From: Zheng Liu <wenqing.lz@xxxxxxxxxx>
By recording the phycisal block and status, extent status tree is able
to track the status of every extents. When we call _map_blocks
functions to lookup an extent or create a new written/unwritten/delayed
extent, this extent will be inserted into extent status tree. The hole
extent is inserted in ext4_ext_put_gap_in_cache(). If there is no any
extent, we will not insert a hole extent [0, ~0] into the extent status
tree in order to reduce the complextiy of code.
We don't load all extents from disk in alloc_inode() because it costs
too much memory, and if a file is opened and closed frequently it will
takes too much time to load all extent information. So currently when
we create/lookup an extent, this extent will be inserted into extent
status tree. Hence, the extent status tree may not comprehensively
contain all of the extents found in the file.
Signed-off-by: Zheng Liu <wenqing.lz@xxxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
Cc: Jan kara <jack@xxxxxxx>
---
fs/ext4/extents.c | 4 +--
fs/ext4/extents_status.c | 27 ++++++++++++------
fs/ext4/extents_status.h | 4 +--
fs/ext4/file.c | 4 +--
fs/ext4/inode.c | 68 ++++++++++++++++++++++++++++-----------------
include/trace/events/ext4.h | 4 +--
6 files changed, 70 insertions(+), 41 deletions(-)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index d92947f..4b065ff 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3526,7 +3526,7 @@ static int ext4_find_delalloc_range(struct inode *inode,
struct extent_status es;
es.es_lblk = lblk_start;
- (void)ext4_es_find_extent(inode, &es);
+ (void)ext4_es_find_delayed_extent(inode, &es);
if (es.es_len == 0)
return 0; /* there is no delay extent in this tree */
else if (es.es_lblk <= lblk_start &&
@@ -4573,7 +4573,7 @@ static int ext4_find_delayed_extent(struct inode *inode,
ext4_lblk_t next_del;
es.es_lblk = newex->ec_block;
- next_del = ext4_es_find_extent(inode, &es);
+ next_del = ext4_es_find_delayed_extent(inode, &es);
if (newex->ec_start == 0) {
/*
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 5093cee..71cb75a 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -229,7 +229,7 @@ static struct extent_status *__es_tree_search(struct rb_root *root,
}
/*
- * ext4_es_find_extent: find the 1st delayed extent covering @es->lblk
+ * ext4_es_find_delayed_extent: find the 1st delayed extent covering @es->lblk
* if it exists, otherwise, the next extent after @es->lblk.
*
* @inode: the inode which owns delayed extents
@@ -239,14 +239,15 @@ static struct extent_status *__es_tree_search(struct rb_root *root,
* 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)
+ext4_lblk_t ext4_es_find_delayed_extent(struct inode *inode,
+ struct extent_status *es)
{
struct ext4_es_tree *tree = NULL;
struct extent_status *es1 = NULL;
struct rb_node *node;
ext4_lblk_t ret = EXT_MAX_BLOCKS;
- trace_ext4_es_find_extent_enter(inode, es->es_lblk);
+ trace_ext4_es_find_delayed_extent_enter(inode, es->es_lblk);
read_lock(&EXT4_I(inode)->i_es_lock);
tree = &EXT4_I(inode)->i_es_tree;
@@ -266,21 +267,31 @@ ext4_lblk_t ext4_es_find_extent(struct inode *inode, struct extent_status *es)
es1 = __es_tree_search(&tree->root, es->es_lblk);
out:
- if (es1) {
+ if (es1 && !ext4_es_is_delayed(es1)) {
+ while ((node = rb_next(&es1->rb_node)) != NULL) {
+ es1 = rb_entry(node, struct extent_status, rb_node);
+ if (ext4_es_is_delayed(es1))
+ break;
+ }
+ }
+
+ if (es1 && ext4_es_is_delayed(es1)) {
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) {
+ while ((node = rb_next(&es1->rb_node)) != NULL) {
es1 = rb_entry(node, struct extent_status, rb_node);
- ret = es1->es_lblk;
+ if (ext4_es_is_delayed(es1)) {
+ ret = es1->es_lblk;
+ break;
+ }
}
}
read_unlock(&EXT4_I(inode)->i_es_lock);
- trace_ext4_es_find_extent_exit(inode, es, ret);
+ trace_ext4_es_find_delayed_extent_exit(inode, es, ret);
return ret;
}
diff --git a/fs/ext4/extents_status.h b/fs/ext4/extents_status.h
index 2a5d69e..b5788eb 100644
--- a/fs/ext4/extents_status.h
+++ b/fs/ext4/extents_status.h
@@ -51,8 +51,8 @@ extern int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
unsigned long long status);
extern int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk,
ext4_lblk_t len);
-extern ext4_lblk_t ext4_es_find_extent(struct inode *inode,
- struct extent_status *es);
+extern ext4_lblk_t ext4_es_find_delayed_extent(struct inode *inode,
+ struct extent_status *es);
static inline int ext4_es_is_written(struct extent_status *es)
{
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 718c49f..bbfbf78 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -465,7 +465,7 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize)
* it will be as a data.
