ext4: add physical block and status member into extent status tree
This commit adds two members in extent_status structure to let it record
physical block and extent status. Here es_pblk is used to record both
of them because physical block only has 48 bits. So extent status could
be stashed into it so that we can save some memory. Now written,
unwritten, delayed and hole are defined as status.
Due to new member is added into extent status tree, all interfaces need
to be adjusted.
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index c9921cf..1f5fd44 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -179,7 +179,9 @@
while (node) {
struct extent_status *es;
es = rb_entry(node, struct extent_status, rb_node);
- printk(KERN_DEBUG " [%u/%u)", es->es_lblk, es->es_len);
+ printk(KERN_DEBUG " [%u/%u) %llu %llx",
+ es->es_lblk, es->es_len,
+ ext4_es_pblock(es), ext4_es_status(es));
node = rb_next(node);
}
printk(KERN_DEBUG "\n");
@@ -234,7 +236,7 @@
* @es: delayed extent that we found
*
* Returns the first block of the next extent after es, otherwise
- * EXT_MAX_BLOCKS if no delay extent is found.
+ * EXT_MAX_BLOCKS if no extent is found.
* Delayed extent is returned via @es.
*/
ext4_lblk_t ext4_es_find_extent(struct inode *inode, struct extent_status *es)
@@ -249,17 +251,18 @@
read_lock(&EXT4_I(inode)->i_es_lock);
tree = &EXT4_I(inode)->i_es_tree;
- /* find delay extent in cache firstly */
+ /* find extent in cache firstly */
+ es->es_len = es->es_pblk = 0;
if (tree->cache_es) {
es1 = tree->cache_es;
if (in_range(es->es_lblk, es1->es_lblk, es1->es_len)) {
- es_debug("%u cached by [%u/%u)\n",
- es->es_lblk, es1->es_lblk, es1->es_len);
+ es_debug("%u cached by [%u/%u) %llu %llx\n",
+ es->es_lblk, es1->es_lblk, es1->es_len,
+ ext4_es_pblock(es1), ext4_es_status(es1));
goto out;
}
}
- es->es_len = 0;
es1 = __es_tree_search(&tree->root, es->es_lblk);
out:
@@ -267,6 +270,7 @@
tree->cache_es = es1;
es->es_lblk = es1->es_lblk;
es->es_len = es1->es_len;
+ es->es_pblk = es1->es_pblk;
node = rb_next(&es1->rb_node);
if (node) {
es1 = rb_entry(node, struct extent_status, rb_node);
@@ -281,7 +285,7 @@
}
static struct extent_status *
-ext4_es_alloc_extent(ext4_lblk_t lblk, ext4_lblk_t len)
+ext4_es_alloc_extent(ext4_lblk_t lblk, ext4_lblk_t len, ext4_fsblk_t pblk)
{
struct extent_status *es;
es = kmem_cache_alloc(ext4_es_cachep, GFP_ATOMIC);
@@ -289,6 +293,7 @@
return NULL;
es->es_lblk = lblk;
es->es_len = len;
+ es->es_pblk = pblk;
return es;
}
@@ -301,6 +306,8 @@
* Check whether or not two extents can be merged
* Condition:
* - logical block number is contiguous
+ * - physical block number is contiguous
+ * - status is equal
*/
static int ext4_es_can_be_merged(struct extent_status *es1,
struct extent_status *es2)
@@ -308,6 +315,13 @@
if (es1->es_lblk + es1->es_len != es2->es_lblk)
return 0;
+ if (ext4_es_status(es1) != ext4_es_status(es2))
+ return 0;
+
+ if ((ext4_es_is_written(es1) || ext4_es_is_unwritten(es1)) &&
+ (ext4_es_pblock(es1) + es1->es_len != ext4_es_pblock(es2)))
+ return 0;
+
return 1;
}
@@ -371,6 +385,10 @@
*/
es->es_lblk = newes->es_lblk;
es->es_len += newes->es_len;
+ if (ext4_es_is_written(es) ||
+ ext4_es_is_unwritten(es))
+ ext4_es_store_pblock(es,
+ newes->es_pblk);
es = ext4_es_try_to_merge_left(tree, es);
goto out;
}
@@ -388,7 +406,8 @@
}
}
- es = ext4_es_alloc_extent(newes->es_lblk, newes->es_len);
+ es = ext4_es_alloc_extent(newes->es_lblk, newes->es_len,
+ newes->es_pblk);
if (!es)
return -ENOMEM;
rb_link_node(&es->rb_node, parent, p);
@@ -408,21 +427,24 @@
* Return 0 on success, error code on failure.
*/
int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
- ext4_lblk_t len)
+ ext4_lblk_t len, ext4_fsblk_t pblk,
+ unsigned long long status)
{
struct ext4_es_tree *tree;
struct extent_status newes;
ext4_lblk_t end = lblk + len - 1;
int err = 0;
- trace_ext4_es_insert_extent(inode, lblk, len);
- es_debug("add [%u/%u) to extent status tree of inode %lu\n",
- lblk, len, inode->i_ino);
+ es_debug("add [%u/%u) %llu %llx to extent status tree of inode %lu\n",
+ lblk, len, pblk, status, inode->i_ino);
BUG_ON(end < lblk);
newes.es_lblk = lblk;
newes.es_len = len;
+ ext4_es_store_pblock(&newes, pblk);
+ ext4_es_store_status(&newes, status);
+ trace_ext4_es_insert_extent(inode, &newes);
write_lock(&EXT4_I(inode)->i_es_lock);
tree = &EXT4_I(inode)->i_es_tree;
@@ -446,6 +468,7 @@
struct extent_status *es;
struct extent_status orig_es;
ext4_lblk_t len1, len2;
+ ext4_fsblk_t block;
int err = 0;
es = __es_tree_search(&tree->root, lblk);
@@ -459,6 +482,8 @@
orig_es.es_lblk = es->es_lblk;
orig_es.es_len = es->es_len;
+ orig_es.es_pblk = es->es_pblk;
+
len1 = lblk > es->es_lblk ? lblk - es->es_lblk : 0;
len2 = ext4_es_end(es) > end ? ext4_es_end(es) - end : 0;
if (len1 > 0)
@@ -469,6 +494,13 @@
newes.es_lblk = end + 1;
newes.es_len = len2;
+ if (ext4_es_is_written(&orig_es) ||
+ ext4_es_is_unwritten(&orig_es)) {
+ block = ext4_es_pblock(&orig_es) +
+ orig_es.es_len - len2;
+ ext4_es_store_pblock(&newes, block);
+ }
+ ext4_es_store_status(&newes, ext4_es_status(&orig_es));
err = __es_insert_extent(tree, &newes);
if (err) {
es->es_lblk = orig_es.es_lblk;
@@ -478,6 +510,11 @@
} else {
es->es_lblk = end + 1;
es->es_len = len2;
+ if (ext4_es_is_written(es) ||
+ ext4_es_is_unwritten(es)) {
+ block = orig_es.es_pblk + orig_es.es_len - len2;
+ ext4_es_store_pblock(es, block);
+ }
}
goto out;
}
@@ -502,9 +539,15 @@
}
if (es && es->es_lblk < end + 1) {
+ ext4_lblk_t orig_len = es->es_len;
+
len1 = ext4_es_end(es) - end;
es->es_lblk = end + 1;
es->es_len = len1;
+ if (ext4_es_is_written(es) || ext4_es_is_unwritten(es)) {
+ block = es->es_pblk + orig_len - len1;
+ ext4_es_store_pblock(es, block);
+ }
}
out: