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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [fs/] [hpfs/] [alloc.c] - Blame information for rev 1765

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/*
 *  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;
        unsigned *bmp;
        if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "chk"))) goto fail;
        if ((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 >= s->s_hpfs_dirband_start && sec < s->s_hpfs_dirband_start + s->s_hpfs_dirband_size) {
                unsigned ssec = (sec - s->s_hpfs_dirband_start) / 4;
                if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto fail;
                if ((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 > s->s_hpfs_fs_size) {
                hpfs_error(s, "sector(s) '%s' badly placed at %08x", msg, start);
                return 1;
        }
        if (s->s_hpfs_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;
        unsigned *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;
        }
        lock_super(s);
        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, n + forward)) {
                ret = bs + nr;
                goto rt;
        }
        if (!tstbits(bmp, nr + 2*n, n + forward)) {
                ret = bs + nr + n;
                goto rt;
        }*/
        q = nr + n; b = 0;
        while ((a = tstbits(bmp, q, n + forward))) {
                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) {
                if (!bmp[i]) continue;
                if (n + forward >= 0x3f && bmp[i] != -1) continue;
                q = i<<5;
                if (i > 0) {
                        unsigned k = 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))) {
                        q += a;
                        if (n != 1) q = ((q-1)&~(n-1))+n;
                        if (q>>5 > i) break;
                }
                if (!a) {
                        ret = bs + q;
                        goto rt;
                }
        }
        rt:
        if (ret) {
                if (s->s_hpfs_chk && ((ret >> 14) != (bs >> 14) || (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] &= ~(((1 << n) - 1) << (ret & 0x1f));
                hpfs_mark_4buffers_dirty(&qbh);
        }
        b:
        hpfs_brelse4(&qbh);
        uls:
        unlock_super(s);
        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, int lock)
{
        secno sec;
        unsigned i;
        unsigned n_bmps;
        int b = s->s_hpfs_c_bitmap;
        int f_p = 0;
        if (forward < 0) {
                forward = -forward;
                f_p = 1;
        }
        if (lock) hpfs_lock_creation(s);
        if (near && near < s->s_hpfs_fs_size)
                if ((sec = alloc_in_bmp(s, near, n, f_p ? forward : forward/4))) goto ret;
        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;
        }
        n_bmps = (s->s_hpfs_fs_size + 0x4000 - 1) >> 14;
        for (i = 0; i < n_bmps / 2; i++) {
                if ((sec = alloc_in_bmp(s, (n_bmps/2+i) << 14, n, forward))) {
                        s->s_hpfs_c_bitmap = n_bmps/2+i;
                        goto ret;
                }
                if ((sec = alloc_in_bmp(s, (n_bmps/2-i-1) << 14, n, forward))) {
                        s->s_hpfs_c_bitmap = n_bmps/2-i-1;
                        goto ret;
