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authorAl Viro <viro@zeniv.linux.org.uk>2014-03-21 12:58:33 +0400
committerAl Viro <viro@zeniv.linux.org.uk>2014-05-07 01:32:53 +0400
commit91f79c43d1b54d7154b118860d81b39bad07dfff (patch)
treea5b142ba57fdabf835476b6dbca24288a78f0c53 /fs/nfs/direct.c
parentf67da30c1d5fc9e341bc8121708874bfd7b31e45 (diff)
downloadlinux-91f79c43d1b54d7154b118860d81b39bad07dfff.tar.xz
new helper: iov_iter_get_pages_alloc()
same as iov_iter_get_pages(), except that pages array is allocated (kmalloc if possible, vmalloc if that fails) and left for caller to free. Lustre and NFS ->direct_IO() switched to it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/nfs/direct.c')
-rw-r--r--fs/nfs/direct.c290
1 files changed, 88 insertions, 202 deletions
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 1d34f454989e..b122fe21fea0 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -322,60 +322,37 @@ static const struct nfs_pgio_completion_ops nfs_direct_read_completion_ops = {
* handled automatically by nfs_direct_read_result(). Otherwise, if
* no requests have been sent, just return an error.
*/
-static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *desc,
- const struct iovec *iov,
- loff_t pos, bool uio)
-{
- struct nfs_direct_req *dreq = desc->pg_dreq;
- struct nfs_open_context *ctx = dreq->ctx;
- struct inode *inode = ctx->dentry->d_inode;
- unsigned long user_addr = (unsigned long)iov->iov_base;
- size_t count = iov->iov_len;
- size_t rsize = NFS_SERVER(inode)->rsize;
- unsigned int pgbase;
- int result;
- ssize_t started = 0;
- struct page **pagevec = NULL;
- unsigned int npages;
-
- do {
- size_t bytes;
- int i;
- pgbase = user_addr & ~PAGE_MASK;
- bytes = min(max_t(size_t, rsize, PAGE_SIZE), count);
+static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
+ struct iov_iter *iter,
+ loff_t pos)
+{
+ struct nfs_pageio_descriptor desc;
+ struct inode *inode = dreq->inode;
+ ssize_t result = -EINVAL;
+ size_t requested_bytes = 0;
+ size_t rsize = max_t(size_t, NFS_SERVER(inode)->rsize, PAGE_SIZE);
- result = -ENOMEM;
- npages = nfs_page_array_len(pgbase, bytes);
- if (!pagevec)
- pagevec = kmalloc(npages * sizeof(struct page *),
- GFP_KERNEL);
- if (!pagevec)
- break;
- if (uio) {
- down_read(&current->mm->mmap_sem);
- result = get_user_pages(current, current->mm, user_addr,
- npages, 1, 0, pagevec, NULL);
- up_read(&current->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;
- }
+ NFS_PROTO(dreq->inode)->read_pageio_init(&desc, dreq->inode,
+ &nfs_direct_read_completion_ops);
+ get_dreq(dreq);
+ desc.pg_dreq = dreq;
+ atomic_inc(&inode->i_dio_count);
- if ((unsigned)result < npages) {
- bytes = result * PAGE_SIZE;
- if (bytes <= pgbase) {
- nfs_direct_release_pages(pagevec, result);
- break;
- }
- bytes -= pgbase;
- npages = result;
- }
+ while (iov_iter_count(iter)) {
+ struct page **pagevec;
+ size_t bytes;
+ size_t pgbase;
+ unsigned npages, i;
+ result = iov_iter_get_pages_alloc(iter, &pagevec,
+ rsize, &pgbase);
+ if (result < 0)
+ break;
+
+ bytes = result;
+ iov_iter_advance(iter, bytes);
+ npages = (result + pgbase + PAGE_SIZE - 1) / PAGE_SIZE;
for (i = 0; i < npages; i++) {
struct nfs_page *req;
unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
@@ -389,55 +366,21 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
}
req->wb_index = pos >> PAGE_SHIFT;
req->wb_offset = pos & ~PAGE_MASK;
- if (!nfs_pageio_add_request(desc, req)) {
- result = desc->pg_error;
+ if (!nfs_pageio_add_request(&desc, req)) {
+ result = desc.pg_error;
nfs_release_request(req);
break;
}
pgbase = 0;
bytes -= req_len;
- started += req_len;
- user_addr += req_len;
+ requested_bytes += req_len;
pos += req_len;
- count -= req_len;
dreq->bytes_left -= req_len;
}
- /* The nfs_page now hold references to these pages */
nfs_direct_release_pages(pagevec, npages);
- } while (count != 0 && result >= 0);
-
- kfree(pagevec);
-
- if (started)
- return started;
- return result < 0 ? (ssize_t) result : -EFAULT;
-}
-
-static ssize_t nfs_direct_read_schedule_iovec(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 = -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;
- atomic_inc(&inode->i_dio_count);
-
- for (seg = 0; seg < iter->nr_segs; seg++) {
- const struct iovec *vec = &iter->iov[seg];
- result = nfs_direct_read_schedule_segment(&desc, vec, pos, uio);
+ kvfree(pagevec);
if (result < 0)
break;
- requested_bytes += result;
- if ((size_t)result < vec->iov_len)
- break;
- pos += vec->iov_len;
}
nfs_pageio_complete(&desc);
@@ -521,7 +464,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
dreq->iocb = iocb;
NFS_I(inode)->read_io += count;
- result = nfs_direct_read_schedule_iovec(dreq, iter, pos, uio);
+ result = nfs_direct_read_schedule_iovec(dreq, iter, pos);
mutex_unlock(&inode->i_mutex);
@@ -677,109 +620,6 @@ static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode
}
#endif
-/*
- * NB: Return the value of the first error return code. Subsequent
- * errors after the first one are ignored.
