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-rw-r--r--block/fops.c307
1 files changed, 174 insertions, 133 deletions
diff --git a/block/fops.c b/block/fops.c
index ffce6f6c68dd..4e22b0794c82 100644
--- a/block/fops.c
+++ b/block/fops.c
@@ -14,9 +14,10 @@
#include <linux/task_io_accounting_ops.h>
#include <linux/falloc.h>
#include <linux/suspend.h>
+#include <linux/fs.h>
#include "blk.h"
-static struct inode *bdev_file_inode(struct file *file)
+static inline struct inode *bdev_file_inode(struct file *file)
{
return file->f_mapping->host;
}
@@ -53,14 +54,12 @@ static void blkdev_bio_end_io_simple(struct bio *bio)
static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
struct iov_iter *iter, unsigned int nr_pages)
{
- struct file *file = iocb->ki_filp;
- struct block_device *bdev = I_BDEV(bdev_file_inode(file));
+ struct block_device *bdev = iocb->ki_filp->private_data;
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;
if ((pos | iov_iter_alignment(iter)) &
(bdev_logical_block_size(bdev) - 1))
@@ -77,7 +76,7 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
bio_init(&bio, vecs, nr_pages);
bio_set_dev(&bio, bdev);
- bio.bi_iter.bi_sector = pos >> 9;
+ bio.bi_iter.bi_sector = pos >> SECTOR_SHIFT;
bio.bi_write_hint = iocb->ki_hint;
bio.bi_private = current;
bio.bi_end_io = blkdev_bio_end_io_simple;
@@ -101,13 +100,12 @@ static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
if (iocb->ki_flags & IOCB_HIPRI)
bio_set_polled(&bio, iocb);
- qc = submit_bio(&bio);
+ submit_bio(&bio);
for (;;) {
set_current_state(TASK_UNINTERRUPTIBLE);
if (!READ_ONCE(bio.bi_private))
break;
- if (!(iocb->ki_flags & IOCB_HIPRI) ||
- !blk_poll(bdev_get_queue(bdev), qc, true))
+ if (!(iocb->ki_flags & IOCB_HIPRI) || !bio_poll(&bio, NULL, 0))
blk_io_schedule();
}
__set_current_state(TASK_RUNNING);
@@ -125,6 +123,11 @@ out:
return ret;
}
+enum {
+ DIO_SHOULD_DIRTY = 1,
+ DIO_IS_SYNC = 2,
+};
+
struct blkdev_dio {
union {
struct kiocb *iocb;
@@ -132,35 +135,27 @@ struct blkdev_dio {
};
size_t size;
atomic_t ref;
- bool multi_bio : 1;
- bool should_dirty : 1;
- bool is_sync : 1;
- struct bio bio;
+ unsigned int flags;
+ struct bio bio ____cacheline_aligned_in_smp;
};
static struct bio_set blkdev_dio_pool;
-static int blkdev_iopoll(struct kiocb *kiocb, bool wait)
-{
- struct block_device *bdev = I_BDEV(kiocb->ki_filp->f_mapping->host);
- struct request_queue *q = bdev_get_queue(bdev);
-
- return blk_poll(q, READ_ONCE(kiocb->ki_cookie), wait);
-}
-
static void blkdev_bio_end_io(struct bio *bio)
{
struct blkdev_dio *dio = bio->bi_private;
- bool should_dirty = dio->should_dirty;
+ bool should_dirty = dio->flags & DIO_SHOULD_DIRTY;
if (bio->bi_status && !dio->bio.bi_status)
dio->bio.bi_status = bio->bi_status;
- if (!dio->multi_bio || atomic_dec_and_test(&dio->ref)) {
- if (!dio->is_sync) {
+ if (atomic_dec_and_test(&dio->ref)) {
+ if (!(dio->flags & DIO_IS_SYNC)) {
struct kiocb *iocb = dio->iocb;
ssize_t ret;
+ WRITE_ONCE(iocb->private, NULL);
+
if (likely(!dio->bio.bi_status)) {
ret = dio->size;
iocb->ki_pos += ret;
@@ -168,9 +163,8 @@ static void blkdev_bio_end_io(struct bio *bio)
ret = blk_status_to_errno(dio->bio.bi_status);
}
- dio->iocb->ki_complete(iocb, ret, 0);
- if (dio->multi_bio)
- bio_put(&dio->bio);
+ dio->iocb->ki_complete(iocb, ret);
+ bio_put(&dio->bio);
} else {
struct task_struct *waiter = dio->waiter;
@@ -190,16 +184,12 @@ static void blkdev_bio_end_io(struct bio *bio)
static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
unsigned int nr_pages)
{
- struct file *file = iocb->ki_filp;
- struct inode *inode = bdev_file_inode(file);
- struct block_device *bdev = I_BDEV(inode);
+ struct block_device *bdev = iocb->ki_filp->private_data;
struct blk_plug plug;
struct blkdev_dio *dio;
struct bio *bio;
- bool is_poll = (iocb->ki_flags & IOCB_HIPRI) != 0;
bool is_read = (iov_iter_rw(iter) == READ), is_sync;
loff_t pos = iocb->ki_pos;
- blk_qc_t qc = BLK_QC_T_NONE;
int ret = 0;
if ((pos | iov_iter_alignment(iter)) &
@@ -209,28 +199,31 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
bio = bio_alloc_kiocb(iocb, nr_pages, &blkdev_dio_pool);
dio = container_of(bio, struct blkdev_dio, bio);
- dio->is_sync = is_sync = is_sync_kiocb(iocb);
- if (dio->is_sync) {
+ atomic_set(&dio->ref, 1);
+ /*
+ * Grab an extra reference to ensure the dio structure which is embedded
+ * into the first bio stays around.
