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/*
* linux/fs/ufs/ufs_dir.c
*
* Copyright (C) 1996
* Adrian Rodriguez (adrian@franklins-tower.rutgers.edu)
* Laboratory for Computer Science Research Computing Facility
* Rutgers, The State University of New Jersey
*
* swab support by Francois-Rene Rideau <fare@tunes.org> 19970406
*
* 4.4BSD (FreeBSD) support added on February 1st 1998 by
* Niels Kristian Bech Jensen <nkbj@image.dk> partially based
* on code by Martin von Loewis <martin@mira.isdn.cs.tu-berlin.de>.
*/
#include <linux/fs.h>
#include <linux/ufs_fs.h>
#include "swab.h"
#include "util.h"
#undef UFS_DIR_DEBUG
#ifdef UFS_DIR_DEBUG
#define UFSD(x) printk("(%s, %d), %s: ", __FILE__, __LINE__, __FUNCTION__); printk x;
#else
#define UFSD(x)
#endif
/*
* This is blatantly stolen from ext2fs
*/
static int
ufs_readdir (struct file * filp, void * dirent, filldir_t filldir)
{
struct inode *inode = filp->f_dentry->d_inode;
int error = 0;
unsigned long offset, lblk, blk;
int i, stored;
struct buffer_head * bh;
struct ufs_dir_entry * de;
struct super_block * sb;
int de_reclen;
unsigned flags, swab;
sb = inode->i_sb;
swab = sb->u.ufs_sb.s_swab;
flags = sb->u.ufs_sb.s_flags;
UFSD(("ENTER, ino %lu f_pos %lu\n", inode->i_ino, (unsigned long) filp->f_pos))
stored = 0;
bh = NULL;
offset = filp->f_pos & (sb->s_blocksize - 1);
while (!error && !stored && filp->f_pos < inode->i_size) {
lblk = (filp->f_pos) >> sb->s_blocksize_bits;
blk = ufs_frag_map(inode, lblk);
if (!blk || !(bh = bread (sb->s_dev, blk, sb->s_blocksize))) {
/* XXX - error - skip to the next block */
printk("ufs_readdir: "
"dir inode %lu has a hole at offset %lu\n",
inode->i_ino, (unsigned long int)filp->f_pos);
filp->f_pos += sb->s_blocksize - offset;
continue;
}
revalidate:
/* If the dir block has changed since the last call to
* readdir(2), then we might be pointing to an invalid
* dirent right now. Scan from the start of the block
* to make sure. */
if (filp->f_version != inode->i_version) {
for (i = 0; i < sb->s_blocksize && i < offset; ) {
de = (struct ufs_dir_entry *)(bh->b_data + i);
/* It's too expensive to do a full
* dirent test each time round this
* loop, but we do have to test at
* least that it is non-zero. A
* failure will be detected in the
* dirent test below. */
de_reclen = SWAB16(de->d_reclen);
if (de_reclen < 1)
break;
i += de_reclen;
}
offset = i;
filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
| offset;
filp->f_version = inode->i_version;
}
while (!error && filp->f_pos < inode->i_size
&& offset < sb->s_blocksize) {
de = (struct ufs_dir_entry *) (bh->b_data + offset);
/* XXX - put in a real ufs_check_dir_entry() */
if ((de->d_reclen == 0) || (ufs_get_de_namlen(de) == 0)) {
/* SWAB16() was unneeded -- compare to 0 */
filp->f_pos = (filp->f_pos &
(sb->s_blocksize - 1)) +
sb->s_blocksize;
brelse(bh);
return stored;
}
if (!ufs_check_dir_entry ("ufs_readdir", inode, de,
bh, offset)) {
/* On error, skip the f_pos to the
next block. */
filp->f_pos = (filp->f_pos |
(sb->s_blocksize - 1)) +
1;
brelse (bh);
return stored;
}
offset += SWAB16(de->d_reclen);
if (de->d_ino) {
/* SWAB16() was unneeded -- compare to 0 */
/* We might block in the next section
* if the data destination is
* currently swapped out. So, use a
* version stamp to detect whether or
* not the directory has been modified
* during the copy operation. */
unsigned long version = filp->f_version;
unsigned char d_type = DT_UNKNOWN;
UFSD(("filldir(%s,%u)\n", de->d_name, SWAB32(de->d_ino)))
UFSD(("namlen %u\n", ufs_get_de_namlen(de)))
if ((flags & UFS_DE_MASK) == UFS_DE_44BSD)
d_type = de->d_u.d_44.d_type;
error = filldir(dirent, de->d_name, ufs_get_de_namlen(de),
filp->f_pos, SWAB32(de->d_ino), d_type);
if (error)
break;
if (version != filp->f_version)
goto revalidate;
stored ++;
}
filp->f_pos += SWAB16(de->d_reclen);
}
offset = 0;
brelse (bh);
}
UPDATE_ATIME(inode);
return 0;
}
int ufs_check_dir_entry (const char * function, struct inode * dir,
struct ufs_dir_entry * de, struct buffer_head * bh,
unsigned long offset)
{
struct super_block * sb;
const char * error_msg;
unsigned flags, swab;
sb = dir->i_sb;
flags = sb->u.ufs_sb.s_flags;
swab = sb->u.ufs_sb.s_swab;
error_msg = NULL;
if (SWAB16(de->d_reclen) < UFS_DIR_REC_LEN(1))
error_msg = "reclen is smaller than minimal";
else if (SWAB16(de->d_reclen) % 4 != 0)
error_msg = "reclen % 4 != 0";
else if (SWAB16(de->d_reclen) < UFS_DIR_REC_LEN(ufs_get_de_namlen(de)))
error_msg = "reclen is too small for namlen";
else if (dir && ((char *) de - bh->b_data) + SWAB16(de->d_reclen) >
dir->i_sb->s_blocksize)
error_msg = "directory entry across blocks";
else if (dir && SWAB32(de->d_ino) > (sb->u.ufs_sb.s_uspi->s_ipg * sb->u.ufs_sb.s_uspi->s_ncg))
error_msg = "inode out of bounds";
if (error_msg != NULL)
ufs_error (sb, function, "bad entry in directory #%lu, size %Lu: %s - "
"offset=%lu, inode=%lu, reclen=%d, namlen=%d",
dir->i_ino, dir->i_size, error_msg, offset,
(unsigned long) SWAB32(de->d_ino),
SWAB16(de->d_reclen), ufs_get_de_namlen(de));
return (error_msg == NULL ? 1 : 0);
}
struct file_operations ufs_dir_operations = {
read: generic_read_dir,
readdir: ufs_readdir,
fsync: file_fsync,
};
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