diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index b90cd3776f8e0a41635ce7cf5447e7b9652e6cca..f6dac40f87ff5d4022559e6701b506589aad0353 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1406,7 +1406,8 @@ char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
read_extent_buffer(eb, dest + bytes_left,
name_off, name_len);
if (eb != eb_in) {
- btrfs_tree_read_unlock_blocking(eb);
+ if (!path->skip_locking)
+ btrfs_tree_read_unlock_blocking(eb);
free_extent_buffer(eb);
}
ret = btrfs_find_item(fs_root, path, parent, 0,
@@ -1426,9 +1427,10 @@ char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
eb = path->nodes[0];
/* make sure we can use eb after releasing the path */
if (eb != eb_in) {
- atomic_inc(&eb->refs);
- btrfs_tree_read_lock(eb);
- btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+ if (!path->skip_locking)
+ btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
+ path->nodes[0] = NULL;
+ path->locks[0] = 0;
}
btrfs_release_path(path);
iref = btrfs_item_ptr(eb, slot, struct btrfs_inode_ref);
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index c473c42d7d6c4d559dbe1587491cd2fb93804145..3346cd8f991032f2457b4c48a8e3440780d53a9a 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -637,11 +637,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
faili = nr_pages - 1;
cb->nr_pages = nr_pages;
- /* In the parent-locked case, we only locked the range we are
- * interested in. In all other cases, we can opportunistically
- * cache decompressed data that goes beyond the requested range. */
- if (!(bio_flags & EXTENT_BIO_PARENT_LOCKED))
- add_ra_bio_pages(inode, em_start + em_len, cb);
+ add_ra_bio_pages(inode, em_start + em_len, cb);
/* include any pages we added in add_ra-bio_pages */
uncompressed_len = bio->bi_vcnt * PAGE_CACHE_SIZE;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 2e7c97a3f3444aec33a688a4d1f705b0486026cf..392592dc70106e72f61a76b9e2924b5aa99363af 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2897,12 +2897,11 @@ static int __do_readpage(struct extent_io_tree *tree,
struct block_device *bdev;
int ret;
int nr = 0;
- int parent_locked = *bio_flags & EXTENT_BIO_PARENT_LOCKED;
size_t pg_offset = 0;
size_t iosize;
size_t disk_io_size;
size_t blocksize = inode->i_sb->s_blocksize;
- unsigned long this_bio_flag = *bio_flags & EXTENT_BIO_PARENT_LOCKED;
+ unsigned long this_bio_flag = 0;
set_page_extent_mapped(page);
@@ -2942,18 +2941,16 @@ static int __do_readpage(struct extent_io_tree *tree,
kunmap_atomic(userpage);
set_extent_uptodate(tree, cur, cur + iosize - 1,
&cached, GFP_NOFS);
- if (!parent_locked)
- unlock_extent_cached(tree, cur,
- cur + iosize - 1,
- &cached, GFP_NOFS);
+ unlock_extent_cached(tree, cur,
+ cur + iosize - 1,
+ &cached, GFP_NOFS);
break;
}
em = __get_extent_map(inode, page, pg_offset, cur,
end - cur + 1, get_extent, em_cached);
if (IS_ERR_OR_NULL(em)) {
SetPageError(page);
- if (!parent_locked)
- unlock_extent(tree, cur, end);
+ unlock_extent(tree, cur, end);
break;
}
extent_offset = cur - em->start;
@@ -3038,12 +3035,9 @@ static int __do_readpage(struct extent_io_tree *tree,
set_extent_uptodate(tree, cur, cur + iosize - 1,
&cached, GFP_NOFS);
- if (parent_locked)
- free_extent_state(cached);
- else
- unlock_extent_cached(tree, cur,
- cur + iosize - 1,
- &cached, GFP_NOFS);
+ unlock_extent_cached(tree, cur,
+ cur + iosize - 1,
+ &cached, GFP_NOFS);
cur = cur + iosize;
pg_offset += iosize;
continue;
@@ -3052,8 +3046,7 @@ static int __do_readpage(struct extent_io_tree *tree,
if (test_range_bit(tree, cur, cur_end,
EXTENT_UPTODATE, 1, NULL)) {
check_page_uptodate(tree, page);
- if (!parent_locked)
- unlock_extent(tree, cur, cur + iosize - 1);
+ unlock_extent(tree, cur, cur + iosize - 1);
cur = cur + iosize;
pg_offset += iosize;
continue;
