Implement the helpers for the new write code in cachefiles. There's now an optional ->prepare_write() that allows the filesystem to set the parameters for the next write, such as maximum size and maximum segment count, and an ->issue_write() that is called to initiate an (asynchronous) write operation. Signed-off-by: David Howells <dhowells@xxxxxxxxxx> cc: Jeff Layton <jlayton@xxxxxxxxxx> cc: netfs@xxxxxxxxxxxxxxx cc: linux-erofs@xxxxxxxxxxxxxxxx cc: linux-fsdevel@xxxxxxxxxxxxxxx --- fs/cachefiles/io.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) diff --git a/fs/cachefiles/io.c b/fs/cachefiles/io.c index 5ba5c7814fe4..437b24b0fd1c 100644 --- a/fs/cachefiles/io.c +++ b/fs/cachefiles/io.c @@ -622,6 +622,77 @@ static int cachefiles_prepare_write(struct netfs_cache_resources *cres, return ret; } +static void cachefiles_prepare_write_subreq(struct netfs_io_subrequest *subreq) +{ + struct netfs_io_request *wreq = subreq->rreq; + struct netfs_cache_resources *cres = &wreq->cache_resources; + + _enter("W=%x[%x] %llx", wreq->debug_id, subreq->debug_index, subreq->start); + + subreq->max_len = ULONG_MAX; + subreq->max_nr_segs = BIO_MAX_VECS; + + if (!cachefiles_cres_file(cres)) { + if (!fscache_wait_for_operation(cres, FSCACHE_WANT_WRITE)) + return netfs_prepare_write_failed(subreq); + if (!cachefiles_cres_file(cres)) + return netfs_prepare_write_failed(subreq); + } +} + +static void cachefiles_issue_write(struct netfs_io_subrequest *subreq) +{ + struct netfs_io_request *wreq = subreq->rreq; + struct netfs_cache_resources *cres = &wreq->cache_resources; + struct cachefiles_object *object = cachefiles_cres_object(cres); + struct cachefiles_cache *cache = object->volume->cache; + const struct cred *saved_cred; + size_t off, pre, post, len = subreq->len; + loff_t start = subreq->start; + int ret; + + _enter("W=%x[%x] %llx-%llx", + wreq->debug_id, subreq->debug_index, start, start + len - 1); + + /* We need to start on the cache granularity boundary */ + off = start & (CACHEFILES_DIO_BLOCK_SIZE - 1); + if (off) { + pre = CACHEFILES_DIO_BLOCK_SIZE - off; + if (pre >= len) { + netfs_write_subrequest_terminated(subreq, len, false); + return; + } + subreq->transferred += pre; + start += pre; + len -= pre; + iov_iter_advance(&subreq->io_iter, pre); + } + + /* We also need to end on the cache granularity boundary */ + post = len & (CACHEFILES_DIO_BLOCK_SIZE - 1); + if (post) { + len -= post; + if (len == 0) { + netfs_write_subrequest_terminated(subreq, post, false); + return; + } + iov_iter_truncate(&subreq->io_iter, len); + } + + cachefiles_begin_secure(cache, &saved_cred); + ret = __cachefiles_prepare_write(object, cachefiles_cres_file(cres), + &start, &len, len, true); + cachefiles_end_secure(cache, saved_cred); + if (ret < 0) { + netfs_write_subrequest_terminated(subreq, ret, false); + return; + } + + cachefiles_write(&subreq->rreq->cache_resources, + subreq->start, &subreq->io_iter, + netfs_write_subrequest_terminated, subreq); +} + /* * Clean up an operation. */ @@ -638,8 +709,10 @@ static const struct netfs_cache_ops cachefiles_netfs_cache_ops = { .end_operation = cachefiles_end_operation, .read = cachefiles_read, .write = cachefiles_write, + .issue_write = cachefiles_issue_write, .prepare_read = cachefiles_prepare_read, .prepare_write = cachefiles_prepare_write, + .prepare_write_subreq = cachefiles_prepare_write_subreq, .prepare_ondemand_read = cachefiles_prepare_ondemand_read, .query_occupancy = cachefiles_query_occupancy, }; -- You received this message because you are subscribed to the Google Groups "linux-cachefs@xxxxxxxxxx" group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-cachefs+unsubscribe@xxxxxxxxxx.