*/
es.es_lblk = last;
- (void)ext4_es_find_extent(inode, &es);
+ (void)ext4_es_find_delayed_extent(inode, &es);
if (last >= es.es_lblk && last < es.es_lblk + es.es_len) {
if (last != start)
dataoff = last << blkbits;
@@ -549,7 +549,7 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize)
* we will skip this extent.
*/
es.es_lblk = last;
- (void)ext4_es_find_extent(inode, &es);
+ (void)ext4_es_find_delayed_extent(inode, &es);
if (last >= es.es_lblk && last < es.es_lblk + es.es_len) {
last = es.es_lblk + es.es_len;
holeoff = last << blkbits;
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index c7e9665..16454fc 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -527,20 +527,22 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
retval = ext4_ind_map_blocks(handle, inode, map, flags &
EXT4_GET_BLOCKS_KEEP_SIZE);
}
+ if (retval > 0) {
+ int ret;
+ unsigned long long status;
+
+ status = map->m_flags & EXT4_MAP_UNWRITTEN ?
+ EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
+ ret = ext4_es_insert_extent(inode, map->m_lblk,
+ map->m_len, map->m_pblk, status);
+ if (ret < 0)
+ retval = ret;
+ }
if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
up_read((&EXT4_I(inode)->i_data_sem));
if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
- int ret;
- if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
- /* delayed alloc may be allocated by fallocate and
- * coverted to initialized by directIO.
- * we need to handle delayed extent here.
- */
- down_write((&EXT4_I(inode)->i_data_sem));
- goto delayed_mapped;
- }
- ret = check_block_validity(inode, map);
+ int ret = check_block_validity(inode, map);
if (ret != 0)
return ret;
}
@@ -609,18 +611,19 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE))
ext4_da_update_reserve_space(inode, retval, 1);
}
- if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
+ if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
ext4_clear_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
- if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
- int ret;
-delayed_mapped:
- /* delayed allocation blocks has been allocated */
- ret = ext4_es_remove_extent(inode, map->m_lblk,
- map->m_len);
- if (ret < 0)
- retval = ret;
- }
+ if (retval > 0) {
+ int ret;
+ unsigned long long status;
+
+ status = map->m_flags & EXT4_MAP_UNWRITTEN ?
+ EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
+ ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
+ map->m_pblk, status);
+ if (ret < 0)
+ retval = ret;
}
up_write((&EXT4_I(inode)->i_data_sem));
@@ -1802,6 +1805,7 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
retval = ext4_ind_map_blocks(NULL, inode, map, 0);
if (retval == 0) {
+ int ret;
/*
* XXX: __block_prepare_write() unmaps passed block,
* is it OK?
@@ -1809,16 +1813,20 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
/* If the block was allocated from previously allocated cluster,
* then we dont need to reserve it again. */
if (!(map->m_flags & EXT4_MAP_FROM_CLUSTER)) {
- retval = ext4_da_reserve_space(inode, iblock);
- if (retval)
+ ret = ext4_da_reserve_space(inode, iblock);
+ if (ret) {
/* not enough space to reserve */
+ retval = ret;
goto out_unlock;
+ }
}
- retval = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
- ~0, EXTENT_STATUS_DELAYED);
- if (retval)
+ ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
+ ~0, EXTENT_STATUS_DELAYED);
+ if (ret) {
+ retval = ret;
goto out_unlock;
+ }
/* Clear EXT4_MAP_FROM_CLUSTER flag since its purpose is served
* and it should not appear on the bh->b_state.
@@ -1828,6 +1836,16 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
map_bh(bh, inode->i_sb, invalid_block);
set_buffer_new(bh);
set_buffer_delay(bh);
+ } else if (retval > 0) {
+ int ret;
+ unsigned long long status;
+
+ status = map->m_flags & EXT4_MAP_UNWRITTEN ?
+ EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
+ ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
+ map->m_pblk, status);
+ if (ret != 0)
+ retval = ret;
}
out_unlock:
diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
index ef2f96e..d278ced 100644
--- a/include/trace/events/ext4.h
+++ b/include/trace/events/ext4.h
@@ -2122,7 +2122,7 @@ TRACE_EVENT(ext4_es_remove_extent,
__entry->lblk, __entry->len)
);
-TRACE_EVENT(ext4_es_find_extent_enter,
+TRACE_EVENT(ext4_es_find_delayed_extent_enter,
TP_PROTO(struct inode *inode, ext4_lblk_t lblk),
TP_ARGS(inode, lblk),
@@ -2144,7 +2144,7 @@ TRACE_EVENT(ext4_es_find_extent_enter,
(unsigned long) __entry->ino, __entry->lblk)
);
-TRACE_EVENT(ext4_es_find_extent_exit,
+TRACE_EVENT(ext4_es_find_delayed_extent_exit,
TP_PROTO(struct inode *inode, struct extent_status *es,
ext4_lblk_t ret),
--
1.7.12.rc2.18.g61b472e
--
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