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nilfs2: direct block mapping
authorKoji Sato <sato.koji@lab.ntt.co.jp>
Tue, 7 Apr 2009 02:01:25 +0000 (19:01 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 7 Apr 2009 15:31:13 +0000 (08:31 -0700)
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>
fs/nilfs2/direct.c [new file with mode: 0644]
fs/nilfs2/direct.h [new file with mode: 0644]

diff --git a/fs/nilfs2/direct.c b/fs/nilfs2/direct.c
new file mode 100644 (file)
index 0000000..303d7f1
--- /dev/null
@@ -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;
+}
diff --git a/fs/nilfs2/direct.h b/fs/nilfs2/direct.h
new file mode 100644 (file)
index 0000000..45d2c5c
--- /dev/null
@@ -0,0 +1,78 @@
+/*
+ * direct.h - 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>.
+ */
+
+#ifndef _NILFS_DIRECT_H
+#define _NILFS_DIRECT_H
+
+#include <linux/types.h>
+#include <linux/buffer_head.h>
+#include "bmap.h"
+
+
+struct nilfs_direct;
+
+/**
+ * struct nilfs_direct_operations - direct mapping operation table
+ */
+struct nilfs_direct_operations {
+       __u64 (*dop_find_target)(const struct nilfs_direct *, __u64);
+       void (*dop_set_target)(struct nilfs_direct *, __u64, __u64);
+       int (*dop_propagate)(struct nilfs_direct *, struct buffer_head *);
+       int (*dop_assign)(struct nilfs_direct *, __u64, __u64,
+                         struct buffer_head **, sector_t,
+                         union nilfs_binfo *);
+};
+
+/**
+ * struct nilfs_direct_node - direct node
+ * @dn_flags: flags
+ * @dn_pad: padding
+ */
+struct nilfs_direct_node {
+       __u8 dn_flags;
+       __u8 pad[7];
+};
+
+/**
+ * struct nilfs_direct - direct mapping
+ * @d_bmap: bmap structure
+ * @d_ops: direct mapping operation table
+ */
+struct nilfs_direct {
+       struct nilfs_bmap d_bmap;
+
+       /* direct-mapping-specific members */
+       const struct nilfs_direct_operations *d_ops;
+};
+
+
+#define NILFS_DIRECT_NBLOCKS   (NILFS_BMAP_SIZE / sizeof(__le64) - 1)
+#define NILFS_DIRECT_KEY_MIN   0
+#define NILFS_DIRECT_KEY_MAX   (NILFS_DIRECT_NBLOCKS - 1)
+
+
+int nilfs_direct_init(struct nilfs_bmap *, __u64, __u64);
+int nilfs_direct_delete_and_convert(struct nilfs_bmap *, __u64, __u64 *,
+                                   __u64 *, int, __u64, __u64);
+
+
+#endif /* _NILFS_DIRECT_H */