* [PATCH v4 22/31] nfs: add support for read_iter, write_iter
[not found] <1353537671-26284-1-git-send-email-dave.kleikamp@oracle.com>
@ 2012-11-21 22:41 ` Dave Kleikamp
2012-11-21 22:41 ` [PATCH v4 23/31] nfs: simplify swap Dave Kleikamp
1 sibling, 0 replies; 4+ messages in thread
From: Dave Kleikamp @ 2012-11-21 22:41 UTC (permalink / raw)
To: linux-fsdevel
Cc: linux-kernel, Zach Brown, Maxim V. Patlasov, Dave Kleikamp,
Trond Myklebust, linux-nfs
This patch implements the read_iter and write_iter file operations which
allow kernel code to initiate directIO. This allows the loop device to
read and write directly to the server, bypassing the page cache.
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: linux-nfs@vger.kernel.org
---
fs/nfs/direct.c | 239 +++++++++++++++++++++++++++++++++++++------------
fs/nfs/file.c | 33 ++++---
fs/nfs/internal.h | 4 +-
fs/nfs/nfs4file.c | 4 +-
include/linux/nfs_fs.h | 6 +-
5 files changed, 202 insertions(+), 84 deletions(-)
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 4532781..6754588 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -90,6 +90,7 @@ struct nfs_direct_req {
int flags;
#define NFS_ODIRECT_DO_COMMIT (1) /* an unstable reply was received */
#define NFS_ODIRECT_RESCHED_WRITES (2) /* write verification failed */
+#define NFS_ODIRECT_MARK_DIRTY (4) /* mark read pages dirty */
struct nfs_writeverf verf; /* unstable write verifier */
};
@@ -131,15 +132,13 @@ ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter,
return -EINVAL;
#else
- const struct iovec *iov = iov_iter_iovec(iter);
-
VM_BUG_ON(iocb->ki_left != PAGE_SIZE);
VM_BUG_ON(iocb->ki_nbytes != PAGE_SIZE);
if (rw == READ || rw == KERNEL_READ)
- return nfs_file_direct_read(iocb, iov, iter->nr_segs, pos,
+ return nfs_file_direct_read(iocb, iter, pos,
rw == READ ? true : false);
- return nfs_file_direct_write(iocb, iov, iter->nr_segs, pos,
+ return nfs_file_direct_write(iocb, iter, pos,
rw == WRITE ? true : false);
#endif /* CONFIG_NFS_SWAP */
}
@@ -277,7 +276,8 @@ static void nfs_direct_read_completion(struct nfs_pgio_header *hdr)
hdr->good_bytes & ~PAGE_MASK,
PAGE_SIZE);
}
- if (!PageCompound(page)) {
+ if ((dreq->flags & NFS_ODIRECT_MARK_DIRTY) &&
+ !PageCompound(page)) {
if (test_bit(NFS_IOHDR_ERROR, &hdr->flags)) {
if (bytes < hdr->good_bytes)
set_page_dirty(page);
@@ -414,24 +414,17 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
return result < 0 ? (ssize_t) result : -EFAULT;
}
-static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
- const struct iovec *iov,
- unsigned long nr_segs,
- loff_t pos, bool uio)
+static ssize_t nfs_direct_do_schedule_read_iovec(
+ struct nfs_pageio_descriptor *desc, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos, bool uio)
{
- struct nfs_pageio_descriptor desc;
ssize_t result = -EINVAL;
size_t requested_bytes = 0;
unsigned long seg;
- NFS_PROTO(dreq->inode)->read_pageio_init(&desc, dreq->inode,
- &nfs_direct_read_completion_ops);
- get_dreq(dreq);
- desc.pg_dreq = dreq;
-
for (seg = 0; seg < nr_segs; seg++) {
const struct iovec *vec = &iov[seg];
- result = nfs_direct_read_schedule_segment(&desc, vec, pos, uio);
+ result = nfs_direct_read_schedule_segment(desc, vec, pos, uio);
if (result < 0)
break;
requested_bytes += result;
@@ -439,6 +432,74 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
break;
pos += vec->iov_len;
}
+ if (requested_bytes)
+ return requested_bytes;
+
+ return result < 0 ? result : -EIO;
+}
+
+static ssize_t nfs_direct_do_schedule_read_bvec(
+ struct nfs_pageio_descriptor *desc,
+ struct bio_vec *bvec, unsigned long nr_segs, loff_t pos)
+{
+ struct nfs_direct_req *dreq = desc->pg_dreq;
+ struct nfs_open_context *ctx = dreq->ctx;
+ struct inode *inode = ctx->dentry->d_inode;
+ ssize_t result = -EINVAL;
+ size_t requested_bytes = 0;
+ unsigned long seg;
+ struct nfs_page *req;
+ unsigned int req_len;
+
+ for (seg = 0; seg < nr_segs; seg++) {
