nilfs2: direct block mapping

This adds block mappings using direct pointers which are stored in the
i_bmap array of inode.

Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 429 insertions, 0 deletions

diff --git a/fs/nilfs2/direct.c b/fs/nilfs2/direct.c
new file mode 100644
index 000000000000..303d7f1982f9
--- /dev/null
+++ b/fs/nilfs2/direct.c
@@ -0,0 +1,429 @@
+/*
+ * direct.c - NILFS direct block pointer.
+ *
+ * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Written by Koji Sato <koji@osrg.net>.
+ */
+
+#include <linux/errno.h>
+#include "nilfs.h"
+#include "page.h"
+#include "direct.h"
+#include "alloc.h"
+
+static inline __le64 *nilfs_direct_dptrs(const struct nilfs_direct *direct)
+{
+        return (__le64 *)
+                ((struct nilfs_direct_node *)direct->d_bmap.b_u.u_data + 1);
+}
+
+static inline __u64
+nilfs_direct_get_ptr(const struct nilfs_direct *direct, __u64 key)
+{
+        return nilfs_bmap_dptr_to_ptr(*(nilfs_direct_dptrs(direct) + key));
+}
+
+static inline void nilfs_direct_set_ptr(struct nilfs_direct *direct,
+                                        __u64 key, __u64 ptr)
+{
+        *(nilfs_direct_dptrs(direct) + key) = nilfs_bmap_ptr_to_dptr(ptr);
+}
+
+static int nilfs_direct_lookup(const struct nilfs_bmap *bmap,
+                               __u64 key, int level, __u64 *ptrp)
+{
+        struct nilfs_direct *direct;
+        __u64 ptr;
+
+        direct = (struct nilfs_direct *)bmap;
+        if ((key > NILFS_DIRECT_KEY_MAX) ||
+            (level != 1) ||     /* XXX: use macro for level 1 */
+            ((ptr = nilfs_direct_get_ptr(direct, key)) ==
+             NILFS_BMAP_INVALID_PTR))
+                return -ENOENT;
+
+        if (ptrp != NULL)
+                *ptrp = ptr;
+        return 0;
+}
+
+static __u64
+nilfs_direct_find_target_v(const struct nilfs_direct *direct, __u64 key)
+{
+        __u64 ptr;
+
+        ptr = nilfs_bmap_find_target_seq(&direct->d_bmap, key);
+        if (ptr != NILFS_BMAP_INVALID_PTR)
+                /* sequential access */
+                return ptr;
+        else
+                /* block group */
+                return nilfs_bmap_find_target_in_group(&direct->d_bmap);
+}
+
+static void nilfs_direct_set_target_v(struct nilfs_direct *direct,
+                                      __u64 key, __u64 ptr)
+{
+        direct->d_bmap.b_last_allocated_key = key;
+        direct->d_bmap.b_last_allocated_ptr = ptr;
+}
+
+static int nilfs_direct_prepare_insert(struct nilfs_direct *direct,
+                                       __u64 key,
+                                       union nilfs_bmap_ptr_req *req,
+                                       struct nilfs_bmap_stats *stats)
+{
+        int ret;
+
+        if (direct->d_ops->dop_find_target != NULL)
+                req->bpr_ptr = (*direct->d_ops->dop_find_target)(direct, key);
+        ret = (*direct->d_bmap.b_pops->bpop_prepare_alloc_ptr)(&direct->d_bmap,
+                                                               req);
+        if (ret < 0)
+                return ret;
+
+        stats->bs_nblocks = 1;
+        return 0;
+}
+
+static void nilfs_direct_commit_insert(struct nilfs_direct *direct,
+                                       union nilfs_bmap_ptr_req *req,
+                                       __u64 key, __u64 ptr)
+{
+        struct buffer_head *bh;
+
+        /* ptr must be a pointer to a buffer head. */
+        bh = (struct buffer_head *)((unsigned long)ptr);
