When we read in an extent tree leaf block from disk, arrange to have
all of its entries cached. In nearly all cases the in-memory
representation will be more compact than the on-disk representation in
the buffer cache, and it allows us to get the information without
having to traverse the extent tree for successive extents.
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
Cc: Zheng Liu <wenqing.lz@xxxxxxxxxx>
---
fs/ext4/ext4.h | 14 +++++++-
fs/ext4/extents.c | 84 +++++++++++++++++++++++++++++++--------------
fs/ext4/extents_status.c | 39 ++++++++++++++++++++-
fs/ext4/extents_status.h | 3 ++
fs/ext4/migrate.c | 2 +-
fs/ext4/move_extent.c | 2 +-
include/trace/events/ext4.h | 14 +++++++-
7 files changed, 127 insertions(+), 31 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 6ed348d..a8497b0 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -561,6 +561,17 @@ enum {
#define EXT4_GET_BLOCKS_NO_PUT_HOLE 0x0200
/*
+ * The bit position of this flag must not overlap with any of the
+ * EXT4_GET_BLOCKS_*. It is used by ext4_ext_find_extent(),
+ * read_extent_tree_block(), ext4_split_extent_at(),
+ * ext4_ext_insert_extent(), and ext4_ext_create_new_leaf() to
+ * indicate that the we shouldn't be caching the extents when reading
+ * from the extent tree while a truncate or punch hole operation
+ * is in progress.
+ */
+#define EXT4_EX_NOCACHE 0x0400
+
+/*
* Flags used by ext4_free_blocks
*/
#define EXT4_FREE_BLOCKS_METADATA 0x0001
@@ -2683,7 +2694,8 @@ extern int ext4_ext_insert_extent(handle_t *, struct inode *,
struct ext4_ext_path *,
struct ext4_extent *, int);
extern struct ext4_ext_path *ext4_ext_find_extent(struct inode *, ext4_lblk_t,
- struct ext4_ext_path *);
+ struct ext4_ext_path *,
+ int flags);
extern void ext4_ext_drop_refs(struct ext4_ext_path *);
extern int ext4_ext_check_inode(struct inode *inode);
extern int ext4_find_delalloc_range(struct inode *inode,
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index e174814..506c3fe 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -466,7 +466,8 @@ int ext4_ext_check_inode(struct inode *inode)
static struct buffer_head *
__read_extent_tree_block(const char *function, unsigned int line,
- struct inode *inode, ext4_fsblk_t pblk, int depth)
+ struct inode *inode, ext4_fsblk_t pblk, int depth,
+ int flags)
{
struct buffer_head *bh;
int err;
@@ -490,6 +491,31 @@ __read_extent_tree_block(const char *function, unsigned int line,
if (err)
goto errout;
set_buffer_verified(bh);
+ /*
+ * If this is a leaf block, cache all of its entries
+ */
+ if (!(flags & EXT4_EX_NOCACHE) && depth == 0) {
+ struct ext4_extent_header *eh = ext_block_hdr(bh);
+ struct ext4_extent *ex = EXT_FIRST_EXTENT(eh);
+ int i;
+
+ for (i = eh->eh_entries; i > 0; i--, ex++) {
+ unsigned int status = EXTENT_STATUS_WRITTEN;
+ ext4_lblk_t prev = 0, lblk = le32_to_cpu(ex->ee_block);
+ int len = ext4_ext_get_actual_len(ex);
+
+ if (prev && (prev != lblk))
+ ext4_es_cache_extent(inode, prev,
+ lblk - prev, ~0,
+ EXTENT_STATUS_HOLE);
+
+ if (ext4_ext_is_uninitialized(ex))
+ status = EXTENT_STATUS_UNWRITTEN;
+ ext4_es_cache_extent(inode, lblk, len,
+ ext4_ext_pblock(ex), status);
+ prev = lblk + len;
+ }
+ }
return bh;
errout:
put_bh(bh);
@@ -497,8 +523,9 @@ errout:
}
-#define read_extent_tree_block(inode, pblk, depth) \
- __read_extent_tree_block(__func__, __LINE__, (inode), (pblk), (depth))
+#define read_extent_tree_block(inode, pblk, depth, flags) \
+ __read_extent_tree_block(__func__, __LINE__, (inode), (pblk), \
+ (depth), (flags))
#ifdef EXT_DEBUG
static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
@@ -732,7 +759,7 @@ int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
struct ext4_ext_path *
ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
- struct ext4_ext_path *path)
+ struct ext4_ext_path *path, int flags)
{
struct ext4_extent_header *eh;
struct buffer_head *bh;
@@ -764,7 +791,8 @@ ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
path[ppos].p_depth = i;
path[ppos].p_ext = NULL;
- bh = read_extent_tree_block(inode, path[ppos].p_block, --i);
+ bh = read_extent_tree_block(inode, path[ppos].p_block, --i,
+ flags);
if (IS_ERR(bh)) {
ret = PTR_ERR(bh);
goto err;
@@ -1201,7 +1229,8 @@ out:
* if no free index is found, then it requests in-depth growing.
*/
static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
- unsigned int flags,
+ unsigned int mb_flags,
+ unsigned int gb_flags,
struct ext4_ext_path *path,
struct ext4_extent *newext)
{
@@ -1223,7 +1252,7 @@ repeat:
if (EXT_HAS_FREE_INDEX(curp)) {
/* if we found index with free entry, then use that
* entry: create all needed subtree and add new leaf */
- err = ext4_ext_split(handle, inode, flags, path, newext, i);
+ err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
if (err)
goto out;
@@ -1231,12 +1260,12 @@ repeat:
ext4_ext_drop_refs(path);
path = ext4_ext_find_extent(inode,
(ext4_lblk_t)le32_to_cpu(newext->ee_block),
- path);
+ path, gb_flags);
if (IS_ERR(path))
err = PTR_ERR(path);
} else {
/* tree is full, time to grow in depth */
- err = ext4_ext_grow_indepth(handle, inode, flags, newext);
+ err = ext4_ext_grow_indepth(handle, inode, mb_flags, newext);
if (err)
goto out;
@@ -1244,7 +1273,7 @@ repeat:
ext4_ext_drop_refs(path);
path = ext4_ext_find_extent(inode,
(ext4_lblk_t)le32_to_cpu(newext->ee_block),
- path);
+ path, gb_flags);
if (IS_ERR(path)) {
err = PTR_ERR(path);
goto out;
@@ -1417,7 +1446,7 @@ got_index:
while (++depth < path->p_depth) {
/* subtract from p_depth to get proper eh_depth */
bh = read_extent_tree_block(inode, *logical,
- path->p_depth - depth);
+ path->p_depth - depth, 0);
if (IS_ERR(bh))
return PTR_ERR(bh);
eh = ext_block_hdr(bh);
@@ -1426,7 +1455,7 @@ got_index:
put_bh(bh);
}
- bh = read_extent_tree_block(inode, *logical, path->p_depth - depth);
+ bh = read_extent_tree_block(inode, *logical, path->p_depth - depth, 0);
if (IS_ERR(bh))
return PTR_ERR(bh);
eh = ext_block_hdr(bh);
@@ -1788,7 +1817,7 @@ out:
*/
int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
struct ext4_ext_path *path,
- struct ext4_extent *newext, int flag)
+ struct ext4_extent *newext, int gb_flags)
{
struct ext4_extent_header *eh;
struct ext4_extent *ex, *fex;
@@ -1797,7 +1826,7 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
int depth, len, err;
ext4_lblk_t next;
unsigned uninitialized = 0;
- int flags = 0;
+ int mb_flags = 0;
if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
@@ -1812,7 +1841,7 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
}
/* try to insert block into found extent and return */
- if (ex && !(flag & EXT4_GET_BLOCKS_PRE_IO)) {
+ if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) {
/*
* Try to see whether we should rather test the extent on
@@ -1915,7 +1944,7 @@ prepend:
if (next != EXT_MAX_BLOCKS) {
ext_debug("next leaf block - %u\n", next);
BUG_ON(npath != NULL);
- npath = ext4_ext_find_extent(inode, next, NULL);
+ npath = ext4_ext_find_extent(inode, next, NULL, 0);
if (IS_ERR(npath))
return PTR_ERR(npath);
BUG_ON(npath->p_depth != path->p_depth);
@@ -1934,9 +1963,10 @@ prepend:
* There is no free space in the found leaf.
* We're gonna add a new leaf in the tree.
*/
- if (flag & EXT4_GET_BLOCKS_METADATA_NOFAIL)
- flags = EXT4_MB_USE_RESERVED;
- err = ext4_ext_create_new_leaf(handle, inode, flags, path, newext);
+ if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
+ mb_flags = EXT4_MB_USE_RESERVED;
+ err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
+ path, newext);
if (err)
goto cleanup;
depth = ext_depth(inode);
@@ -2002,7 +2032,7 @@ has_space:
merge:
/* try to merge extents */
- if (!(flag & EXT4_GET_BLOCKS_PRE_IO))
+ if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
ext4_ext_try_to_merge(handle, inode, path, nearex);
@@ -2045,7 +2075,7 @@ static int ext4_fill_fiemap_extents(struct inode *inode,
path = NULL;
}
- path = ext4_ext_find_extent(inode, block, path);
+ path = ext4_ext_find_extent(inode, block, path, 0);
if (IS_ERR(path)) {
up_read(&EXT4_I(inode)->i_data_sem);
err = PTR_ERR(path);
@@ -2707,7 +2737,7 @@ again:
ext4_lblk_t ee_block;
/* find extent for this block */
- path = ext4_ext_find_extent(inode, end, NULL);
+ path = ext4_ext_find_extent(inode, end, NULL, EXT4_EX_NOCACHE);
if (IS_ERR(path)) {
ext4_journal_stop(handle);
return PTR_ERR(path);
@@ -2749,6 +2779,7 @@ again:
*/
err = ext4_split_extent_at(handle, inode, path,
end + 1, split_flag,
+ EXT4_EX_NOCACHE |
EXT4_GET_BLOCKS_PRE_IO |
EXT4_GET_BLOCKS_METADATA_NOFAIL);
@@ -2825,7 +2856,8 @@ again:
i + 1, ext4_idx_pblock(path[i].p_idx));
memset(path + i + 1, 0, sizeof(*path));
bh = read_extent_tree_block(inode,
- ext4_idx_pblock(path[i].p_idx), depth - i - 1);
+ ext4_idx_pblock(path[i].p_idx), depth - i - 1,
+ EXT4_EX_NOCACHE);
if (IS_ERR(bh)) {
err = PTR_ERR(bh);
break;
@@ -3168,7 +3200,7 @@ static int ext4_split_extent(handle_t *handle,
* result in split of original leaf or extent zeroout.
*/
ext4_ext_drop_refs(path);
- path = ext4_ext_find_extent(inode, map->m_lblk, path);
+ path = ext4_ext_find_extent(inode, map->m_lblk, path, 0);
if (IS_ERR(path))
return PTR_ERR(path);
depth = ext_depth(inode);
@@ -3552,7 +3584,7 @@ static int ext4_convert_unwritten_extents_endio(handle_t *handle,
if (err < 0)
goto out;
ext4_ext_drop_refs(path);
- path = ext4_ext_find_extent(inode, map->m_lblk, path);
+ path = ext4_ext_find_extent(inode, map->m_lblk, path, 0);
if (IS_ERR(path)) {
err = PTR_ERR(path);
goto out;
@@ -4039,7 +4071,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
/* find extent for this block */
- path = ext4_ext_find_extent(inode, map->m_lblk, NULL);
+ path = ext4_ext_find_extent(inode, map->m_lblk, NULL, 0);
if (IS_ERR(path)) {
err = PTR_ERR(path);
path = NULL;
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 7358fb3..a84804c 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -417,7 +417,7 @@ static void ext4_es_insert_extent_ext_check(struct inode *inode,
unsigned short ee_len;
int depth, ee_status, es_status;
- path = ext4_ext_find_extent(inode, es->es_lblk, NULL);
+ path = ext4_ext_find_extent(inode, es->es_lblk, NULL, EXT4_EX_NOCACHE);
if (IS_ERR(path))
return;
@@ -678,6 +678,43 @@ error:
}
/*
+ * ext4_es_cache_extent() inserts information into the extent status
+ * tree if and only if there isn't information about the range in
+ * question already.