+ result = -EIO;
+ req_len = bvec[seg].bv_len;
+ req = nfs_create_request(ctx, inode,
+ bvec[seg].bv_page,
+ bvec[seg].bv_offset, req_len);
+ if (IS_ERR(req)) {
+ result = PTR_ERR(req);
+ break;
+ }
+ req->wb_index = pos >> PAGE_SHIFT;
+ req->wb_offset = pos & ~PAGE_MASK;
+ if (!nfs_pageio_add_request(desc, req)) {
+ result = desc->pg_error;
+ nfs_release_request(req);
+ break;
+ }
+ requested_bytes += req_len;
+ pos += req_len;
+ }
+
+ if (requested_bytes)
+ return requested_bytes;
+
+ return result < 0 ? result : -EIO;
+}
+
+static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq,
+ struct iov_iter *iter, loff_t pos,
+ bool uio)
+{
+ struct nfs_pageio_descriptor desc;
+ ssize_t result;
+
+ NFS_PROTO(dreq->inode)->read_pageio_init(&desc, dreq->inode,
+ &nfs_direct_read_completion_ops);
+ get_dreq(dreq);
+ desc.pg_dreq = dreq;
+
+ if (iov_iter_has_iovec(iter)) {
+ if (uio)
+ dreq->flags = NFS_ODIRECT_MARK_DIRTY;
+ result = nfs_direct_do_schedule_read_iovec(&desc,
+ iov_iter_iovec(iter), iter->nr_segs, pos, uio);
+ } else if (iov_iter_has_bvec(iter)) {
+ result = nfs_direct_do_schedule_read_bvec(&desc,
+ iov_iter_bvec(iter), iter->nr_segs, pos);
+ } else
+ BUG();
nfs_pageio_complete(&desc);
@@ -446,9 +507,9 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
* If no bytes were started, return the error, and let the
* generic layer handle the completion.
*/
- if (requested_bytes == 0) {
+ if (result < 0) {
nfs_direct_req_release(dreq);
- return result < 0 ? result : -EIO;
+ return result;
}
if (put_dreq(dreq))
@@ -456,8 +517,8 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
return 0;
}
-static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos, bool uio)
+static ssize_t nfs_direct_read(struct kiocb *iocb, struct iov_iter *iter,
+ loff_t pos, bool uio)
{
ssize_t result = -ENOMEM;
struct inode *inode = iocb->ki_filp->f_mapping->host;
@@ -469,7 +530,7 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov,
goto out;
dreq->inode = inode;
- dreq->bytes_left = iov_length(iov, nr_segs);
+ dreq->bytes_left = iov_iter_count(iter);
dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
l_ctx = nfs_get_lock_context(dreq->ctx);
if (IS_ERR(l_ctx)) {
@@ -480,8 +541,8 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov,
if (!is_sync_kiocb(iocb))
dreq->iocb = iocb;
- NFS_I(inode)->read_io += iov_length(iov, nr_segs);
- result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos, uio);
+ NFS_I(inode)->read_io += iov_iter_count(iter);
+ result = nfs_direct_read_schedule(dreq, iter, pos, uio);
if (!result)
result = nfs_direct_wait(dreq);
out_release:
@@ -815,27 +876,18 @@ static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops = {
.completion = nfs_direct_write_completion,
};
-static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
- const struct iovec *iov,
- unsigned long nr_segs,
- loff_t pos, bool uio)
+static ssize_t nfs_direct_do_schedule_write_iovec(
+ struct nfs_pageio_descriptor *desc, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos, bool uio)
{
- struct nfs_pageio_descriptor desc;
- struct inode *inode = dreq->inode;
- ssize_t result = 0;
+ ssize_t result = -EINVAL;
size_t requested_bytes = 0;
unsigned long seg;
- NFS_PROTO(inode)->write_pageio_init(&desc, inode, FLUSH_COND_STABLE,
- &nfs_direct_write_completion_ops);
- desc.pg_dreq = dreq;
- get_dreq(dreq);
- atomic_inc(&inode->i_dio_count);
-
- NFS_I(dreq->inode)->write_io += iov_length(iov, nr_segs);
for (seg = 0; seg < nr_segs; seg++) {
const struct iovec *vec = &iov[seg];
- result = nfs_direct_write_schedule_segment(&desc, vec, pos, uio);
+ result = nfs_direct_write_schedule_segment(desc, vec,
+ pos, uio);
if (result < 0)
break;
requested_bytes += result;
@@ -843,16 +895,88 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
break;
pos += vec->iov_len;
}
+
+ if (requested_bytes)
+ return requested_bytes;
+
