linux-stable/fs/hpfs/alloc.c
Mikulas Patocka 2cbe5c76fc hpfs: remember free space
Previously, hpfs scanned all bitmaps each time the user asked for free
space using statfs.  This patch changes it so that hpfs scans the
bitmaps only once, remembes the free space and on next invocation of
statfs it returns the value instantly.

New versions of wine are hammering on the statfs syscall very heavily,
making some games unplayable when they're stored on hpfs, with load
times in minutes.

This should be backported to the stable kernels because it fixes
user-visible problem (excessive level load times in wine).

Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-02 16:24:07 -08:00

486 lines
12 KiB
C

/*
* linux/fs/hpfs/alloc.c
*
* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
*
* HPFS bitmap operations
*/
#include "hpfs_fn.h"
static void hpfs_claim_alloc(struct super_block *s, secno sec)
{
struct hpfs_sb_info *sbi = hpfs_sb(s);
if (sbi->sb_n_free != (unsigned)-1) {
if (unlikely(!sbi->sb_n_free)) {
hpfs_error(s, "free count underflow, allocating sector %08x", sec);
sbi->sb_n_free = -1;
return;
}
sbi->sb_n_free--;
}
}
static void hpfs_claim_free(struct super_block *s, secno sec)
{
struct hpfs_sb_info *sbi = hpfs_sb(s);
if (sbi->sb_n_free != (unsigned)-1) {
if (unlikely(sbi->sb_n_free >= sbi->sb_fs_size)) {
hpfs_error(s, "free count overflow, freeing sector %08x", sec);
sbi->sb_n_free = -1;
return;
}
sbi->sb_n_free++;
}
}
static void hpfs_claim_dirband_alloc(struct super_block *s, secno sec)
{
struct hpfs_sb_info *sbi = hpfs_sb(s);
if (sbi->sb_n_free_dnodes != (unsigned)-1) {
if (unlikely(!sbi->sb_n_free_dnodes)) {
hpfs_error(s, "dirband free count underflow, allocating sector %08x", sec);
sbi->sb_n_free_dnodes = -1;
return;
}
sbi->sb_n_free_dnodes--;
}
}
static void hpfs_claim_dirband_free(struct super_block *s, secno sec)
{
struct hpfs_sb_info *sbi = hpfs_sb(s);
if (sbi->sb_n_free_dnodes != (unsigned)-1) {
if (unlikely(sbi->sb_n_free_dnodes >= sbi->sb_dirband_size / 4)) {
hpfs_error(s, "dirband free count overflow, freeing sector %08x", sec);
sbi->sb_n_free_dnodes = -1;
return;
}
sbi->sb_n_free_dnodes++;
}
}
/*
* Check if a sector is allocated in bitmap
* This is really slow. Turned on only if chk==2
*/
static int chk_if_allocated(struct super_block *s, secno sec, char *msg)
{
struct quad_buffer_head qbh;
__le32 *bmp;
if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "chk"))) goto fail;
if ((le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) >> (sec & 0x1f)) & 1) {
hpfs_error(s, "sector '%s' - %08x not allocated in bitmap", msg, sec);
goto fail1;
}
hpfs_brelse4(&qbh);
if (sec >= hpfs_sb(s)->sb_dirband_start && sec < hpfs_sb(s)->sb_dirband_start + hpfs_sb(s)->sb_dirband_size) {
unsigned ssec = (sec - hpfs_sb(s)->sb_dirband_start) / 4;
if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto fail;
if ((le32_to_cpu(bmp[ssec >> 5]) >> (ssec & 0x1f)) & 1) {
hpfs_error(s, "sector '%s' - %08x not allocated in directory bitmap", msg, sec);
goto fail1;
}
hpfs_brelse4(&qbh);
}
return 0;
fail1:
hpfs_brelse4(&qbh);
fail:
return 1;
}
/*
* Check if sector(s) have proper number and additionally check if they're
* allocated in bitmap.