                }
        }
        if ((sec = alloc_in_bmp(s, (n_bmps-1) << 14, n, forward))) {
                s->s_hpfs_c_bitmap = n_bmps-1;
                goto ret;
        }
        if (!f_p) {
                for (i = 0; i < n_bmps; i++)
                        if ((sec = alloc_in_bmp(s, i << 14, n, 0))) {
                                s->s_hpfs_c_bitmap = 0x10000000 + i;
                                goto ret;
                        }
        }
        sec = 0;
        ret:
        if (sec && f_p) {
                for (i = 0; i < forward; i++) {
                        if (!hpfs_alloc_if_possible_nolock(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;
                        }
                }
        }
        if (lock) hpfs_unlock_creation(s);
        return sec;
}
 
static secno alloc_in_dirband(struct super_block *s, secno near, int lock)
{
        unsigned nr = near;
        secno sec;
        if (nr < s->s_hpfs_dirband_start)
                nr = s->s_hpfs_dirband_start;
        if (nr >= s->s_hpfs_dirband_start + s->s_hpfs_dirband_size)
                nr = s->s_hpfs_dirband_start + s->s_hpfs_dirband_size - 4;
        nr -= s->s_hpfs_dirband_start;
        nr >>= 2;
        if (lock) hpfs_lock_creation(s);
        sec = alloc_in_bmp(s, (~0x3fff) | nr, 1, 0);
        if (lock) hpfs_unlock_creation(s);
        if (!sec) return 0;
        return ((sec & 0x3fff) << 2) + s->s_hpfs_dirband_start;
}
 
/* Alloc sector if it's free */
 
int hpfs_alloc_if_possible_nolock(struct super_block *s, secno sec)
{
        struct quad_buffer_head qbh;
        unsigned *bmp;
        lock_super(s);
        if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "aip"))) goto end;
        if (bmp[(sec & 0x3fff) >> 5] & (1 << (sec & 0x1f))) {
                bmp[(sec & 0x3fff) >> 5] &= ~(1 << (sec & 0x1f));
                hpfs_mark_4buffers_dirty(&qbh);
                hpfs_brelse4(&qbh);
                unlock_super(s);
                return 1;
        }
        hpfs_brelse4(&qbh);
        end:
        unlock_super(s);
        return 0;
}
 
int hpfs_alloc_if_possible(struct super_block *s, secno sec)
{
        int r;
        hpfs_lock_creation(s);
        r = hpfs_alloc_if_possible_nolock(s, sec);
        hpfs_unlock_creation(s);
        return r;
}
 
/* Free sectors in bitmaps */
 
void hpfs_free_sectors(struct super_block *s, secno sec, unsigned n)
{
        struct quad_buffer_head qbh;
        unsigned *bmp;
        /*printk("2 - ");*/
        if (!n) return;
        if (sec < 0x12) {
                hpfs_error(s, "Trying to free reserved sector %08x", sec);
                return;
        }
        lock_super(s);
        new_map:
        if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "free"))) {
                unlock_super(s);
                return;
        }
        new_tst:
        if ((bmp[(sec & 0x3fff) >> 5] >> (sec & 0x1f) & 1)) {
                hpfs_error(s, "sector %08x not allocated", sec);
                hpfs_brelse4(&qbh);
                unlock_super(s);
                return;
        }
        bmp[(sec & 0x3fff) >> 5] |= 1 << (sec & 0x1f);
        if (!--n) {
                hpfs_mark_4buffers_dirty(&qbh);
                hpfs_brelse4(&qbh);
                unlock_super(s);
                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 = (s->s_hpfs_fs_size + 0x4000 - 1) >> 14;
        int b = s->s_hpfs_c_bitmap & 0x0fffffff;
        int i, j;
        unsigned *bmp;
        struct quad_buffer_head qbh;
        if ((bmp = hpfs_map_dnode_bitmap(s, &qbh))) {
                for (j = 0; j < 512; j++) {
                        unsigned k;
                        if (!bmp[j]) continue;
                        for (k = bmp[j]; k; k >>= 1) if (k & 1) if (!--n) {
                                hpfs_brelse4(&qbh);
                                return 0;
                        }
                }
        }
        hpfs_brelse4(&qbh);
        i = 0;
        if (s->s_hpfs_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++) {
                        unsigned k;
                        if (!bmp[j]) continue;
                        for (k = 0xf; k; k <<= 4)
                                if ((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 (s->s_hpfs_chk) if (dno & 3) {
                hpfs_error(s, "hpfs_free_dnode: dnode %08x not aligned", dno);
                return;
        }
        if (dno < s->s_hpfs_dirband_start ||
            dno >= s->s_hpfs_dirband_start + s->s_hpfs_dirband_size) {
                hpfs_free_sectors(s, dno, 4);
        } else {
                struct quad_buffer_head qbh;
                unsigned *bmp;
                unsigned ssec = (dno - s->s_hpfs_dirband_start) / 4;
                lock_super(s);
                if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) {
                        unlock_super(s);
                        return;
                }
                bmp[ssec >> 5] |= 1 << (ssec & 0x1f);
                hpfs_mark_4buffers_dirty(&qbh);
                hpfs_brelse4(&qbh);
                unlock_super(s);
        }
}
 
struct dnode *hpfs_alloc_dnode(struct super_block *s, secno near,
                         dnode_secno *dno, struct quad_buffer_head *qbh,
                         int lock)
{
        struct dnode *d;
        if (hpfs_count_one_bitmap(s, s->s_hpfs_dmap) > FREE_DNODES_ADD) {
                if (!(*dno = alloc_in_dirband(s, near, lock)))
                        if (!(*dno = hpfs_alloc_sector(s, near, 4, 0, lock))) return NULL;
        } else {
                if (!(*dno = hpfs_alloc_sector(s, near, 4, 0, lock)))
                        if (!(*dno = alloc_in_dirband(s, near, lock))) return NULL;
        }
        if (!(d = hpfs_get_4sectors(s, *dno, qbh))) {
                hpfs_free_dnode(s, *dno);
                return NULL;
        }
        memset(d, 0, 2048);
        d->magic = DNODE_MAGIC;
        d->first_free = 52;
        d->dirent[0] = 32;
        d->dirent[2] = 8;
        d->dirent[30] = 1;
        d->dirent[31] = 255;
        d->self = *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, 1))) return NULL;
        if (!(f = hpfs_get_sector(s, *fno, bh))) {
                hpfs_free_sectors(s, *fno, 1);
                return NULL;
        }
        memset(f, 0, 512);
        f->magic = FNODE_MAGIC;
        f->ea_offs = 0xc4;
        f->btree.n_free_nodes = 8;
        f->btree.first_free = 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, 1))) return NULL;
        if (!(a = hpfs_get_sector(s, *ano, bh))) {
                hpfs_free_sectors(s, *ano, 1);
                return NULL;
        }
        memset(a, 0, 512);
        a->magic = ANODE_MAGIC;
        a->self = *ano;
        a->btree.n_free_nodes = 40;