+ return result < 0 ? result : -EIO;
+}
+
+static ssize_t nfs_direct_do_schedule_write_bvec(
+ struct nfs_pageio_descriptor *desc,
+ struct bio_vec *bvec, unsigned long nr_segs, loff_t pos)
+{
+ struct nfs_direct_req *dreq = desc->pg_dreq;
+ struct nfs_open_context *ctx = dreq->ctx;
+ struct inode *inode = dreq->inode;
+ ssize_t result = 0;
+ size_t requested_bytes = 0;
+ unsigned long seg;
+ struct nfs_page *req;
+ unsigned int req_len;
+
+ for (seg = 0; seg < nr_segs; seg++) {
+ req_len = bvec[seg].bv_len;
+
+ req = nfs_create_request(ctx, inode, bvec[seg].bv_page,
+ bvec[seg].bv_offset, req_len);
+ if (IS_ERR(req)) {
+ result = PTR_ERR(req);
+ break;
+ }
+ nfs_lock_request(req);
+ req->wb_index = pos >> PAGE_SHIFT;
+ req->wb_offset = pos & ~PAGE_MASK;
+ if (!nfs_pageio_add_request(desc, req)) {
+ result = desc->pg_error;
+ nfs_unlock_and_release_request(req);
+ break;
+ }
+ requested_bytes += req_len;
+ pos += req_len;
+ }
+
+ if (requested_bytes)
+ return requested_bytes;
+
+ return result < 0 ? result : -EIO;
+}
+
+static ssize_t nfs_direct_write_schedule(struct nfs_direct_req *dreq,
+ struct iov_iter *iter, loff_t pos,
+ bool uio)
+{
+ struct nfs_pageio_descriptor desc;
+ struct inode *inode = dreq->inode;
+ ssize_t result = 0;
+
+ NFS_PROTO(inode)->write_pageio_init(&desc, inode, FLUSH_COND_STABLE,
+ &nfs_direct_write_completion_ops);
+ desc.pg_dreq = dreq;
+ get_dreq(dreq);
+ atomic_inc(&inode->i_dio_count);
+
+ NFS_I(dreq->inode)->write_io += iov_iter_count(iter);
+
+ if (iov_iter_has_iovec(iter)) {
+ result = nfs_direct_do_schedule_write_iovec(&desc,
+ iov_iter_iovec(iter), iter->nr_segs, pos, uio);
+ } else if (iov_iter_has_bvec(iter)) {
+ result = nfs_direct_do_schedule_write_bvec(&desc,
+ iov_iter_bvec(iter), iter->nr_segs, pos);
+ } else
+ BUG();
+
nfs_pageio_complete(&desc);
/*
* If no bytes were started, return the error, and let the
* generic layer handle the completion.
*/
- if (requested_bytes == 0) {
+ if (result < 0) {
inode_dio_done(inode);
nfs_direct_req_release(dreq);
- return result < 0 ? result : -EIO;
+ return result;
}
if (put_dreq(dreq))
@@ -860,9 +984,8 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
return 0;
}
-static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos,
- size_t count, bool uio)
+static ssize_t nfs_direct_write(struct kiocb *iocb, struct iov_iter *iter,
+ loff_t pos, bool uio)
{
ssize_t result = -ENOMEM;
struct inode *inode = iocb->ki_filp->f_mapping->host;
@@ -874,7 +997,7 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov,
goto out;
dreq->inode = inode;
- dreq->bytes_left = count;
+ dreq->bytes_left = iov_iter_count(iter);
dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
l_ctx = nfs_get_lock_context(dreq->ctx);
if (IS_ERR(l_ctx)) {
@@ -885,7 +1008,7 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov,
if (!is_sync_kiocb(iocb))
dreq->iocb = iocb;
- result = nfs_direct_write_schedule_iovec(dreq, iov, nr_segs, pos, uio);
+ result = nfs_direct_write_schedule(dreq, iter, pos, uio);
if (!result)
result = nfs_direct_wait(dreq);
out_release:
@@ -897,12 +1020,11 @@ out:
/**
* nfs_file_direct_read - file direct read operation for NFS files
* @iocb: target I/O control block
- * @iov: vector of user buffers into which to read data
- * @nr_segs: size of iov vector
+ * @iter: vector of buffers into which to read data
* @pos: byte offset in file where reading starts
*
* We use this function for direct reads instead of calling
- * generic_file_aio_read() in order to avoid gfar's check to see if
+ * generic_file_read_iter() in order to avoid gfar's check to see if
* the request starts before the end of the file. For that check
* to work, we must generate a GETATTR before each direct read, and
* even then there is a window between the GETATTR and the subsequent
@@ -915,15 +1037,15 @@ out:
* client must read the updated atime from the server back into its
* cache.