+        set_buffer_nilfs_volatile(bh);
+
+        if (direct->d_bmap.b_pops->bpop_commit_alloc_ptr != NULL)
+                (*direct->d_bmap.b_pops->bpop_commit_alloc_ptr)(
+                        &direct->d_bmap, req);
+        nilfs_direct_set_ptr(direct, key, req->bpr_ptr);
+
+        if (!nilfs_bmap_dirty(&direct->d_bmap))
+                nilfs_bmap_set_dirty(&direct->d_bmap);
+
+        if (direct->d_ops->dop_set_target != NULL)
+                (*direct->d_ops->dop_set_target)(direct, key, req->bpr_ptr);
+}
+
+static int nilfs_direct_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
+{
+        struct nilfs_direct *direct;
+        union nilfs_bmap_ptr_req req;
+        struct nilfs_bmap_stats stats;
+        int ret;
+
+        direct = (struct nilfs_direct *)bmap;
+        if (key > NILFS_DIRECT_KEY_MAX)
+                return -ENOENT;
+        if (nilfs_direct_get_ptr(direct, key) != NILFS_BMAP_INVALID_PTR)
+                return -EEXIST;
+
+        ret = nilfs_direct_prepare_insert(direct, key, &req, &stats);
+        if (ret < 0)
+                return ret;
+        nilfs_direct_commit_insert(direct, &req, key, ptr);
+        nilfs_bmap_add_blocks(bmap, stats.bs_nblocks);
+
+        return 0;
+}
+
+static int nilfs_direct_prepare_delete(struct nilfs_direct *direct,
+                                       union nilfs_bmap_ptr_req *req,
+                                       __u64 key,
+                                       struct nilfs_bmap_stats *stats)
+{
+        int ret;
+
+        if (direct->d_bmap.b_pops->bpop_prepare_end_ptr != NULL) {
+                req->bpr_ptr = nilfs_direct_get_ptr(direct, key);
+                ret = (*direct->d_bmap.b_pops->bpop_prepare_end_ptr)(
+                        &direct->d_bmap, req);
+                if (ret < 0)
+                        return ret;
+        }
+
+        stats->bs_nblocks = 1;
+        return 0;
+}
+
+static void nilfs_direct_commit_delete(struct nilfs_direct *direct,
+                                       union nilfs_bmap_ptr_req *req,
+                                       __u64 key)
+{
+        if (direct->d_bmap.b_pops->bpop_commit_end_ptr != NULL)
+                (*direct->d_bmap.b_pops->bpop_commit_end_ptr)(
+                        &direct->d_bmap, req);
+        nilfs_direct_set_ptr(direct, key, NILFS_BMAP_INVALID_PTR);
+}
+
+static int nilfs_direct_delete(struct nilfs_bmap *bmap, __u64 key)
+{
+        struct nilfs_direct *direct;
+        union nilfs_bmap_ptr_req req;
+        struct nilfs_bmap_stats stats;
+        int ret;
+
+        direct = (struct nilfs_direct *)bmap;
+        if ((key > NILFS_DIRECT_KEY_MAX) ||
+            nilfs_direct_get_ptr(direct, key) == NILFS_BMAP_INVALID_PTR)
+                return -ENOENT;
+
+        ret = nilfs_direct_prepare_delete(direct, &req, key, &stats);
+        if (ret < 0)
+                return ret;
+        nilfs_direct_commit_delete(direct, &req, key);
+        nilfs_bmap_sub_blocks(bmap, stats.bs_nblocks);
+
+        return 0;
+}
+
+static int nilfs_direct_last_key(const struct nilfs_bmap *bmap, __u64 *keyp)
+{
+        struct nilfs_direct *direct;
+        __u64 key, lastkey;
+
+        direct = (struct nilfs_direct *)bmap;
+        lastkey = NILFS_DIRECT_KEY_MAX + 1;
+        for (key = NILFS_DIRECT_KEY_MIN; key <= NILFS_DIRECT_KEY_MAX; key++)
+                if (nilfs_direct_get_ptr(direct, key) !=
+                    NILFS_BMAP_INVALID_PTR)
+                        lastkey = key;