+ */
+ bio_get(bio);
+
+ is_sync = is_sync_kiocb(iocb);
+ if (is_sync) {
+ dio->flags = DIO_IS_SYNC;
dio->waiter = current;
- bio_get(bio);
} else {
+ dio->flags = 0;
dio->iocb = iocb;
}
dio->size = 0;
- dio->multi_bio = false;
- dio->should_dirty = is_read && iter_is_iovec(iter);
+ if (is_read && iter_is_iovec(iter))
+ dio->flags |= DIO_SHOULD_DIRTY;
- /*
- * Don't plug for HIPRI/polled IO, as those should go straight
- * to issue
- */
- if (!is_poll)
- blk_start_plug(&plug);
+ blk_start_plug(&plug);
for (;;) {
bio_set_dev(bio, bdev);
- bio->bi_iter.bi_sector = pos >> 9;
+ bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT;
bio->bi_write_hint = iocb->ki_hint;
bio->bi_private = dio;
bio->bi_end_io = blkdev_bio_end_io;
@@ -245,7 +238,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
if (is_read) {
bio->bi_opf = REQ_OP_READ;
- if (dio->should_dirty)
+ if (dio->flags & DIO_SHOULD_DIRTY)
bio_set_pages_dirty(bio);
} else {
bio->bi_opf = dio_bio_write_op(iocb);
@@ -259,40 +252,15 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS);
if (!nr_pages) {
- bool polled = false;
-
- if (iocb->ki_flags & IOCB_HIPRI) {
- bio_set_polled(bio, iocb);
- polled = true;
- }
-
- qc = submit_bio(bio);
-
- if (polled)
- WRITE_ONCE(iocb->ki_cookie, qc);
+ submit_bio(bio);
break;
}
-
- if (!dio->multi_bio) {
- /*
- * AIO needs an extra reference to ensure the dio
- * structure which is embedded into the first bio
- * stays around.
- */
- if (!is_sync)
- bio_get(bio);
- dio->multi_bio = true;
- atomic_set(&dio->ref, 2);
- } else {
- atomic_inc(&dio->ref);
- }
-
+ atomic_inc(&dio->ref);
submit_bio(bio);
bio = bio_alloc(GFP_KERNEL, nr_pages);
}
- if (!is_poll)
- blk_finish_plug(&plug);
+ blk_finish_plug(&plug);
if (!is_sync)
return -EIOCBQUEUED;
@@ -301,10 +269,7 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
set_current_state(TASK_UNINTERRUPTIBLE);
if (!READ_ONCE(dio->waiter))
break;
-
- if (!(iocb->ki_flags & IOCB_HIPRI) ||
- !blk_poll(bdev_get_queue(bdev), qc, true))
- blk_io_schedule();
+ blk_io_schedule();
}
__set_current_state(TASK_RUNNING);
@@ -317,6 +282,94 @@ static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
return ret;
}
+static void blkdev_bio_end_io_async(struct bio *bio)
+{
+ struct blkdev_dio *dio = container_of(bio, struct blkdev_dio, bio);
+ struct kiocb *iocb = dio->iocb;
+ ssize_t ret;
+
+ if (likely(!bio->bi_status)) {
+ ret = dio->size;
+ iocb->ki_pos += ret;
+ } else {
+ ret = blk_status_to_errno(bio->bi_status);
+ }
+
+ iocb->ki_complete(iocb, ret);
+
+ if (dio->flags & DIO_SHOULD_DIRTY) {
+ bio_check_pages_dirty(bio);
+ } else {
+ bio_release_pages(bio, false);
+ bio_put(bio);
+ }
+}
+
+static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb,
+ struct iov_iter *iter,
+ unsigned int nr_pages)
+{
+ struct block_device *bdev = iocb->ki_filp->private_data;
+ struct blkdev_dio *dio;
+ struct bio *bio;
+ loff_t pos = iocb->ki_pos;
+ int ret = 0;
+
+ if ((pos | iov_iter_alignment(iter)) &
+ (bdev_logical_block_size(bdev) - 1))
+ return -EINVAL;
+
+ bio = bio_alloc_kiocb(iocb, nr_pages, &blkdev_dio_pool);
+ dio = container_of(bio, struct blkdev_dio, bio);
+ dio->flags = 0;
+ dio->iocb = iocb;
+ bio_set_dev(bio, bdev);
+ bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT;
+ bio->bi_write_hint = iocb->ki_hint;
+ bio->bi_end_io = blkdev_bio_end_io_async;
+ bio->bi_ioprio = iocb->ki_ioprio;
+
+ if (iov_iter_is_bvec(iter)) {
+ /*
+ * Users don't rely on the iterator being in any particular
+ * state for async I/O returning -EIOCBQUEUED, hence we can
+ * avoid expensive iov_iter_advance(). Bypass
+ * bio_iov_iter_get_pages() and set the bvec directly.
