struct ufs_dir_entry * de;
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struct buffer_head *bh;
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de = ufs_find_entry (dentry, &bh);
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if (de) {
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res = fs32_to_cpu(dir->i_sb, de->d_ino);
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brelse(bh);
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}
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return res;
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}
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void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
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struct buffer_head *bh, struct inode *inode)
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{
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dir->i_version++;
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de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino);
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mark_buffer_dirty(bh);
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if (IS_DIRSYNC(dir))
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sync_dirty_buffer(bh);
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brelse (bh);
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}
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/*
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* ufs_add_entry()
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*
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* adds a file entry to the specified directory, using the same
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* semantics as ufs_find_entry(). It returns NULL if it failed.
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*/
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int ufs_add_link(struct dentry *dentry, struct inode *inode)
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{
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struct super_block * sb;
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struct ufs_sb_private_info * uspi;
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unsigned long offset;
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unsigned fragoff;
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unsigned short rec_len;
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struct buffer_head * bh;
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struct ufs_dir_entry * de, * de1;
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struct inode *dir = dentry->d_parent->d_inode;
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const char *name = dentry->d_name.name;
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int namelen = dentry->d_name.len;
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int err;
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UFSD(("ENTER, name %s, namelen %u\n", name, namelen))
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sb = dir->i_sb;
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uspi = UFS_SB(sb)->s_uspi;
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if (!namelen)
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return -EINVAL;
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bh = ufs_bread (dir, 0, 0, &err);
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if (!bh)
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return err;
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rec_len = UFS_DIR_REC_LEN(namelen);
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offset = 0;
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de = (struct ufs_dir_entry *) bh->b_data;
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while (1) {
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if ((char *)de >= UFS_SECTOR_SIZE + bh->b_data) {
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fragoff = offset & ~uspi->s_fmask;
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if (fragoff != 0 && fragoff != UFS_SECTOR_SIZE)
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ufs_error (sb, "ufs_add_entry", "internal error"
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" fragoff %u", fragoff);
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if (!fragoff) {
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brelse (bh);
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bh = ufs_bread (dir, offset >> sb->s_blocksize_bits, 1, &err);
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if (!bh)
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return err;
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}
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if (dir->i_size <= offset) {
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if (dir->i_size == 0) {
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brelse(bh);
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return -ENOENT;
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}
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de = (struct ufs_dir_entry *) (bh->b_data + fragoff);
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de->d_ino = 0;
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de->d_reclen = cpu_to_fs16(sb, UFS_SECTOR_SIZE);
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ufs_set_de_namlen(sb, de, 0);
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dir->i_size = offset + UFS_SECTOR_SIZE;
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mark_inode_dirty(dir);
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} else {
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de = (struct ufs_dir_entry *) bh->b_data;
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}
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}
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if (!ufs_check_dir_entry ("ufs_add_entry", dir, de, bh, offset)) {
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brelse (bh);
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return -ENOENT;
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}
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if (ufs_match(sb, namelen, name, de)) {
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brelse (bh);
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return -EEXIST;
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}
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if (de->d_ino == 0 && fs16_to_cpu(sb, de->d_reclen) >= rec_len)
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break;
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if (fs16_to_cpu(sb, de->d_reclen) >=
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UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)) + rec_len)
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break;
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offset += fs16_to_cpu(sb, de->d_reclen);
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de = (struct ufs_dir_entry *) ((char *) de + fs16_to_cpu(sb, de->d_reclen));
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}
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if (de->d_ino) {
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de1 = (struct ufs_dir_entry *) ((char *) de +
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UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)));
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de1->d_reclen =
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cpu_to_fs16(sb, fs16_to_cpu(sb, de->d_reclen) -
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UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)));
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de->d_reclen =
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cpu_to_fs16(sb, UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de)));
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de = de1;
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}
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de->d_ino = 0;
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ufs_set_de_namlen(sb, de, namelen);
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memcpy (de->d_name, name, namelen + 1);
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de->d_ino = cpu_to_fs32(sb, inode->i_ino);
|
|
ufs_set_de_type(sb, de, inode->i_mode);
|
|
mark_buffer_dirty(bh);
|
|
if (IS_DIRSYNC(dir))
|
|
sync_dirty_buffer(bh);
|
|
brelse (bh);
|
|
dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
|
|
dir->i_version++;
|
|
mark_inode_dirty(dir);
|
|
|
|
UFSD(("EXIT\n"))
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* ufs_delete_entry deletes a directory entry by merging it with the
|
|
* previous entry.