*/
-ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos, bool uio)
+ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
+ loff_t pos, bool uio)
{
ssize_t retval = -EINVAL;
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
size_t count;
- count = iov_length(iov, nr_segs);
+ count = iov_iter_count(iter);
nfs_add_stats(mapping->host, NFSIOS_DIRECTREADBYTES, count);
dfprintk(FILE, "NFS: direct read(%s/%s, %zd@%Ld)\n",
@@ -941,7 +1063,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov,
task_io_account_read(count);
- retval = nfs_direct_read(iocb, iov, nr_segs, pos, uio);
+ retval = nfs_direct_read(iocb, iter, pos, uio);
if (retval > 0)
iocb->ki_pos = pos + retval;
@@ -952,12 +1074,11 @@ out:
/**
* nfs_file_direct_write - file direct write operation for NFS files
* @iocb: target I/O control block
- * @iov: vector of user buffers from which to write data
- * @nr_segs: size of iov vector
+ * @iter: vector of buffers from which to write data
* @pos: byte offset in file where writing starts
*
* We use this function for direct writes instead of calling
- * generic_file_aio_write() in order to avoid taking the inode
+ * generic_file_write_iter() in order to avoid taking the inode
* semaphore and updating the i_size. The NFS server will set
* the new i_size and this client must read the updated size
* back into its cache. We let the server do generic write
@@ -971,15 +1092,15 @@ out:
* Note that O_APPEND is not supported for NFS direct writes, as there
* is no atomic O_APPEND write facility in the NFS protocol.
*/
-ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos, bool uio)
+ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
+ loff_t pos, bool uio)
{
ssize_t retval = -EINVAL;
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
size_t count;
- count = iov_length(iov, nr_segs);
+ count = iov_iter_count(iter);
nfs_add_stats(mapping->host, NFSIOS_DIRECTWRITTENBYTES, count);
dfprintk(FILE, "NFS: direct write(%s/%s, %zd@%Ld)\n",
@@ -1004,7 +1125,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
task_io_account_write(count);
- retval = nfs_direct_write(iocb, iov, nr_segs, pos, count, uio);
+ retval = nfs_direct_write(iocb, iter, pos, uio);
if (retval > 0) {
struct inode *inode = mapping->host;
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 582bb88..1b7d325 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -172,29 +172,28 @@ nfs_file_flush(struct file *file, fl_owner_t id)
EXPORT_SYMBOL_GPL(nfs_file_flush);
ssize_t
-nfs_file_read(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos)
+nfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
{
struct dentry * dentry = iocb->ki_filp->f_path.dentry;
struct inode * inode = dentry->d_inode;
ssize_t result;
if (iocb->ki_filp->f_flags & O_DIRECT)
- return nfs_file_direct_read(iocb, iov, nr_segs, pos, true);
+ return nfs_file_direct_read(iocb, iter, pos, true);
- dprintk("NFS: read(%s/%s, %lu@%lu)\n",
+ dprintk("NFS: read_iter(%s/%s, %lu@%lu)\n",
dentry->d_parent->d_name.name, dentry->d_name.name,
- (unsigned long) iov_length(iov, nr_segs), (unsigned long) pos);
+ (unsigned long) iov_iter_count(iter), (unsigned long) pos);
result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping);
if (!result) {
- result = generic_file_aio_read(iocb, iov, nr_segs, pos);
+ result = generic_file_read_iter(iocb, iter, pos);
if (result > 0)
nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, result);
}
return result;
}
-EXPORT_SYMBOL_GPL(nfs_file_read);
+EXPORT_SYMBOL_GPL(nfs_file_read_iter);
ssize_t
nfs_file_splice_read(struct file *filp, loff_t *ppos,
@@ -250,7 +249,7 @@ EXPORT_SYMBOL_GPL(nfs_file_mmap);
* disk, but it retrieves and clears ctx->error after synching, despite
* the two being set at the same time in nfs_context_set_write_error().