+ */
+void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
+ ext4_lblk_t len, ext4_fsblk_t pblk,
+ unsigned int status)
+{
+ struct extent_status *es;
+ struct extent_status newes;
+ ext4_lblk_t end = lblk + len - 1;
+
+ es_debug("cache [%u/%u) %llu %x to extent status tree of inode %lu\n",
+ lblk, len, pblk, status, inode->i_ino);
+ if (!len)
+ return;
+
+ BUG_ON(end < lblk);
+
+ write_lock(&EXT4_I(inode)->i_es_lock);
+
+ es = __es_tree_search(&EXT4_I(inode)->i_es_tree.root, lblk);
+ if (es && ((es->es_lblk <= lblk) || (es->es_lblk <= end)))
+ goto out;
+
+ newes.es_lblk = lblk;
+ newes.es_len = len;
+ ext4_es_store_pblock(&newes, pblk);
+ ext4_es_store_status(&newes, status);
+ trace_ext4_es_cache_extent(inode, &newes);
+
+ __es_insert_extent(inode, &newes);
+out:
+ write_unlock(&EXT4_I(inode)->i_es_lock);
+}
+
+/*
* ext4_es_lookup_extent() looks up an extent in extent status tree.
*
* ext4_es_lookup_extent is called by ext4_map_blocks/ext4_da_map_blocks.
diff --git a/fs/ext4/extents_status.h b/fs/ext4/extents_status.h
index ae1be58..23348d1 100644
--- a/fs/ext4/extents_status.h
+++ b/fs/ext4/extents_status.h
@@ -71,6 +71,9 @@ extern void ext4_es_init_tree(struct ext4_es_tree *tree);
extern int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
ext4_lblk_t len, ext4_fsblk_t pblk,
unsigned int status);
+extern void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
+ ext4_lblk_t len, ext4_fsblk_t pblk,
+ unsigned int status);
extern int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
ext4_lblk_t len);
extern void ext4_es_find_delayed_extent_range(struct inode *inode,
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index 49e8bdf..f99bdb8 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -39,7 +39,7 @@ static int finish_range(handle_t *handle, struct inode *inode,
newext.ee_block = cpu_to_le32(lb->first_block);
newext.ee_len = cpu_to_le16(lb->last_block - lb->first_block + 1);
ext4_ext_store_pblock(&newext, lb->first_pblock);
- path = ext4_ext_find_extent(inode, lb->first_block, NULL);
+ path = ext4_ext_find_extent(inode, lb->first_block, NULL, 0);
if (IS_ERR(path)) {
retval = PTR_ERR(path);
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index e86dddb..7fa4d85 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -37,7 +37,7 @@ get_ext_path(struct inode *inode, ext4_lblk_t lblock,
int ret = 0;
struct ext4_ext_path *path;
- path = ext4_ext_find_extent(inode, lblock, *orig_path);
+ path = ext4_ext_find_extent(inode, lblock, *orig_path, EXT4_EX_NOCACHE);
if (IS_ERR(path))
ret = PTR_ERR(path);
else if (path[ext_depth(inode)].p_ext == NULL)
diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
index 47a355b..d892b55 100644
--- a/include/trace/events/ext4.h
+++ b/include/trace/events/ext4.h
@@ -2192,7 +2192,7 @@ TRACE_EVENT(ext4_ext_remove_space_done,
(unsigned short) __entry->eh_entries)
);
-TRACE_EVENT(ext4_es_insert_extent,
+DECLARE_EVENT_CLASS(ext4__es_extent,
TP_PROTO(struct inode *inode, struct extent_status *es),
TP_ARGS(inode, es),
@@ -2222,6 +2222,18 @@ TRACE_EVENT(ext4_es_insert_extent,
__entry->pblk, show_extent_status(__entry->status))
);
+DEFINE_EVENT(ext4__es_extent, ext4_es_insert_extent,
+ TP_PROTO(struct inode *inode, struct extent_status *es),
+
+ TP_ARGS(inode, es)
+);
+
+DEFINE_EVENT(ext4__es_extent, ext4_es_cache_extent,
+ TP_PROTO(struct inode *inode, struct extent_status *es),
+
+ TP_ARGS(inode, es)
+);
+
TRACE_EVENT(ext4_es_remove_extent,
TP_PROTO(struct inode *inode, ext4_lblk_t lblk, ext4_lblk_t len),
--
1.7.12.rc0.22.gcdd159b
--
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