*/
int hpfs_chk_sectors(struct super_block *s, secno start, int len, char *msg)
{
if (start + len < start || start < 0x12 ||
start + len > hpfs_sb(s)->sb_fs_size) {
hpfs_error(s, "sector(s) '%s' badly placed at %08x", msg, start);
return 1;
}
if (hpfs_sb(s)->sb_chk>=2) {
int i;
for (i = 0; i < len; i++)
if (chk_if_allocated(s, start + i, msg)) return 1;
}
return 0;
}
static secno alloc_in_bmp(struct super_block *s, secno near, unsigned n, unsigned forward)
{
struct quad_buffer_head qbh;
__le32 *bmp;
unsigned bs = near & ~0x3fff;
unsigned nr = (near & 0x3fff) & ~(n - 1);
/*unsigned mnr;*/
unsigned i, q;
int a, b;
secno ret = 0;
if (n != 1 && n != 4) {
hpfs_error(s, "Bad allocation size: %d", n);
return 0;
}
if (bs != ~0x3fff) {
if (!(bmp = hpfs_map_bitmap(s, near >> 14, &qbh, "aib"))) goto uls;
} else {
if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto uls;
}
if (!tstbits(bmp, nr, n + forward)) {
ret = bs + nr;
goto rt;
}
q = nr + n; b = 0;
while ((a = tstbits(bmp, q, n + forward)) != 0) {
q += a;
if (n != 1) q = ((q-1)&~(n-1))+n;
if (!b) {
if (q>>5 != nr>>5) {
b = 1;
q = nr & 0x1f;
}
} else if (q > nr) break;
}
if (!a) {
ret = bs + q;
goto rt;
}
nr >>= 5;
/*for (i = nr + 1; i != nr; i++, i &= 0x1ff) */
i = nr;
do {
if (!le32_to_cpu(bmp[i])) goto cont;
if (n + forward >= 0x3f && le32_to_cpu(bmp[i]) != 0xffffffff) goto cont;
q = i<<5;
if (i > 0) {
unsigned k = le32_to_cpu(bmp[i-1]);
while (k & 0x80000000) {
q--; k <<= 1;
}
}
if (n != 1) q = ((q-1)&~(n-1))+n;
while ((a = tstbits(bmp, q, n + forward)) != 0) {
q += a;
if (n != 1) q = ((q-1)&~(n-1))+n;
if (q>>5 > i) break;
}
if (!a) {
ret = bs + q;
goto rt;
}
cont:
i++, i &= 0x1ff;
} while (i != nr);
rt:
if (ret) {
if (hpfs_sb(s)->sb_chk && ((ret >> 14) != (bs >> 14) || (le32_to_cpu(bmp[(ret & 0x3fff) >> 5]) | ~(((1 << n) - 1) << (ret & 0x1f))) != 0xffffffff)) {
hpfs_error(s, "Allocation doesn't work! Wanted %d, allocated at %08x", n, ret);
ret = 0;
goto b;
}
bmp[(ret & 0x3fff) >> 5] &= cpu_to_le32(~(((1 << n) - 1) << (ret & 0x1f)));
hpfs_mark_4buffers_dirty(&qbh);
}
b:
hpfs_brelse4(&qbh);
uls:
return ret;
}
/*
* Allocation strategy: 1) search place near the sector specified
* 2) search bitmap where free sectors last found
* 3) search all bitmaps
* 4) search all bitmaps ignoring number of pre-allocated
* sectors
*/
secno hpfs_alloc_sector(struct super_block *s, secno near, unsigned n, int forward)
{
secno sec;
int i;
unsigned n_bmps;
struct hpfs_sb_info *sbi = hpfs_sb(s);
int f_p = 0;
int near_bmp;
if (forward < 0) {
forward = -forward;
f_p = 1;
}
n_bmps = (sbi->sb_fs_size + 0x4000 - 1) >> 14;
if (near && near < sbi->sb_fs_size) {
if ((sec = alloc_in_bmp(s, near, n, f_p ? forward : forward/4))) goto ret;
near_bmp = near >> 14;
} else near_bmp = n_bmps / 2;
/*
if (b != -1) {
if ((sec = alloc_in_bmp(s, b<<14, n, f_p ? forward : forward/2))) {
b &= 0x0fffffff;
goto ret;
}
if (b > 0x10000000) if ((sec = alloc_in_bmp(s, (b&0xfffffff)<<14, n, f_p ? forward : 0))) goto ret;
*/
if (!f_p) if (forward > sbi->sb_max_fwd_alloc) forward = sbi->sb_max_fwd_alloc;
less_fwd:
for (i = 0; i < n_bmps; i++) {
