linux/fs/ufs/dir.c
Evgeniy Dushistov f336953bfd [PATCH] ufs: restore back support of openstep
This is a fix of regression, which triggered by ~2.6.16.

Patch with name ufs-directory-and-page-cache-from-blocks-to-pages.patch: in
additional to conversation from block to page cache mechanism added new
checks of directory integrity, one of them that directory entry do not
across directory chunks.

But some kinds of UFS: OpenStep UFS and Apple UFS (looks like these are the
same filesystems) have different directory chunk size, then common
UFSes(BSD and Solaris UFS).

So this patch adds ability to works with variable size of directory chunks,
and set it for ufstype=openstep to right size.

Tested on darwin ufs.

Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-09 09:25:46 -08:00

658 lines
16 KiB
C

/*
* 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>.
*
* Migration to usage of "page cache" on May 2006 by
* Evgeniy Dushistov <dushistov@mail.ru> based on ext2 code base.
*/
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/ufs_fs.h>
#include <linux/smp_lock.h>
#include <linux/sched.h>
#include "swab.h"
#include "util.h"
/*
* NOTE! unlike strncmp, ufs_match returns 1 for success, 0 for failure.
*
* len <= UFS_MAXNAMLEN and de != NULL are guaranteed by caller.
*/
static inline int ufs_match(struct super_block *sb, int len,
const char * const name, struct ufs_dir_entry * de)
{
if (len != ufs_get_de_namlen(sb, de))
return 0;
if (!de->d_ino)
return 0;
return !memcmp(name, de->d_name, len);
}
static int ufs_commit_chunk(struct page *page, unsigned from, unsigned to)
{
struct inode *dir = page->mapping->host;
int err = 0;
dir->i_version++;
page->mapping->a_ops->commit_write(NULL, page, from, to);
if (IS_DIRSYNC(dir))
err = write_one_page(page, 1);
else
unlock_page(page);
return err;
}
static inline void ufs_put_page(struct page *page)
{
kunmap(page);
page_cache_release(page);
}
static inline unsigned long ufs_dir_pages(struct inode *inode)
{
return (inode->i_size+PAGE_CACHE_SIZE-1)>>PAGE_CACHE_SHIFT;
}
ino_t ufs_inode_by_name(struct inode *dir, struct dentry *dentry)
{
ino_t res = 0;
struct ufs_dir_entry *de;
struct page *page;
de = ufs_find_entry(dir, dentry, &page);
if (de) {
res = fs32_to_cpu(dir->i_sb, de->d_ino);
ufs_put_page(page);
}
return res;
}
/* Releases the page */
void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de,
struct page *page, struct inode *inode)
{
unsigned from = (char *) de - (char *) page_address(page);
unsigned to = from + fs16_to_cpu(dir->i_sb, de->d_reclen);
int err;
lock_page(page);
err = page->mapping->a_ops->prepare_write(NULL, page, from, to);
BUG_ON(err);
de->d_ino = cpu_to_fs32(dir->i_sb, inode->i_ino);
ufs_set_de_type(dir->i_sb, de, inode->i_mode);
err = ufs_commit_chunk(page, from, to);
ufs_put_page(page);
dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(dir);
}
static void ufs_check_page(struct page *page)
{
struct inode *dir = page->mapping->host;
struct super_block *sb = dir->i_sb;
char *kaddr = page_address(page);
unsigned offs, rec_len;
unsigned limit = PAGE_CACHE_SIZE;
const unsigned chunk_mask = UFS_SB(sb)->s_uspi->s_dirblksize - 1;
struct ufs_dir_entry *p;
