[JFFS2] Switch to using an array of jffs2_raw_node_refs instead of a list.

This allows us to drop another pointer from the struct jffs2_raw_node_ref,
shrinking it to 8 bytes on 32-bit machines (if the TEST_TOTLEN) paranoia
check is turned off, which will be committed soon).

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 203 insertions, 84 deletions

diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c
index e16e45ea0474..2febece89062 100644
--- a/fs/jffs2/wbuf.c
+++ b/fs/jffs2/wbuf.c
@@ -156,72 +156,126 @@ static void jffs2_block_refile(struct jffs2_sb_info *c, struct jffs2_eraseblock
                 jffs2_erase_pending_trigger(c);
         }
 
-        /* Adjust its size counts accordingly */
-        c->wasted_size += jeb->free_size;
-        c->free_size -= jeb->free_size;
-        jeb->wasted_size += jeb->free_size;
-        jeb->free_size = 0;
+        if (!jffs2_prealloc_raw_node_refs(c, jeb, 1)) {
+                uint32_t oldfree = jeb->free_size;
+
+                jffs2_link_node_ref(c, jeb, 
+                                    (jeb->offset+c->sector_size-oldfree) | REF_OBSOLETE,
+                                    oldfree, NULL);
+                /* convert to wasted */
+                c->wasted_size += oldfree;
+                jeb->wasted_size += oldfree;
+                c->dirty_size -= oldfree;
+                jeb->dirty_size -= oldfree;
+        }
 
         jffs2_dbg_dump_block_lists_nolock(c);
         jffs2_dbg_acct_sanity_check_nolock(c,jeb);
         jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 }
 
+static struct jffs2_raw_node_ref **jffs2_incore_replace_raw(struct jffs2_sb_info *c,
+                                                            struct jffs2_inode_info *f,
+                                                            struct jffs2_raw_node_ref *raw,
+                                                            union jffs2_node_union *node)
+{
+        struct jffs2_node_frag *frag;
+        struct jffs2_full_dirent *fd;
+
+        dbg_noderef("incore_replace_raw: node at %p is {%04x,%04x}\n",
+                    node, je16_to_cpu(node->u.magic), je16_to_cpu(node->u.nodetype));
+
+        BUG_ON(je16_to_cpu(node->u.magic) != 0x1985 &&
+               je16_to_cpu(node->u.magic) != 0);
+
+        switch (je16_to_cpu(node->u.nodetype)) {
+        case JFFS2_NODETYPE_INODE:
+                frag = jffs2_lookup_node_frag(&f->fragtree, je32_to_cpu(node->i.offset));
+                BUG_ON(!frag);
+                /* Find a frag which refers to the full_dnode we want to modify */
+                while (!frag->node || frag->node->raw != raw) {
+                        frag = frag_next(frag);
+                        BUG_ON(!frag);
+                }
+                dbg_noderef("Will replace ->raw in full_dnode at %p\n", frag->node);
+                return &frag->node->raw;
+                break;
+
+        case JFFS2_NODETYPE_DIRENT:
+                for (fd = f->dents; fd; fd = fd->next) {
+                        if (fd->raw == raw) {
+                                dbg_noderef("Will replace ->raw in full_dirent at %p\n", fd);
+                                return &fd->raw;
+                        }
+                }
+                BUG();
+        default:
+                dbg_noderef("Don't care about replacing raw for nodetype %x\n",
+                            je16_to_cpu(node->u.nodetype));
+                break;
+        }
+        return NULL;
+}
+
 /* Recover from failure to write wbuf. Recover the nodes up to the
  * wbuf, not the one which we were starting to try to write. */
 
 static void jffs2_wbuf_recover(struct jffs2_sb_info *c)
 {
         struct jffs2_eraseblock *jeb, *new_jeb;
-        struct jffs2_raw_node_ref **first_raw, **raw;
+        struct jffs2_raw_node_ref *raw, *next, *first_raw = NULL;
         size_t retlen;
         int ret;
+        int nr_refile = 0;
         unsigned char *buf;
         uint32_t start, end, ofs, len;
 
         jeb = &c->blocks[c->wbuf_ofs / c->sector_size];
 
-        if (jffs2_prealloc_raw_node_refs(c, jeb, c->reserved_refs + 1))
-                return;
-
         spin_lock(&c->erase_completion_lock);
-
         jffs2_block_refile(c, jeb, REFILE_NOTEMPTY);
+        spin_unlock(&c->erase_completion_lock);
+
+        BUG_ON(!ref_obsolete(jeb->last_node));
 