if (near_bmp+i < n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i) << 14, n, forward)))) {
sbi->sb_c_bitmap = near_bmp+i;
goto ret;
}
if (!forward) {
if (near_bmp-i-1 >= 0 && ((sec = alloc_in_bmp(s, (near_bmp-i-1) << 14, n, forward)))) {
sbi->sb_c_bitmap = near_bmp-i-1;
goto ret;
}
} else {
if (near_bmp+i >= n_bmps && ((sec = alloc_in_bmp(s, (near_bmp+i-n_bmps) << 14, n, forward)))) {
sbi->sb_c_bitmap = near_bmp+i-n_bmps;
goto ret;
}
}
if (i == 1 && sbi->sb_c_bitmap != -1 && ((sec = alloc_in_bmp(s, (sbi->sb_c_bitmap) << 14, n, forward)))) {
goto ret;
}
}
if (!f_p) {
if (forward) {
sbi->sb_max_fwd_alloc = forward * 3 / 4;
forward /= 2;
goto less_fwd;
}
}
sec = 0;
ret:
if (sec) {
i = 0;
do
hpfs_claim_alloc(s, sec + i);
while (unlikely(++i < n));
}
if (sec && f_p) {
for (i = 0; i < forward; i++) {
if (!hpfs_alloc_if_possible(s, sec + n + i)) {
hpfs_error(s, "Prealloc doesn't work! Wanted %d, allocated at %08x, can't allocate %d", forward, sec, i);
sec = 0;
break;
}
}
}
return sec;
}
static secno alloc_in_dirband(struct super_block *s, secno near)
{
unsigned nr = near;
secno sec;
struct hpfs_sb_info *sbi = hpfs_sb(s);
if (nr < sbi->sb_dirband_start)
nr = sbi->sb_dirband_start;
if (nr >= sbi->sb_dirband_start + sbi->sb_dirband_size)
nr = sbi->sb_dirband_start + sbi->sb_dirband_size - 4;
nr -= sbi->sb_dirband_start;
nr >>= 2;
sec = alloc_in_bmp(s, (~0x3fff) | nr, 1, 0);
if (!sec) return 0;
hpfs_claim_dirband_alloc(s, sec);
return ((sec & 0x3fff) << 2) + sbi->sb_dirband_start;
}
/* Alloc sector if it's free */
int hpfs_alloc_if_possible(struct super_block *s, secno sec)
{
struct quad_buffer_head qbh;
__le32 *bmp;
if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "aip"))) goto end;
if (le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) & (1 << (sec & 0x1f))) {
bmp[(sec & 0x3fff) >> 5] &= cpu_to_le32(~(1 << (sec & 0x1f)));
hpfs_mark_4buffers_dirty(&qbh);
hpfs_brelse4(&qbh);
hpfs_claim_alloc(s, sec);
return 1;
}
hpfs_brelse4(&qbh);
end:
return 0;
}
/* Free sectors in bitmaps */
void hpfs_free_sectors(struct super_block *s, secno sec, unsigned n)
{
struct quad_buffer_head qbh;
__le32 *bmp;
struct hpfs_sb_info *sbi = hpfs_sb(s);
/*printk("2 - ");*/
if (!n) return;
if (sec < 0x12) {
hpfs_error(s, "Trying to free reserved sector %08x", sec);
return;
}
sbi->sb_max_fwd_alloc += n > 0xffff ? 0xffff : n;
if (sbi->sb_max_fwd_alloc > 0xffffff) sbi->sb_max_fwd_alloc = 0xffffff;
new_map:
if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "free"))) {
return;
}
new_tst:
if ((le32_to_cpu(bmp[(sec & 0x3fff) >> 5]) >> (sec & 0x1f) & 1)) {
hpfs_error(s, "sector %08x not allocated", sec);
hpfs_brelse4(&qbh);
return;
}
bmp[(sec & 0x3fff) >> 5] |= cpu_to_le32(1 << (sec & 0x1f));
hpfs_claim_free(s, sec);
if (!--n) {
hpfs_mark_4buffers_dirty(&qbh);
hpfs_brelse4(&qbh);
return;
}
if (!(++sec & 0x3fff)) {
hpfs_mark_4buffers_dirty(&qbh);
hpfs_brelse4(&qbh);
goto new_map;
}
goto new_tst;
}
/*
* Check if there are at least n free dnodes on the filesystem.
* Called before adding to dnode. If we run out of space while
* splitting dnodes, it would corrupt dnode tree.
