linux/fs/ufs/truncate.c
Evgeniy Dushistov 8682164a66 [PATCH] ufs: truncate negative to unsigned fix
During ufs_trunc_direct which is subroutine of ufs::truncate, we try the first
of all free parts of block and then whole blocks.  But we calculate size of
block's part to free in the wrong way.

This may cause bad update of used blocks and fragments statistic, and you can
got report that you have free 32T on 1Gb partition.

Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-30 08:26:45 -08:00

508 lines
12 KiB
C

/*
* linux/fs/ufs/truncate.c
*
* Copyright (C) 1998
* Daniel Pirkl <daniel.pirkl@email.cz>
* Charles University, Faculty of Mathematics and Physics
*
* from
*
* linux/fs/ext2/truncate.c
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* from
*
* linux/fs/minix/truncate.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*
* Big-endian to little-endian byte-swapping/bitmaps by
* David S. Miller (davem@caip.rutgers.edu), 1995
*/
/*
* Real random numbers for secure rm added 94/02/18
* Idea from Pierre del Perugia <delperug@gla.ecoledoc.ibp.fr>
*/
/*
* Modified to avoid infinite loop on 2006 by
* Evgeniy Dushistov <dushistov@mail.ru>
*/
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/ufs_fs.h>
#include <linux/fcntl.h>
#include <linux/time.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
#include <linux/buffer_head.h>
#include <linux/blkdev.h>
#include <linux/sched.h>
#include "swab.h"
#include "util.h"
/*
* Secure deletion currently doesn't work. It interacts very badly
* with buffers shared with memory mappings, and for that reason
* can't be done in the truncate() routines. It should instead be
* done separately in "release()" before calling the truncate routines
* that will release the actual file blocks.
*
* Linus
*/
#define DIRECT_BLOCK ((inode->i_size + uspi->s_bsize - 1) >> uspi->s_bshift)
#define DIRECT_FRAGMENT ((inode->i_size + uspi->s_fsize - 1) >> uspi->s_fshift)
static int ufs_trunc_direct (struct inode * inode)
{
struct ufs_inode_info *ufsi = UFS_I(inode);
struct super_block * sb;
struct ufs_sb_private_info * uspi;
__fs32 * p;
unsigned frag1, frag2, frag3, frag4, block1, block2;
unsigned frag_to_free, free_count;
unsigned i, tmp;
int retry;
UFSD("ENTER\n");
sb = inode->i_sb;
uspi = UFS_SB(sb)->s_uspi;
frag_to_free = 0;
free_count = 0;
retry = 0;
frag1 = DIRECT_FRAGMENT;
frag4 = min_t(u32, UFS_NDIR_FRAGMENT, ufsi->i_lastfrag);
frag2 = ((frag1 & uspi->s_fpbmask) ? ((frag1 | uspi->s_fpbmask) + 1) : frag1);
frag3 = frag4 & ~uspi->s_fpbmask;
block1 = block2 = 0;
if (frag2 > frag3) {
frag2 = frag4;
frag3 = frag4 = 0;
}
else if (frag2 < frag3) {
block1 = ufs_fragstoblks (frag2);
block2 = ufs_fragstoblks (frag3);
}
UFSD("frag1 %u, frag2 %u, block1 %u, block2 %u, frag3 %u, frag4 %u\n", frag1, frag2, block1, block2, frag3, frag4);
if (frag1 >= frag2)