char *error;
if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) {
limit = dir->i_size & ~PAGE_CACHE_MASK;
if (limit & chunk_mask)
goto Ebadsize;
if (!limit)
goto out;
}
for (offs = 0; offs <= limit - UFS_DIR_REC_LEN(1); offs += rec_len) {
p = (struct ufs_dir_entry *)(kaddr + offs);
rec_len = fs16_to_cpu(sb, p->d_reclen);
if (rec_len < UFS_DIR_REC_LEN(1))
goto Eshort;
if (rec_len & 3)
goto Ealign;
if (rec_len < UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, p)))
goto Enamelen;
if (((offs + rec_len - 1) ^ offs) & ~chunk_mask)
goto Espan;
if (fs32_to_cpu(sb, p->d_ino) > (UFS_SB(sb)->s_uspi->s_ipg *
UFS_SB(sb)->s_uspi->s_ncg))
goto Einumber;
}
if (offs != limit)
goto Eend;
out:
SetPageChecked(page);
return;
/* Too bad, we had an error */
Ebadsize:
ufs_error(sb, "ufs_check_page",
"size of directory #%lu is not a multiple of chunk size",
dir->i_ino
);
goto fail;
Eshort:
error = "rec_len is smaller than minimal";
goto bad_entry;
Ealign:
error = "unaligned directory entry";
goto bad_entry;
Enamelen:
error = "rec_len is too small for name_len";
goto bad_entry;
Espan:
error = "directory entry across blocks";
goto bad_entry;
Einumber:
error = "inode out of bounds";
bad_entry:
ufs_error (sb, "ufs_check_page", "bad entry in directory #%lu: %s - "
"offset=%lu, rec_len=%d, name_len=%d",
dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
rec_len, ufs_get_de_namlen(sb, p));
goto fail;
Eend:
p = (struct ufs_dir_entry *)(kaddr + offs);
ufs_error (sb, "ext2_check_page",
"entry in directory #%lu spans the page boundary"
"offset=%lu",
dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs);
fail:
SetPageChecked(page);
SetPageError(page);
}
static struct page *ufs_get_page(struct inode *dir, unsigned long n)
{
struct address_space *mapping = dir->i_mapping;
struct page *page = read_cache_page(mapping, n,
(filler_t*)mapping->a_ops->readpage, NULL);
if (!IS_ERR(page)) {
wait_on_page_locked(page);
kmap(page);
if (!PageUptodate(page))
goto fail;
if (!PageChecked(page))
ufs_check_page(page);
if (PageError(page))
goto fail;
}
return page;
fail:
ufs_put_page(page);
return ERR_PTR(-EIO);
}
/*
* Return the offset into page `page_nr' of the last valid
* byte in that page, plus one.
*/
static unsigned
ufs_last_byte(struct inode *inode, unsigned long page_nr)
{
unsigned last_byte = inode->i_size;
last_byte -= page_nr << PAGE_CACHE_SHIFT;
if (last_byte > PAGE_CACHE_SIZE)
last_byte = PAGE_CACHE_SIZE;
return last_byte;
}
static inline struct ufs_dir_entry *
ufs_next_entry(struct super_block *sb, struct ufs_dir_entry *p)
{
return (struct ufs_dir_entry *)((char *)p +
fs16_to_cpu(sb, p->d_reclen));
}
struct ufs_dir_entry *ufs_dotdot(struct inode *dir, struct page **p)
{
struct page *page = ufs_get_page(dir, 0);
struct ufs_dir_entry *de = NULL;
if (!IS_ERR(page)) {
de = ufs_next_entry(dir->i_sb,
(struct ufs_dir_entry *)page_address(page));
*p = page;
}
return de;
}
/*
* ufs_find_entry()
*
* finds an entry in the specified directory with the wanted name. It
* returns the page in which the entry was found, and the entry itself
* (as a parameter - res_dir). Page is returned mapped and unlocked.
* Entry is guaranteed to be valid.
