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>
diff --git a/drivers/staging/lustre/lustre/llite/rw26.c b/drivers/staging/lustre/lustre/llite/rw26.c
index f718585..6b59945 100644
--- a/drivers/staging/lustre/lustre/llite/rw26.c
+++ b/drivers/staging/lustre/lustre/llite/rw26.c
@@ -218,14 +218,11 @@
int i;
for (i = 0; i < npages; i++) {
- if (pages[i] == NULL)
- break;
if (do_dirty)
set_page_dirty_lock(pages[i]);
page_cache_release(pages[i]);
}
-
- OBD_FREE_LARGE(pages, npages * sizeof(*pages));
+ kvfree(pages);
}
ssize_t ll_direct_rw_pages(const struct lu_env *env, struct cl_io *io,
@@ -370,10 +367,9 @@
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
struct ccc_object *obj = cl_inode2ccc(inode);
- long count = iov_iter_count(iter);
- long tot_bytes = 0, result = 0;
+ ssize_t count = iov_iter_count(iter);
+ ssize_t tot_bytes = 0, result = 0;
struct ll_inode_info *lli = ll_i2info(inode);
- unsigned long seg = 0;
long size = MAX_DIO_SIZE;
int refcheck;
@@ -407,63 +403,49 @@
mutex_lock(&inode->i_mutex);
LASSERT(obj->cob_transient_pages == 0);
- for (seg = 0; seg < iter->nr_segs; seg++) {
- long iov_left = iter->iov[seg].iov_len;
- unsigned long user_addr = (unsigned long)iter->iov[seg].iov_base;
+ while (iov_iter_count(iter)) {
+ struct page **pages;
+ size_t offs;
+ count = min_t(size_t, iov_iter_count(iter), size);
if (rw == READ) {
if (file_offset >= i_size_read(inode))
break;
- if (file_offset + iov_left > i_size_read(inode))
- iov_left = i_size_read(inode) - file_offset;
+ if (file_offset + count > i_size_read(inode))
+ count = i_size_read(inode) - file_offset;
}
- while (iov_left > 0) {
- struct page **pages;
- int page_count, max_pages = 0;
- long bytes;
-
- bytes = min(size, iov_left);
- page_count = ll_get_user_pages(rw, user_addr, bytes,
- &pages, &max_pages);
- if (likely(page_count > 0)) {
- if (unlikely(page_count < max_pages))
- bytes = page_count << PAGE_CACHE_SHIFT;
- result = ll_direct_IO_26_seg(env, io, rw, inode,
- file->f_mapping,
- bytes, file_offset,
- pages, page_count);
- ll_free_user_pages(pages, max_pages, rw==READ);
- } else if (page_count == 0) {
- GOTO(out, result = -EFAULT);
- } else {
- result = page_count;
- }
- if (unlikely(result <= 0)) {
- /* If we can't allocate a large enough buffer
- * for the request, shrink it to a smaller
- * PAGE_SIZE multiple and try again.
- * We should always be able to kmalloc for a
- * page worth of page pointers = 4MB on i386. */
- if (result == -ENOMEM &&
- size > (PAGE_CACHE_SIZE / sizeof(*pages)) *
- PAGE_CACHE_SIZE) {
- size = ((((size / 2) - 1) |
- ~CFS_PAGE_MASK) + 1) &
- CFS_PAGE_MASK;
- CDEBUG(D_VFSTRACE,"DIO size now %lu\n",
- size);
- continue;
- }
-
- GOTO(out, result);
- }
-
- tot_bytes += result;
- file_offset += result;
- iov_left -= result;
- user_addr += result;
+ result = iov_iter_get_pages_alloc(iter, &pages, count, &offs);
+ if (likely(result > 0)) {
+ int n = (result + offs + PAGE_SIZE - 1) / PAGE_SIZE;
+ result = ll_direct_IO_26_seg(env, io, rw, inode,
+ file->f_mapping,
+ result, file_offset,
+ pages, n);
+ ll_free_user_pages(pages, n, rw==READ);
}
+ if (unlikely(result <= 0)) {
+ /* If we can't allocate a large enough buffer
+ * for the request, shrink it to a smaller
+ * PAGE_SIZE multiple and try again.
