From: Trond Myklebust trond.myklebust@hammerspace.com
commit 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb upstream.
The nfsd_file nf_rwsem is currently being used to separate file write and commit instances to ensure that we catch errors and apply them to the correct write/commit. We can improve scalability at the expense of a little accuracy (some extra false positives) by replacing the nf_rwsem with more careful use of the errseq_t mechanism to track errors across the different operations.
Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Chuck Lever chuck.lever@oracle.com [ cel: rebased on zero-verifier fix ] Signed-off-by: Leah Rumancik leah.rumancik@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/nfsd/filecache.c | 1 - fs/nfsd/filecache.h | 1 - fs/nfsd/nfs4proc.c | 16 +++++++++------- fs/nfsd/vfs.c | 40 +++++++++++++++------------------------- 4 files changed, 24 insertions(+), 34 deletions(-)
--- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -194,7 +194,6 @@ nfsd_file_alloc(struct inode *inode, uns __set_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags); } nf->nf_mark = NULL; - init_rwsem(&nf->nf_rwsem); trace_nfsd_file_alloc(nf); } return nf; --- a/fs/nfsd/filecache.h +++ b/fs/nfsd/filecache.h @@ -46,7 +46,6 @@ struct nfsd_file { refcount_t nf_ref; unsigned char nf_may; struct nfsd_file_mark *nf_mark; - struct rw_semaphore nf_rwsem; };
int nfsd_file_cache_init(void); --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -1515,6 +1515,9 @@ static void nfsd4_init_copy_res(struct n
static ssize_t _nfsd_copy_file_range(struct nfsd4_copy *copy) { + struct file *dst = copy->nf_dst->nf_file; + struct file *src = copy->nf_src->nf_file; + errseq_t since; ssize_t bytes_copied = 0; u64 bytes_total = copy->cp_count; u64 src_pos = copy->cp_src_pos; @@ -1527,9 +1530,8 @@ static ssize_t _nfsd_copy_file_range(str do { if (kthread_should_stop()) break; - bytes_copied = nfsd_copy_file_range(copy->nf_src->nf_file, - src_pos, copy->nf_dst->nf_file, dst_pos, - bytes_total); + bytes_copied = nfsd_copy_file_range(src, src_pos, dst, dst_pos, + bytes_total); if (bytes_copied <= 0) break; bytes_total -= bytes_copied; @@ -1539,11 +1541,11 @@ static ssize_t _nfsd_copy_file_range(str } while (bytes_total > 0 && !copy->cp_synchronous); /* for a non-zero asynchronous copy do a commit of data */ if (!copy->cp_synchronous && copy->cp_res.wr_bytes_written > 0) { - down_write(©->nf_dst->nf_rwsem); - status = vfs_fsync_range(copy->nf_dst->nf_file, - copy->cp_dst_pos, + since = READ_ONCE(dst->f_wb_err); + status = vfs_fsync_range(dst, copy->cp_dst_pos, copy->cp_res.wr_bytes_written, 0); - up_write(©->nf_dst->nf_rwsem); + if (!status) + status = filemap_check_wb_err(dst->f_mapping, since); if (!status) copy->committed = true; } --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -525,10 +525,11 @@ __be32 nfsd4_clone_file_range(struct nfs { struct file *src = nf_src->nf_file; struct file *dst = nf_dst->nf_file; + errseq_t since; loff_t cloned; __be32 ret = 0;
- down_write(&nf_dst->nf_rwsem); + since = READ_ONCE(dst->f_wb_err); cloned = vfs_clone_file_range(src, src_pos, dst, dst_pos, count, 0); if (cloned < 0) { ret = nfserrno(cloned); @@ -543,6 +544,8 @@ __be32 nfsd4_clone_file_range(struct nfs int status = vfs_fsync_range(dst, dst_pos, dst_end, 0);
if (!status) + status = filemap_check_wb_err(dst->f_mapping, since); + if (!status) status = commit_inode_metadata(file_inode(src)); if (status < 0) { nfsd_reset_boot_verifier(net_generic(nf_dst->nf_net, @@ -551,7 +554,6 @@ __be32 nfsd4_clone_file_range(struct nfs } } out_err: - up_write(&nf_dst->nf_rwsem); return ret; }
@@ -954,6 +956,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, s struct super_block *sb = file_inode(file)->i_sb; struct svc_export *exp; struct iov_iter iter; + errseq_t since; __be32 nfserr; int host_err; int use_wgather; @@ -991,8 +994,8 @@ nfsd_vfs_write(struct svc_rqst *rqstp, s flags |= RWF_SYNC;
iov_iter_kvec(&iter, WRITE, vec, vlen, *cnt); + since = READ_ONCE(file->f_wb_err); if (flags & RWF_SYNC) { - down_write(&nf->nf_rwsem); if (verf) nfsd_copy_boot_verifier(verf, net_generic(SVC_NET(rqstp), @@ -1001,15 +1004,12 @@ nfsd_vfs_write(struct svc_rqst *rqstp, s if (host_err < 0) nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp), nfsd_net_id)); - up_write(&nf->nf_rwsem); } else { - down_read(&nf->nf_rwsem); if (verf) nfsd_copy_boot_verifier(verf, net_generic(SVC_NET(rqstp), nfsd_net_id)); host_err = vfs_iter_write(file, &iter, &pos, flags); - up_read(&nf->nf_rwsem); } if (host_err < 0) { nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp), @@ -1019,6 +1019,9 @@ nfsd_vfs_write(struct svc_rqst *rqstp, s *cnt = host_err; nfsd_stats_io_write_add(exp, *cnt); fsnotify_modify(file); + host_err = filemap_check_wb_err(file->f_mapping, since); + if (host_err < 0) + goto out_nfserr;
if (stable && use_wgather) { host_err = wait_for_concurrent_writes(file); @@ -1099,19 +1102,6 @@ out: }
#ifdef CONFIG_NFSD_V3 -static int -nfsd_filemap_write_and_wait_range(struct nfsd_file *nf, loff_t offset, - loff_t end) -{ - struct address_space *mapping = nf->nf_file->f_mapping; - int ret = filemap_fdatawrite_range(mapping, offset, end); - - if (ret) - return ret; - filemap_fdatawait_range_keep_errors(mapping, offset, end); - return 0; -} - /* * Commit all pending writes to stable storage. * @@ -1142,25 +1132,25 @@ nfsd_commit(struct svc_rqst *rqstp, stru if (err) goto out; if (EX_ISSYNC(fhp->fh_export)) { - int err2 = nfsd_filemap_write_and_wait_range(nf, offset, end); + errseq_t since = READ_ONCE(nf->nf_file->f_wb_err); + int err2;
- down_write(&nf->nf_rwsem); - if (!err2) - err2 = vfs_fsync_range(nf->nf_file, offset, end, 0); + err2 = vfs_fsync_range(nf->nf_file, offset, end, 0); switch (err2) { case 0: nfsd_copy_boot_verifier(verf, net_generic(nf->nf_net, nfsd_net_id)); + err2 = filemap_check_wb_err(nf->nf_file->f_mapping, + since); break; case -EINVAL: err = nfserr_notsupp; break; default: - err = nfserrno(err2); nfsd_reset_boot_verifier(net_generic(nf->nf_net, nfsd_net_id)); } - up_write(&nf->nf_rwsem); + err = nfserrno(err2); } else nfsd_copy_boot_verifier(verf, net_generic(nf->nf_net, nfsd_net_id));