         /* Find the first node to be recovered, by skipping over every
            node which ends before the wbuf starts, or which is obsolete. */
-        first_raw = &jeb->first_node;
-        while (*first_raw &&
-               (ref_obsolete(*first_raw) ||
-                (ref_offset(*first_raw)+ref_totlen(c, jeb, *first_raw)) < c->wbuf_ofs)) {
-                D1(printk(KERN_DEBUG "Skipping node at 0x%08x(%d)-0x%08x which is either before 0x%08x or obsolete\n",
-                          ref_offset(*first_raw), ref_flags(*first_raw),
-                          (ref_offset(*first_raw) + ref_totlen(c, jeb, *first_raw)),
-                          c->wbuf_ofs));
-                first_raw = &(*first_raw)->next_phys;
+        for (next = raw = jeb->first_node; next; raw = next) {
+                next = ref_next(raw);
+
+                if (ref_obsolete(raw) || 
+                    (next && ref_offset(next) <= c->wbuf_ofs)) {
+                        dbg_noderef("Skipping node at 0x%08x(%d)-0x%08x which is either before 0x%08x or obsolete\n",
+                                    ref_offset(raw), ref_flags(raw),
+                                    (ref_offset(raw) + ref_totlen(c, jeb, raw)),
+                                    c->wbuf_ofs);
+                        continue;
+                }
+                dbg_noderef("First node to be recovered is at 0x%08x(%d)-0x%08x\n",
+                            ref_offset(raw), ref_flags(raw),
+                            (ref_offset(raw) + ref_totlen(c, jeb, raw)));
+
+                first_raw = raw;
+                break;
         }
 
-        if (!*first_raw) {
+        if (!first_raw) {
                 /* All nodes were obsolete. Nothing to recover. */
                 D1(printk(KERN_DEBUG "No non-obsolete nodes to be recovered. Just filing block bad\n"));
-                spin_unlock(&c->erase_completion_lock);
+                c->wbuf_len = 0;
                 return;
         }
 
-        start = ref_offset(*first_raw);
-        end = ref_offset(*first_raw) + ref_totlen(c, jeb, *first_raw);
+        start = ref_offset(first_raw);
+        end = ref_offset(jeb->last_node);
+        nr_refile = 1;
 
-        /* Find the last node to be recovered */
-        raw = first_raw;
-        while ((*raw)) {
-                if (!ref_obsolete(*raw))
-                        end = ref_offset(*raw) + ref_totlen(c, jeb, *raw);
+        /* Count the number of refs which need to be copied */
+        while ((raw = ref_next(raw)) != jeb->last_node)
+                nr_refile++;
 
-                raw = &(*raw)->next_phys;
-        }
-        spin_unlock(&c->erase_completion_lock);
-
-        D1(printk(KERN_DEBUG "wbuf recover %08x-%08x\n", start, end));
+        dbg_noderef("wbuf recover %08x-%08x (%d bytes in %d nodes)\n",
+                    start, end, end - start, nr_refile);
 
         buf = NULL;
         if (start < c->wbuf_ofs) {
@@ -248,13 +302,24 @@ static void jffs2_wbuf_recover(struct jffs2_sb_info *c)
                         kfree(buf);
                         buf = NULL;
                 read_failed:
-                        first_raw = &(*first_raw)->next_phys;
+                        first_raw = ref_next(first_raw);
+                        nr_refile--;
+                        while (first_raw && ref_obsolete(first_raw)) {
+                                first_raw = ref_next(first_raw);
+                                nr_refile--;
+                        }
+
                         /* If this was the only node to be recovered, give up */
-                        if (!(*first_raw))
+                        if (!first_raw) {
+                                c->wbuf_len = 0;
                                 return;
+                        }
 
                         /* It wasn't. Go on and try to recover nodes complete in the wbuf */
-                        start = ref_offset(*first_raw);
+                        start = ref_offset(first_raw);
+                        dbg_noderef("wbuf now recover %08x-%08x (%d bytes in %d nodes)\n",
+                                    start, end, end - start, nr_refile);
+
                 } else {
                         /* Read succeeded. Copy the remaining data from the wbuf */
                         memcpy(buf + (c->wbuf_ofs - start), c->wbuf, end - c->wbuf_ofs);
@@ -263,7 +328,6 @@ static void jffs2_wbuf_recover(struct jffs2_sb_info *c)
         /* OK... we're to rewrite (end-start) bytes of data from first_raw onwards.
            Either 'buf' contains the data, or we find it in the wbuf */
 