+ * We should always be able to kmalloc for a
+ * page worth of page pointers = 4MB on i386. */
+ if (result == -ENOMEM &&
+ size > (PAGE_CACHE_SIZE / sizeof(*pages)) *
+ PAGE_CACHE_SIZE) {
+ size = ((((size / 2) - 1) |
+ ~CFS_PAGE_MASK) + 1) &
+ CFS_PAGE_MASK;
+ CDEBUG(D_VFSTRACE,"DIO size now %lu\n",
+ size);
+ continue;
+ }
+
+ GOTO(out, result);
+ }
+ iov_iter_advance(iter, result);
+ tot_bytes += result;
+ file_offset += result;
}
out:
LASSERT(obj->cob_transient_pages == 0);
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 1d34f45..b122fe2 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -322,60 +322,37 @@
* 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)
+
+static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
+ struct iov_iter *iter,
+ 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;
- 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;
+ 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);
- do {
+ 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);
+
+ while (iov_iter_count(iter)) {
+ struct page **pagevec;
size_t bytes;
- int i;
+ size_t pgbase;
+ unsigned npages, i;
- pgbase = user_addr & ~PAGE_MASK;
- bytes = min(max_t(size_t, rsize, PAGE_SIZE), count);
-
- result = -ENOMEM;
- npages = nfs_page_array_len(pgbase, bytes);
- if (!pagevec)
- pagevec = kmalloc(npages * sizeof(struct page *),
- GFP_KERNEL);
- if (!pagevec)
+ result = iov_iter_get_pages_alloc(iter, &pagevec,
+ rsize, &pgbase);
+ if (result < 0)
break;
- if (uio) {
- 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;
- }
-
- if ((unsigned)result < npages) {
- bytes = result * PAGE_SIZE;
- if (bytes <= pgbase) {
- nfs_direct_release_pages(pagevec, result);
- break;
- }
- bytes -= pgbase;
- npages = result;
- }
-
+
+ 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 @@
}
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 @@
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 @@
}
#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(¤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;
- }
-
- 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 @@
.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 @@
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 @@
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,
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 2f8825b..4876e9f 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -73,6 +73,8 @@
unsigned long nr_segs, size_t count);
ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,
size_t maxsize, size_t *start);
+ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages,
+ size_t maxsize, size_t *start);
int iov_iter_npages(const struct iov_iter *i, int maxpages);
static inline size_t iov_iter_count(struct iov_iter *i)
diff --git a/mm/iov_iter.c b/mm/iov_iter.c
index 0b677f8..a5c691c 100644
--- a/mm/iov_iter.c
+++ b/mm/iov_iter.c
@@ -1,6 +1,8 @@
#include <linux/export.h>
#include <linux/uio.h>
#include <linux/pagemap.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i)
@@ -263,6 +265,44 @@
}
EXPORT_SYMBOL(iov_iter_get_pages);
+ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
+ struct page ***pages, size_t maxsize,
+ size_t *start)
+{
+ size_t offset = i->iov_offset;
+ const struct iovec *iov = i->iov;
+ size_t len;
+ unsigned long addr;
+ void *p;
+ int n;
+ int res;
+
+ len = iov->iov_len - offset;
+ if (len > i->count)
+ len = i->count;
+ if (len > maxsize)
+ len = maxsize;
+ addr = (unsigned long)iov->iov_base + offset;
+ len += *start = addr & (PAGE_SIZE - 1);
+ addr &= ~(PAGE_SIZE - 1);
+ n = (len + PAGE_SIZE - 1) / PAGE_SIZE;
+
+ p = kmalloc(n * sizeof(struct page *), GFP_KERNEL);
+ if (!p)
+ p = vmalloc(n * sizeof(struct page *));
+ if (!p)
+ return -ENOMEM;
+
+ res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p);
+ if (unlikely(res < 0)) {
+ kvfree(p);
+ return res;
+ }
+ *pages = p;
+ return (res == n ? len : res * PAGE_SIZE) - *start;
+}
+EXPORT_SYMBOL(iov_iter_get_pages_alloc);
+
int iov_iter_npages(const struct iov_iter *i, int maxpages)
{
size_t offset = i->iov_offset;