diff options
Diffstat (limited to 'fs/btrfs/compression.c')
| -rw-r--r-- | fs/btrfs/compression.c | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 38c058bcf359..c70625560265 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -785,8 +785,10 @@ void __init btrfs_init_compress(void) } /* - * this finds an available workspace or allocates a new one - * ERR_PTR is returned if things go bad. + * This finds an available workspace or allocates a new one. + * If it's not possible to allocate a new one, waits until there's one. + * Preallocation makes a forward progress guarantees and we do not return + * errors. */ static struct list_head *find_workspace(int type) { @@ -826,6 +828,14 @@ again: if (IS_ERR(workspace)) { atomic_dec(total_ws); wake_up(ws_wait); + + /* + * Do not return the error but go back to waiting. There's a + * workspace preallocated for each type and the compression + * time is bounded so we get to a workspace eventually. This + * makes our caller's life easier. + */ + goto again; } return workspace; } @@ -913,8 +923,6 @@ int btrfs_compress_pages(int type, struct address_space *mapping, int ret; workspace = find_workspace(type); - if (IS_ERR(workspace)) - return PTR_ERR(workspace); ret = btrfs_compress_op[type-1]->compress_pages(workspace, mapping, start, len, pages, @@ -949,8 +957,6 @@ static int btrfs_decompress_biovec(int type, struct page **pages_in, int ret; workspace = find_workspace(type); - if (IS_ERR(workspace)) - return PTR_ERR(workspace); ret = btrfs_compress_op[type-1]->decompress_biovec(workspace, pages_in, disk_start, @@ -971,8 +977,6 @@ int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page, int ret; workspace = find_workspace(type); - if (IS_ERR(workspace)) - return PTR_ERR(workspace); ret = btrfs_compress_op[type-1]->decompress(workspace, data_in, dest_page, start_byte, |