-
         /* ... and get an allocation of space from a shiny new block instead */
         ret = jffs2_reserve_space_gc(c, end-start, &len, JFFS2_SUMMARY_NOSUM_SIZE);
         if (ret) {
@@ -271,6 +335,14 @@ static void jffs2_wbuf_recover(struct jffs2_sb_info *c)
                 kfree(buf);
                 return;
         }
+
+        ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, nr_refile);
+        if (ret) {
+                printk(KERN_WARNING "Failed to allocate node refs for wbuf recovery. Data loss ensues.\n");
+                kfree(buf);
+                return;
+        }
+
         ofs = write_ofs(c);
 
         if (end-start >= c->wbuf_pagesize) {
@@ -304,7 +376,7 @@ static void jffs2_wbuf_recover(struct jffs2_sb_info *c)
                         kfree(buf);
 
                         if (retlen)
-                                jffs2_add_physical_node_ref(c, ofs | REF_OBSOLETE, ref_totlen(c, jeb, *first_raw), NULL);
+                                jffs2_add_physical_node_ref(c, ofs | REF_OBSOLETE, ref_totlen(c, jeb, first_raw), NULL);
 
                         return;
                 }
@@ -314,12 +386,10 @@ static void jffs2_wbuf_recover(struct jffs2_sb_info *c)
                 c->wbuf_ofs = ofs + towrite;
                 memmove(c->wbuf, rewrite_buf + towrite, c->wbuf_len);
                 /* Don't muck about with c->wbuf_inodes. False positives are harmless. */
-                kfree(buf);
         } else {
                 /* OK, now we're left with the dregs in whichever buffer we're using */
                 if (buf) {
                         memcpy(c->wbuf, buf, end-start);
-                        kfree(buf);
                 } else {
                         memmove(c->wbuf, c->wbuf + (start - c->wbuf_ofs), end - start);
                 }
@@ -331,62 +401,111 @@ static void jffs2_wbuf_recover(struct jffs2_sb_info *c)
         new_jeb = &c->blocks[ofs / c->sector_size];
 
         spin_lock(&c->erase_completion_lock);
-        if (new_jeb->first_node) {
-                /* Odd, but possible with ST flash later maybe */
-                new_jeb->last_node->next_phys = *first_raw;
-        } else {
-                new_jeb->first_node = *first_raw;
-        }
-
-        raw = first_raw;
-        while (*raw) {
-                uint32_t rawlen = ref_totlen(c, jeb, *raw);
+        for (raw = first_raw; raw != jeb->last_node; raw = ref_next(raw)) {
+                uint32_t rawlen = ref_totlen(c, jeb, raw);
+                struct jffs2_inode_cache *ic;
+                struct jffs2_raw_node_ref *new_ref;
+                struct jffs2_raw_node_ref **adjust_ref = NULL;
+                struct jffs2_inode_info *f = NULL;
 
                 D1(printk(KERN_DEBUG "Refiling block of %08x at %08x(%d) to %08x\n",
-                          rawlen, ref_offset(*raw), ref_flags(*raw), ofs));
+                          rawlen, ref_offset(raw), ref_flags(raw), ofs));
+
+                ic = jffs2_raw_ref_to_ic(raw);
+
+                /* Ick. This XATTR mess should be fixed shortly... */
+                if (ic && ic->class == RAWNODE_CLASS_XATTR_DATUM) {
+                        struct jffs2_xattr_datum *xd = (void *)ic;
+                        BUG_ON(xd->node != raw);
+                        adjust_ref = &xd->node;
+                        raw->next_in_ino = NULL;
+                        ic = NULL;
+                } else if (ic && ic->class == RAWNODE_CLASS_XATTR_REF) {
+                        struct jffs2_xattr_datum *xr = (void *)ic;
+                        BUG_ON(xr->node != raw);
+                        adjust_ref = &xr->node;
+                        raw->next_in_ino = NULL;
+                        ic = NULL;
+                } else if (ic && ic->class == RAWNODE_CLASS_INODE_CACHE) {
+                        struct jffs2_raw_node_ref **p = &ic->nodes;
+
+                        /* Remove the old node from the per-inode list */
+                        while (*p && *p != (void *)ic) {
+                                if (*p == raw) {
+                                        (*p) = (raw->next_in_ino);
+                                        raw->next_in_ino = NULL;
+                                        break;
+                                }
+                                p = &((*p)->next_in_ino);
+                        }
 
