ext4: remove single extent cache
Single extent cache could be removed because we have extent status tree
as a extent cache, and it would be better.
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jan kara <jack@suse.cz>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 329e7fb..0c565c9 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -809,17 +809,6 @@
#endif /* defined(__KERNEL__) || defined(__linux__) */
-/*
- * storage for cached extent
- * If ec_len == 0, then the cache is invalid.
- * If ec_start == 0, then the cache represents a gap (null mapping)
- */
-struct ext4_ext_cache {
- ext4_fsblk_t ec_start;
- ext4_lblk_t ec_block;
- __u32 ec_len; /* must be 32bit to return holes */
-};
-
#include "extents_status.h"
/*
@@ -886,7 +875,6 @@
struct inode vfs_inode;
struct jbd2_inode *jinode;
- struct ext4_ext_cache i_cached_extent;
/*
* File creation time. Its function is same as that of
* struct timespec i_{a,c,m}time in the generic inode.
diff --git a/fs/ext4/ext4_extents.h b/fs/ext4/ext4_extents.h
index 487fda1..8643ff5 100644
--- a/fs/ext4/ext4_extents.h
+++ b/fs/ext4/ext4_extents.h
@@ -193,12 +193,6 @@
return le16_to_cpu(ext_inode_hdr(inode)->eh_depth);
}
-static inline void
-ext4_ext_invalidate_cache(struct inode *inode)
-{
- EXT4_I(inode)->i_cached_extent.ec_len = 0;
-}
-
static inline void ext4_ext_mark_uninitialized(struct ext4_extent *ext)
{
/* We can not have an uninitialized extent of zero length! */
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index b9d7a23..372b2cbe 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -112,7 +112,7 @@
int flags);
static int ext4_find_delayed_extent(struct inode *inode,
- struct ext4_ext_cache *newex);
+ struct extent_status *newes);
static int ext4_ext_truncate_extend_restart(handle_t *handle,
struct inode *inode,
@@ -714,7 +714,6 @@
eh->eh_magic = EXT4_EXT_MAGIC;
eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
ext4_mark_inode_dirty(handle, inode);
- ext4_ext_invalidate_cache(inode);
return 0;
}
@@ -1963,7 +1962,6 @@
ext4_ext_drop_refs(npath);
kfree(npath);
}
- ext4_ext_invalidate_cache(inode);
return err;
}
@@ -1972,8 +1970,8 @@
struct fiemap_extent_info *fieinfo)
{
struct ext4_ext_path *path = NULL;
- struct ext4_ext_cache newex;
struct ext4_extent *ex;
+ struct extent_status es;
ext4_lblk_t next, next_del, start = 0, end = 0;
ext4_lblk_t last = block + num;
int exists, depth = 0, err = 0;
@@ -2047,31 +2045,31 @@
BUG_ON(end <= start);
if (!exists) {
- newex.ec_block = start;
- newex.ec_len = end - start;
- newex.ec_start = 0;
+ es.es_lblk = start;
+ es.es_len = end - start;
+ es.es_pblk = 0;
} else {
- newex.ec_block = le32_to_cpu(ex->ee_block);
- newex.ec_len = ext4_ext_get_actual_len(ex);
- newex.ec_start = ext4_ext_pblock(ex);
+ es.es_lblk = le32_to_cpu(ex->ee_block);
+ es.es_len = ext4_ext_get_actual_len(ex);
+ es.es_pblk = ext4_ext_pblock(ex);
if (ext4_ext_is_uninitialized(ex))
flags |= FIEMAP_EXTENT_UNWRITTEN;
}
/*
- * Find delayed extent and update newex accordingly. We call
- * it even in !exists case to find out whether newex is the
+ * Find delayed extent and update es accordingly. We call
+ * it even in !exists case to find out whether es is the
* last existing extent or not.
