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orangefs: make pvfs2_inode_read() take iov_iter

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... and make the only caller use page-backed iov_iter,
getting rid of kmap/kunmap *and* of the bug with
attempted use of iovec-backed copy_page_to_iter()
on a kernel pointer.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
This commit is contained in:
Al Viro 2015-10-08 18:31:05 -04:00 committed by Mike Marshall
parent 0071ed1ec6
commit 74f68fce2a
3 changed files with 11 additions and 21 deletions
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12
fs/orangefs/file.c
View file

@ -369,22 +369,17 @@ static ssize_t do_readv_writev(enum PVFS_io_type type, struct file *file,
* Data may be placed either in a user or kernel buffer.
*/
ssize_t pvfs2_inode_read(struct inode *inode,
char __user *buf,
size_t count,
struct iov_iter *iter,
loff_t *offset,
loff_t readahead_size)
{
struct pvfs2_inode_s *pvfs2_inode = PVFS2_I(inode);
size_t count = iov_iter_count(iter);
size_t bufmap_size;
struct iovec vec;
struct iov_iter iter;
ssize_t ret = -EINVAL;
g_pvfs2_stats.reads++;
vec.iov_base = buf;
vec.iov_len = count;
bufmap_size = pvfs_bufmap_size_query();
if (count > bufmap_size) {
gossip_debug(GOSSIP_FILE_DEBUG,
@ -400,8 +395,7 @@ ssize_t pvfs2_inode_read(struct inode *inode,
count,
llu(*offset));
iov_iter_init(&iter, READ, &vec, 1, count);
ret = wait_for_direct_io(PVFS_IO_READ, inode, offset, &iter,
ret = wait_for_direct_io(PVFS_IO_READ, inode, offset, iter,
count, readahead_size);
if (ret > 0)
*offset += ret;

17
fs/orangefs/inode.c
View file

@ -14,18 +14,20 @@
static int read_one_page(struct page *page)
{
void *page_data;
int ret;
int max_block;
ssize_t bytes_read = 0;
struct inode *inode = page->mapping->host;
const __u32 blocksize = PAGE_CACHE_SIZE; /* inode->i_blksize */
const __u32 blockbits = PAGE_CACHE_SHIFT; /* inode->i_blkbits */
struct iov_iter to;
struct bio_vec bv = {.bv_page = page, .bv_len = PAGE_SIZE};
iov_iter_bvec(&to, ITER_BVEC | READ, &bv, 1, PAGE_SIZE);
gossip_debug(GOSSIP_INODE_DEBUG,
"pvfs2_readpage called with page %p\n",
page);
page_data = pvfs2_kmap(page);
max_block = ((inode->i_size / blocksize) + 1);
@ -33,16 +35,12 @@ static int read_one_page(struct page *page)
loff_t blockptr_offset = (((loff_t) page->index) << blockbits);
bytes_read = pvfs2_inode_read(inode,
(char __user *) page_data,
blocksize,
&to,
&blockptr_offset,
inode->i_size);
}
/* only zero remaining unread portions of the page data */
if (bytes_read > 0)
memset(page_data + bytes_read, 0, blocksize - bytes_read);
else
memset(page_data, 0, blocksize);
/* this will only zero remaining unread portions of the page data */
iov_iter_zero(~0U, &to);
/* takes care of potential aliasing */
flush_dcache_page(page);
if (bytes_read < 0) {
@ -54,7 +52,6 @@ static int read_one_page(struct page *page)
ClearPageError(page);
ret = 0;
}
pvfs2_kunmap(page);
/* unlock the page after the ->readpage() routine completes */
unlock_page(page);
return ret;

3
fs/orangefs/pvfs2-kernel.h
View file

@ -605,8 +605,7 @@ struct inode *pvfs2_iget(struct super_block *sb,
struct pvfs2_object_kref *ref);
ssize_t pvfs2_inode_read(struct inode *inode,
char __user *buf,
size_t count,
struct iov_iter *iter,
loff_t *offset,
loff_t readahead_size);