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path: root/fs/btrfs/extent_io.c
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Diffstat (limited to 'fs/btrfs/extent_io.c')
-rw-r--r--fs/btrfs/extent_io.c82
1 files changed, 62 insertions, 20 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 20ddb28602a8..315138605088 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -690,6 +690,15 @@ 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;
+ *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 +949,10 @@ 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 +1021,7 @@ 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 +1743,9 @@ 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 +1760,20 @@ 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, EXTENT_LOCKED);
+ if (state && state->start == start) {
+ /*
+ * 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 +1786,16 @@ 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 +1834,7 @@ 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 +1845,14 @@ 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 +2041,17 @@ 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 +2091,17 @@ 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;
@@ -2789,9 +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);
@@ -3457,7 +3491,7 @@ 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))) ||
@@ -3885,6 +3919,12 @@ static void move_pages(struct page *dst_page, struct page *src_page,
kunmap_atomic(dst_kaddr, KM_USER0);
}
+static inline bool areas_overlap(unsigned long src, unsigned long dst, unsigned long len)
+{
+ unsigned long distance = (src > dst) ? src - dst : dst - src;
+ return distance < len;
+}
+
static void copy_pages(struct page *dst_page, struct page *src_page,
unsigned long dst_off, unsigned long src_off,
unsigned long len)
@@ -3892,10 +3932,12 @@ static void copy_pages(struct page *dst_page, struct page *src_page,
char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);
char *src_kaddr;
- if (dst_page != src_page)
+ if (dst_page != src_page) {
src_kaddr = kmap_atomic(src_page, KM_USER1);
- else
+ } else {
src_kaddr = dst_kaddr;
+ BUG_ON(areas_overlap(src_off, dst_off, len));
+ }
memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);
kunmap_atomic(dst_kaddr, KM_USER0);
@@ -3970,7 +4012,7 @@ void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
"len %lu len %lu\n", dst_offset, len, dst->len);
BUG_ON(1);
}
- if (dst_offset < src_offset) {
+ if (!areas_overlap(src_offset, dst_offset, len)) {
memcpy_extent_buffer(dst, dst_offset, src_offset, len);
return;
}
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