--- /dev/null
+#include <lunaix/mm/valloc.h>
+
+#include "ext2.h"
+
+bcache_zone_t gdesc_bcache_zone;
+
+static void
+__cached_gdesc_evict(struct bcache* bc, void* data)
+{
+ struct ext2_gdesc* gd;
+ gd = (struct ext2_gdesc*)data;
+
+ llist_delete(&gd->groups);
+ llist_delete(&gd->free_grps_blk);
+ llist_delete(&gd->free_grps_ino);
+
+ fsblock_put(gd->buf);
+
+ vfree(gd);
+}
+
+static void
+__cached_gdesc_sync(struct bcache*, unsigned long tag, void* data)
+{
+ // since all mods to gdesc goes directly into fs buffer,
+ // we just need to invoke the sync on the underlying.
+
+ struct ext2_gdesc* gd;
+ gd = (struct ext2_gdesc*)data;
+
+ fsblock_sync(gd->buf);
+}
+
+static struct bcache_ops gdesc_bc_ops = {
+ .release_on_evict = __cached_gdesc_evict,
+ .sync_cached = __cached_gdesc_sync
+};
+
+void
+ext2gd_prepare_gdt(struct v_superblock* vsb)
+{
+ struct ext2b_super* sb;
+ unsigned int nr_parts;
+ unsigned int nr_gd_pb, nr_gd;
+ struct ext2_sbinfo* ext2sb;
+
+ ext2sb = EXT2_SB(vsb);
+ sb = ext2sb->raw;
+
+ nr_gd_pb = ext2sb->block_size / sizeof(struct ext2b_gdesc);
+ nr_gd = ICEIL(sb->s_blk_cnt, sb->s_blk_per_grp);
+ nr_parts = ICEIL(nr_gd, nr_gd_pb);
+
+ ext2sb->gdt_frag = (bbuf_t*)vcalloc(sizeof(bbuf_t), nr_parts);
+ ext2sb->nr_gdesc_pb = nr_gd_pb;
+ ext2sb->nr_gdesc = nr_gd;
+
+ bcache_init_zone(&ext2sb->gd_caches, gdesc_bcache_zone,
+ ilog2(64), 0, sizeof(struct ext2b_gdesc), &gdesc_bc_ops);
+
+ llist_init_head(&ext2sb->gds);
+ llist_init_head(&ext2sb->free_grps_blk);
+ llist_init_head(&ext2sb->free_grps_ino);
+}
+
+void
+ext2gd_release_gdt(struct v_superblock* vsb)
+{
+ unsigned int parts_cnt;
+ struct ext2_sbinfo* ext2sb;
+
+ ext2sb = EXT2_SB(vsb);
+ parts_cnt = ICEIL(ext2sb->nr_gdesc, ext2sb->nr_gdesc_pb);
+ for (size_t i = 0; i < parts_cnt; i++)
+ {
+ if (!ext2sb->gdt_frag[i]) {
+ continue;
+ }
+
+ fsblock_put(ext2sb->gdt_frag[i]);
+ ext2sb->gdt_frag[i] = NULL;
+ }
+}
+
+static inline bool
+__try_load_bitmap(struct v_superblock* vsb,
+ struct ext2_gdesc* gd, int type)
+{
+ struct ext2_sbinfo* ext2sb;
+ struct ext2_bmp* bmp;
+ struct llist_header* flist, *flist_entry;
+ bbuf_t buf;
+ unsigned int blk_id, bmp_blk_id, bmp_size;
+
+ ext2sb = EXT2_SB(vsb);
+
+ if (type == GDESC_INO_SEL) {
+ bmp_blk_id = gd->info->bg_ino_map;
+ bmp_size = ext2sb->raw->s_ino_per_grp;
+ bmp = &gd->ino_bmp;
+ }
+ else if (type == GDESC_BLK_SEL) {
+ bmp_blk_id = gd->info->bg_blk_map;
+ bmp_size = ext2sb->raw->s_blk_per_grp;
+ bmp = &gd->blk_bmp;
+ }
+ else {
+ fail_fs("unknown bitmap type");
+ }
+
+ flist = &ext2sb->free_list_sel[type];
+ flist_entry = &gd->free_list_sel[type];
+
+ blk_id = ext2_datablock(vsb, bmp_blk_id);
+ buf = fsblock_get(vsb, blk_id);
+ if (blkbuf_errbuf(buf)) {
+ return false;
+ }
+
+ ext2bmp_init(bmp, buf, bmp_size);
+
+ if (ext2bmp_check_free(bmp)) {
+ llist_append(flist, flist_entry);
+ }
+
+ return true;
+}
+
+int
+ext2gd_take(struct v_superblock* vsb,
+ unsigned int index, struct ext2_gdesc** out)
+{
+ bbuf_t part, buf;
+ struct ext2_sbinfo* ext2sb;
+ unsigned int blk_id, blk_off;
+
+ ext2sb = EXT2_SB(vsb);
+
+ if (index >= ext2sb->nr_gdesc) {