* This is because the former is used to notify the _next_ call to
- * nfs_file_write() that a write error occurred, and hence cause it to
+ * nfs_file_write_iter() that a write error occurred, and hence cause it to
* fall back to doing a synchronous write.
*/
int
@@ -610,19 +609,19 @@ static int nfs_need_sync_write(struct file *filp, struct inode *inode)
return 0;
}
-ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos)
+ssize_t nfs_file_write_iter(struct kiocb *iocb, struct iov_iter *iter,
+ loff_t pos)
{
struct dentry * dentry = iocb->ki_filp->f_path.dentry;
struct inode * inode = dentry->d_inode;
unsigned long written = 0;
ssize_t result;
- size_t count = iov_length(iov, nr_segs);
+ size_t count = iov_iter_count(iter);
if (iocb->ki_filp->f_flags & O_DIRECT)
- return nfs_file_direct_write(iocb, iov, nr_segs, pos, true);
+ return nfs_file_direct_write(iocb, iter, pos, true);
- dprintk("NFS: write(%s/%s, %lu@%Ld)\n",
+ dprintk("NFS: write_iter(%s/%s, %lu@%lld)\n",
dentry->d_parent->d_name.name, dentry->d_name.name,
(unsigned long) count, (long long) pos);
@@ -642,7 +641,7 @@ ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov,
if (!count)
goto out;
- result = generic_file_aio_write(iocb, iov, nr_segs, pos);
+ result = generic_file_write_iter(iocb, iter, pos);
if (result > 0)
written = result;
@@ -661,7 +660,7 @@ out_swapfile:
printk(KERN_INFO "NFS: attempt to write to active swap file!\n");
goto out;
}
-EXPORT_SYMBOL_GPL(nfs_file_write);
+EXPORT_SYMBOL_GPL(nfs_file_write_iter);
ssize_t nfs_file_splice_write(struct pipe_inode_info *pipe,
struct file *filp, loff_t *ppos,
@@ -912,8 +911,8 @@ const struct file_operations nfs_file_operations = {
.llseek = nfs_file_llseek,
.read = do_sync_read,
.write = do_sync_write,
- .aio_read = nfs_file_read,
- .aio_write = nfs_file_write,
+ .read_iter = nfs_file_read_iter,
+ .write_iter = nfs_file_write_iter,
.mmap = nfs_file_mmap,
.open = nfs_file_open,
.flush = nfs_file_flush,
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 05521ca..51c5f52 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -301,11 +301,11 @@ int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *)
int nfs_file_fsync_commit(struct file *, loff_t, loff_t, int);
loff_t nfs_file_llseek(struct file *, loff_t, int);
int nfs_file_flush(struct file *, fl_owner_t);
-ssize_t nfs_file_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
+ssize_t nfs_file_read_iter(struct kiocb *, struct iov_iter *, loff_t);
ssize_t nfs_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *,
size_t, unsigned int);
int nfs_file_mmap(struct file *, struct vm_area_struct *);
-ssize_t nfs_file_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
+ssize_t nfs_file_write_iter(struct kiocb *, struct iov_iter *, loff_t);
int nfs_file_release(struct inode *, struct file *);
int nfs_lock(struct file *, int, struct file_lock *);
int nfs_flock(struct file *, int, struct file_lock *);
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index afddd66..de6f644 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -121,8 +121,8 @@ const struct file_operations nfs4_file_operations = {
.llseek = nfs_file_llseek,
.read = do_sync_read,
.write = do_sync_write,
- .aio_read = nfs_file_read,
- .aio_write = nfs_file_write,
+ .read_iter = nfs_file_read_iter,
+ .write_iter = nfs_file_write_iter,
.mmap = nfs_file_mmap,
.open = nfs4_file_open,
.flush = nfs_file_flush,
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 4913e3c..9f8e8a9 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -445,11 +445,9 @@ extern int nfs3_removexattr (struct dentry *, const char *name);
* linux/fs/nfs/direct.c
*/
extern ssize_t nfs_direct_IO(int, struct kiocb *, struct iov_iter *, loff_t);
-extern ssize_t nfs_file_direct_read(struct kiocb *iocb,
- const struct iovec *iov, unsigned long nr_segs,
+extern ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
loff_t pos, bool uio);
-extern ssize_t nfs_file_direct_write(struct kiocb *iocb,
- const struct iovec *iov, unsigned long nr_segs,
+extern ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
loff_t pos, bool uio);
/*
--
1.8.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v4 23/31] nfs: simplify swap
[not found] <1353537671-26284-1-git-send-email-dave.kleikamp@oracle.com>
2012-11-21 22:41 ` [PATCH v4 22/31] nfs: add support for read_iter, write_iter Dave Kleikamp
@ 2012-11-21 22:41 ` Dave Kleikamp
2012-11-23 8:21 ` Christoph Hellwig
1 sibling, 1 reply; 4+ messages in thread
From: Dave Kleikamp @ 2012-11-21 22:41 UTC (permalink / raw)
To: linux-fsdevel
Cc: linux-kernel, Zach Brown, Maxim V. Patlasov, Dave Kleikamp,
Mel Gorman, Trond Myklebust, linux-nfs, Rik van Riel
swap_writepage can now call nfs's write_iter f_op, eliminating the need to
implement for the special-case direct_IO a_op. There is no longer a need to
pass the uio flag through the direct write path.