+
+        if (lastkey == NILFS_DIRECT_KEY_MAX + 1)
+                return -ENOENT;
+
+        BUG_ON(keyp == NULL);
+        *keyp = lastkey;
+
+        return 0;
+}
+
+static int nilfs_direct_check_insert(const struct nilfs_bmap *bmap, __u64 key)
+{
+        return key > NILFS_DIRECT_KEY_MAX;
+}
+
+static int nilfs_direct_gather_data(struct nilfs_bmap *bmap,
+                                    __u64 *keys, __u64 *ptrs, int nitems)
+{
+        struct nilfs_direct *direct;
+        __u64 key;
+        __u64 ptr;
+        int n;
+
+        direct = (struct nilfs_direct *)bmap;
+        if (nitems > NILFS_DIRECT_NBLOCKS)
+                nitems = NILFS_DIRECT_NBLOCKS;
+        n = 0;
+        for (key = 0; key < nitems; key++) {
+                ptr = nilfs_direct_get_ptr(direct, key);
+                if (ptr != NILFS_BMAP_INVALID_PTR) {
+                        keys[n] = key;
+                        ptrs[n] = ptr;
+                        n++;
+                }
+        }
+        return n;
+}
+
+int nilfs_direct_delete_and_convert(struct nilfs_bmap *bmap,
+                                    __u64 key, __u64 *keys, __u64 *ptrs,
+                                    int n, __u64 low, __u64 high)
+{
+        struct nilfs_direct *direct;
+        __le64 *dptrs;
+        int ret, i, j;
+
+        /* no need to allocate any resource for conversion */
+
+        /* delete */
+        ret = (*bmap->b_ops->bop_delete)(bmap, key);
+        if (ret < 0)
+                return ret;
+
+        /* free resources */
+        if (bmap->b_ops->bop_clear != NULL)
+                (*bmap->b_ops->bop_clear)(bmap);
+
+        /* convert */
+        direct = (struct nilfs_direct *)bmap;
+        dptrs = nilfs_direct_dptrs(direct);
+        for (i = 0, j = 0; i < NILFS_DIRECT_NBLOCKS; i++) {
+                if ((j < n) && (i == keys[j])) {
+                        dptrs[i] = (i != key) ?
+                                nilfs_bmap_ptr_to_dptr(ptrs[j]) :
+                                NILFS_BMAP_INVALID_PTR;
+                        j++;
+                } else
+                        dptrs[i] = NILFS_BMAP_INVALID_PTR;
+        }
+
+        nilfs_direct_init(bmap, low, high);
+
+        return 0;
+}
+
+static int nilfs_direct_propagate_v(struct nilfs_direct *direct,
+                                    struct buffer_head *bh)
+{
+        union nilfs_bmap_ptr_req oldreq, newreq;
+        __u64 key;
+        __u64 ptr;
+        int ret;
+
+        key = nilfs_bmap_data_get_key(&direct->d_bmap, bh);
+        ptr = nilfs_direct_get_ptr(direct, key);
+        if (!buffer_nilfs_volatile(bh)) {
+                oldreq.bpr_ptr = ptr;
+                newreq.bpr_ptr = ptr;
+                ret = nilfs_bmap_prepare_update(&direct->d_bmap, &oldreq,
+                                                &newreq);
+                if (ret < 0)
+                        return ret;
+                nilfs_bmap_commit_update(&direct->d_bmap, &oldreq, &newreq);
+                set_buffer_nilfs_volatile(bh);
+                nilfs_direct_set_ptr(direct, key, newreq.bpr_ptr);
+        } else
+                ret = nilfs_bmap_mark_dirty(&direct->d_bmap, ptr);
+
+        return ret;
+}
+
+static int nilfs_direct_propagate(const struct nilfs_bmap *bmap,
+                                  struct buffer_head *bh)
+{
+        struct nilfs_direct *direct;
+
+        direct = (struct nilfs_direct *)bmap;
+        return (direct->d_ops->dop_propagate != NULL) ?