        a->btree.n_used_nodes = 0;
        a->btree.first_free = 8;
        return a;
}

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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [fs/] [hpfs/] [alloc.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	1275	phoenix	`/*`
2			`* linux/fs/hpfs/alloc.c`
3			`*`
4			`* Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999`
5			`*`
6			`* HPFS bitmap operations`
7			`*/`
8
9			`#include "hpfs_fn.h"`
10
11			`/*`
12			`* Check if a sector is allocated in bitmap`
13			`* This is really slow. Turned on only if chk==2`
14			`*/`
15
16			`static int chk_if_allocated(struct super_block s, secno sec, char msg)`
17			`{`
18			`struct quad_buffer_head qbh;`
19			`unsigned *bmp;`
20			`if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "chk"))) goto fail;`
21			`if ((bmp[(sec & 0x3fff) >> 5] >> (sec & 0x1f)) & 1) {`
22			`hpfs_error(s, "sector '%s' - %08x not allocated in bitmap", msg, sec);`
23			`goto fail1;`
24			`}`
25			`hpfs_brelse4(&qbh);`
26			`if (sec >= s->s_hpfs_dirband_start && sec < s->s_hpfs_dirband_start + s->s_hpfs_dirband_size) {`
27			`unsigned ssec = (sec - s->s_hpfs_dirband_start) / 4;`
28			`if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto fail;`
29			`if ((bmp[ssec >> 5] >> (ssec & 0x1f)) & 1) {`
30			`hpfs_error(s, "sector '%s' - %08x not allocated in directory bitmap", msg, sec);`
31			`goto fail1;`
32			`}`
33			`hpfs_brelse4(&qbh);`
34			`}`
35			`return 0;`
36			`fail1:`
37			`hpfs_brelse4(&qbh);`
38			`fail:`
39			`return 1;`
40			`}`
41
42			`/*`
43			`* Check if sector(s) have proper number and additionally check if they're`
44			`* allocated in bitmap.`
45			`*/`
46
47			`int hpfs_chk_sectors(struct super_block s, secno start, int len, char msg)`
48			`{`
49			`if (start + len < start \|\| start < 0x12 \|\|`
50			`start + len > s->s_hpfs_fs_size) {`
51			`hpfs_error(s, "sector(s) '%s' badly placed at %08x", msg, start);`
52			`return 1;`
53			`}`
54			`if (s->s_hpfs_chk>=2) {`
55			`int i;`
56			`for (i = 0; i < len; i++)`
57			`if (chk_if_allocated(s, start + i, msg)) return 1;`
58			`}`
59			`return 0;`
60			`}`
61
62			`static secno alloc_in_bmp(struct super_block *s, secno near, unsigned n, unsigned forward)`
63			`{`
64			`struct quad_buffer_head qbh;`
65			`unsigned *bmp;`
66			`unsigned bs = near & ~0x3fff;`
67			`unsigned nr = (near & 0x3fff) & ~(n - 1);`
68			`/unsigned mnr;/`
69			`unsigned i, q;`
70			`int a, b;`
71			`secno ret = 0;`
72			`if (n != 1 && n != 4) {`
73			`hpfs_error(s, "Bad allocation size: %d", n);`
74			`return 0;`
75			`}`
76			`lock_super(s);`
77			`if (bs != ~0x3fff) {`
78			`if (!(bmp = hpfs_map_bitmap(s, near >> 14, &qbh, "aib"))) goto uls;`
79			`} else {`
80			`if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) goto uls;`
81			`}`
82			`/*if (!tstbits(bmp, nr + n, n + forward)) {`
83			`ret = bs + nr;`
84			`goto rt;`
85			`}`
86			`if (!tstbits(bmp, nr + 2*n, n + forward)) {`
87			`ret = bs + nr + n;`
88			`goto rt;`
89			`}*/`
90			`q = nr + n; b = 0;`
91			`while ((a = tstbits(bmp, q, n + forward))) {`
92			`q += a;`
93			`if (n != 1) q = ((q-1)&~(n-1))+n;`
94			`if (!b) {`
95			`if (q>>5 != nr>>5) {`
96			`b = 1;`
97			`q = nr & 0x1f;`
98			`}`
99			`} else if (q > nr) break;`
100			`}`
101			`if (!a) {`
102			`ret = bs + q;`
103			`goto rt;`
104			`}`
105			`nr >>= 5;`
