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-rw-r--r--mm/cleancache.c2
-rw-r--r--mm/filemap.c64
-rw-r--r--mm/page_io.c4
-rw-r--r--mm/shmem.c2
4 files changed, 62 insertions, 10 deletions
diff --git a/mm/cleancache.c b/mm/cleancache.c
index ba5d8f3e6d68..f7b9fdc79d97 100644
--- a/mm/cleancache.c
+++ b/mm/cleancache.c
@@ -130,7 +130,7 @@ void __cleancache_init_shared_fs(struct super_block *sb)
int pool_id = CLEANCACHE_NO_BACKEND_SHARED;
if (cleancache_ops) {
- pool_id = cleancache_ops->init_shared_fs(sb->s_uuid, PAGE_SIZE);
+ pool_id = cleancache_ops->init_shared_fs(&sb->s_uuid, PAGE_SIZE);
if (pool_id < 0)
pool_id = CLEANCACHE_NO_POOL;
}
diff --git a/mm/filemap.c b/mm/filemap.c
index 926484561624..aea58e983a73 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -376,6 +376,38 @@ int filemap_flush(struct address_space *mapping)
}
EXPORT_SYMBOL(filemap_flush);
+/**
+ * filemap_range_has_page - check if a page exists in range.
+ * @mapping: address space within which to check
+ * @start_byte: offset in bytes where the range starts
+ * @end_byte: offset in bytes where the range ends (inclusive)
+ *
+ * Find at least one page in the range supplied, usually used to check if
+ * direct writing in this range will trigger a writeback.
+ */
+bool filemap_range_has_page(struct address_space *mapping,
+ loff_t start_byte, loff_t end_byte)
+{
+ pgoff_t index = start_byte >> PAGE_SHIFT;
+ pgoff_t end = end_byte >> PAGE_SHIFT;
+ struct pagevec pvec;
+ bool ret;
+
+ if (end_byte < start_byte)
+ return false;
+
+ if (mapping->nrpages == 0)
+ return false;
+
+ pagevec_init(&pvec, 0);
+ if (!pagevec_lookup(&pvec, mapping, index, 1))
+ return false;
+ ret = (pvec.pages[0]->index <= end);
+ pagevec_release(&pvec);
+ return ret;
+}
+EXPORT_SYMBOL(filemap_range_has_page);
+
static int __filemap_fdatawait_range(struct address_space *mapping,
loff_t start_byte, loff_t end_byte)
{
@@ -2038,10 +2070,17 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
loff_t size;
size = i_size_read(inode);
- retval = filemap_write_and_wait_range(mapping, iocb->ki_pos,
- iocb->ki_pos + count - 1);
- if (retval < 0)
- goto out;
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ if (filemap_range_has_page(mapping, iocb->ki_pos,
+ iocb->ki_pos + count - 1))
+ return -EAGAIN;
+ } else {
+ retval = filemap_write_and_wait_range(mapping,
+ iocb->ki_pos,
+ iocb->ki_pos + count - 1);
+ if (retval < 0)
+ goto out;
+ }
file_accessed(file);
@@ -2642,6 +2681,9 @@ inline ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from)
pos = iocb->ki_pos;
+ if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
+ return -EINVAL;
+
if (limit != RLIM_INFINITY) {
if (iocb->ki_pos >= limit) {
send_sig(SIGXFSZ, current, 0);
@@ -2710,9 +2752,17 @@ generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from)
write_len = iov_iter_count(from);
end = (pos + write_len - 1) >> PAGE_SHIFT;
- written = filemap_write_and_wait_range(mapping, pos, pos + write_len - 1);
- if (written)
- goto out;
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ /* If there are pages to writeback, return */
+ if (filemap_range_has_page(inode->i_mapping, pos,
+ pos + iov_iter_count(from)))
+ return -EAGAIN;
+ } else {
+ written = filemap_write_and_wait_range(mapping, pos,
+ pos + write_len - 1);
+ if (written)
+ goto out;
+ }
/*
* After a write we want buffered reads to be sure to go to disk to get
diff --git a/mm/page_io.c b/mm/page_io.c
index 23f6d0d3470f..2da71e627812 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -45,7 +45,7 @@ void end_swap_bio_write(struct bio *bio)
{
struct page *page = bio->bi_io_vec[0].bv_page;
- if (bio->bi_error) {
+ if (bio->bi_status) {
SetPageError(page);
/*
* We failed to write the page out to swap-space.
@@ -118,7 +118,7 @@ static void end_swap_bio_read(struct bio *bio)
{
struct page *page = bio->bi_io_vec[0].bv_page;
- if (bio->bi_error) {
+ if (bio->bi_status) {
SetPageError(page);
ClearPageUptodate(page);
pr_alert("Read-error on swap-device (%u:%u:%llu)\n",
diff --git a/mm/shmem.c b/mm/shmem.c
index fdc413f82a99..9100c4952698 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -75,6 +75,7 @@ static struct vfsmount *shm_mnt;
#include <uapi/linux/memfd.h>
#include <linux/userfaultfd_k.h>
#include <linux/rmap.h>
+#include <linux/uuid.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
@@ -3761,6 +3762,7 @@ int shmem_fill_super(struct super_block *sb, void *data, int silent)
#ifdef CONFIG_TMPFS_POSIX_ACL
sb->s_flags |= MS_POSIXACL;
#endif
+ uuid_gen(&sb->s_uuid);
inode = shmem_get_inode(sb, NULL, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE);
if (!inode)