- */
-/*
- * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE
- * operation. If nfs_writedata_alloc() or get_user_pages() fails,
- * bail and stop sending more writes. Write length accounting is
- * handled automatically by nfs_direct_write_result(). Otherwise, if
- * no requests have been sent, just return an error.
- */
-static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *desc,
- const struct iovec *iov,
- loff_t pos, bool uio)
-{
- struct nfs_direct_req *dreq = desc->pg_dreq;
- struct nfs_open_context *ctx = dreq->ctx;
- struct inode *inode = ctx->dentry->d_inode;
- unsigned long user_addr = (unsigned long)iov->iov_base;
- size_t count = iov->iov_len;
- size_t wsize = NFS_SERVER(inode)->wsize;
- unsigned int pgbase;
- int result;
- ssize_t started = 0;
- struct page **pagevec = NULL;
- unsigned int npages;
-
- do {
- size_t bytes;
- int i;
-
- pgbase = user_addr & ~PAGE_MASK;
- bytes = min(max_t(size_t, wsize, PAGE_SIZE), count);
-
- result = -ENOMEM;
- npages = nfs_page_array_len(pgbase, bytes);
- if (!pagevec)
- pagevec = kmalloc(npages * sizeof(struct page *), GFP_KERNEL);
- if (!pagevec)
- break;
-
- if (uio) {
- down_read(&current->mm->mmap_sem);
- result = get_user_pages(current, current->mm, user_addr,
- npages, 0, 0, pagevec, NULL);
- up_read(&current->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;
- }
-
- if ((unsigned)result < npages) {
- bytes = result * PAGE_SIZE;
- if (bytes <= pgbase) {
- nfs_direct_release_pages(pagevec, result);
- break;
- }
- bytes -= pgbase;
- npages = result;
- }
-
- for (i = 0; i < npages; i++) {
- struct nfs_page *req;
- unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
-
- req = nfs_create_request(dreq->ctx, dreq->inode,
- pagevec[i],
- pgbase, 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;
- }
- pgbase = 0;
- bytes -= req_len;
- started += req_len;
- user_addr += req_len;
- pos += req_len;
- count -= req_len;
- dreq->bytes_left -= req_len;
- }
- /* The nfs_page now hold references to these pages */
- nfs_direct_release_pages(pagevec, npages);
- } while (count != 0 && result >= 0);
-
- kfree(pagevec);
-
- if (started)
- return started;
- return result < 0 ? (ssize_t) result : -EFAULT;
-}
-
static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
{
struct nfs_direct_req *dreq = hdr->dreq;
@@ -859,15 +699,27 @@ static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops = {
.completion = nfs_direct_write_completion,
};
+
+/*
+ * NB: Return the value of the first error return code. Subsequent
+ * errors after the first one are ignored.
+ */
+/*
+ * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE
+ * operation. If nfs_writedata_alloc() or get_user_pages() fails,
+ * bail and stop sending more writes. Write length accounting is
+ * handled automatically by nfs_direct_write_result(). Otherwise, if
+ * no requests have been sent, just return an error.
+ */
static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
struct iov_iter *iter,
- loff_t pos, bool uio)
+ loff_t pos)
{
struct nfs_pageio_descriptor desc;
struct inode *inode = dreq->inode;
ssize_t result = 0;
size_t requested_bytes = 0;
- unsigned long seg;
+ size_t wsize = max_t(size_t, NFS_SERVER(inode)->wsize, PAGE_SIZE);
NFS_PROTO(inode)->write_pageio_init(&desc, inode, FLUSH_COND_STABLE,
&nfs_direct_write_completion_ops);
@@ -875,16 +727,50 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
get_dreq(dreq);
atomic_inc(&inode->i_dio_count);
- NFS_I(dreq->inode)->write_io += iov_iter_count(iter);
- for (seg = 0; seg < iter->nr_segs; seg++) {
- const struct iovec *vec = &iter->iov[seg];
- result = nfs_direct_write_schedule_segment(&desc, vec, pos, uio);
+ NFS_I(inode)->write_io += iov_iter_count(iter);
+ while (iov_iter_count(iter)) {
+ struct page **pagevec;
+ size_t bytes;
+ size_t pgbase;
+ unsigned npages, i;
+
+ result = iov_iter_get_pages_alloc(iter, &pagevec,
+ wsize, &pgbase);
if (result < 0)
break;
- requested_bytes += result;
- if ((size_t)result < vec->iov_len)
+
+ bytes = result;
+ iov_iter_advance(iter, bytes);
+ npages = (result + pgbase + PAGE_SIZE - 1) / PAGE_SIZE;
+ for (i = 0; i < npages; i++) {
+ struct nfs_page *req;
+ unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
+
+ req = nfs_create_request(dreq->ctx, inode,
+ pagevec[i],
+ pgbase, 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;
+ }
+ pgbase = 0;
+ bytes -= req_len;
+ requested_bytes += req_len;
+ pos += req_len;
+ dreq->bytes_left -= req_len;
+ }
+ nfs_direct_release_pages(pagevec, npages);
+ kvfree(pagevec);
+ if (result < 0)
break;
- pos += vec->iov_len;
}
nfs_pageio_complete(&desc);
@@ -985,7 +871,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
if (!is_sync_kiocb(iocb))
dreq->iocb = iocb;
- result = nfs_direct_write_schedule_iovec(dreq, iter, pos, uio);
+ result = nfs_direct_write_schedule_iovec(dreq, iter, pos);
if (mapping->nrpages) {
invalidate_inode_pages2_range(mapping,