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-rw-r--r--fs/block_dev.c120
1 files changed, 79 insertions, 41 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 0f7552a87d54..c2a85b587922 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/fs/block_dev.c
*
@@ -25,6 +26,7 @@
#include <linux/writeback.h>
#include <linux/mpage.h>
#include <linux/mount.h>
+#include <linux/pseudo_fs.h>
#include <linux/uio.h>
#include <linux/namei.h>
#include <linux/log2.h>
@@ -202,13 +204,12 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
{
struct file *file = iocb->ki_filp;
struct block_device *bdev = I_BDEV(bdev_file_inode(file));
- struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs, *bvec;
+ struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs;
loff_t pos = iocb->ki_pos;
bool should_dirty = false;
struct bio bio;
ssize_t ret;
blk_qc_t qc;
- struct bvec_iter_all iter_all;
if ((pos | iov_iter_alignment(iter)) &
(bdev_logical_block_size(bdev) - 1))
@@ -258,13 +259,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
}
__set_current_state(TASK_RUNNING);
- bio_for_each_segment_all(bvec, &bio, iter_all) {
- if (should_dirty && !PageCompound(bvec->bv_page))
- set_page_dirty_lock(bvec->bv_page);
- if (!bio_flagged(&bio, BIO_NO_PAGE_REF))
- put_page(bvec->bv_page);
- }
-
+ bio_release_pages(&bio, should_dirty);
if (unlikely(bio.bi_status))
ret = blk_status_to_errno(bio.bi_status);
@@ -334,13 +329,7 @@ static void blkdev_bio_end_io(struct bio *bio)
if (should_dirty) {
bio_check_pages_dirty(bio);
} else {
- if (!bio_flagged(bio, BIO_NO_PAGE_REF)) {
- struct bvec_iter_all iter_all;
- struct bio_vec *bvec;
-
- bio_for_each_segment_all(bvec, bio, iter_all)
- put_page(bvec->bv_page);
- }
+ bio_release_pages(bio, false);
bio_put(bio);
}
}
@@ -356,15 +345,24 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
struct bio *bio;
bool is_poll = (iocb->ki_flags & IOCB_HIPRI) != 0;
bool is_read = (iov_iter_rw(iter) == READ), is_sync;
+ bool nowait = (iocb->ki_flags & IOCB_NOWAIT) != 0;
loff_t pos = iocb->ki_pos;
blk_qc_t qc = BLK_QC_T_NONE;
- int ret = 0;
+ gfp_t gfp;
+ ssize_t ret;
if ((pos | iov_iter_alignment(iter)) &
(bdev_logical_block_size(bdev) - 1))
return -EINVAL;
- bio = bio_alloc_bioset(GFP_KERNEL, nr_pages, &blkdev_dio_pool);
+ if (nowait)
+ gfp = GFP_NOWAIT;
+ else
+ gfp = GFP_KERNEL;
+
+ bio = bio_alloc_bioset(gfp, nr_pages, &blkdev_dio_pool);
+ if (!bio)
+ return -EAGAIN;
dio = container_of(bio, struct blkdev_dio, bio);
dio->is_sync = is_sync = is_sync_kiocb(iocb);
@@ -386,7 +384,10 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
if (!is_poll)
blk_start_plug(&plug);
+ ret = 0;
for (;;) {
+ int err;
+
bio_set_dev(bio, bdev);
bio->bi_iter.bi_sector = pos >> 9;
bio->bi_write_hint = iocb->ki_hint;
@@ -394,8 +395,10 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
bio->bi_end_io = blkdev_bio_end_io;
bio->bi_ioprio = iocb->ki_ioprio;
- ret = bio_iov_iter_get_pages(bio, iter);
- if (unlikely(ret)) {
+ err = bio_iov_iter_get_pages(bio, iter);
+ if (unlikely(err)) {
+ if (!ret)
+ ret = err;
bio->bi_status = BLK_STS_IOERR;
bio_endio(bio);
break;
@@ -410,6 +413,14 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
task_io_account_write(bio->bi_iter.bi_size);
}
+ /*
+ * Tell underlying layer to not block for resource shortage.