*/
struct ufs_dir_entry *ufs_find_entry(struct inode *dir, struct dentry *dentry,
struct page **res_page)
{
struct super_block *sb = dir->i_sb;
const char *name = dentry->d_name.name;
int namelen = dentry->d_name.len;
unsigned reclen = UFS_DIR_REC_LEN(namelen);
unsigned long start, n;
unsigned long npages = ufs_dir_pages(dir);
struct page *page = NULL;
struct ufs_inode_info *ui = UFS_I(dir);
struct ufs_dir_entry *de;
UFSD("ENTER, dir_ino %lu, name %s, namlen %u\n", dir->i_ino, name, namelen);
if (npages == 0 || namelen > UFS_MAXNAMLEN)
goto out;
/* OFFSET_CACHE */
*res_page = NULL;
start = ui->i_dir_start_lookup;
if (start >= npages)
start = 0;
n = start;
do {
char *kaddr;
page = ufs_get_page(dir, n);
if (!IS_ERR(page)) {
kaddr = page_address(page);
de = (struct ufs_dir_entry *) kaddr;
kaddr += ufs_last_byte(dir, n) - reclen;
while ((char *) de <= kaddr) {
if (de->d_reclen == 0) {
ufs_error(dir->i_sb, __FUNCTION__,
"zero-length directory entry");
ufs_put_page(page);
goto out;
}
if (ufs_match(sb, namelen, name, de))
goto found;
de = ufs_next_entry(sb, de);
}
ufs_put_page(page);
}
if (++n >= npages)
n = 0;
} while (n != start);
out:
return NULL;
found:
*res_page = page;
ui->i_dir_start_lookup = n;
return de;
}
/*
* Parent is locked.
*/
int ufs_add_link(struct dentry *dentry, struct inode *inode)
{
struct inode *dir = dentry->d_parent->d_inode;
const char *name = dentry->d_name.name;
int namelen = dentry->d_name.len;
struct super_block *sb = dir->i_sb;
unsigned reclen = UFS_DIR_REC_LEN(namelen);
const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
unsigned short rec_len, name_len;
struct page *page = NULL;
struct ufs_dir_entry *de;
unsigned long npages = ufs_dir_pages(dir);
unsigned long n;
char *kaddr;
unsigned from, to;
int err;
UFSD("ENTER, name %s, namelen %u\n", name, namelen);
/*
* We take care of directory expansion in the same loop.
* This code plays outside i_size, so it locks the page
* to protect that region.
*/
for (n = 0; n <= npages; n++) {
char *dir_end;
page = ufs_get_page(dir, n);
err = PTR_ERR(page);
if (IS_ERR(page))
goto out;
lock_page(page);
kaddr = page_address(page);
dir_end = kaddr + ufs_last_byte(dir, n);
de = (struct ufs_dir_entry *)kaddr;
kaddr += PAGE_CACHE_SIZE - reclen;
while ((char *)de <= kaddr) {
if ((char *)de == dir_end) {
/* We hit i_size */
name_len = 0;
rec_len = chunk_size;
de->d_reclen = cpu_to_fs16(sb, chunk_size);
de->d_ino = 0;
goto got_it;
}
if (de->d_reclen == 0) {
ufs_error(dir->i_sb, __FUNCTION__,
"zero-length directory entry");
err = -EIO;
goto out_unlock;
}
err = -EEXIST;
if (ufs_match(sb, namelen, name, de))
goto out_unlock;
name_len = UFS_DIR_REC_LEN(ufs_get_de_namlen(sb, de));
rec_len = fs16_to_cpu(sb, de->d_reclen);
if (!de->d_ino && rec_len >= reclen)
goto got_it;
if (rec_len >= name_len + reclen)
goto got_it;
de = (struct ufs_dir_entry *) ((char *) de + rec_len);
}
unlock_page(page);
ufs_put_page(page);
}
BUG();
return -EINVAL;
got_it:
from = (char*)de - (char*)page_address(page);
to = from + rec_len;
err = page->mapping->a_ops->prepare_write(NULL, page, from, to);
