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: David 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: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
David Howells 2023-05-22 14:50:07 +01:00 committed by Jens Axboe
parent ceb11d0e2d
commit a7db503401
3 changed files with 25 additions and 2 deletions

View File

@ -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,

View File

@ -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 *);

View File

@ -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,