+ * And if we would have blocked, return error inline instead
+ * of through the bio->bi_end_io() callback.
+ */
+ if (nowait)
+ bio->bi_opf |= (REQ_NOWAIT | REQ_NOWAIT_INLINE);
+
dio->size += bio->bi_iter.bi_size;
pos += bio->bi_iter.bi_size;
@@ -423,6 +434,11 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
}
qc = submit_bio(bio);
+ if (qc == BLK_QC_T_EAGAIN) {
+ if (!ret)
+ ret = -EAGAIN;
+ goto error;
+ }
if (polled)
WRITE_ONCE(iocb->ki_cookie, qc);
@@ -443,8 +459,20 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
atomic_inc(&dio->ref);
}
- submit_bio(bio);
- bio = bio_alloc(GFP_KERNEL, nr_pages);
+ qc = submit_bio(bio);
+ if (qc == BLK_QC_T_EAGAIN) {
+ if (!ret)
+ ret = -EAGAIN;
+ goto error;
+ }
+ ret += bio->bi_iter.bi_size;
+
+ bio = bio_alloc(gfp, nr_pages);
+ if (!bio) {
+ if (!ret)
+ ret = -EAGAIN;
+ goto error;
+ }
}
if (!is_poll)
@@ -464,13 +492,16 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
}
__set_current_state(TASK_RUNNING);
+out:
if (!ret)
ret = blk_status_to_errno(dio->bio.bi_status);
- if (likely(!ret))
- ret = dio->size;
bio_put(&dio->bio);
return ret;
+error:
+ if (!is_poll)
+ blk_finish_plug(&plug);
+ goto out;
}
static ssize_t
@@ -833,19 +864,19 @@ static const struct super_operations bdev_sops = {
.evict_inode = bdev_evict_inode,
};
-static struct dentry *bd_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data)
+static int bd_init_fs_context(struct fs_context *fc)
{
- struct dentry *dent;
- dent = mount_pseudo(fs_type, "bdev:", &bdev_sops, NULL, BDEVFS_MAGIC);
- if (!IS_ERR(dent))
- dent->d_sb->s_iflags |= SB_I_CGROUPWB;
- return dent;
+ struct pseudo_fs_context *ctx = init_pseudo(fc, BDEVFS_MAGIC);
+ if (!ctx)
+ return -ENOMEM;
+ fc->s_iflags |= SB_I_CGROUPWB;
+ ctx->ops = &bdev_sops;
+ return 0;
}
static struct file_system_type bd_type = {
.name = "bdev",
- .mount = bd_mount,
+ .init_fs_context = bd_init_fs_context,
.kill_sb = kill_anon_super,
};
@@ -1405,20 +1436,27 @@ void check_disk_size_change(struct gendisk *disk, struct block_device *bdev,
*/
int revalidate_disk(struct gendisk *disk)
{
- struct block_device *bdev;
int ret = 0;
if (disk->fops->revalidate_disk)
ret = disk->fops->revalidate_disk(disk);
- bdev = bdget_disk(disk, 0);
- if (!bdev)
- return ret;
- mutex_lock(&bdev->bd_mutex);
- check_disk_size_change(disk, bdev, ret == 0);
- bdev->bd_invalidated = 0;
- mutex_unlock(&bdev->bd_mutex);
- bdput(bdev);
+ /*
+ * Hidden disks don't have associated bdev so there's no point in
+ * revalidating it.
+ */
+ if (!(disk->flags & GENHD_FL_HIDDEN)) {
+ struct block_device *bdev = bdget_disk(disk, 0);
+
+ if (!bdev)
+ return ret;
+
+ mutex_lock(&bdev->bd_mutex);
+ check_disk_size_change(disk, bdev, ret == 0);
+ bdev->bd_invalidated = 0;
+ mutex_unlock(&bdev->bd_mutex);
+ bdput(bdev);
+ }
return ret;
}
EXPORT_SYMBOL(revalidate_disk);
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-06-12 10:06:24 +0200