@@ -3063,8 +3056,7 @@ static int __do_readpage(struct extent_io_tree *tree,
*/
if (block_start == EXTENT_MAP_INLINE) {
SetPageError(page);
- if (!parent_locked)
- unlock_extent(tree, cur, cur + iosize - 1);
+ unlock_extent(tree, cur, cur + iosize - 1);
cur = cur + iosize;
pg_offset += iosize;
continue;
@@ -3083,8 +3075,7 @@ static int __do_readpage(struct extent_io_tree *tree,
*bio_flags = this_bio_flag;
} else {
SetPageError(page);
- if (!parent_locked)
- unlock_extent(tree, cur, cur + iosize - 1);
+ unlock_extent(tree, cur, cur + iosize - 1);
}
cur = cur + iosize;
pg_offset += iosize;
@@ -3213,20 +3204,6 @@ int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
return ret;
}
-int extent_read_full_page_nolock(struct extent_io_tree *tree, struct page *page,
- get_extent_t *get_extent, int mirror_num)
-{
- struct bio *bio = NULL;
- unsigned long bio_flags = EXTENT_BIO_PARENT_LOCKED;
- int ret;
-
- ret = __do_readpage(tree, page, get_extent, NULL, &bio, mirror_num,
- &bio_flags, READ, NULL);
- if (bio)
- ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
- return ret;
-}
-
static noinline void update_nr_written(struct page *page,
struct writeback_control *wbc,
unsigned long nr_written)
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 0377413bd4b98257eae07d12041d4dce45ac2c4f..880d5292e9721f6f2c59dfd0f85d3f6fd2cde3bb 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -29,7 +29,6 @@
*/
#define EXTENT_BIO_COMPRESSED 1
#define EXTENT_BIO_TREE_LOG 2
-#define EXTENT_BIO_PARENT_LOCKED 4
#define EXTENT_BIO_FLAG_SHIFT 16
/* these are bit numbers for test/set bit */
@@ -210,8 +209,6 @@ static inline int lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end);
int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
get_extent_t *get_extent, int mirror_num);
-int extent_read_full_page_nolock(struct extent_io_tree *tree, struct page *page,
- get_extent_t *get_extent, int mirror_num);
int __init extent_io_init(void);
void extent_io_exit(void);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 83c9ad3f2621ea74a4b7764fdac29c81ec738744..561aa6292c1ec0551bb58f49d90afb447d5c1c14 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2794,24 +2794,29 @@ static long btrfs_ioctl_dev_info(struct btrfs_root *root, void __user *arg)
static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
{
struct page *page;
- struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
page = grab_cache_page(inode->i_mapping, index);
if (!page)
- return NULL;
+ return ERR_PTR(-ENOMEM);
if (!PageUptodate(page)) {
- if (extent_read_full_page_nolock(tree, page, btrfs_get_extent,
- 0))
- return NULL;
+ int ret;
+
+ ret = btrfs_readpage(NULL, page);
+ if (ret)
+ return ERR_PTR(ret);
lock_page(page);
if (!PageUptodate(page)) {
unlock_page(page);
page_cache_release(page);
- return NULL;
+ return ERR_PTR(-EIO);
+ }
+ if (page->mapping != inode->i_mapping) {
+ unlock_page(page);
+ page_cache_release(page);
+ return ERR_PTR(-EAGAIN);
}
}
- unlock_page(page);
return page;
}
@@ -2823,17 +2828,31 @@ static int gather_extent_pages(struct inode *inode, struct page **pages,
pgoff_t index = off >> PAGE_CACHE_SHIFT;
for (i = 0; i < num_pages; i++) {
+again:
pages[i] = extent_same_get_page(inode, index + i);
- if (!pages[i])
- return -ENOMEM;
+ if (IS_ERR(pages[i])) {
+ int err = PTR_ERR(pages[i]);
+
+ if (err == -EAGAIN)
+ goto again;
+ pages[i] = NULL;
+ return err;
+ }
}
return 0;
}
-static inline void lock_extent_range(struct inode *inode, u64 off, u64 len)
+static int lock_extent_range(struct inode *inode, u64 off, u64 len,
+ bool retry_range_locking)
{
- /* do any pending delalloc/csum calc on src, one way or
- another, and lock file content */
+ /*
+ * Do any pending delalloc/csum calculations on inode, one way or
+ * another, and lock file content.
