static ssize_t
zpl_read_common_iovec(struct inode *ip, const struct iovec *iovp, size_t count,
unsigned long nr_segs, loff_t *ppos, uio_seg_t segment, int flags,
cred_t *cr, size_t skip)
{
ssize_t read;
uio_t uio;
int error;
fstrans_cookie_t cookie;
uio.uio_iov = iovp;
uio.uio_skip = skip;
uio.uio_resid = count;
uio.uio_iovcnt = nr_segs;
uio.uio_loffset = *ppos;
uio.uio_limit = MAXOFFSET_T;
uio.uio_segflg = segment;
cookie = spl_fstrans_mark();
error = -zfs_read(ip, &uio, flags, cr);
spl_fstrans_unmark(cookie);
if (error < 0)
return (error);
read = count - uio.uio_resid;
*ppos += read;
task_io_account_read(read);
return (read);
}
ssize_t
zpl_read_common(struct inode *ip, const char *buf, size_t len, loff_t pos,
uio_seg_t segment, int flags, cred_t *cr)
{
int error;
ssize_t read;
struct iovec iov;
uio_t uio;
iov.iov_base = (void *)buf;
iov.iov_len = len;
uio.uio_iov = &iov;
uio.uio_resid = len;
uio.uio_iovcnt = 1;
uio.uio_loffset = pos;
uio.uio_limit = MAXOFFSET_T;
uio.uio_segflg = segment;
error = -zfs_read(ip, &uio, flags, cr);
if (error < 0)
return (error);
read = len - uio.uio_resid;
task_io_account_read(read);
return (read);
}
/**
* read_cache_pages - populate an address space with some pages & start reads against them
* @mapping: the address_space
* @pages: The address of a list_head which contains the target pages. These
* pages have their ->index populated and are otherwise uninitialised.
* @filler: callback routine for filling a single page.
* @data: private data for the callback routine.
*
* Hides the details of the LRU cache etc from the filesystems.
*/
int read_cache_pages(struct address_space *mapping, struct list_head *pages,
int (*filler)(void *, struct page *), void *data)
{
struct page *page;
int ret = 0;
while (!list_empty(pages)) {
page = list_to_page(pages);
list_del(&page->lru);
if (add_to_page_cache_lru(page, mapping,
page->index, GFP_KERNEL)) {
read_cache_pages_invalidate_page(mapping, page);
continue;
}
page_cache_release(page);
ret = filler(data, page);
if (unlikely(ret)) {
read_cache_pages_invalidate_pages(mapping, pages);
break;
}
task_io_account_read(PAGE_CACHE_SIZE);
}
return ret;
}