*/
- next_del = ext4_find_delayed_extent(inode, &newex);
+ next_del = ext4_find_delayed_extent(inode, &es);
if (!exists && next_del) {
exists = 1;
flags |= FIEMAP_EXTENT_DELALLOC;
}
up_read(&EXT4_I(inode)->i_data_sem);
- if (unlikely(newex.ec_len == 0)) {
- EXT4_ERROR_INODE(inode, "newex.ec_len == 0");
+ if (unlikely(es.es_len == 0)) {
+ EXT4_ERROR_INODE(inode, "es.es_len == 0");
err = -EIO;
break;
}
@@ -2102,9 +2100,9 @@
if (exists) {
err = fiemap_fill_next_extent(fieinfo,
- (__u64)newex.ec_block << blksize_bits,
- (__u64)newex.ec_start << blksize_bits,
- (__u64)newex.ec_len << blksize_bits,
+ (__u64)es.es_lblk << blksize_bits,
+ (__u64)es.es_pblk << blksize_bits,
+ (__u64)es.es_len << blksize_bits,
flags);
if (err < 0)
break;
@@ -2114,7 +2112,7 @@
}
}
- block = newex.ec_block + newex.ec_len;
+ block = es.es_lblk + es.es_len;
}
if (path) {
@@ -2125,21 +2123,6 @@
return err;
}
-static void
-ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
- __u32 len, ext4_fsblk_t start)
-{
- struct ext4_ext_cache *cex;
- BUG_ON(len == 0);
- spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
- trace_ext4_ext_put_in_cache(inode, block, len, start);
- cex = &EXT4_I(inode)->i_cached_extent;
- cex->ec_block = block;
- cex->ec_len = len;
- cex->ec_start = start;
- spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
-}
-
/*
* ext4_ext_put_gap_in_cache:
* calculate boundaries of the gap that the requested block fits into
@@ -2156,9 +2139,10 @@
ex = path[depth].p_ext;
if (ex == NULL) {
- /* there is no extent yet, so gap is [0;-] */
- lblock = 0;
- len = EXT_MAX_BLOCKS;
+ /*
+ * there is no extent yet, so gap is [0;-] and we
+ * don't cache it
+ */
ext_debug("cache gap(whole file):");
} else if (block < le32_to_cpu(ex->ee_block)) {
lblock = block;
@@ -2192,52 +2176,6 @@
}
ext_debug(" -> %u:%lu\n", lblock, len);
- ext4_ext_put_in_cache(inode, lblock, len, 0);
-}
-
-/*
- * ext4_ext_in_cache()
- * Checks to see if the given block is in the cache.
- * If it is, the cached extent is stored in the given
- * cache extent pointer.
- *
- * @inode: The files inode
- * @block: The block to look for in the cache
- * @ex: Pointer where the cached extent will be stored
- * if it contains block
- *
- * Return 0 if cache is invalid; 1 if the cache is valid
- */
-static int
-ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
- struct ext4_extent *ex)
-{
- struct ext4_ext_cache *cex;
- int ret = 0;
-
- /*
- * We borrow i_block_reservation_lock to protect i_cached_extent
- */
- spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
- cex = &EXT4_I(inode)->i_cached_extent;
-
- /* has cache valid data? */
- if (cex->ec_len == 0)
- goto errout;
-
- if (in_range(block, cex->ec_block, cex->ec_len)) {
- ex->ee_block = cpu_to_le32(cex->ec_block);
- ext4_ext_store_pblock(ex, cex->ec_start);
- ex->ee_len = cpu_to_le16(cex->ec_len);
- ext_debug("%u cached by %u:%u:%llu\n",
- block,
- cex->ec_block, cex->ec_len, cex->ec_start);
- ret = 1;
- }
-errout:
- trace_ext4_ext_in_cache(inode, block, ret);
- spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
- return ret;
}
/*
@@ -2677,8 +2615,6 @@
return PTR_ERR(handle);
again:
- ext4_ext_invalidate_cache(inode);
-
trace_ext4_ext_remove_space(inode, start, depth);
/*
@@ -3920,35 +3856,6 @@
map->m_lblk, map->m_len, inode->i_ino);
trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
- /* check in cache */
- if (ext4_ext_in_cache(inode, map->m_lblk, &newex)) {
- if (!newex.ee_start_lo && !newex.ee_start_hi) {
- if ((sbi->s_cluster_ratio > 1) &&
- ext4_find_delalloc_cluster(inode, map->m_lblk))
- map->m_flags |= EXT4_MAP_FROM_CLUSTER;
-
- if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
- /*
- * block isn't allocated yet and
- * user doesn't want to allocate it
- */
- goto out2;
- }
- /* we should allocate requested block */
- } else {
- /* block is already allocated */
- if (sbi->s_cluster_ratio > 1)
- map->m_flags |= EXT4_MAP_FROM_CLUSTER;
- newblock = map->m_lblk
- - le32_to_cpu(newex.ee_block)
- + ext4_ext_pblock(&newex);
- /* number of remaining blocks in the extent */
- allocated = ext4_ext_get_actual_len(&newex) -
- (map->m_lblk - le32_to_cpu(newex.ee_block));
- goto out;
- }
- }
-
/* find extent for this block */
path = ext4_ext_find_extent(inode, map->m_lblk, NULL);
if (IS_ERR(path)) {
@@ -3995,15 +3902,9 @@
ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
ee_block, ee_len, newblock);
- /*
- * Do not put uninitialized extent
- * in the cache
- */
- if (!ext4_ext_is_uninitialized(ex)) {
- ext4_ext_put_in_cache(inode, ee_block,
- ee_len, ee_start);
+ if (!ext4_ext_is_uninitialized(ex))
goto out;
- }
+
allocated = ext4_ext_handle_uninitialized_extents(
handle, inode, map, path, flags,
allocated, newblock);
@@ -4265,10 +4166,9 @@
* Cache the extent and update transaction to commit on fdatasync only
* when it is _not_ an uninitialized extent.
