--- /dev/null
+/*
+ * 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);
+ /*pr_info("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;
+}
Code Review / kvmfornfv.git / blobdiff