106			`for (i = nr + 1; i != nr; i++, i &= 0x1ff) {`
107			`if (!bmp[i]) continue;`
108			`if (n + forward >= 0x3f && bmp[i] != -1) continue;`
109			`q = i<<5;`
110			`if (i > 0) {`
111			`unsigned k = bmp[i-1];`
112			`while (k & 0x80000000) {`
113			`q--; k <<= 1;`
114			`}`
115			`}`
116			`if (n != 1) q = ((q-1)&~(n-1))+n;`
117			`while ((a = tstbits(bmp, q, n + forward))) {`
118			`q += a;`
119			`if (n != 1) q = ((q-1)&~(n-1))+n;`
120			`if (q>>5 > i) break;`
121			`}`
122			`if (!a) {`
123			`ret = bs + q;`
124			`goto rt;`
125			`}`
126			`}`
127			`rt:`
128			`if (ret) {`
129			`if (s->s_hpfs_chk && ((ret >> 14) != (bs >> 14) \|\| (bmp[(ret & 0x3fff) >> 5] \| ~(((1 << n) - 1) << (ret & 0x1f))) != 0xffffffff)) {`
130			`hpfs_error(s, "Allocation doesn't work! Wanted %d, allocated at %08x", n, ret);`
131			`ret = 0;`
132			`goto b;`
133			`}`
134			`bmp[(ret & 0x3fff) >> 5] &= ~(((1 << n) - 1) << (ret & 0x1f));`
135			`hpfs_mark_4buffers_dirty(&qbh);`
136			`}`
137			`b:`
138			`hpfs_brelse4(&qbh);`
139			`uls:`
140			`unlock_super(s);`
141			`return ret;`
142			`}`
143
144			`/*`
145			`* Allocation strategy: 1) search place near the sector specified`
146			`* 2) search bitmap where free sectors last found`
147			`* 3) search all bitmaps`
148			`* 4) search all bitmaps ignoring number of pre-allocated`
149			`* sectors`
150			`*/`
151
152			`secno hpfs_alloc_sector(struct super_block *s, secno near, unsigned n, int forward, int lock)`
153			`{`
154			`secno sec;`
155			`unsigned i;`
156			`unsigned n_bmps;`
157			`int b = s->s_hpfs_c_bitmap;`
158			`int f_p = 0;`
159			`if (forward < 0) {`
160			`forward = -forward;`
161			`f_p = 1;`
162			`}`
163			`if (lock) hpfs_lock_creation(s);`
164			`if (near && near < s->s_hpfs_fs_size)`
165			`if ((sec = alloc_in_bmp(s, near, n, f_p ? forward : forward/4))) goto ret;`
166			`if (b != -1) {`
167			`if ((sec = alloc_in_bmp(s, b<<14, n, f_p ? forward : forward/2))) {`
168			`b &= 0x0fffffff;`
169			`goto ret;`
170			`}`
171			`if (b > 0x10000000) if ((sec = alloc_in_bmp(s, (b&0xfffffff)<<14, n, f_p ? forward : 0))) goto ret;`
172			`}`
173			`n_bmps = (s->s_hpfs_fs_size + 0x4000 - 1) >> 14;`
174			`for (i = 0; i < n_bmps / 2; i++) {`
175			`if ((sec = alloc_in_bmp(s, (n_bmps/2+i) << 14, n, forward))) {`
176			`s->s_hpfs_c_bitmap = n_bmps/2+i;`
177			`goto ret;`
178			`}`
179			`if ((sec = alloc_in_bmp(s, (n_bmps/2-i-1) << 14, n, forward))) {`
180			`s->s_hpfs_c_bitmap = n_bmps/2-i-1;`
181			`goto ret;`
182			`}`
183			`}`
184			`if ((sec = alloc_in_bmp(s, (n_bmps-1) << 14, n, forward))) {`
185			`s->s_hpfs_c_bitmap = n_bmps-1;`
186			`goto ret;`
187			`}`
188			`if (!f_p) {`
189			`for (i = 0; i < n_bmps; i++)`
190			`if ((sec = alloc_in_bmp(s, i << 14, n, 0))) {`
191			`s->s_hpfs_c_bitmap = 0x10000000 + i;`
192			`goto ret;`
193			`}`
194			`}`
195			`sec = 0;`
196			`ret:`
197			`if (sec && f_p) {`
198			`for (i = 0; i < forward; i++) {`
199			`if (!hpfs_alloc_if_possible_nolock(s, sec + i + 1)) {`
200			`hpfs_error(s, "Prealloc doesn't work! Wanted %d, allocated at %08x, can't allocate %d", forward, sec, i);`
201			`sec = 0;`
202			`break;`
203			`}`
204			`}`
205			`}`
206			`if (lock) hpfs_unlock_creation(s);`
207			`return sec;`
208			`}`
209
210			`static secno alloc_in_dirband(struct super_block *s, secno near, int lock)`
211			`{`
212			`unsigned nr = near;`
213			`secno sec;`
