Commit a7db5034 authored by David Howells's avatar David Howells Committed by Jens Axboe
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nfs: Provide a splice-read wrapper 



Provide a splice_read wrapper for NFS.  This locks the inode around
filemap_splice_read() and revalidates the mapping.  Splicing from direct
I/O is handled by the caller.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: Jens Axboe <axboe@kernel.dk>
cc: Trond Myklebust <trond.myklebust@hammerspace.com>
cc: Anna Schumaker <anna@kernel.org>
cc: linux-nfs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-block@vger.kernel.org
cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20230522135018.2742245-21-dhowells@redhat.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ceb11d0e

fs/nfs/file.c

+22 −1
Original line number Diff line number Diff line
@@ -178,6 +178,27 @@ nfs_file_read(struct kiocb *iocb, struct iov_iter *to) 
}

EXPORT_SYMBOL_GPL(nfs_file_read);



ssize_t

nfs_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe,

		     size_t len, unsigned int flags)

{

	struct inode *inode = file_inode(in);

	ssize_t result;



	dprintk("NFS: splice_read(%pD2, %zu@%llu)\n", in, len, *ppos);



	nfs_start_io_read(inode);

	result = nfs_revalidate_mapping(inode, in->f_mapping);

	if (!result) {

		result = filemap_splice_read(in, ppos, pipe, len, flags);

		if (result > 0)

			nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, result);

	}

	nfs_end_io_read(inode);

	return result;

}

EXPORT_SYMBOL_GPL(nfs_file_splice_read);



int

nfs_file_mmap(struct file * file, struct vm_area_struct * vma)

{
@@ -879,7 +900,7 @@ const struct file_operations nfs_file_operations = { 
	.fsync		= nfs_file_fsync,

	.lock		= nfs_lock,

	.flock		= nfs_flock,

	.splice_read	= generic_file_splice_read,

	.splice_read	= nfs_file_splice_read,

	.splice_write	= iter_file_splice_write,

	.check_flags	= nfs_check_flags,

	.setlease	= simple_nosetlease,

fs/nfs/internal.h

+2 −0
Original line number Diff line number Diff line
@@ -416,6 +416,8 @@ static inline __u32 nfs_access_xattr_mask(const struct nfs_server *server) 
int nfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync);

loff_t nfs_file_llseek(struct file *, loff_t, int);

ssize_t nfs_file_read(struct kiocb *, struct iov_iter *);

ssize_t nfs_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe,

			     size_t len, unsigned int flags);

int nfs_file_mmap(struct file *, struct vm_area_struct *);

ssize_t nfs_file_write(struct kiocb *, struct iov_iter *);

int nfs_file_release(struct inode *, struct file *);

fs/nfs/nfs4file.c

+1 −1
Original line number Diff line number Diff line
@@ -454,7 +454,7 @@ const struct file_operations nfs4_file_operations = { 
	.fsync		= nfs_file_fsync,

	.lock		= nfs_lock,

	.flock		= nfs_flock,

	.splice_read	= generic_file_splice_read,

	.splice_read	= nfs_file_splice_read,

	.splice_write	= iter_file_splice_write,

	.check_flags	= nfs_check_flags,

	.setlease	= nfs4_setlease,