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: linux-nfs@vger.kernel.org
Cc: Rik van Riel <riel@redhat.com>
---
fs/nfs/direct.c | 94 +++++++++++++++++---------------------------------
fs/nfs/file.c | 4 +--
include/linux/nfs_fs.h | 4 +--
mm/page_io.c | 13 ++++---
4 files changed, 42 insertions(+), 73 deletions(-)
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 6754588..b8be1e1 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -118,29 +118,18 @@ static inline int put_dreq(struct nfs_direct_req *dreq)
* @nr_segs: size of iovec array
*
* The presence of this routine in the address space ops vector means
- * the NFS client supports direct I/O. However, for most direct IO, we
- * shunt off direct read and write requests before the VFS gets them,
- * so this method is only ever called for swap.
+ * the NFS client supports direct I/O. However, we shunt off direct
+ * read and write requests before the VFS gets them, so this method
+ * should never be called.
*/
ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter,
loff_t pos)
{
-#ifndef CONFIG_NFS_SWAP
dprintk("NFS: nfs_direct_IO (%s) off/no(%Ld/%lu) EINVAL\n",
iocb->ki_filp->f_path.dentry->d_name.name,
(long long) pos, iter->nr_segs);
return -EINVAL;
-#else
- VM_BUG_ON(iocb->ki_left != PAGE_SIZE);
- VM_BUG_ON(iocb->ki_nbytes != PAGE_SIZE);
-
- if (rw == READ || rw == KERNEL_READ)
- return nfs_file_direct_read(iocb, iter, pos,
- rw == READ ? true : false);
- return nfs_file_direct_write(iocb, iter, pos,
- rw == WRITE ? true : false);
-#endif /* CONFIG_NFS_SWAP */
}
static void nfs_direct_release_pages(struct page **pages, unsigned int npages)
@@ -325,7 +314,7 @@ static const struct nfs_pgio_completion_ops nfs_direct_read_completion_ops = {
*/
static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *desc,
const struct iovec *iov,
- loff_t pos, bool uio)
+ loff_t pos)
{
struct nfs_direct_req *dreq = desc->pg_dreq;
struct nfs_open_context *ctx = dreq->ctx;
@@ -353,20 +342,12 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
GFP_KERNEL);
if (!pagevec)
break;
- if (uio) {
- down_read(¤t->mm->mmap_sem);
- result = get_user_pages(current, current->mm, user_addr,
+ down_read(¤t->mm->mmap_sem);
+ result = get_user_pages(current, current->mm, user_addr,
npages, 1, 0, pagevec, NULL);
- up_read(¤t->mm->mmap_sem);
- if (result < 0)
- break;
- } else {
- WARN_ON(npages != 1);
- result = get_kernel_page(user_addr, 1, pagevec);
- if (WARN_ON(result != 1))
- break;
- }
-
+ up_read(¤t->mm->mmap_sem);
+ if (result < 0)
+ break;
if ((unsigned)result < npages) {
bytes = result * PAGE_SIZE;
if (bytes <= pgbase) {
@@ -416,7 +397,7 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
static ssize_t nfs_direct_do_schedule_read_iovec(
struct nfs_pageio_descriptor *desc, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos, bool uio)
+ unsigned long nr_segs, loff_t pos)
{
ssize_t result = -EINVAL;
size_t requested_bytes = 0;
@@ -424,7 +405,7 @@ static ssize_t nfs_direct_do_schedule_read_iovec(
for (seg = 0; seg < nr_segs; seg++) {
const struct iovec *vec = &iov[seg];
- result = nfs_direct_read_schedule_segment(desc, vec, pos, uio);
+ result = nfs_direct_read_schedule_segment(desc, vec, pos);
if (result < 0)
break;
requested_bytes += result;
@@ -479,8 +460,7 @@ static ssize_t nfs_direct_do_schedule_read_bvec(
}
static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq,
- struct iov_iter *iter, loff_t pos,
- bool uio)
+ struct iov_iter *iter, loff_t pos)
{
struct nfs_pageio_descriptor desc;
ssize_t result;
@@ -491,10 +471,8 @@ static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq,
desc.pg_dreq = dreq;
if (iov_iter_has_iovec(iter)) {
- if (uio)
- dreq->flags = NFS_ODIRECT_MARK_DIRTY;
result = nfs_direct_do_schedule_read_iovec(&desc,
