From e0639dc5805a9d4faaa2c07ad98fa853b9529dd3 Mon Sep 17 00:00:00 2001 From: Olga Kornievskaia Date: Fri, 20 Jul 2018 18:19:20 -0400 Subject: NFSD introduce async copy feature Upon receiving a request for async copy, create a new kthread. If we get asynchronous request, make sure to copy the needed arguments/state from the stack before starting the copy. Then start the thread and reply back to the client indicating copy is asynchronous. nfsd_copy_file_range() will copy in a loop over the total number of bytes is needed to copy. In case a failure happens in the middle, we ignore the error and return how much we copied so far. Once done creating a workitem for the callback workqueue and send CB_OFFLOAD with the results. The lifetime of the copy stateid is bound to the vfs copy. This way we don't need to keep the nfsd_net structure for the callback. We could keep it around longer so that an OFFLOAD_STATUS that came late would still get results, but clients should be able to deal without that. We handle OFFLOAD_CANCEL by sending a signal to the copy thread and calling kthread_stop. A client should cancel any ongoing copies before calling DESTROY_CLIENT; if not, we return a CLIENT_BUSY error. If the client is destroyed for some other reason (lease expiration, or server shutdown), we must clean up any ongoing copies ourselves. Signed-off-by: Olga Kornievskaia [colin.king@canonical.com: fix leak in error case] [bfields@fieldses.org: remove signalling, merge patches] Signed-off-by: J. Bruce Fields --- fs/nfsd/nfs4proc.c | 261 +++++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 242 insertions(+), 19 deletions(-) (limited to 'fs/nfsd/nfs4proc.c') diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 0c7832321010..edff074d38c7 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -36,6 +36,7 @@ #include #include #include +#include #include "idmap.h" #include "cache.h" @@ -1089,37 +1090,236 @@ out: return status; } +void nfs4_put_copy(struct nfsd4_copy *copy) +{ + if (!refcount_dec_and_test(©->refcount)) + return; + kfree(copy); +} + +static bool +check_and_set_stop_copy(struct nfsd4_copy *copy) +{ + bool value; + + spin_lock(©->cp_clp->async_lock); + value = copy->stopped; + if (!copy->stopped) + copy->stopped = true; + spin_unlock(©->cp_clp->async_lock); + return value; +} + +static void nfsd4_stop_copy(struct nfsd4_copy *copy) +{ + /* only 1 thread should stop the copy */ + if (!check_and_set_stop_copy(copy)) + kthread_stop(copy->copy_task); + nfs4_put_copy(copy); +} + +static struct nfsd4_copy *nfsd4_get_copy(struct nfs4_client *clp) +{ + struct nfsd4_copy *copy = NULL; + + spin_lock(&clp->async_lock); + if (!list_empty(&clp->async_copies)) { + copy = list_first_entry(&clp->async_copies, struct nfsd4_copy, + copies); + refcount_inc(©->refcount); + } + spin_unlock(&clp->async_lock); + return copy; +} + +void nfsd4_shutdown_copy(struct nfs4_client *clp) +{ + struct nfsd4_copy *copy; + + while ((copy = nfsd4_get_copy(clp)) != NULL) + nfsd4_stop_copy(copy); +} + +static void nfsd4_cb_offload_release(struct nfsd4_callback *cb) +{ + struct nfsd4_copy *copy = container_of(cb, struct nfsd4_copy, cp_cb); + + nfs4_put_copy(copy); +} + +static int nfsd4_cb_offload_done(struct nfsd4_callback *cb, + struct rpc_task *task) +{ + return 1; +} + +static const struct nfsd4_callback_ops nfsd4_cb_offload_ops = { + .release = nfsd4_cb_offload_release, + .done = nfsd4_cb_offload_done +}; + +static void nfsd4_init_copy_res(struct nfsd4_copy *copy, bool sync) +{ + copy->cp_res.wr_stable_how = NFS_UNSTABLE; + copy->cp_synchronous = sync; + gen_boot_verifier(©->cp_res.wr_verifier, copy->cp_clp->net); +} + +static ssize_t _nfsd_copy_file_range(struct nfsd4_copy *copy) +{ + ssize_t bytes_copied = 0; + size_t bytes_total = copy->cp_count; + u64 src_pos = copy->cp_src_pos; + u64 dst_pos = copy->cp_dst_pos; + + do { + if (kthread_should_stop()) + break; + bytes_copied = nfsd_copy_file_range(copy->file_src, src_pos, + copy->file_dst, dst_pos, bytes_total); + if (bytes_copied <= 0) + break; + bytes_total -= bytes_copied; + copy->cp_res.wr_bytes_written += bytes_copied; + src_pos += bytes_copied; + dst_pos += bytes_copied; + } while (bytes_total > 0 && !copy->cp_synchronous); + return bytes_copied; +} + +static __be32 nfsd4_do_copy(struct nfsd4_copy *copy, bool sync) +{ + __be32 status; + ssize_t bytes; + + bytes = _nfsd_copy_file_range(copy); + /* for async copy, we ignore the error, client can always retry + * to get the error + */ + if (bytes < 0 && !copy->cp_res.wr_bytes_written) + status = nfserrno(bytes); + else { + nfsd4_init_copy_res(copy, sync); + status = nfs_ok; + } + + fput(copy->file_src); + fput(copy->file_dst); + return