AcoSail/kernel_optimize_test
8
0
Fork 0
forked from luck/tmp_suning_uos_patched
Code Pull Requests Activity

[JFFS2] Remove another bogus optimisation in jffs2_add_tn_to_tree()

Browse Source 
We attempted to insert new nodes into the tree by just using
rb_replace_node to let them replace an earlier node which they
completely overlapped. However, that could place the new node into the
wrong place in the tree, since its start could be node only before the
start of the victim, but before the node _before_ the victim in the tree
(if that previous node actually ends _after_ the new node, thus isn't
entirely overlapped and wasn't itself chosen to be the victim).

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
This commit is contained in:
David Woodhouse 2007-05-07 13:16:13 +01:00
parent 96dd8d25d1
commit fcf3cafb3e
1 changed files with 10 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
fs/jffs2/readinode.c
View File

@ -221,7 +221,7 @@ static int jffs2_add_tn_to_tree(struct jffs2_sb_info *c,
uint32_t fn_end = tn->fn->ofs + tn->fn->size;
struct jffs2_tmp_dnode_info *this;
dbg_readinode("insert fragment %#04x-%#04x, ver %u\n", tn->fn->ofs, fn_end, tn->version);
dbg_readinode("insert fragment %#04x-%#04x, ver %u at %08x\n", tn->fn->ofs, fn_end, tn->version, ref_offset(tn->fn->raw));
/* If a node has zero dsize, we only have to keep if it if it might be the
node with highest version -- i.e. the one which will end up as f->metadata.
@ -271,11 +271,11 @@ static int jffs2_add_tn_to_tree(struct jffs2_sb_info *c,
return 0;
} else {
/* Who cares if the new one is good; keep it for now anyway. */
rb_replace_node(&this->rb, &tn->rb, &rii->tn_root);
/* Same overlapping from in front and behind */
jffs2_kill_tn(c, this);
dbg_readinode("Like new node. Throw away old\n");
goto calc_overlaps;
rb_replace_node(&this->rb, &tn->rb, &rii->tn_root);
jffs2_kill_tn(c, this);
/* Same overlapping from in front and behind */
return 0;
}
}
if (this->version < tn->version &&
@ -287,11 +287,7 @@ static int jffs2_add_tn_to_tree(struct jffs2_sb_info *c,
jffs2_kill_tn(c, tn);
return 0;
}
/* ... and is good. Kill 'this'... */
rb_replace_node(&this->rb, &tn->rb, &rii->tn_root);
jffs2_kill_tn(c, this);
/* ... and any subsequent nodes which are also overlapped */
this = tn_next(tn);
/* ... and is good. Kill 'this' and any subsequent nodes which are also overlapped */
while (this && this->fn->ofs + this->fn->size < fn_end) {
struct jffs2_tmp_dnode_info *next = tn_next(this);
if (this->version < tn->version) {
@ -303,8 +299,8 @@ static int jffs2_add_tn_to_tree(struct jffs2_sb_info *c,
}
this = next;
}
dbg_readinode("Done inserting new\n");
goto calc_overlaps;
dbg_readinode("Done killing overlapped nodes\n");
break;
}
if (this->version > tn->version &&
this->fn->ofs <= tn->fn->ofs &&
@ -316,11 +312,10 @@ static int jffs2_add_tn_to_tree(struct jffs2_sb_info *c,
return 0;
}
/* ... but 'this' was bad. Replace it... */
tn->overlapped = this->overlapped;
rb_replace_node(&this->rb, &tn->rb, &rii->tn_root);
dbg_readinode("Bad CRC on old overlapping node. Kill it\n");
tn_erase(this, &rii->tn_root);
jffs2_kill_tn(c, this);
return 0;
break;
}
this = tn_next(this);