|
|
*/
|
|
int ufs_delete_entry (struct inode * inode, struct ufs_dir_entry * dir,
|
|
struct buffer_head * bh )
|
|
|
|
{
|
|
struct super_block * sb;
|
|
struct ufs_dir_entry * de, * pde;
|
|
unsigned i;
|
|
|
|
UFSD(("ENTER\n"))
|
|
|
|
sb = inode->i_sb;
|
|
i = 0;
|
|
pde = NULL;
|
|
de = (struct ufs_dir_entry *) bh->b_data;
|
|
|
|
UFSD(("ino %u, reclen %u, namlen %u, name %s\n",
|
|
fs32_to_cpu(sb, de->d_ino),
|
|
fs16to_cpu(sb, de->d_reclen),
|
|
ufs_get_de_namlen(sb, de), de->d_name))
|
|
|
|
while (i < bh->b_size) {
|
|
if (!ufs_check_dir_entry ("ufs_delete_entry", inode, de, bh, i)) {
|
|
brelse(bh);
|
|
return -EIO;
|
|
}
|
|
if (de == dir) {
|
|
if (pde)
|
|
fs16_add(sb, &pde->d_reclen,
|
|
fs16_to_cpu(sb, dir->d_reclen));
|
|
dir->d_ino = 0;
|
|
inode->i_version++;
|
|
inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
|
|
mark_inode_dirty(inode);
|
|
mark_buffer_dirty(bh);
|
|
if (IS_DIRSYNC(inode))
|
|
sync_dirty_buffer(bh);
|
|
brelse(bh);
|
|
UFSD(("EXIT\n"))
|
|
return 0;
|
|
}
|
|
i += fs16_to_cpu(sb, de->d_reclen);
|
|
if (i == UFS_SECTOR_SIZE) pde = NULL;
|
|
else pde = de;
|
|
de = (struct ufs_dir_entry *)
|
|
((char *) de + fs16_to_cpu(sb, de->d_reclen));
|
|
if (i == UFS_SECTOR_SIZE && de->d_reclen == 0)
|
|
break;
|
|
}
|
|
UFSD(("EXIT\n"))
|
|
brelse(bh);
|
|
return -ENOENT;
|
|
}
|
|
|
|
int ufs_make_empty(struct inode * inode, struct inode *dir)
|
|
{
|
|
struct super_block * sb = dir->i_sb;
|
|
struct buffer_head * dir_block;
|
|
struct ufs_dir_entry * de;
|
|
int err;
|
|
|
|
dir_block = ufs_bread (inode, 0, 1, &err);
|
|
if (!dir_block)
|
|
return err;
|
|
|
|
inode->i_blocks = sb->s_blocksize / UFS_SECTOR_SIZE;
|
|
de = (struct ufs_dir_entry *) dir_block->b_data;
|
|
de->d_ino = cpu_to_fs32(sb, inode->i_ino);
|
|
ufs_set_de_type(sb, de, inode->i_mode);
|
|
ufs_set_de_namlen(sb, de, 1);
|
|
de->d_reclen = cpu_to_fs16(sb, UFS_DIR_REC_LEN(1));
|
|
strcpy (de->d_name, ".");
|
|
de = (struct ufs_dir_entry *)
|
|
((char *)de + fs16_to_cpu(sb, de->d_reclen));
|
|
de->d_ino = cpu_to_fs32(sb, dir->i_ino);
|
|
ufs_set_de_type(sb, de, dir->i_mode);
|
|
de->d_reclen = cpu_to_fs16(sb, UFS_SECTOR_SIZE - UFS_DIR_REC_LEN(1));
|
|
ufs_set_de_namlen(sb, de, 2);
|
|
strcpy (de->d_name, "..");
|
|
mark_buffer_dirty(dir_block);
|
|
brelse (dir_block);
|
|
mark_inode_dirty(inode);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* routine to check that the specified directory is empty (for rmdir)
|
|
*/
|
|
int ufs_empty_dir (struct inode * inode)
|
|
{
|
|
struct super_block * sb;
|
|
unsigned long offset;
|
|
struct buffer_head * bh;
|
|
struct ufs_dir_entry * de, * de1;
|
|
int err;
|
|
|
|
sb = inode->i_sb;
|
|
|
|
if (inode->i_size < UFS_DIR_REC_LEN(1) + UFS_DIR_REC_LEN(2) ||
|
|
!(bh = ufs_bread (inode, 0, 0, &err))) {
|
|
ufs_warning (inode->i_sb, "empty_dir",
|
|
"bad directory (dir #%lu) - no data block",
|
|
inode->i_ino);
|
|
return 1;
|
|
}
|
|
de = (struct ufs_dir_entry *) bh->b_data;
|
|
de1 = (struct ufs_dir_entry *)
|
|
((char *)de + fs16_to_cpu(sb, de->d_reclen));
|
|
if (fs32_to_cpu(sb, de->d_ino) != inode->i_ino || de1->d_ino == 0 ||
|
|
strcmp (".", de->d_name) || strcmp ("..", de1->d_name)) {
|
|
ufs_warning (inode->i_sb, "empty_dir",
|
|
"bad directory (dir #%lu) - no `.' or `..'",
|
|
inode->i_ino);
|
|
return 1;
|
|
}
|
|
offset = fs16_to_cpu(sb, de->d_reclen) + fs16_to_cpu(sb, de1->d_reclen);
|
|
de = (struct ufs_dir_entry *)
|
|
((char *)de1 + fs16_to_cpu(sb, de1->d_reclen));
|
|
while (offset < inode->i_size ) {
|
|
if (!bh || (void *) de >= (void *) (bh->b_data + sb->s_blocksize)) {
|
|
brelse (bh);
|
|
bh = ufs_bread (inode, offset >> sb->s_blocksize_bits, 1, &err);
|
|
if (!bh) {
|
|
ufs_error (sb, "empty_dir",
|
|
"directory #%lu contains a hole at offset %lu",
|
|
inode->i_ino, offset);
|
|
offset += sb->s_blocksize;
|
|
continue;
|
|
}
|
|
de = (struct ufs_dir_entry *) bh->b_data;
|
|
}
|
|
if (!ufs_check_dir_entry ("empty_dir", inode, de, bh, offset)) {
|
|
brelse (bh);
|
|
return 1;
|
|
}
|
|
if (de->d_ino) {
|
|
brelse (bh);
|
|
return 0;
|
|
}
|
|
offset += fs16_to_cpu(sb, de->d_reclen);
|
|
de = (struct ufs_dir_entry *)
|
|
((char *)de + fs16_to_cpu(sb, de->d_reclen));
|
|
}
|
|
brelse (bh);
|
|
return 1;
|
|
}
|
|
|
|
struct file_operations ufs_dir_operations = {
|
|
.read = generic_read_dir,
|
|
.readdir = ufs_readdir,
|
|
.fsync = file_fsync,
|
|
};
|