goto next1;
/*
* Free first free fragments
*/
p = ufsi->i_u1.i_data + ufs_fragstoblks (frag1);
tmp = fs32_to_cpu(sb, *p);
if (!tmp )
ufs_panic (sb, "ufs_trunc_direct", "internal error");
frag2 -= frag1;
frag1 = ufs_fragnum (frag1);
ufs_free_fragments(inode, tmp + frag1, frag2);
mark_inode_dirty(inode);
frag_to_free = tmp + frag1;
next1:
/*
* Free whole blocks
*/
for (i = block1 ; i < block2; i++) {
p = ufsi->i_u1.i_data + i;
tmp = fs32_to_cpu(sb, *p);
if (!tmp)
continue;
*p = 0;
if (free_count == 0) {
frag_to_free = tmp;
free_count = uspi->s_fpb;
} else if (free_count > 0 && frag_to_free == tmp - free_count)
free_count += uspi->s_fpb;
else {
ufs_free_blocks (inode, frag_to_free, free_count);
frag_to_free = tmp;
free_count = uspi->s_fpb;
}
mark_inode_dirty(inode);
}
if (free_count > 0)
ufs_free_blocks (inode, frag_to_free, free_count);
if (frag3 >= frag4)
goto next3;
/*
* Free last free fragments
*/
p = ufsi->i_u1.i_data + ufs_fragstoblks (frag3);
tmp = fs32_to_cpu(sb, *p);
if (!tmp )
ufs_panic(sb, "ufs_truncate_direct", "internal error");
frag4 = ufs_fragnum (frag4);
*p = 0;
ufs_free_fragments (inode, tmp, frag4);
mark_inode_dirty(inode);
next3:
UFSD("EXIT\n");
return retry;
}
static int ufs_trunc_indirect (struct inode * inode, unsigned offset, __fs32 *p)
{
struct super_block * sb;
struct ufs_sb_private_info * uspi;
struct ufs_buffer_head * ind_ubh;
__fs32 * ind;
unsigned indirect_block, i, tmp;
unsigned frag_to_free, free_count;
int retry;
UFSD("ENTER\n");
sb = inode->i_sb;
uspi = UFS_SB(sb)->s_uspi;
frag_to_free = 0;
free_count = 0;
retry = 0;
tmp = fs32_to_cpu(sb, *p);
if (!tmp)
return 0;
ind_ubh = ubh_bread(sb, tmp, uspi->s_bsize);
if (tmp != fs32_to_cpu(sb, *p)) {
ubh_brelse (ind_ubh);
return 1;
}
if (!ind_ubh) {
*p = 0;
return 0;
}
indirect_block = (DIRECT_BLOCK > offset) ? (DIRECT_BLOCK - offset) : 0;
for (i = indirect_block; i < uspi->s_apb; i++) {
ind = ubh_get_addr32 (ind_ubh, i);
tmp = fs32_to_cpu(sb, *ind);
if (!tmp)
continue;
*ind = 0;
ubh_mark_buffer_dirty(ind_ubh);
if (free_count == 0) {
frag_to_free = tmp;
free_count = uspi->s_fpb;
} else if (free_count > 0 && frag_to_free == tmp - free_count)
free_count += uspi->s_fpb;
else {
ufs_free_blocks (inode, frag_to_free, free_count);
frag_to_free = tmp;
free_count = uspi->s_fpb;
}
mark_inode_dirty(inode);
}
if (free_count > 0) {
ufs_free_blocks (inode, frag_to_free, free_count);
}
for (i = 0; i < uspi->s_apb; i++)
if (*ubh_get_addr32(ind_ubh,i))
break;
if (i >= uspi->s_apb) {
tmp = fs32_to_cpu(sb, *p);
*p = 0;
ufs_free_blocks (inode, tmp, uspi->s_fpb);
mark_inode_dirty(inode);
ubh_bforget(ind_ubh);
ind_ubh = NULL;
}
if (IS_SYNC(inode) && ind_ubh && ubh_buffer_dirty(ind_ubh)) {
ubh_ll_rw_block(SWRITE, ind_ubh);
ubh_wait_on_buffer (ind_ubh);
}
ubh_brelse (ind_ubh);
UFSD("EXIT\n");
return retry;
}