if (err)
goto out_unlock;
if (de->d_ino) {
struct ufs_dir_entry *de1 =
(struct ufs_dir_entry *) ((char *) de + name_len);
de1->d_reclen = cpu_to_fs16(sb, rec_len - name_len);
de->d_reclen = cpu_to_fs16(sb, name_len);
de = de1;
}
ufs_set_de_namlen(sb, de, namelen);
memcpy(de->d_name, name, namelen + 1);
de->d_ino = cpu_to_fs32(sb, inode->i_ino);
ufs_set_de_type(sb, de, inode->i_mode);
err = ufs_commit_chunk(page, from, to);
dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(dir);
/* OFFSET_CACHE */
out_put:
ufs_put_page(page);
out:
return err;
out_unlock:
unlock_page(page);
goto out_put;
}
static inline unsigned
ufs_validate_entry(struct super_block *sb, char *base,
unsigned offset, unsigned mask)
{
struct ufs_dir_entry *de = (struct ufs_dir_entry*)(base + offset);
struct ufs_dir_entry *p = (struct ufs_dir_entry*)(base + (offset&mask));
while ((char*)p < (char*)de) {
if (p->d_reclen == 0)
break;
p = ufs_next_entry(sb, p);
}
return (char *)p - base;
}
/*
* This is blatantly stolen from ext2fs
*/
static int
ufs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
loff_t pos = filp->f_pos;
struct inode *inode = filp->f_path.dentry->d_inode;
struct super_block *sb = inode->i_sb;
unsigned int offset = pos & ~PAGE_CACHE_MASK;
unsigned long n = pos >> PAGE_CACHE_SHIFT;
unsigned long npages = ufs_dir_pages(inode);
unsigned chunk_mask = ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
int need_revalidate = filp->f_version != inode->i_version;
unsigned flags = UFS_SB(sb)->s_flags;
UFSD("BEGIN\n");
if (pos > inode->i_size - UFS_DIR_REC_LEN(1))
return 0;
for ( ; n < npages; n++, offset = 0) {
char *kaddr, *limit;
struct ufs_dir_entry *de;
struct page *page = ufs_get_page(inode, n);
if (IS_ERR(page)) {
ufs_error(sb, __FUNCTION__,
"bad page in #%lu",
inode->i_ino);
filp->f_pos += PAGE_CACHE_SIZE - offset;
return -EIO;
}
kaddr = page_address(page);
if (unlikely(need_revalidate)) {
if (offset) {
offset = ufs_validate_entry(sb, kaddr, offset, chunk_mask);
filp->f_pos = (n<<PAGE_CACHE_SHIFT) + offset;
}
filp->f_version = inode->i_version;
need_revalidate = 0;
}
de = (struct ufs_dir_entry *)(kaddr+offset);
limit = kaddr + ufs_last_byte(inode, n) - UFS_DIR_REC_LEN(1);
for ( ;(char*)de <= limit; de = ufs_next_entry(sb, de)) {
if (de->d_reclen == 0) {
ufs_error(sb, __FUNCTION__,
"zero-length directory entry");
ufs_put_page(page);
return -EIO;
}
if (de->d_ino) {
int over;
unsigned char d_type = DT_UNKNOWN;
offset = (char *)de - kaddr;
UFSD("filldir(%s,%u)\n", de->d_name,
fs32_to_cpu(sb, de->d_ino));
UFSD("namlen %u\n", ufs_get_de_namlen(sb, de));
if ((flags & UFS_DE_MASK) == UFS_DE_44BSD)
d_type = de->d_u.d_44.d_type;
over = filldir(dirent, de->d_name,
ufs_get_de_namlen(sb, de),
(n<<PAGE_CACHE_SHIFT) | offset,
fs32_to_cpu(sb, de->d_ino), d_type);
if (over) {
ufs_put_page(page);
return 0;
}
}
filp->f_pos += fs16_to_cpu(sb, de->d_reclen);
}
ufs_put_page(page);
}
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 page * page)
{
struct super_block *sb = inode->i_sb;
