[PATCH v4 0/2] NFS: ALLOCATE and DEALLOCATE improvemnts

[PATCH v4 0/2] NFS: ALLOCATE and DEALLOCATE improvemnts

[Anna Schumaker]

These patches make a few tweaks that improve the performance of ALLOCATE
and DEALLOCATE requests.  The first patch attempts to update cache
information after a (DE)ALLOCATE call, rather than clearing the cache and
forcing the client to re-read the file later.  The second patch changes
when we lock the i_mutex to give NFS v4.0 and v4.1 a chance to exit without
taking a lock.

Comments are appreciated!

Anna


Anna Schumaker (2):
  NFS: Don't zap caches on fallocate()
  NFS: Reduce time spent holding the i_mutex during fallocate()

 fs/nfs/inode.c          |  1 -
 fs/nfs/nfs42proc.c      | 31 +++++++++++++++++++++++++++----
 fs/nfs/nfs42xdr.c       | 20 ++++++++++++++++----
 fs/nfs/nfs4file.c       | 10 ++--------
 include/linux/nfs_xdr.h |  4 ++++
 5 files changed, 49 insertions(+), 17 deletions(-)

-- 
2.3.3

[PATCH v4 1/2] NFS: Don't zap caches on fallocate()

[Anna Schumaker]

This patch adds a GETATTR to the end of ALLOCATE and DEALLOCATE
operations so we can set the updated inode size and change attribute
directly.  DEALLOCATE will still need to release pagecache pages, so
nfs42_proc_deallocate() now calls truncate_pagecache_range() before
contacting the server.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
---
 fs/nfs/inode.c          |  1 -
 fs/nfs/nfs42proc.c      | 23 +++++++++++++++++++----
 fs/nfs/nfs42xdr.c       | 20 ++++++++++++++++----
 fs/nfs/nfs4file.c       |  1 -
 include/linux/nfs_xdr.h |  4 ++++
 5 files changed, 39 insertions(+), 10 deletions(-)

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index d42dff6..e92386f 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -192,7 +192,6 @@ void nfs_zap_caches(struct inode *inode)
 	nfs_zap_caches_locked(inode);
 	spin_unlock(&inode->i_lock);
 }
-EXPORT_SYMBOL_GPL(nfs_zap_caches);
 
 void nfs_zap_mapping(struct inode *inode, struct address_space *mapping)
 {
diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
index cb17072..b9aa6bb 100644
--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -36,13 +36,16 @@ static int _nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
 				 loff_t offset, loff_t len)
 {
 	struct inode *inode = file_inode(filep);
+	struct nfs_server *server = NFS_SERVER(inode);
 	struct nfs42_falloc_args args = {
 		.falloc_fh	= NFS_FH(inode),
 		.falloc_offset	= offset,
 		.falloc_length	= len,
+		.falloc_bitmask	= server->cache_consistency_bitmask,
+	};
+	struct nfs42_falloc_res res = {
+		.falloc_server	= server,
 	};
-	struct nfs42_falloc_res res;
-	struct nfs_server *server = NFS_SERVER(inode);
 	int status;
 
 	msg->rpc_argp = &args;
@@ -52,8 +55,17 @@ static int _nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
 	if (status)
 		return status;
 
-	return nfs4_call_sync(server->client, server, msg,
-			      &args.seq_args, &res.seq_res, 0);
+	res.falloc_fattr = nfs_alloc_fattr();
+	if (!res.falloc_fattr)
+		return -ENOMEM;
+
+	status = nfs4_call_sync(server->client, server, msg,
+				&args.seq_args, &res.seq_res, 0);
+	if (status == 0)
+		status = nfs_post_op_update_inode(inode, res.falloc_fattr);
+
+	kfree(res.falloc_fattr);
+	return status;
 }
 
 static int nfs42_proc_fallocate(struct rpc_message *msg, struct file *filep,
@@ -101,7 +113,10 @@ int nfs42_proc_deallocate(struct file *filep, loff_t offset, loff_t len)
 	if (!nfs_server_capable(inode, NFS_CAP_DEALLOCATE))
 		return -EOPNOTSUPP;
 
+	nfs_wb_all(inode);
 	err = nfs42_proc_fallocate(&msg, filep, offset, len);
+	if (err == 0)
+		truncate_pagecache_range(inode, offset, (offset + len) -1);
 	if (err == -EOPNOTSUPP)
 		NFS_SERVER(inode)->caps &= ~NFS_CAP_DEALLOCATE;
 	return err;
diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index 038a7e1..1a25b27 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -25,16 +25,20 @@
 
 #define NFS4_enc_allocate_sz		(compound_encode_hdr_maxsz + \
 					 encode_putfh_maxsz + \
-					 encode_allocate_maxsz)
+					 encode_allocate_maxsz + \
+					 encode_getattr_maxsz)
 #define NFS4_dec_allocate_sz		(compound_decode_hdr_maxsz + \
 					 decode_putfh_maxsz + \
-					 decode_allocate_maxsz)
+					 decode_allocate_maxsz + \
+					 decode_getattr_maxsz)
 #define NFS4_enc_deallocate_sz		(compound_encode_hdr_maxsz + \
 					 encode_putfh_maxsz + \
-					 encode_deallocate_maxsz)
+					 encode_deallocate_maxsz + \
+					 encode_getattr_maxsz)
 #define NFS4_dec_deallocate_sz		(compound_decode_hdr_maxsz + \
 					 decode_putfh_maxsz + \
-					 decode_deallocate_maxsz)
+					 decode_deallocate_maxsz + \
+					 decode_getattr_maxsz)
 #define NFS4_enc_seek_sz		(compound_encode_hdr_maxsz + \
 					 encode_putfh_maxsz + \
 					 encode_seek_maxsz)
@@ -92,6 +96,7 @@ static void nfs4_xdr_enc_allocate(struct rpc_rqst *req,
 	encode_sequence(xdr, &args->seq_args, &hdr);
 	encode_putfh(xdr, args->falloc_fh, &hdr);
 	encode_allocate(xdr, args, &hdr);
+	encode_getfattr(xdr, args->falloc_bitmask, &hdr);
 	encode_nops(&hdr);
 }
 