214			`if (nr < s->s_hpfs_dirband_start)`
215			`nr = s->s_hpfs_dirband_start;`
216			`if (nr >= s->s_hpfs_dirband_start + s->s_hpfs_dirband_size)`
217			`nr = s->s_hpfs_dirband_start + s->s_hpfs_dirband_size - 4;`
218			`nr -= s->s_hpfs_dirband_start;`
219			`nr >>= 2;`
220			`if (lock) hpfs_lock_creation(s);`
221			`sec = alloc_in_bmp(s, (~0x3fff) \| nr, 1, 0);`
222			`if (lock) hpfs_unlock_creation(s);`
223			`if (!sec) return 0;`
224			`return ((sec & 0x3fff) << 2) + s->s_hpfs_dirband_start;`
225			`}`
226
227			`/* Alloc sector if it's free */`
228
229			`int hpfs_alloc_if_possible_nolock(struct super_block *s, secno sec)`
230			`{`
231			`struct quad_buffer_head qbh;`
232			`unsigned *bmp;`
233			`lock_super(s);`
234			`if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "aip"))) goto end;`
235			`if (bmp[(sec & 0x3fff) >> 5] & (1 << (sec & 0x1f))) {`
236			`bmp[(sec & 0x3fff) >> 5] &= ~(1 << (sec & 0x1f));`
237			`hpfs_mark_4buffers_dirty(&qbh);`
238			`hpfs_brelse4(&qbh);`
239			`unlock_super(s);`
240			`return 1;`
241			`}`
242			`hpfs_brelse4(&qbh);`
243			`end:`
244			`unlock_super(s);`
245			`return 0;`
246			`}`
247
248			`int hpfs_alloc_if_possible(struct super_block *s, secno sec)`
249			`{`
250			`int r;`
251			`hpfs_lock_creation(s);`
252			`r = hpfs_alloc_if_possible_nolock(s, sec);`
253			`hpfs_unlock_creation(s);`
254			`return r;`
255			`}`
256
257			`/* Free sectors in bitmaps */`
258
259			`void hpfs_free_sectors(struct super_block *s, secno sec, unsigned n)`
260			`{`
261			`struct quad_buffer_head qbh;`
262			`unsigned *bmp;`
263			`/printk("2 - ");/`
264			`if (!n) return;`
265			`if (sec < 0x12) {`
266			`hpfs_error(s, "Trying to free reserved sector %08x", sec);`
267			`return;`
268			`}`
269			`lock_super(s);`
270			`new_map:`
271			`if (!(bmp = hpfs_map_bitmap(s, sec >> 14, &qbh, "free"))) {`
272			`unlock_super(s);`
273			`return;`
274			`}`
275			`new_tst:`
276			`if ((bmp[(sec & 0x3fff) >> 5] >> (sec & 0x1f) & 1)) {`
277			`hpfs_error(s, "sector %08x not allocated", sec);`
278			`hpfs_brelse4(&qbh);`
279			`unlock_super(s);`
280			`return;`
281			`}`
282			`bmp[(sec & 0x3fff) >> 5] \|= 1 << (sec & 0x1f);`
283			`if (!--n) {`
284			`hpfs_mark_4buffers_dirty(&qbh);`
285			`hpfs_brelse4(&qbh);`
286			`unlock_super(s);`
287			`return;`
288			`}`
289			`if (!(++sec & 0x3fff)) {`
290			`hpfs_mark_4buffers_dirty(&qbh);`
291			`hpfs_brelse4(&qbh);`
292			`goto new_map;`
293			`}`
294			`goto new_tst;`
295			`}`
296
297			`/*`
298			`* Check if there are at least n free dnodes on the filesystem.`
299			`* Called before adding to dnode. If we run out of space while`
300			`* splitting dnodes, it would corrupt dnode tree.`
301			`*/`
302
303			`int hpfs_check_free_dnodes(struct super_block *s, int n)`
304			`{`
305			`int n_bmps = (s->s_hpfs_fs_size + 0x4000 - 1) >> 14;`
306			`int b = s->s_hpfs_c_bitmap & 0x0fffffff;`
307			`int i, j;`
308			`unsigned *bmp;`
309			`struct quad_buffer_head qbh;`
310			`if ((bmp = hpfs_map_dnode_bitmap(s, &qbh))) {`
311			`for (j = 0; j < 512; j++) {`
312			`unsigned k;`
313			`if (!bmp[j]) continue;`
314			`for (k = bmp[j]; k; k >>= 1) if (k & 1) if (!--n) {`
315			`hpfs_brelse4(&qbh);`
316			`return 0;`
317			`}`
318			`}`
319			`}`
320			`hpfs_brelse4(&qbh);`
321			`i = 0;`
322			`if (s->s_hpfs_c_bitmap != -1 ) {`
323			`bmp = hpfs_map_bitmap(s, b, &qbh, "chkdn1");`
