1 files changed, 456 insertions, 0 deletions

diff --git a/fs/hpfs/alloc.c b/fs/hpfs/alloc.c
new file mode 100644
index 000000000000..5503e2c28910
--- /dev/null
+++ b/fs/hpfs/alloc.c
@@ -0,0 +1,456 @@
+/*
+ *  linux/fs/hpfs/alloc.c
+ *
+ *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
+ *
+ *  HPFS bitmap operations
+ */
+
+#include "hpfs_fn.h"
+
+static int hpfs_alloc_if_possible_nolock(struct super_block *s, secno sec);
+
+/*
+ * 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 >= 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 ((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;
+        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 + forward)) {
+                ret = bs + nr;
+                goto rt;
+        }
+        /*if (!tstbits(bmp, nr + n, n + forward)) {
+                ret = bs + nr + n;
+                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 (!bmp[i]) goto cont;
+                if (n + forward >= 0x3f && bmp[i] != -1) goto cont;
+                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)) != 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) || (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;
+        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;
+        }
+        if (lock) hpfs_lock_creation(s);
+        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_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;
+        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;
+        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) + sbi->sb_dirband_start;
+}
+
+/* Alloc sector if it's free */
+
+static 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;
+        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;
+        }
+        lock_super(s);
+        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"))) {
+                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 = (hpfs_sb(s)->sb_fs_size + 0x4000 - 1) >> 14;
+        int b = hpfs_sb(s)->sb_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 (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++) {
+                        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 (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;
+                unsigned *bmp;
+                unsigned ssec = (dno - hpfs_sb(s)->sb_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, hpfs_sb(s)->sb_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;
+}