status; +} + +static void dup_copy_fields(struct nfsd4_copy *src, struct nfsd4_copy *dst) +{ + dst->cp_src_pos = src->cp_src_pos; + dst->cp_dst_pos = src->cp_dst_pos; + dst->cp_count = src->cp_count; + dst->cp_synchronous = src->cp_synchronous; + memcpy(&dst->cp_res, &src->cp_res, sizeof(src->cp_res)); + memcpy(&dst->fh, &src->fh, sizeof(src->fh)); + dst->cp_clp = src->cp_clp; + dst->file_dst = get_file(src->file_dst); + dst->file_src = get_file(src->file_src); + memcpy(&dst->cp_stateid, &src->cp_stateid, sizeof(src->cp_stateid)); +} + +static void cleanup_async_copy(struct nfsd4_copy *copy) +{ + nfs4_free_cp_state(copy); + fput(copy->file_dst); + fput(copy->file_src); + spin_lock(©->cp_clp->async_lock); + list_del(©->copies); + spin_unlock(©->cp_clp->async_lock); + nfs4_put_copy(copy); +} + +static int nfsd4_do_async_copy(void *data) +{ + struct nfsd4_copy *copy = (struct nfsd4_copy *)data; + struct nfsd4_copy *cb_copy; + + copy->nfserr = nfsd4_do_copy(copy, 0); + cb_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL); + if (!cb_copy) + goto out; + memcpy(&cb_copy->cp_res, ©->cp_res, sizeof(copy->cp_res)); + cb_copy->cp_clp = copy->cp_clp; + cb_copy->nfserr = copy->nfserr; + memcpy(&cb_copy->fh, ©->fh, sizeof(copy->fh)); + nfsd4_init_cb(&cb_copy->cp_cb, cb_copy->cp_clp, + &nfsd4_cb_offload_ops, NFSPROC4_CLNT_CB_OFFLOAD); + nfsd4_run_cb(&cb_copy->cp_cb); +out: + cleanup_async_copy(copy); + return 0; +} + static __be32 nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, union nfsd4_op_u *u) { struct nfsd4_copy *copy = &u->copy; - struct file *src, *dst; __be32 status; - ssize_t bytes; + struct nfsd4_copy *async_copy = NULL; - status = nfsd4_verify_copy(rqstp, cstate, ©->cp_src_stateid, &src, - ©->cp_dst_stateid, &dst); + status = nfsd4_verify_copy(rqstp, cstate, ©->cp_src_stateid, + ©->file_src, ©->cp_dst_stateid, + ©->file_dst); if (status) goto out; - bytes = nfsd_copy_file_range(src, copy->cp_src_pos, - dst, copy->cp_dst_pos, copy->cp_count); + copy->cp_clp = cstate->clp; + memcpy(©->fh, &cstate->current_fh.fh_handle, + sizeof(struct knfsd_fh)); + if (!copy->cp_synchronous) { + struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); - if (bytes < 0) - status = nfserrno(bytes); - else { - copy->cp_res.wr_bytes_written = bytes; - copy->cp_res.wr_stable_how = NFS_UNSTABLE; - copy->cp_synchronous = 1; - gen_boot_verifier(©->cp_res.wr_verifier, SVC_NET(rqstp)); + status = nfserrno(-ENOMEM); + async_copy = kzalloc(sizeof(struct nfsd4_copy), GFP_KERNEL); + if (!async_copy) + goto out; + if (!nfs4_init_cp_state(nn, copy)) { + kfree(async_copy); + goto out; + } + refcount_set(&async_copy->refcount, 1); + memcpy(©->cp_res.cb_stateid, ©->cp_stateid, + sizeof(copy->cp_stateid)); + dup_copy_fields(copy, async_copy); + async_copy->copy_task = kthread_create(nfsd4_do_async_copy, + async_copy, "%s", "copy thread"); + if (IS_ERR(async_copy->copy_task)) + goto out_err; + spin_lock(&async_copy->cp_clp->async_lock); + list_add(&async_copy->copies, + &async_copy->cp_clp->async_copies); + spin_unlock(&async_copy->cp_clp->async_lock); + wake_up_process(async_copy->copy_task); status = nfs_ok; - } - - fput(src); - fput(dst); + } else + status = nfsd4_do_copy(copy, 1); out: return status; +out_err: + cleanup_async_copy(async_copy); + goto out; +} + +struct nfsd4_copy * +find_async_copy(struct nfs4_client *clp, stateid_t *stateid) +{ + struct nfsd4_copy *copy; + + spin_lock(&clp->async_lock); + list_for_each_entry(copy, &clp->async_copies, copies) { + if (memcmp(©->cp_stateid, stateid, NFS4_STATEID_SIZE)) + continue; + refcount_inc(©->refcount); + spin_unlock(&clp->async_lock); + return copy; + } + spin_unlock(&clp->async_lock); + return NULL; } static __be32 @@ -1127,7 +1327,18 @@ nfsd4_offload_cancel(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, union nfsd4_op_u *u) { - return 0; + struct nfsd4_offload_status *os = &u->offload_status; + __be32 status = 0; + struct nfsd4_copy *copy; + struct nfs4_client *clp = cstate->clp; + + copy = find_async_copy(clp, &os->stateid); + if (copy) + nfsd4_stop_copy(copy); + else + status = nfserr_bad_stateid; + + return status; } static __be32 @@ -1157,7 +1368,19 @@ nfsd4_offload_status(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, union nfsd4_op_u *u) { - return nfserr_notsupp; + struct nfsd4_offload_status *os = &u->offload_status; + __be32 status = 0; + struct nfsd4_copy *copy; + struct nfs4_client *clp = cstate->clp; + + copy = find_async_copy(clp, &os->stateid); + if (copy) { + os->count = copy->cp_res.wr_bytes_written; + nfs4_put_copy(copy); + } else + status = nfserr_bad_stateid; + + return status; } static __be32 -- cgit v1.2.3-59-g8ed1b