+ * The locking order is:
+ *
+ * 1) pages
+ * 2) range in the inode's io tree
+ */
while (1) {
struct btrfs_ordered_extent *ordered;
lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
@@ -2851,8 +2870,11 @@ static inline void lock_extent_range(struct inode *inode, u64 off, u64 len)
unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
if (ordered)
btrfs_put_ordered_extent(ordered);
+ if (!retry_range_locking)
+ return -EAGAIN;
btrfs_wait_ordered_range(inode, off, len);
}
+ return 0;
}
static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
@@ -2877,15 +2899,24 @@ static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
}
-static void btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
- struct inode *inode2, u64 loff2, u64 len)
+static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
+ struct inode *inode2, u64 loff2, u64 len,
+ bool retry_range_locking)
{
+ int ret;
+
if (inode1 < inode2) {
swap(inode1, inode2);
swap(loff1, loff2);
}
- lock_extent_range(inode1, loff1, len);
- lock_extent_range(inode2, loff2, len);
+ ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
+ if (ret)
+ return ret;
+ ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
+ if (ret)
+ unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
+ loff1 + len - 1);
+ return ret;
}
struct cmp_pages {
@@ -2901,11 +2932,15 @@ static void btrfs_cmp_data_free(struct cmp_pages *cmp)
for (i = 0; i < cmp->num_pages; i++) {
pg = cmp->src_pages[i];
- if (pg)
+ if (pg) {
+ unlock_page(pg);
page_cache_release(pg);
+ }
pg = cmp->dst_pages[i];
- if (pg)
+ if (pg) {
+ unlock_page(pg);
page_cache_release(pg);
+ }
}
kfree(cmp->src_pages);
kfree(cmp->dst_pages);
@@ -2966,6 +3001,8 @@ static int btrfs_cmp_data(struct inode *src, u64 loff, struct inode *dst,
src_page = cmp->src_pages[i];
dst_page = cmp->dst_pages[i];
+ ASSERT(PageLocked(src_page));
+ ASSERT(PageLocked(dst_page));
addr = kmap_atomic(src_page);
dst_addr = kmap_atomic(dst_page);
@@ -3078,14 +3115,46 @@ static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
goto out_unlock;
}
+again:
ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, &cmp);
if (ret)
goto out_unlock;
if (same_inode)
- lock_extent_range(src, same_lock_start, same_lock_len);
+ ret = lock_extent_range(src, same_lock_start, same_lock_len,
+ false);
else
- btrfs_double_extent_lock(src, loff, dst, dst_loff, len);
+ ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
+ false);
+ /*
+ * If one of the inodes has dirty pages in the respective range or
+ * ordered extents, we need to flush dellaloc and wait for all ordered
+ * extents in the range. We must unlock the pages and the ranges in the
+ * io trees to avoid deadlocks when flushing delalloc (requires locking
+ * pages) and when waiting for ordered extents to complete (they require
+ * range locking).
+ */
+ if (ret == -EAGAIN) {
+ /*
+ * Ranges in the io trees already unlocked. Now unlock all
+ * pages before waiting for all IO to complete.
+ */
+ btrfs_cmp_data_free(&cmp);
+ if (same_inode) {
+ btrfs_wait_ordered_range(src, same_lock_start,
+ same_lock_len);
+ } else {
+ btrfs_wait_ordered_range(src, loff, len);
+ btrfs_wait_ordered_range(dst, dst_loff, len);
+ }
+ goto again;
+ }
+ ASSERT(ret == 0);
+ if (WARN_ON(ret)) {
+ /* ranges in the io trees already unlocked */
+ btrfs_cmp_data_free(&cmp);
+ return ret;
+ }
/* pass original length for comparison so we stay within i_size */
ret = btrfs_cmp_data(src, loff, dst, dst_loff, olen, &cmp);
@@ -3907,9 +3976,15 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
u64 lock_start = min_t(u64, off, destoff);
u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
- lock_extent_range(src, lock_start, lock_len);
+ ret = lock_extent_range(src, lock_start, lock_len, true);
} else {
- btrfs_double_extent_lock(src, off, inode, destoff, len);
+ ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
+ true);
+ }
+ ASSERT(ret == 0);
+ if (WARN_ON(ret)) {
+ /* ranges in the io trees already unlocked */
+ goto out_unlock;
}
ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);