In several places the sequence (set_extent_uptodate, unlock_extent) is used.
This leads to a duplicate lookup of the extent state. This patch lets
set_extent_uptodate return a cached extent_state which can be passed to
unlock_extent_cached.
The occurences of the above sequences are updated to use the cache. Only
end_bio_extent_readpage is updated that it first gets a cached state to
pass it to the readpage_end_io_hook as the prototype requested and is later
on being used for set/unlock.
Signed-off-by: Arne Jansen <sensi...@gmx.net>
---
fs/btrfs/extent_io.c | 70 +++++++++++++++++++++++++++++++++++++------------
fs/btrfs/extent_io.h | 2 +-
fs/btrfs/inode.c | 2 +-
3 files changed, 55 insertions(+), 19 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 9fcb5ed..9e8230d 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -690,6 +690,17 @@ static void cache_state(struct extent_state *state,
}
}
+static void uncache_state(struct extent_state **cached_ptr)
+{
+ if (cached_ptr && (*cached_ptr)) {
+ struct extent_state *state = *cached_ptr;
+ if (state->state & (EXTENT_IOBITS | EXTENT_BOUNDARY)) {
+ *cached_ptr = NULL;
+ free_extent_state(state);
+ }
+ }
+}
+
/*
* set some bits on a range in the tree. This may require allocations or
* sleeping, so the gfp mask is used to indicate what is allowed.
@@ -940,10 +951,10 @@ static int clear_extent_new(struct extent_io_tree *tree,
u64 start, u64 end,
}
int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
- gfp_t mask)
+ struct extent_state **cached_state, gfp_t mask)
{
- return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, NULL,
- NULL, mask);
+ return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0,
+ NULL, cached_state, mask);
}
static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
@@ -1012,8 +1023,7 @@ int unlock_extent_cached(struct extent_io_tree *tree, u64
start, u64 end,
mask);
}
-int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end,
- gfp_t mask)
+int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask)
{
return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL,
mask);
@@ -1735,6 +1745,9 @@ static void end_bio_extent_readpage(struct bio *bio, int
err)
do {
struct page *page = bvec->bv_page;
+ struct extent_state *cached = NULL;
+ struct extent_state *state;
+
tree = &BTRFS_I(page->mapping->host)->io_tree;
start = ((u64)page->index << PAGE_CACHE_SHIFT) +
@@ -1749,9 +1762,20 @@ static void end_bio_extent_readpage(struct bio *bio, int
err)
if (++bvec <= bvec_end)
prefetchw(&bvec->bv_page->flags);
+ spin_lock(&tree->lock);
+ state = find_first_extent_bit_state(tree, start, 0);
+ if (state) {
+ /*
+ * take a reference on the state, unlock will drop
+ * the ref
+ */
+ cache_state(state, &cached);
+ }
+ spin_unlock(&tree->lock);
+
if (uptodate && tree->ops && tree->ops->readpage_end_io_hook) {
ret = tree->ops->readpage_end_io_hook(page, start, end,
- NULL);
+ state);
if (ret)
uptodate = 0;
}
@@ -1764,15 +1788,16 @@ static void end_bio_extent_readpage(struct bio *bio,
int err)
test_bit(BIO_UPTODATE, &bio->bi_flags);
if (err)
uptodate = 0;
+ uncache_state(&cached);
continue;
}
}
if (uptodate) {
- set_extent_uptodate(tree, start, end,
+ set_extent_uptodate(tree, start, end, &cached,
GFP_ATOMIC);
}
- unlock_extent(tree, start, end, GFP_ATOMIC);
+ unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
if (whole_page) {
if (uptodate) {
@@ -1811,6 +1836,7 @@ static void end_bio_extent_preparewrite(struct bio *bio,
int err)
do {
struct page *page = bvec->bv_page;
+ struct extent_state *cached = NULL;
tree = &BTRFS_I(page->mapping->host)->io_tree;
start = ((u64)page->index << PAGE_CACHE_SHIFT) +
@@ -1821,13 +1847,14 @@ static void end_bio_extent_preparewrite(struct bio
*bio, int err)
prefetchw(&bvec->bv_page->flags);
if (uptodate) {
- set_extent_uptodate(tree, start, end, GFP_ATOMIC);
+ set_extent_uptodate(tree, start, end, &cached,
+ GFP_ATOMIC);
} else {
ClearPageUptodate(page);
SetPageError(page);
}
- unlock_extent(tree, start, end, GFP_ATOMIC);
+ unlock_extent_cached(tree, start, end, &cached, GFP_ATOMIC);
} while (bvec >= bio->bi_io_vec);
@@ -2016,14 +2043,17 @@ static int __extent_read_full_page(struct
extent_io_tree *tree,
while (cur <= end) {
if (cur >= last_byte) {
char *userpage;
+ struct extent_state *cached = NULL;
+
iosize = PAGE_CACHE_SIZE - page_offset;
userpage = kmap_atomic(page, KM_USER0);
memset(userpage + page_offset, 0, iosize);
flush_dcache_page(page);
kunmap_atomic(userpage, KM_USER0);
set_extent_uptodate(tree, cur, cur + iosize - 1,
- GFP_NOFS);
- unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
+ &cached, GFP_NOFS);
+ unlock_extent_cached(tree, cur, cur + iosize - 1,
+ &cached, GFP_NOFS);
break;
}
em = get_extent(inode, page, page_offset, cur,
@@ -2063,14 +2093,17 @@ static int __extent_read_full_page(struct
extent_io_tree *tree,
/* we've found a hole, just zero and go on */
if (block_start == EXTENT_MAP_HOLE) {
char *userpage;
+ struct extent_state *cached = NULL;
+
userpage = kmap_atomic(page, KM_USER0);
memset(userpage + page_offset, 0, iosize);
flush_dcache_page(page);
kunmap_atomic(userpage, KM_USER0);
set_extent_uptodate(tree, cur, cur + iosize - 1,
- GFP_NOFS);
- unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS);
+ &cached, GFP_NOFS);
+ unlock_extent_cached(tree, cur, cur + iosize - 1,
+ &cached, GFP_NOFS);
cur = cur + iosize;
page_offset += iosize;
continue;
@@ -2787,9 +2820,12 @@ int extent_prepare_write(struct extent_io_tree *tree,
iocount++;
block_start = block_start + iosize;
} else {
- set_extent_uptodate(tree, block_start, cur_end,
+ struct extent_state *cached = NULL;
+
+ set_extent_uptodate(tree, block_start, cur_end, &cached,
GFP_NOFS);
- unlock_extent(tree, block_start, cur_end, GFP_NOFS);
+ unlock_extent_cached(tree, block_start, cur_end,
+ &cached, GFP_NOFS);
block_start = cur_end + 1;
}
page_offset = block_start & (PAGE_CACHE_SIZE - 1);
@@ -3456,7 +3492,7 @@ int set_extent_buffer_uptodate(struct extent_io_tree
*tree,
num_pages = num_extent_pages(eb->start, eb->len);
set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1,
- GFP_NOFS);
+ NULL, GFP_NOFS);
for (i = 0; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) ||
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 9318dfe..ceeda49 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -207,7 +207,7 @@ int set_extent_bit(struct extent_io_tree *tree, u64 start,
u64 end,
int bits, int exclusive_bits, u64 *failed_start,
struct extent_state **cached_state, gfp_t mask);
int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
- gfp_t mask);
+ struct extent_state **cached_state, gfp_t mask);
int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
gfp_t mask);
int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index db67821..8aea25c 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5202,7 +5202,7 @@ again:
btrfs_mark_buffer_dirty(leaf);
}
set_extent_uptodate(io_tree, em->start,
- extent_map_end(em) - 1, GFP_NOFS);
+ extent_map_end(em) - 1, NULL, GFP_NOFS);
goto insert;
} else {
printk(KERN_ERR "btrfs unknown found_type %d\n", found_type);
--
1.7.3.4
--
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