From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
---
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(-)
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index fdf89fcf1a0c..36f5a06d1067 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -194,7 +194,6 @@ nfsd_file_alloc(struct inode *inode, unsigned int may, unsigned int hashval,
__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;
diff --git a/fs/nfsd/filecache.h b/fs/nfsd/filecache.h
index 7872df5a0fe3..435ceab27897 100644
--- 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);
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 35f33959a083..8d2b9ad3b84a 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1510,6 +1510,9 @@ static void nfsd4_init_copy_res(struct nfsd4_copy *copy, bool sync)
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;
@@ -1522,9 +1525,8 @@ static ssize_t _nfsd_copy_file_range(struct nfsd4_copy *copy)
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;
@@ -1534,11 +1536,11 @@ static ssize_t _nfsd_copy_file_range(struct nfsd4_copy *copy)
} 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;
}
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 4d2964d08097..8a48bf18028c 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -530,10 +530,11 @@ __be32 nfsd4_clone_file_range(struct svc_rqst *rqstp,
{
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);
@@ -547,6 +548,8 @@ __be32 nfsd4_clone_file_range(struct svc_rqst *rqstp,
loff_t dst_end = count ? dst_pos + count - 1 : LLONG_MAX;
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) {
@@ -562,7 +565,6 @@ __be32 nfsd4_clone_file_range(struct svc_rqst *rqstp,
}
}
out_err:
- up_write(&nf_dst->nf_rwsem);
return ret;
}
@@ -970,6 +972,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
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;
@@ -1010,21 +1013,18 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
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);
host_err = vfs_iter_write(file, &iter, &pos, flags);
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),
@@ -1034,6 +1034,9 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
*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);
@@ -1114,19 +1117,6 @@ nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
}
#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.
*
@@ -1157,25 +1147,25 @@ nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
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));
--
2.33.1
