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linux/fs/ufs/truncate.c
Arnd Bergmann 788257d610 ufs: remove the BKL 
This introduces a new per-superblock mutex in UFS to replace
the big kernel lock. I have been careful to avoid nested
calls to lock_ufs and to get the lock order right with
respect to other mutexes, in particular lock_super.

I did not make any attempt to prove that the big kernel
lock is not needed in a particular place in the code,
which is very possible.

The mutex has a significant performance impact, so it is only
used on SMP or PREEMPT configurations.

As Nick Piggin noticed, any allocation inside of the lock
may end up deadlocking when we get to ufs_getfrag_block
in the reclaim task, so we now use GFP_NOFS.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Nick Bowler <nbowler@elliptictech.com>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Nick Piggin <npiggin@gmail.com>
2011-03-02 22:27:48 +01:00

525 lines
13 KiB
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/*
* 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>
*/
/*
* Adoptation to use page cache and UFS2 write support by
* Evgeniy Dushistov <dushistov@mail.ru>, 2006-2007
*/
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/fcntl.h>
#include <linux/time.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/buffer_head.h>
#include <linux/blkdev.h>
#include <linux/sched.h>
#include "ufs_fs.h"
#include "ufs.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;
void *p;
u64 frag1, frag2, frag3, frag4, block1, block2;
unsigned frag_to_free, free_count;
unsigned i, tmp;
int retry;
UFSD("ENTER: ino %lu\n", inode->i_ino);
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("ino %lu, frag1 %llu, frag2 %llu, block1 %llu, block2 %llu,"
" frag3 %llu, frag4 %llu\n", inode->i_ino,
(unsigned long long)frag1, (unsigned long long)frag2,
(unsigned long long)block1, (unsigned long long)block2,
(unsigned long long)frag3, (unsigned long long)frag4);
if (frag1 >= frag2)
goto next1;
/*
* Free first free fragments
*/
p = ufs_get_direct_data_ptr(uspi, ufsi, ufs_fragstoblks(frag1));
tmp = ufs_data_ptr_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 = ufs_get_direct_data_ptr(uspi, ufsi, i);
tmp = ufs_data_ptr_to_cpu(sb, p);
if (!tmp)
continue;
ufs_data_ptr_clear(uspi, p);
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 = ufs_get_direct_data_ptr(uspi, ufsi, ufs_fragstoblks(frag3));
tmp = ufs_data_ptr_to_cpu(sb, p);
if (!tmp )
ufs_panic(sb, "ufs_truncate_direct", "internal error");
frag4 = ufs_fragnum (frag4);
ufs_data_ptr_clear(uspi, p);
ufs_free_fragments (inode, tmp, frag4);
mark_inode_dirty(inode);
next3:
UFSD("EXIT: ino %lu\n", inode->i_ino);
return retry;
}
static int ufs_trunc_indirect(struct inode *inode, u64 offset, void *p)
{
struct super_block * sb;
struct ufs_sb_private_info * uspi;
struct ufs_buffer_head * ind_ubh;
void *ind;
u64 tmp, indirect_block, i, frag_to_free;
unsigned free_count;
int retry;
UFSD("ENTER: ino %lu, offset %llu, p: %p\n",
inode->i_ino, (unsigned long long)offset, p);
BUG_ON(!p);
sb = inode->i_sb;
uspi = UFS_SB(sb)->s_uspi;
frag_to_free = 0;
free_count = 0;
retry = 0;
tmp = ufs_data_ptr_to_cpu(sb, p);
if (!tmp)
return 0;
ind_ubh = ubh_bread(sb, tmp, uspi->s_bsize);
if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
ubh_brelse (ind_ubh);
return 1;
}
if (!ind_ubh) {
ufs_data_ptr_clear(uspi, p);
return 0;
}
indirect_block = (DIRECT_BLOCK > offset) ? (DIRECT_BLOCK - offset) : 0;
for (i = indirect_block; i < uspi->s_apb; i++) {
ind = ubh_get_data_ptr(uspi, ind_ubh, i);
tmp = ufs_data_ptr_to_cpu(sb, ind);
if (!tmp)
continue;
ufs_data_ptr_clear(uspi, ind);
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 (!ufs_is_data_ptr_zero(uspi,
ubh_get_data_ptr(uspi, ind_ubh, i)))
break;
if (i >= uspi->s_apb) {
tmp = ufs_data_ptr_to_cpu(sb, p);
ufs_data_ptr_clear(uspi, p);
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_sync_block(ind_ubh);
ubh_brelse (ind_ubh);