- iov_iter_iovec(iter), iter->nr_segs, pos, uio);
+ iov_iter_iovec(iter), iter->nr_segs, pos);
} else if (iov_iter_has_bvec(iter)) {
result = nfs_direct_do_schedule_read_bvec(&desc,
iov_iter_bvec(iter), iter->nr_segs, pos);
@@ -518,7 +496,7 @@ static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq,
}
static ssize_t nfs_direct_read(struct kiocb *iocb, struct iov_iter *iter,
- loff_t pos, bool uio)
+ loff_t pos)
{
ssize_t result = -ENOMEM;
struct inode *inode = iocb->ki_filp->f_mapping->host;
@@ -542,7 +520,7 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, struct iov_iter *iter,
dreq->iocb = iocb;
NFS_I(inode)->read_io += iov_iter_count(iter);
- result = nfs_direct_read_schedule(dreq, iter, pos, uio);
+ result = nfs_direct_read_schedule(dreq, iter, pos);
if (!result)
result = nfs_direct_wait(dreq);
out_release:
@@ -707,7 +685,7 @@ static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode
*/
static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *desc,
const struct iovec *iov,
- loff_t pos, bool uio)
+ loff_t pos)
{
struct nfs_direct_req *dreq = desc->pg_dreq;
struct nfs_open_context *ctx = dreq->ctx;
@@ -735,19 +713,12 @@ static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *d
if (!pagevec)
break;
- if (uio) {
- down_read(¤t->mm->mmap_sem);
- result = get_user_pages(current, current->mm, user_addr,
- npages, 0, 0, pagevec, NULL);
- up_read(¤t->mm->mmap_sem);
- if (result < 0)
- break;
- } else {
- WARN_ON(npages != 1);
- result = get_kernel_page(user_addr, 0, pagevec);
- if (WARN_ON(result != 1))
- break;
- }
+ down_read(¤t->mm->mmap_sem);
+ result = get_user_pages(current, current->mm, user_addr,
+ npages, 0, 0, pagevec, NULL);
+ up_read(¤t->mm->mmap_sem);
+ if (result < 0)
+ break;
if ((unsigned)result < npages) {
bytes = result * PAGE_SIZE;
@@ -878,7 +849,7 @@ static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops = {
static ssize_t nfs_direct_do_schedule_write_iovec(
struct nfs_pageio_descriptor *desc, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos, bool uio)
+ unsigned long nr_segs, loff_t pos)
{
ssize_t result = -EINVAL;
size_t requested_bytes = 0;
@@ -887,7 +858,7 @@ static ssize_t nfs_direct_do_schedule_write_iovec(
for (seg = 0; seg < nr_segs; seg++) {
const struct iovec *vec = &iov[seg];
result = nfs_direct_write_schedule_segment(desc, vec,
- pos, uio);
+ pos);
if (result < 0)
break;
requested_bytes += result;
@@ -943,8 +914,7 @@ static ssize_t nfs_direct_do_schedule_write_bvec(
}
static ssize_t nfs_direct_write_schedule(struct nfs_direct_req *dreq,
- struct iov_iter *iter, loff_t pos,
- bool uio)
+ struct iov_iter *iter, loff_t pos)
{
struct nfs_pageio_descriptor desc;
struct inode *inode = dreq->inode;
@@ -960,7 +930,7 @@ static ssize_t nfs_direct_write_schedule(struct nfs_direct_req *dreq,
if (iov_iter_has_iovec(iter)) {
result = nfs_direct_do_schedule_write_iovec(&desc,
- iov_iter_iovec(iter), iter->nr_segs, pos, uio);
+ iov_iter_iovec(iter), iter->nr_segs, pos);
} else if (iov_iter_has_bvec(iter)) {
result = nfs_direct_do_schedule_write_bvec(&desc,
iov_iter_bvec(iter), iter->nr_segs, pos);
@@ -985,7 +955,7 @@ static ssize_t nfs_direct_write_schedule(struct nfs_direct_req *dreq,
}
static ssize_t nfs_direct_write(struct kiocb *iocb, struct iov_iter *iter,
- loff_t pos, bool uio)
+ loff_t pos)
{
ssize_t result = -ENOMEM;
struct inode *inode = iocb->ki_filp->f_mapping->host;
@@ -1008,7 +978,7 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, struct iov_iter *iter,
if (!is_sync_kiocb(iocb))
dreq->iocb = iocb;
- result = nfs_direct_write_schedule(dreq, iter, pos, uio);
+ result = nfs_direct_write_schedule(dreq, iter, pos);
if (!result)
result = nfs_direct_wait(dreq);
out_release:
@@ -1038,7 +1008,7 @@ out:
* cache.