@@ -110,6 +115,7 @@ static void nfs4_xdr_enc_deallocate(struct rpc_rqst *req,
 	encode_sequence(xdr, &args->seq_args, &hdr);
 	encode_putfh(xdr, args->falloc_fh, &hdr);
 	encode_deallocate(xdr, args, &hdr);
+	encode_getfattr(xdr, args->falloc_bitmask, &hdr);
 	encode_nops(&hdr);
 }
 
@@ -183,6 +189,9 @@ static int nfs4_xdr_dec_allocate(struct rpc_rqst *rqstp,
 	if (status)
 		goto out;
 	status = decode_allocate(xdr, res);
+	if (status)
+		goto out;
+	decode_getfattr(xdr, res->falloc_fattr, res->falloc_server);
 out:
 	return status;
 }
@@ -207,6 +216,9 @@ static int nfs4_xdr_dec_deallocate(struct rpc_rqst *rqstp,
 	if (status)
 		goto out;
 	status = decode_deallocate(xdr, res);
+	if (status)
+		goto out;
+	decode_getfattr(xdr, res->falloc_fattr, res->falloc_server);
 out:
 	return status;
 }
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index 8b46389..d09c689 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -159,7 +159,6 @@ static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t
 		ret = nfs42_proc_allocate(filep, offset, len);
 	mutex_unlock(&inode->i_mutex);
 
-	nfs_zap_caches(inode);
 	return ret;
 }
 #endif /* CONFIG_NFS_V4_2 */
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 3d88908..93ab607 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1273,11 +1273,15 @@ struct nfs42_falloc_args {
 	nfs4_stateid			 falloc_stateid;
 	u64				 falloc_offset;
 	u64				 falloc_length;
+	const u32			*falloc_bitmask;
 };
 
 struct nfs42_falloc_res {
 	struct nfs4_sequence_res	seq_res;
 	unsigned int			status;
+
+	struct nfs_fattr		*falloc_fattr;
+	const struct nfs_server		*falloc_server;
 };
 
 struct nfs42_seek_args {
-- 
2.3.3

[PATCH v4 2/2] NFS: Reduce time spent holding the i_mutex during fallocate()

[Anna Schumaker]

At the very least, we should not be taking the i_mutex until after
checking if the server even supports ALLOCATE or DEALLOCATE, allowing
v4.0 or v4.1 to exit without potentially waiting on a lock.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
---
 fs/nfs/nfs42proc.c | 8 ++++++++
 fs/nfs/nfs4file.c  | 9 ++-------
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/fs/nfs/nfs42proc.c b/fs/nfs/nfs42proc.c
index b9aa6bb..3a9e752 100644
--- a/fs/nfs/nfs42proc.c
+++ b/fs/nfs/nfs42proc.c
@@ -96,9 +96,13 @@ int nfs42_proc_allocate(struct file *filep, loff_t offset, loff_t len)
 	if (!nfs_server_capable(inode, NFS_CAP_ALLOCATE))
 		return -EOPNOTSUPP;
 
+	mutex_lock(&inode->i_mutex);
+
 	err = nfs42_proc_fallocate(&msg, filep, offset, len);
 	if (err == -EOPNOTSUPP)
 		NFS_SERVER(inode)->caps &= ~NFS_CAP_ALLOCATE;
+
+	mutex_unlock(&inode->i_mutex);
 	return err;
 }
 
@@ -114,11 +118,15 @@ int nfs42_proc_deallocate(struct file *filep, loff_t offset, loff_t len)
 		return -EOPNOTSUPP;
 
 	nfs_wb_all(inode);
+	mutex_lock(&inode->i_mutex);
+
 	err = nfs42_proc_fallocate(&msg, filep, offset, len);
 	if (err == 0)
 		truncate_pagecache_range(inode, offset, (offset + len) -1);
 	if (err == -EOPNOTSUPP)
 		NFS_SERVER(inode)->caps &= ~NFS_CAP_DEALLOCATE;
+
+	mutex_unlock(&inode->i_mutex);
 	return err;
 }
 
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index d09c689..1d1848e 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -152,14 +152,9 @@ static long nfs42_fallocate(struct file *filep, int mode, loff_t offset, loff_t
 	if (ret < 0)
 		return ret;
 
-	mutex_lock(&inode->i_mutex);
 	if (mode & FALLOC_FL_PUNCH_HOLE)
-		ret = nfs42_proc_deallocate(filep, offset, len);
-	else
-		ret = nfs42_proc_allocate(filep, offset, len);
-	mutex_unlock(&inode->i_mutex);
-
-	return ret;
+		return nfs42_proc_deallocate(filep, offset, len);
+	return nfs42_proc_allocate(filep, offset, len);
 }
 #endif /* CONFIG_NFS_V4_2 */
 
-- 
2.3.3