+ return ENOENT;
+ }
+
+ bcobj_t cached;
+ if (bcache_tryget(&ext2sb->gd_caches, index, &cached)) {
+ *out = (struct ext2_gdesc*)bcached_data(cached);
+ return 0;
+ }
+
+ blk_id = index / ext2sb->nr_gdesc_pb;
+ blk_off = index % ext2sb->nr_gdesc_pb;
+
+ part = ext2sb->gdt_frag[blk_id];
+ if (!part) {
+ blk_id = ext2_datablock(vsb, blk_id + 1);
+ part = fsblock_get(vsb, blk_id);
+ if (!part) {
+ return EIO;
+ }
+
+ ext2sb->gdt_frag[blk_id] = part;
+ }
+
+ struct ext2_gdesc* gd;
+
+ gd = valloc(sizeof(struct ext2_gdesc));
+ *gd = (struct ext2_gdesc) {
+ .info = &block_buffer(part, struct ext2b_gdesc)[blk_off],
+ .buf = part,
+ .base = index * ext2sb->raw->s_blk_per_grp,
+ .ino_base = index * ext2sb->raw->s_ino_per_grp
+ };
+
+ *out = gd;
+
+ if (!ext2sb->read_only) {
+ if (!__try_load_bitmap(vsb, gd, GDESC_INO_SEL)) {
+ goto cleanup;
+ }
+
+ if (!__try_load_bitmap(vsb, gd, GDESC_BLK_SEL)) {
+ llist_delete(&gd->free_grps_ino);
+ goto cleanup;
+ }
+ }
+
+ llist_append(&ext2sb->gds, &gd->groups);
+
+ cached = bcache_put_and_ref(&ext2sb->gd_caches, index, gd);
+ gd->cache_ref = cached;
+ gd->sb = ext2sb;
+
+ return 0;
+
+cleanup:
+ *out = NULL;
+
+ vfree(gd);
+ return EIO;
+}
+
+static void
+__ext2bmp_update_next_free_cell(struct ext2_bmp* e_bmp)
+{
+ unsigned int i;
+ unsigned int end;
+
+ i = valid_bmp_slot(e_bmp->next_free) ? e_bmp->next_free : 0;
+ end = i;
+
+ // next fit, try to maximize our locality without going after
+ // some crazy algorithm
+ do {
+ if (e_bmp->bmp[i] != 0xff) {
+ e_bmp->next_free = i;
+ return;
+ }
+
+ if (++i == e_bmp->nr_bytes) {
+ i = 0;
+ }
+ }
+ while (i != end);
+
+ e_bmp->next_free = ALLOC_FAIL;
+}
+
+void
+ext2bmp_init(struct ext2_bmp* e_bmp, bbuf_t bmp_buf, unsigned int nr_bits)
+{
+ assert(nr_bits % 8 == 0);
+
+ e_bmp->bmp = blkbuf_data(bmp_buf);
+ e_bmp->raw = bmp_buf;
+ e_bmp->nr_bytes = nr_bits / 8;
+
+ __ext2bmp_update_next_free_cell(e_bmp);
+}
+
+bool
+ext2bmp_check_free(struct ext2_bmp* e_bmp)
+{
+ assert(e_bmp->raw);
+
+ return valid_bmp_slot(e_bmp->next_free);
+}
+
+int
+ext2bmp_alloc_one(struct ext2_bmp* e_bmp)
+{
+ assert(e_bmp->raw);
+
+ u8_t cell;
+ int slot, next_free;
+
+ if (!valid_bmp_slot(e_bmp->next_free)) {
+ return ALLOC_FAIL;
+ }
+
+ slot = 0;
+ next_free = e_bmp->next_free;
+ cell = e_bmp->bmp[next_free];
+ assert(cell != 0xff);
+
+ while ((cell & (1 << slot++)));
+
+ cell |= (1 << --slot);
+ slot += (next_free * 8);
+ e_bmp->bmp[next_free] = cell;
+
+ if (cell == 0xff) {
+ __ext2bmp_update_next_free_cell(e_bmp);
+ }
+
+ fsblock_dirty(e_bmp->raw);
+ return slot;
+}
+
+void
+ext2bmp_free_one(struct ext2_bmp* e_bmp, unsigned int pos)
+{
+ assert(e_bmp->raw);
+
+ int cell_idx = pos / 8;
+ u8_t cell_mask = 1 << (pos % 8);
+ e_bmp->bmp[cell_idx] &= ~cell_mask;
+
+ if (!valid_bmp_slot(e_bmp->next_free)) {
+ e_bmp->next_free = cell_idx;
+ }
+
+ fsblock_dirty(e_bmp->raw);
+}
+
+void
+ext2bmp_discard(struct ext2_bmp* e_bmp)
+{
+ assert(e_bmp->raw);
+
+ fsblock_put(e_bmp->raw);
+ e_bmp->raw = NULL;
+}
\ No newline at end of file
git://scm.lunaixsky.com / lunaix-os.git / blobdiff