mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 19:00:25 +00:00
424 lines
11 KiB
C
424 lines
11 KiB
C
/*
|
|
* linux/fs/hpfs/alloc.c
|
|
*
|
|
* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
|
|
*
|
|
* HPFS bitmap operations
|
|
*/
|
|
|
|
#include "hpfs_fn.h"
|
|
|
|
/*
|
|
* 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 && f_p) {
|
|
for (i = 0; i < forward; i++) {
|
|
if (!hpfs_alloc_if_possible(s, sec + i + 1)) {
|
|
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;
|
|
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);
|
|
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));
|
|
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);
|
|
}
|
|
}
|
|
|
|
struct dnode *hpfs_alloc_dnode(struct super_block *s, secno near,
|
|
dnode_secno *dno, struct quad_buffer_head *qbh)
|
|
{
|
|
struct dnode *d;
|
|
if (hpfs_count_one_bitmap(s, hpfs_sb(s)->sb_dmap) > 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;
|
|
}
|