-                if (ref_obsolete(*raw)) {
-                        /* Shouldn't really happen much */
-                        new_jeb->dirty_size += rawlen;
-                        new_jeb->free_size -= rawlen;
-                        c->dirty_size += rawlen;
-                } else {
-                        new_jeb->used_size += rawlen;
-                        new_jeb->free_size -= rawlen;
+                        if (ic->state == INO_STATE_PRESENT && !ref_obsolete(raw)) {
+                                /* If it's an in-core inode, then we have to adjust any
+                                   full_dirent or full_dnode structure to point to the
+                                   new version instead of the old */
+                                f = jffs2_gc_fetch_inode(c, ic->ino, ic->nlink);
+                                if (IS_ERR(f)) {
+                                        /* Should never happen; it _must_ be present */
+                                        JFFS2_ERROR("Failed to iget() ino #%u, err %ld\n",
+                                                    ic->ino, PTR_ERR(f));
+                                        BUG();
+                                }
+                                /* We don't lock f->sem. There's a number of ways we could
+                                   end up in here with it already being locked, and nobody's
+                                   going to modify it on us anyway because we hold the
+                                   alloc_sem. We're only changing one ->raw pointer too,
+                                   which we can get away with without upsetting readers. */
+                                adjust_ref = jffs2_incore_replace_raw(c, f, raw,
+                                                                      (void *)(buf?:c->wbuf) + (ref_offset(raw) - start));
+                        } else if (unlikely(ic->state != INO_STATE_PRESENT &&
+                                            ic->state != INO_STATE_CHECKEDABSENT &&
+                                            ic->state != INO_STATE_GC)) {
+                                JFFS2_ERROR("Inode #%u is in strange state %d!\n", ic->ino, ic->state);
+                                BUG();
+                        }
+                }
+
+                new_ref = jffs2_link_node_ref(c, new_jeb, ofs | ref_flags(raw), rawlen, ic);
+
+                if (adjust_ref) {
+                        BUG_ON(*adjust_ref != raw);
+                        *adjust_ref = new_ref;
+                }
+                if (f)
+                        jffs2_gc_release_inode(c, f);
+
+                if (!ref_obsolete(raw)) {
                         jeb->dirty_size += rawlen;
                         jeb->used_size  -= rawlen;
                         c->dirty_size += rawlen;
+                        c->used_size -= rawlen;
+                        raw->flash_offset = ref_offset(raw) | REF_OBSOLETE;
+                        BUG_ON(raw->next_in_ino);
                 }
-                c->free_size -= rawlen;
-                (*raw)->flash_offset = ofs | ref_flags(*raw);
                 ofs += rawlen;
-                new_jeb->last_node = *raw;
-
-                raw = &(*raw)->next_phys;
         }
 
+        kfree(buf);
+
         /* Fix up the original jeb now it's on the bad_list */
-        *first_raw = NULL;
-        if (first_raw == &jeb->first_node) {
-                jeb->last_node = NULL;
+        if (first_raw == jeb->first_node) {
                 D1(printk(KERN_DEBUG "Failing block at %08x is now empty. Moving to erase_pending_list\n", jeb->offset));
                 list_del(&jeb->list);
                 list_add(&jeb->list, &c->erase_pending_list);
                 c->nr_erasing_blocks++;
                 jffs2_erase_pending_trigger(c);
         }
-        else
-                jeb->last_node = container_of(first_raw, struct jffs2_raw_node_ref, next_phys);
 
         jffs2_dbg_acct_sanity_check_nolock(c, jeb);
-        jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
+        jffs2_dbg_acct_paranoia_check_nolock(c, jeb);
 
         jffs2_dbg_acct_sanity_check_nolock(c, new_jeb);
-        jffs2_dbg_acct_paranoia_check_nolock(c, new_jeb);
+        jffs2_dbg_acct_paranoia_check_nolock(c, new_jeb);
 
         spin_unlock(&c->erase_completion_lock);
 
-        D1(printk(KERN_DEBUG "wbuf recovery completed OK\n"));
+        D1(printk(KERN_DEBUG "wbuf recovery completed OK. wbuf_ofs 0x%08x, len 0x%x\n", c->wbuf_ofs, c->wbuf_len));
+
 }
 