static int ufs_trunc_dindirect (struct inode *inode, unsigned offset, __fs32 *p)
{
struct super_block * sb;
struct ufs_sb_private_info * uspi;
struct ufs_buffer_head * dind_bh;
unsigned i, tmp, dindirect_block;
__fs32 * dind;
int retry = 0;
UFSD("ENTER\n");
sb = inode->i_sb;
uspi = UFS_SB(sb)->s_uspi;
dindirect_block = (DIRECT_BLOCK > offset)
? ((DIRECT_BLOCK - offset) >> uspi->s_apbshift) : 0;
retry = 0;
tmp = fs32_to_cpu(sb, *p);
if (!tmp)
return 0;
dind_bh = ubh_bread(sb, tmp, uspi->s_bsize);
if (tmp != fs32_to_cpu(sb, *p)) {
ubh_brelse (dind_bh);
return 1;
}
if (!dind_bh) {
*p = 0;
return 0;
}
for (i = dindirect_block ; i < uspi->s_apb ; i++) {
dind = ubh_get_addr32 (dind_bh, i);
tmp = fs32_to_cpu(sb, *dind);
if (!tmp)
continue;
retry |= ufs_trunc_indirect (inode, offset + (i << uspi->s_apbshift), dind);
ubh_mark_buffer_dirty(dind_bh);
}
for (i = 0; i < uspi->s_apb; i++)
if (*ubh_get_addr32 (dind_bh, i))
break;
if (i >= uspi->s_apb) {
tmp = fs32_to_cpu(sb, *p);
*p = 0;
ufs_free_blocks(inode, tmp, uspi->s_fpb);
mark_inode_dirty(inode);
ubh_bforget(dind_bh);
dind_bh = NULL;
}
if (IS_SYNC(inode) && dind_bh && ubh_buffer_dirty(dind_bh)) {
ubh_ll_rw_block(SWRITE, dind_bh);
ubh_wait_on_buffer (dind_bh);
}
ubh_brelse (dind_bh);
UFSD("EXIT\n");
return retry;
}
static int ufs_trunc_tindirect (struct inode * inode)
{
struct ufs_inode_info *ufsi = UFS_I(inode);
struct super_block * sb;
struct ufs_sb_private_info * uspi;
struct ufs_buffer_head * tind_bh;
unsigned tindirect_block, tmp, i;
__fs32 * tind, * p;
int retry;
UFSD("ENTER\n");
sb = inode->i_sb;
uspi = UFS_SB(sb)->s_uspi;
retry = 0;
tindirect_block = (DIRECT_BLOCK > (UFS_NDADDR + uspi->s_apb + uspi->s_2apb))
? ((DIRECT_BLOCK - UFS_NDADDR - uspi->s_apb - uspi->s_2apb) >> uspi->s_2apbshift) : 0;
p = ufsi->i_u1.i_data + UFS_TIND_BLOCK;
if (!(tmp = fs32_to_cpu(sb, *p)))
return 0;
tind_bh = ubh_bread (sb, tmp, uspi->s_bsize);
if (tmp != fs32_to_cpu(sb, *p)) {
ubh_brelse (tind_bh);
return 1;
}
if (!tind_bh) {
*p = 0;
return 0;
}
for (i = tindirect_block ; i < uspi->s_apb ; i++) {
tind = ubh_get_addr32 (tind_bh, i);
retry |= ufs_trunc_dindirect(inode, UFS_NDADDR +
uspi->s_apb + ((i + 1) << uspi->s_2apbshift), tind);
ubh_mark_buffer_dirty(tind_bh);
}
for (i = 0; i < uspi->s_apb; i++)
if (*ubh_get_addr32 (tind_bh, i))
break;
if (i >= uspi->s_apb) {
tmp = fs32_to_cpu(sb, *p);
*p = 0;
ufs_free_blocks(inode, tmp, uspi->s_fpb);
mark_inode_dirty(inode);
ubh_bforget(tind_bh);
tind_bh = NULL;
}
if (IS_SYNC(inode) && tind_bh && ubh_buffer_dirty(tind_bh)) {
ubh_ll_rw_block(SWRITE, tind_bh);
ubh_wait_on_buffer (tind_bh);
}
ubh_brelse (tind_bh);
UFSD("EXIT\n");
return retry;
}
static int ufs_alloc_lastblock(struct inode *inode)
{
int err = 0;
struct address_space *mapping = inode->i_mapping;
struct ufs_sb_private_info *uspi = UFS_SB(inode->i_sb)->s_uspi;
unsigned lastfrag, i, end;
