Skip to content

Commit

Permalink
btrfs: add an extra wait mode to read_extent_buffer_pages
Browse files Browse the repository at this point in the history
read_extent_buffer_pages currently has two modes, either trigger a read
without waiting for anything, or wait for the I/O to finish. The former
also bails when it's unable to lock the page. This patch now adds an
additional parameter to allow it to block on page lock, but don't wait
for completion.

Changes v5:
 - merge the 2 wait parameters into one and define WAIT_NONE, WAIT_COMPLETE and
   WAIT_PAGE_LOCK

Change v6:
 - fix bug introduced in v5

Signed-off-by: Arne Jansen <sensille@gmx.net>
  • Loading branch information
Arne Jansen committed Oct 2, 2011
1 parent 286d6e7 commit bb82ab8
Show file tree
Hide file tree
Showing 3 changed files with 9 additions and 6 deletions.
5 changes: 3 additions & 2 deletions fs/btrfs/disk-io.c
Original file line number Diff line number Diff line change
Expand Up @@ -367,7 +367,8 @@ static int btree_read_extent_buffer_pages(struct btrfs_root *root,
clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
while (1) {
ret = read_extent_buffer_pages(io_tree, eb, start, 1,
ret = read_extent_buffer_pages(io_tree, eb, start,
WAIT_COMPLETE,
btree_get_extent, mirror_num);
if (!ret &&
!verify_parent_transid(io_tree, eb, parent_transid))
Expand Down Expand Up @@ -974,7 +975,7 @@ int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
if (!buf)
return 0;
read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
buf, 0, 0, btree_get_extent, 0);
buf, 0, WAIT_NONE, btree_get_extent, 0);
free_extent_buffer(buf);
return ret;
}
Expand Down
7 changes: 3 additions & 4 deletions fs/btrfs/extent_io.c
Original file line number Diff line number Diff line change
Expand Up @@ -3349,8 +3349,7 @@ int extent_buffer_uptodate(struct extent_io_tree *tree,
}

int read_extent_buffer_pages(struct extent_io_tree *tree,
struct extent_buffer *eb,
u64 start, int wait,
struct extent_buffer *eb, u64 start, int wait,
get_extent_t *get_extent, int mirror_num)
{
unsigned long i;
Expand Down Expand Up @@ -3386,7 +3385,7 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
num_pages = num_extent_pages(eb->start, eb->len);
for (i = start_i; i < num_pages; i++) {
page = extent_buffer_page(eb, i);
if (!wait) {
if (wait == WAIT_NONE) {
if (!trylock_page(page))
goto unlock_exit;
} else {
Expand Down Expand Up @@ -3430,7 +3429,7 @@ int read_extent_buffer_pages(struct extent_io_tree *tree,
if (bio)
submit_one_bio(READ, bio, mirror_num, bio_flags);

if (ret || !wait)
if (ret || wait != WAIT_COMPLETE)
return ret;

for (i = start_i; i < num_pages; i++) {
Expand Down
3 changes: 3 additions & 0 deletions fs/btrfs/extent_io.h
Original file line number Diff line number Diff line change
Expand Up @@ -248,6 +248,9 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
u64 start, unsigned long len);
void free_extent_buffer(struct extent_buffer *eb);
#define WAIT_NONE 0
#define WAIT_COMPLETE 1
#define WAIT_PAGE_LOCK 2
int read_extent_buffer_pages(struct extent_io_tree *tree,
struct extent_buffer *eb, u64 start, int wait,
get_extent_t *get_extent, int mirror_num);
Expand Down

0 comments on commit bb82ab8

Please sign in to comment.