 /* Meaning of pad argument:
@@ -400,6 +519,7 @@ static void jffs2_wbuf_recover(struct jffs2_sb_info *c)
 
 static int __jffs2_flush_wbuf(struct jffs2_sb_info *c, int pad)
 {
+        struct jffs2_eraseblock *wbuf_jeb;
         int ret;
         size_t retlen;
 
@@ -417,7 +537,8 @@ static int __jffs2_flush_wbuf(struct jffs2_sb_info *c, int pad)
         if (!c->wbuf_len)       /* already checked c->wbuf above */
                 return 0;
 
-        if (jffs2_prealloc_raw_node_refs(c, c->nextblock, c->reserved_refs + 1))
+        wbuf_jeb = &c->blocks[c->wbuf_ofs / c->sector_size];
+        if (jffs2_prealloc_raw_node_refs(c, wbuf_jeb, c->nextblock->allocated_refs + 1))
                 return -ENOMEM;
 
         /* claim remaining space on the page
@@ -473,32 +594,29 @@ static int __jffs2_flush_wbuf(struct jffs2_sb_info *c, int pad)
 
         /* Adjust free size of the block if we padded. */
         if (pad) {
-                struct jffs2_eraseblock *jeb;
                 uint32_t waste = c->wbuf_pagesize - c->wbuf_len;
 
-                jeb = &c->blocks[c->wbuf_ofs / c->sector_size];
-
                 D1(printk(KERN_DEBUG "jffs2_flush_wbuf() adjusting free_size of %sblock at %08x\n",
-                          (jeb==c->nextblock)?"next":"", jeb->offset));
+                          (wbuf_jeb==c->nextblock)?"next":"", wbuf_jeb->offset));
 
                 /* wbuf_pagesize - wbuf_len is the amount of space that's to be
                    padded. If there is less free space in the block than that,
                    something screwed up */
-                if (jeb->free_size < waste) {
+                if (wbuf_jeb->free_size < waste) {
                         printk(KERN_CRIT "jffs2_flush_wbuf(): Accounting error. wbuf at 0x%08x has 0x%03x bytes, 0x%03x left.\n",
                                c->wbuf_ofs, c->wbuf_len, waste);
                         printk(KERN_CRIT "jffs2_flush_wbuf(): But free_size for block at 0x%08x is only 0x%08x\n",
-                               jeb->offset, jeb->free_size);
+                               wbuf_jeb->offset, wbuf_jeb->free_size);
                         BUG();
                 }
 
                 spin_lock(&c->erase_completion_lock);
 
-                jffs2_link_node_ref(c, jeb, (c->wbuf_ofs + c->wbuf_len) | REF_OBSOLETE, waste, NULL);
+                jffs2_link_node_ref(c, wbuf_jeb, (c->wbuf_ofs + c->wbuf_len) | REF_OBSOLETE, waste, NULL);
                 /* FIXME: that made it count as dirty. Convert to wasted */
-                jeb->dirty_size -= waste;
+                wbuf_jeb->dirty_size -= waste;
                 c->dirty_size -= waste;
-                jeb->wasted_size += waste;
+                wbuf_jeb->wasted_size += waste;
                 c->wasted_size += waste;
         } else
                 spin_lock(&c->erase_completion_lock);
@@ -758,7 +876,8 @@ outerr:
  *      This is the entry for flash write.
  *      Check, if we work on NAND FLASH, if so build an kvec and write it via vritev
 */
-int jffs2_flash_write(struct jffs2_sb_info *c, loff_t ofs, size_t len, size_t *retlen, const u_char *buf)
+int jffs2_flash_write(struct jffs2_sb_info *c, loff_t ofs, size_t len,
+                      size_t *retlen, const u_char *buf)
 {
         struct kvec vecs[1];
 
@@ -953,7 +1072,7 @@ int jffs2_check_nand_cleanmarker (struct jffs2_sb_info *c, struct jffs2_eraseblo
                         }
                         D1(if (retval == 1) {
                                 printk(KERN_WARNING "jffs2_check_nand_cleanmarker(): Cleanmarker node not detected in block at %08x\n", jeb->offset);
-                                printk(KERN_WARNING "OOB at %08x was ", offset);
+                                printk(KERN_WARNING "OOB at %08zx was ", offset);
                                 for (i=0; i < oob_size; i++) {
                                         printk("%02x ", buf[i]);
                                 }