*/
ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
- loff_t pos, bool uio)
+ loff_t pos)
{
ssize_t retval = -EINVAL;
struct file *file = iocb->ki_filp;
@@ -1063,7 +1033,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
task_io_account_read(count);
- retval = nfs_direct_read(iocb, iter, pos, uio);
+ retval = nfs_direct_read(iocb, iter, pos);
if (retval > 0)
iocb->ki_pos = pos + retval;
@@ -1093,7 +1063,7 @@ out:
* is no atomic O_APPEND write facility in the NFS protocol.
*/
ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
- loff_t pos, bool uio)
+ loff_t pos)
{
ssize_t retval = -EINVAL;
struct file *file = iocb->ki_filp;
@@ -1125,7 +1095,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
task_io_account_write(count);
- retval = nfs_direct_write(iocb, iter, pos, uio);
+ retval = nfs_direct_write(iocb, iter, pos);
if (retval > 0) {
struct inode *inode = mapping->host;
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 1b7d325..b93f44f 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -179,7 +179,7 @@ nfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
ssize_t result;
if (iocb->ki_filp->f_flags & O_DIRECT)
- return nfs_file_direct_read(iocb, iter, pos, true);
+ return nfs_file_direct_read(iocb, iter, pos);
dprintk("NFS: read_iter(%s/%s, %lu@%lu)\n",
dentry->d_parent->d_name.name, dentry->d_name.name,
@@ -619,7 +619,7 @@ ssize_t nfs_file_write_iter(struct kiocb *iocb, struct iov_iter *iter,
size_t count = iov_iter_count(iter);
if (iocb->ki_filp->f_flags & O_DIRECT)
- return nfs_file_direct_write(iocb, iter, pos, true);
+ return nfs_file_direct_write(iocb, iter, pos);
dprintk("NFS: write_iter(%s/%s, %lu@%lld)\n",
dentry->d_parent->d_name.name, dentry->d_name.name,
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 9f8e8a9..6033367 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -446,9 +446,9 @@ extern int nfs3_removexattr (struct dentry *, const char *name);
*/
extern ssize_t nfs_direct_IO(int, struct kiocb *, struct iov_iter *, loff_t);
extern ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
- loff_t pos, bool uio);
+ loff_t pos);
extern ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
- loff_t pos, bool uio);
+ loff_t pos);
/*
* linux/fs/nfs/dir.c
diff --git a/mm/page_io.c b/mm/page_io.c
index 33da274..60a5503 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -203,14 +203,14 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
if (sis->flags & SWP_FILE) {
struct kiocb kiocb;
struct file *swap_file = sis->swap_file;
- struct address_space *mapping = swap_file->f_mapping;
- struct iovec iov = {
- .iov_base = kmap(page),
- .iov_len = PAGE_SIZE,
+ struct bio_vec bvec = {
+ .bv_page = kmap(page),
+ .bv_len = PAGE_SIZE,
+ .bv_offset = 0,
};
struct iov_iter iter;
- iov_iter_init(&iter, &iov, 1, PAGE_SIZE, 0);
+ iov_iter_init_bvec(&iter, &bvec, 1, PAGE_SIZE, 0);
init_sync_kiocb(&kiocb, swap_file);
kiocb.ki_pos = page_file_offset(page);
@@ -218,8 +218,7 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
kiocb.ki_nbytes = PAGE_SIZE;
unlock_page(page);
- ret = mapping->a_ops->direct_IO(KERNEL_WRITE, &kiocb, &iter,
- kiocb.ki_pos);
+ ret = swap_file->f_op->write_iter(&kiocb, &iter, kiocb.ki_pos);
kunmap(page);
if (ret == PAGE_SIZE) {
count_vm_event(PSWPOUT);
--
1.8.0
^ permalink raw reply related [flat|nested] 4+ messages in thread