324			`goto chk_bmp;`
325			`}`
326			`chk_next:`
327			`if (i == b) i++;`
328			`if (i >= n_bmps) return 1;`
329			`bmp = hpfs_map_bitmap(s, i, &qbh, "chkdn2");`
330			`chk_bmp:`
331			`if (bmp) {`
332			`for (j = 0; j < 512; j++) {`
333			`unsigned k;`
334			`if (!bmp[j]) continue;`
335			`for (k = 0xf; k; k <<= 4)`
336			`if ((bmp[j] & k) == k) {`
337			`if (!--n) {`
338			`hpfs_brelse4(&qbh);`
339			`return 0;`
340			`}`
341			`}`
342			`}`
343			`hpfs_brelse4(&qbh);`
344			`}`
345			`i++;`
346			`goto chk_next;`
347			`}`
348
349			`void hpfs_free_dnode(struct super_block *s, dnode_secno dno)`
350			`{`
351			`if (s->s_hpfs_chk) if (dno & 3) {`
352			`hpfs_error(s, "hpfs_free_dnode: dnode %08x not aligned", dno);`
353			`return;`
354			`}`
355			`if (dno < s->s_hpfs_dirband_start \|\|`
356			`dno >= s->s_hpfs_dirband_start + s->s_hpfs_dirband_size) {`
357			`hpfs_free_sectors(s, dno, 4);`
358			`} else {`
359			`struct quad_buffer_head qbh;`
360			`unsigned *bmp;`
361			`unsigned ssec = (dno - s->s_hpfs_dirband_start) / 4;`
362			`lock_super(s);`
363			`if (!(bmp = hpfs_map_dnode_bitmap(s, &qbh))) {`
364			`unlock_super(s);`
365			`return;`
366			`}`
367			`bmp[ssec >> 5] \|= 1 << (ssec & 0x1f);`
368			`hpfs_mark_4buffers_dirty(&qbh);`
369			`hpfs_brelse4(&qbh);`
370			`unlock_super(s);`
371			`}`
372			`}`
373
374			`struct dnode hpfs_alloc_dnode(struct super_block s, secno near,`
375			`dnode_secno dno, struct quad_buffer_head qbh,`
376			`int lock)`
377			`{`
378			`struct dnode *d;`
379			`if (hpfs_count_one_bitmap(s, s->s_hpfs_dmap) > FREE_DNODES_ADD) {`
380			`if (!(*dno = alloc_in_dirband(s, near, lock)))`
381			`if (!(*dno = hpfs_alloc_sector(s, near, 4, 0, lock))) return NULL;`
382			`} else {`
383			`if (!(*dno = hpfs_alloc_sector(s, near, 4, 0, lock)))`
384			`if (!(*dno = alloc_in_dirband(s, near, lock))) return NULL;`
385			`}`
386			`if (!(d = hpfs_get_4sectors(s, *dno, qbh))) {`
387			`hpfs_free_dnode(s, *dno);`
388			`return NULL;`
389			`}`
390			`memset(d, 0, 2048);`
391			`d->magic = DNODE_MAGIC;`
392			`d->first_free = 52;`
393			`d->dirent[0] = 32;`
394			`d->dirent[2] = 8;`
395			`d->dirent[30] = 1;`
396			`d->dirent[31] = 255;`
397			`d->self = *dno;`
398			`return d;`
399			`}`
400
401			`struct fnode hpfs_alloc_fnode(struct super_block s, secno near, fnode_secno *fno,`
402			`struct buffer_head **bh)`
403			`{`
404			`struct fnode *f;`
405			`if (!(*fno = hpfs_alloc_sector(s, near, 1, FNODE_ALLOC_FWD, 1))) return NULL;`
406			`if (!(f = hpfs_get_sector(s, *fno, bh))) {`
407			`hpfs_free_sectors(s, *fno, 1);`
408			`return NULL;`
409			`}`
410			`memset(f, 0, 512);`
411			`f->magic = FNODE_MAGIC;`
412			`f->ea_offs = 0xc4;`
413			`f->btree.n_free_nodes = 8;`
414			`f->btree.first_free = 8;`
415			`return f;`
416			`}`
417
418			`struct anode hpfs_alloc_anode(struct super_block s, secno near, anode_secno *ano,`
419			`struct buffer_head **bh)`
420			`{`
421			`struct anode *a;`
422			`if (!(*ano = hpfs_alloc_sector(s, near, 1, ANODE_ALLOC_FWD, 1))) return NULL;`
423			`if (!(a = hpfs_get_sector(s, *ano, bh))) {`
424			`hpfs_free_sectors(s, *ano, 1);`
425			`return NULL;`
426			`}`
427			`memset(a, 0, 512);`
428			`a->magic = ANODE_MAGIC;`
429			`a->self = *ano;`
430			`a->btree.n_free_nodes = 40;`
431			`a->btree.n_used_nodes = 0;`
432			`a->btree.first_free = 8;`
433			`return a;`
434			`}`