*/
int hpfs_check_free_dnodes(struct super_block *s, int n)
{
int n_bmps = (hpfs_sb(s)->sb_fs_size + 0x4000 - 1) >> 14;
int b = hpfs_sb(s)->sb_c_bitmap & 0x0fffffff;
int i, j;
__le32 *bmp;
struct quad_buffer_head qbh;
if ((bmp = hpfs_map_dnode_bitmap(s, &qbh))) {
for (j = 0; j < 512; j++) {
unsigned k;
if (!le32_to_cpu(bmp[j])) continue;
for (k = le32_to_cpu(bmp[j]); k; k >>= 1) if (k & 1) if (!--n) {
hpfs_brelse4(&qbh);
return 0;
}
}
}
hpfs_brelse4(&qbh);
i = 0;
if (hpfs_sb(s)->sb_c_bitmap != -1) {
bmp = hpfs_map_bitmap(s, b, &qbh, "chkdn1");
goto chk_bmp;
}
chk_next:
if (i == b) i++;
if (i >= n_bmps) return 1;
bmp = hpfs_map_bitmap(s, i, &qbh, "chkdn2");
chk_bmp:
if (bmp) {
for (j = 0; j < 512; j++) {
u32 k;
if (!le32_to_cpu(bmp[j])) continue;
for (k = 0xf; k; k <<= 4)
if ((le32_to_cpu(bmp[j]) & k) == k) {
if (!--n) {
hpfs_brelse4(&qbh);
return 0;
}
}
}
hpfs_brelse4(&qbh);
}
i++;
goto chk_next;
}
void hpfs_free_dnode(struct super_block *s, dnode_secno dno)
{
if (hpfs_sb(s)->sb_chk) if (dno & 3) {
hpfs_error(s, "hpfs_free_dnode: dnode %08x not aligned", dno);
return;
}
if (dno < hpfs_sb(s)->sb_dirband_start ||
dno >= hpfs_sb(s)->sb_dirband_start + hpfs_sb(s)->sb_dirband_size) {
hpfs_free_sectors(s, dno, 4);
} else {
struct quad_buffer_head qbh;
__le32 *bmp;
unsigned ssec = (dno - hpfs_sb(s)->sb_dirband_start) / 4;
if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) {
return;
}
bmp[ssec >> 5] |= cpu_to_le32(1 << (ssec & 0x1f));
hpfs_mark_4buffers_dirty(&qbh);
hpfs_brelse4(&qbh);
hpfs_claim_dirband_free(s, dno);
}
}
struct dnode *hpfs_alloc_dnode(struct super_block *s, secno near,
dnode_secno *dno, struct quad_buffer_head *qbh)
{
struct dnode *d;
if (hpfs_get_free_dnodes(s) > FREE_DNODES_ADD) {
if (!(*dno = alloc_in_dirband(s, near)))
if (!(*dno = hpfs_alloc_sector(s, near, 4, 0))) return NULL;
} else {
if (!(*dno = hpfs_alloc_sector(s, near, 4, 0)))
if (!(*dno = alloc_in_dirband(s, near))) return NULL;
}
if (!(d = hpfs_get_4sectors(s, *dno, qbh))) {
hpfs_free_dnode(s, *dno);
return NULL;
}
memset(d, 0, 2048);
d->magic = cpu_to_le32(DNODE_MAGIC);
d->first_free = cpu_to_le32(52);
d->dirent[0] = 32;
d->dirent[2] = 8;
d->dirent[30] = 1;
d->dirent[31] = 255;
d->self = cpu_to_le32(*dno);
return d;
}
struct fnode *hpfs_alloc_fnode(struct super_block *s, secno near, fnode_secno *fno,
struct buffer_head **bh)
{
struct fnode *f;
if (!(*fno = hpfs_alloc_sector(s, near, 1, FNODE_ALLOC_FWD))) return NULL;
if (!(f = hpfs_get_sector(s, *fno, bh))) {
hpfs_free_sectors(s, *fno, 1);
return NULL;
}
memset(f, 0, 512);
f->magic = cpu_to_le32(FNODE_MAGIC);
f->ea_offs = cpu_to_le16(0xc4);
f->btree.n_free_nodes = 8;
f->btree.first_free = cpu_to_le16(8);
return f;
}
struct anode *hpfs_alloc_anode(struct super_block *s, secno near, anode_secno *ano,
struct buffer_head **bh)
{
struct anode *a;
if (!(*ano = hpfs_alloc_sector(s, near, 1, ANODE_ALLOC_FWD))) return NULL;
if (!(a = hpfs_get_sector(s, *ano, bh))) {
hpfs_free_sectors(s, *ano, 1);
return NULL;
}
memset(a, 0, 512);
a->magic = cpu_to_le32(ANODE_MAGIC);
a->self = cpu_to_le32(*ano);
a->btree.n_free_nodes = 40;
a->btree.n_used_nodes = 0;
a->btree.first_free = cpu_to_le16(8);
return a;
}