+                (*direct->d_ops->dop_propagate)(direct, bh) :
+                0;
+}
+
+static int nilfs_direct_assign_v(struct nilfs_direct *direct,
+                                 __u64 key, __u64 ptr,
+                                 struct buffer_head **bh,
+                                 sector_t blocknr,
+                                 union nilfs_binfo *binfo)
+{
+        union nilfs_bmap_ptr_req req;
+        int ret;
+
+        req.bpr_ptr = ptr;
+        ret = (*direct->d_bmap.b_pops->bpop_prepare_start_ptr)(
+                &direct->d_bmap, &req);
+        if (ret < 0)
+                return ret;
+        (*direct->d_bmap.b_pops->bpop_commit_start_ptr)(&direct->d_bmap,
+                                                        &req, blocknr);
+
+        binfo->bi_v.bi_vblocknr = nilfs_bmap_ptr_to_dptr(ptr);
+        binfo->bi_v.bi_blkoff = nilfs_bmap_key_to_dkey(key);
+
+        return 0;
+}
+
+static int nilfs_direct_assign_p(struct nilfs_direct *direct,
+                                 __u64 key, __u64 ptr,
+                                 struct buffer_head **bh,
+                                 sector_t blocknr,
+                                 union nilfs_binfo *binfo)
+{
+        nilfs_direct_set_ptr(direct, key, blocknr);
+
+        binfo->bi_dat.bi_blkoff = nilfs_bmap_key_to_dkey(key);
+        binfo->bi_dat.bi_level = 0;
+
+        return 0;
+}
+
+static int nilfs_direct_assign(struct nilfs_bmap *bmap,
+                               struct buffer_head **bh,
+                               sector_t blocknr,
+                               union nilfs_binfo *binfo)
+{
+        struct nilfs_direct *direct;
+        __u64 key;
+        __u64 ptr;
+
+        direct = (struct nilfs_direct *)bmap;
+        key = nilfs_bmap_data_get_key(bmap, *bh);
+        BUG_ON(key > NILFS_DIRECT_KEY_MAX);
+        ptr = nilfs_direct_get_ptr(direct, key);
+        BUG_ON(ptr == NILFS_BMAP_INVALID_PTR);
+
+        return (*direct->d_ops->dop_assign)(direct, key, ptr, bh,
+                                            blocknr, binfo);
+}
+
+static const struct nilfs_bmap_operations nilfs_direct_ops = {
+        .bop_lookup             =       nilfs_direct_lookup,
+        .bop_insert             =       nilfs_direct_insert,
+        .bop_delete             =       nilfs_direct_delete,
+        .bop_clear              =       NULL,
+
+        .bop_propagate          =       nilfs_direct_propagate,
+
+        .bop_lookup_dirty_buffers       =       NULL,
+
+        .bop_assign             =       nilfs_direct_assign,
+        .bop_mark               =       NULL,
+
+        .bop_last_key           =       nilfs_direct_last_key,
+        .bop_check_insert       =       nilfs_direct_check_insert,
+        .bop_check_delete       =       NULL,
+        .bop_gather_data        =       nilfs_direct_gather_data,
+};
+
+
+static const struct nilfs_direct_operations nilfs_direct_ops_v = {
+        .dop_find_target        =       nilfs_direct_find_target_v,
+        .dop_set_target         =       nilfs_direct_set_target_v,
+        .dop_propagate          =       nilfs_direct_propagate_v,
+        .dop_assign             =       nilfs_direct_assign_v,
+};
+
+static const struct nilfs_direct_operations nilfs_direct_ops_p = {
+        .dop_find_target        =       NULL,
+        .dop_set_target         =       NULL,
+        .dop_propagate          =       NULL,
+        .dop_assign             =       nilfs_direct_assign_p,
+};
+
+int nilfs_direct_init(struct nilfs_bmap *bmap, __u64 low, __u64 high)
+{
+        struct nilfs_direct *direct;
+
+        direct = (struct nilfs_direct *)bmap;
+        bmap->b_ops = &nilfs_direct_ops;
+        bmap->b_low = low;
+        bmap->b_high = high;
+        switch (bmap->b_inode->i_ino) {
+        case NILFS_DAT_INO:
+                direct->d_ops = &nilfs_direct_ops_p;
+                break;
+        default:
+                direct->d_ops = &nilfs_direct_ops_v;
+                break;
+        }
+
+        return 0;
+}