UFSD("EXIT: ino %lu\n", inode->i_ino);
return retry;
}
static int ufs_trunc_dindirect(struct inode *inode, u64 offset, void *p)
{
struct super_block * sb;
struct ufs_sb_private_info * uspi;
struct ufs_buffer_head *dind_bh;
u64 i, tmp, dindirect_block;
void *dind;
int retry = 0;
UFSD("ENTER: ino %lu\n", inode->i_ino);
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 = ufs_data_ptr_to_cpu(sb, p);
if (!tmp)
return 0;
dind_bh = ubh_bread(sb, tmp, uspi->s_bsize);
if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
ubh_brelse (dind_bh);
return 1;
}
if (!dind_bh) {
ufs_data_ptr_clear(uspi, p);
return 0;
}
for (i = dindirect_block ; i < uspi->s_apb ; i++) {
dind = ubh_get_data_ptr(uspi, dind_bh, i);
tmp = ufs_data_ptr_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 (!ufs_is_data_ptr_zero(uspi,
ubh_get_data_ptr(uspi, dind_bh, i)))
break;
if (i >= uspi->s_apb) {
tmp = ufs_data_ptr_to_cpu(sb, p);
ufs_data_ptr_clear(uspi, p);
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_sync_block(dind_bh);
ubh_brelse (dind_bh);
UFSD("EXIT: ino %lu\n", inode->i_ino);
return retry;
}
static int ufs_trunc_tindirect(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
struct ufs_inode_info *ufsi = UFS_I(inode);
struct ufs_buffer_head * tind_bh;
u64 tindirect_block, tmp, i;
void *tind, *p;
int retry;
UFSD("ENTER: ino %lu\n", inode->i_ino);
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 = ufs_get_direct_data_ptr(uspi, ufsi, UFS_TIND_BLOCK);
if (!(tmp = ufs_data_ptr_to_cpu(sb, p)))
return 0;
tind_bh = ubh_bread (sb, tmp, uspi->s_bsize);
if (tmp != ufs_data_ptr_to_cpu(sb, p)) {
ubh_brelse (tind_bh);
return 1;
}
if (!tind_bh) {
ufs_data_ptr_clear(uspi, p);
return 0;
}
for (i = tindirect_block ; i < uspi->s_apb ; i++) {
tind = ubh_get_data_ptr(uspi, 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 (!ufs_is_data_ptr_zero(uspi,
ubh_get_data_ptr(uspi, tind_bh, i)))
break;
if (i >= uspi->s_apb) {
tmp = ufs_data_ptr_to_cpu(sb, p);
ufs_data_ptr_clear(uspi, p);
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_sync_block(tind_bh);
ubh_brelse (tind_bh);
UFSD("EXIT: ino %lu\n", inode->i_ino);
return retry;
}
static int ufs_alloc_lastblock(struct inode *inode)
{
int err = 0;
struct super_block *sb = inode->i_sb;
struct address_space *mapping = inode->i_mapping;
struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
unsigned i, end;
sector_t lastfrag;
struct page *lastpage;
struct buffer_head *bh;
u64 phys64;
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);
}
if (lastfrag >= UFS_IND_FRAGMENT) {
end = uspi->s_fpb - ufs_fragnum(lastfrag) - 1;
phys64 = bh->b_blocknr + 1;
for (i = 0; i < end; ++i) {
bh = sb_getblk(sb, i + phys64);
lock_buffer(bh);
memset(bh->b_data, 0, sb->s_blocksize);
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
unlock_buffer(bh);
sync_dirty_buffer(bh);
brelse(bh);
}
}
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: ino %lu, i_size: %llu, old_i_size: %llu\n",
inode->i_ino, (unsigned long long)i_size_read(inode),
(unsigned long long)old_i_size);
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);
while (1) {
retry = ufs_trunc_direct(inode);
retry |= ufs_trunc_indirect(inode, UFS_IND_BLOCK,
ufs_get_direct_data_ptr(uspi, ufsi,
UFS_IND_BLOCK));
retry |= ufs_trunc_dindirect(inode, UFS_IND_BLOCK + uspi->s_apb,
ufs_get_direct_data_ptr(uspi, ufsi,
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;
mark_inode_dirty(inode);
out:
UFSD("EXIT: err %d\n", err);
return err;
}
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 != inode->i_size) {
loff_t old_i_size = inode->i_size;
/* XXX(truncate): truncate_setsize should be called last */
truncate_setsize(inode, attr->ia_size);
lock_ufs(inode->i_sb);
error = ufs_truncate(inode, old_i_size);
unlock_ufs(inode->i_sb);
if (error)
return error;
}
setattr_copy(inode, attr);
mark_inode_dirty(inode);
return 0;
}
const struct inode_operations ufs_file_inode_operations = {
.setattr = ufs_setattr,
};
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