*/
- if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0) {
- ext4_ext_put_in_cache(inode, map->m_lblk, allocated, newblock);
+ if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0)
ext4_update_inode_fsync_trans(handle, inode, 1);
- } else
+ else
ext4_update_inode_fsync_trans(handle, inode, 0);
out:
if (allocated > map->m_len)
@@ -4327,7 +4227,6 @@
goto out_stop;
down_write(&EXT4_I(inode)->i_data_sem);
- ext4_ext_invalidate_cache(inode);
ext4_discard_preallocations(inode);
@@ -4576,42 +4475,42 @@
}
/*
- * If newex is not existing extent (newex->ec_start equals zero) find
- * delayed extent at start of newex and update newex accordingly and
+ * If newes is not existing extent (newes->ec_pblk equals zero) find
+ * delayed extent at start of newes and update newes accordingly and
* return start of the next delayed extent.
*
- * If newex is existing extent (newex->ec_start is not equal zero)
+ * If newes is existing extent (newes->ec_pblk is not equal zero)
* return start of next delayed extent or EXT_MAX_BLOCKS if no delayed
- * extent found. Leave newex unmodified.
+ * extent found. Leave newes unmodified.
*/
static int ext4_find_delayed_extent(struct inode *inode,
- struct ext4_ext_cache *newex)
+ struct extent_status *newes)
{
struct extent_status es;
ext4_lblk_t block, next_del;
- ext4_es_find_delayed_extent(inode, newex->ec_block, &es);
+ ext4_es_find_delayed_extent(inode, newes->es_lblk, &es);
- if (newex->ec_start == 0) {
+ if (newes->es_pblk == 0) {
/*
- * No extent in extent-tree contains block @newex->ec_start,
+ * No extent in extent-tree contains block @newes->es_pblk,
* then the block may stay in 1)a hole or 2)delayed-extent.
*/
if (es.es_len == 0)
/* A hole found. */
return 0;
- if (es.es_lblk > newex->ec_block) {
+ if (es.es_lblk > newes->es_lblk) {
/* A hole found. */
- newex->ec_len = min(es.es_lblk - newex->ec_block,
- newex->ec_len);
+ newes->es_len = min(es.es_lblk - newes->es_lblk,
+ newes->es_len);
return 0;
}
- newex->ec_len = es.es_lblk + es.es_len - newex->ec_block;
+ newes->es_len = es.es_lblk + es.es_len - newes->es_lblk;
}
- block = newex->ec_block + newex->ec_len;
+ block = newes->es_lblk + newes->es_len;
ext4_es_find_delayed_extent(inode, block, &es);
if (es.es_len == 0)
next_del = EXT_MAX_BLOCKS;
@@ -4815,14 +4714,12 @@
goto out;
down_write(&EXT4_I(inode)->i_data_sem);
- ext4_ext_invalidate_cache(inode);
ext4_discard_preallocations(inode);
err = ext4_es_remove_extent(inode, first_block,
stop_block - first_block);
err = ext4_ext_remove_space(inode, first_block, stop_block - 1);
- ext4_ext_invalidate_cache(inode);
ext4_discard_preallocations(inode);
if (IS_SYNC(inode))
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index 0d67343..d78c33e 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -764,9 +764,6 @@
kfree(donor_path);
}
- ext4_ext_invalidate_cache(orig_inode);
- ext4_ext_invalidate_cache(donor_inode);
-
return replaced_count;
}
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index ef6ac59..d80bfe5 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -836,7 +836,6 @@
return NULL;
ei->vfs_inode.i_version = 1;
- memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
INIT_LIST_HEAD(&ei->i_prealloc_list);
spin_lock_init(&ei->i_prealloc_lock);
ext4_es_init_tree(&ei->i_es_tree);