struct address_space *mapping = page->mapping;
char *kaddr = page_address(page);
unsigned from = ((char*)dir - kaddr) & ~(UFS_SB(sb)->s_uspi->s_dirblksize - 1);
unsigned to = ((char*)dir - kaddr) + fs16_to_cpu(sb, dir->d_reclen);
struct ufs_dir_entry *pde = NULL;
struct ufs_dir_entry *de = (struct ufs_dir_entry *) (kaddr + from);
int err;
UFSD("ENTER\n");
UFSD("ino %u, reclen %u, namlen %u, name %s\n",
fs32_to_cpu(sb, de->d_ino),
fs16_to_cpu(sb, de->d_reclen),
ufs_get_de_namlen(sb, de), de->d_name);
while ((char*)de < (char*)dir) {
if (de->d_reclen == 0) {
ufs_error(inode->i_sb, __FUNCTION__,
"zero-length directory entry");
err = -EIO;
goto out;
}
pde = de;
de = ufs_next_entry(sb, de);
}
if (pde)
from = (char*)pde - (char*)page_address(page);
lock_page(page);
err = mapping->a_ops->prepare_write(NULL, page, from, to);
BUG_ON(err);
if (pde)
pde->d_reclen = cpu_to_fs16(sb, to-from);
dir->d_ino = 0;
err = ufs_commit_chunk(page, from, to);
inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
mark_inode_dirty(inode);
out:
ufs_put_page(page);
UFSD("EXIT\n");
return err;
}
int ufs_make_empty(struct inode * inode, struct inode *dir)
{
struct super_block * sb = dir->i_sb;
struct address_space *mapping = inode->i_mapping;
struct page *page = grab_cache_page(mapping, 0);
const unsigned int chunk_size = UFS_SB(sb)->s_uspi->s_dirblksize;
struct ufs_dir_entry * de;
char *base;
int err;
if (!page)
return -ENOMEM;
kmap(page);
err = mapping->a_ops->prepare_write(NULL, page, 0, chunk_size);
if (err) {
unlock_page(page);
goto fail;
}
base = (char*)page_address(page);
memset(base, 0, PAGE_CACHE_SIZE);
de = (struct ufs_dir_entry *) base;
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, chunk_size - UFS_DIR_REC_LEN(1));
ufs_set_de_namlen(sb, de, 2);
strcpy (de->d_name, "..");
err = ufs_commit_chunk(page, 0, chunk_size);
fail:
kunmap(page);
page_cache_release(page);
return err;
}
/*
* routine to check that the specified directory is empty (for rmdir)
*/
int ufs_empty_dir(struct inode * inode)
{
struct super_block *sb = inode->i_sb;
struct page *page = NULL;
unsigned long i, npages = ufs_dir_pages(inode);
for (i = 0; i < npages; i++) {
char *kaddr;
struct ufs_dir_entry *de;
page = ufs_get_page(inode, i);
if (IS_ERR(page))
continue;
kaddr = page_address(page);
de = (struct ufs_dir_entry *)kaddr;
kaddr += ufs_last_byte(inode, i) - UFS_DIR_REC_LEN(1);
while ((char *)de <= kaddr) {
if (de->d_reclen == 0) {
ufs_error(inode->i_sb, __FUNCTION__,
"zero-length directory entry: "
"kaddr=%p, de=%p\n", kaddr, de);
goto not_empty;
}
if (de->d_ino) {
u16 namelen=ufs_get_de_namlen(sb, de);
/* check for . and .. */
if (de->d_name[0] != '.')
goto not_empty;
if (namelen > 2)
goto not_empty;
if (namelen < 2) {
if (inode->i_ino !=
fs32_to_cpu(sb, de->d_ino))
goto not_empty;
} else if (de->d_name[1] != '.')
goto not_empty;
}
de = ufs_next_entry(sb, de);
}
ufs_put_page(page);
}
return 1;
not_empty:
ufs_put_page(page);
return 0;
}
const struct file_operations ufs_dir_operations = {
.read = generic_read_dir,
.readdir = ufs_readdir,
.fsync = file_fsync,
};