struct page *lastpage;
struct buffer_head *bh;
lastfrag = (i_size_read(inode) + uspi->s_fsize - 1) >> uspi->s_fshift;
if (!lastfrag)
goto out;
lastfrag--;
lastpage = ufs_get_locked_page(mapping, lastfrag >>
(PAGE_CACHE_SHIFT - inode->i_blkbits));
if (IS_ERR(lastpage)) {
err = -EIO;
goto out;
}
end = lastfrag & ((1 << (PAGE_CACHE_SHIFT - inode->i_blkbits)) - 1);
bh = page_buffers(lastpage);
for (i = 0; i < end; ++i)
bh = bh->b_this_page;
err = ufs_getfrag_block(inode, lastfrag, bh, 1);
if (unlikely(err))
goto out_unlock;
if (buffer_new(bh)) {
clear_buffer_new(bh);
unmap_underlying_metadata(bh->b_bdev,
bh->b_blocknr);
/*
* we do not zeroize fragment, because of
* if it maped to hole, it already contains zeroes
*/
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
set_page_dirty(lastpage);
}
out_unlock:
ufs_put_locked_page(lastpage);
out:
return err;
}
int ufs_truncate(struct inode *inode, loff_t old_i_size)
{
struct ufs_inode_info *ufsi = UFS_I(inode);
struct super_block *sb = inode->i_sb;
struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
int retry, err = 0;
UFSD("ENTER\n");
if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
S_ISLNK(inode->i_mode)))
return -EINVAL;
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
return -EPERM;
err = ufs_alloc_lastblock(inode);
if (err) {
i_size_write(inode, old_i_size);
goto out;
}
block_truncate_page(inode->i_mapping, inode->i_size, ufs_getfrag_block);
lock_kernel();
while (1) {
retry = ufs_trunc_direct(inode);
retry |= ufs_trunc_indirect (inode, UFS_IND_BLOCK,
(__fs32 *) &ufsi->i_u1.i_data[UFS_IND_BLOCK]);
retry |= ufs_trunc_dindirect (inode, UFS_IND_BLOCK + uspi->s_apb,
(__fs32 *) &ufsi->i_u1.i_data[UFS_DIND_BLOCK]);
retry |= ufs_trunc_tindirect (inode);
if (!retry)
break;
if (IS_SYNC(inode) && (inode->i_state & I_DIRTY))
ufs_sync_inode (inode);
blk_run_address_space(inode->i_mapping);
yield();
}
inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
ufsi->i_lastfrag = DIRECT_FRAGMENT;
unlock_kernel();
mark_inode_dirty(inode);
out:
UFSD("EXIT: err %d\n", err);
return err;
}
/*
* We don't define our `inode->i_op->truncate', and call it here,
* because of:
* - there is no way to know old size
* - there is no way inform user about error, if it happens in `truncate'
*/
static int ufs_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = dentry->d_inode;
unsigned int ia_valid = attr->ia_valid;
int error;
error = inode_change_ok(inode, attr);
if (error)
return error;
if (ia_valid & ATTR_SIZE &&
attr->ia_size != i_size_read(inode)) {
loff_t old_i_size = inode->i_size;
error = vmtruncate(inode, attr->ia_size);
if (error)
return error;
error = ufs_truncate(inode, old_i_size);
if (error)
return error;
}
return inode_setattr(inode, attr);
}
struct inode_operations ufs_file_inode_operations = {
.setattr = ufs_setattr,
};