+ */
+ bio_iov_bvec_set(bio, iter);
+ } else {
+ ret = bio_iov_iter_get_pages(bio, iter);
+ if (unlikely(ret)) {
+ bio->bi_status = BLK_STS_IOERR;
+ bio_endio(bio);
+ return ret;
+ }
+ }
+ dio->size = bio->bi_iter.bi_size;
+
+ if (iov_iter_rw(iter) == READ) {
+ bio->bi_opf = REQ_OP_READ;
+ if (iter_is_iovec(iter)) {
+ dio->flags |= DIO_SHOULD_DIRTY;
+ bio_set_pages_dirty(bio);
+ }
+ } else {
+ bio->bi_opf = dio_bio_write_op(iocb);
+ task_io_account_write(bio->bi_iter.bi_size);
+ }
+
+ if (iocb->ki_flags & IOCB_HIPRI) {
+ bio->bi_opf |= REQ_POLLED | REQ_NOWAIT;
+ submit_bio(bio);
+ WRITE_ONCE(iocb->private, bio);
+ } else {
+ if (iocb->ki_flags & IOCB_NOWAIT)
+ bio->bi_opf |= REQ_NOWAIT;
+ submit_bio(bio);
+ }
+ return -EIOCBQUEUED;
+}
+
static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
unsigned int nr_pages;
@@ -325,9 +378,11 @@ static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
return 0;
nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1);
- if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_VECS)
- return __blkdev_direct_IO_simple(iocb, iter, nr_pages);
-
+ if (likely(nr_pages <= BIO_MAX_VECS)) {
+ if (is_sync_kiocb(iocb))
+ return __blkdev_direct_IO_simple(iocb, iter, nr_pages);
+ return __blkdev_direct_IO_async(iocb, iter, nr_pages);
+ }
return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages));
}
@@ -404,8 +459,7 @@ static loff_t blkdev_llseek(struct file *file, loff_t offset, int whence)
static int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
int datasync)
{
- struct inode *bd_inode = bdev_file_inode(filp);
- struct block_device *bdev = I_BDEV(bd_inode);
+ struct block_device *bdev = filp->private_data;
int error;
error = file_write_and_wait_range(filp, start, end);
@@ -447,6 +501,8 @@ static int blkdev_open(struct inode *inode, struct file *filp)
bdev = blkdev_get_by_dev(inode->i_rdev, filp->f_mode, filp);
if (IS_ERR(bdev))
return PTR_ERR(bdev);
+
+ filp->private_data = bdev;
filp->f_mapping = bdev->bd_inode->i_mapping;
filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping);
return 0;
@@ -454,29 +510,12 @@ static int blkdev_open(struct inode *inode, struct file *filp)
static int blkdev_close(struct inode *inode, struct file *filp)
{
- struct block_device *bdev = I_BDEV(bdev_file_inode(filp));
+ struct block_device *bdev = filp->private_data;
blkdev_put(bdev, filp->f_mode);
return 0;
}
-static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
-{
- struct block_device *bdev = I_BDEV(bdev_file_inode(file));
- fmode_t mode = file->f_mode;
-
- /*
- * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
- * to updated it before every ioctl.
- */
- if (file->f_flags & O_NDELAY)
- mode |= FMODE_NDELAY;
- else
- mode &= ~FMODE_NDELAY;
-
- return blkdev_ioctl(bdev, mode, cmd, arg);
-}
-
/*
* Write data to the block device. Only intended for the block device itself
* and the raw driver which basically is a fake block device.
@@ -486,14 +525,14 @@ static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
*/
static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
- struct file *file = iocb->ki_filp;
- struct inode *bd_inode = bdev_file_inode(file);
+ struct block_device *bdev = iocb->ki_filp->private_data;
+ struct inode *bd_inode = bdev->bd_inode;
loff_t size = i_size_read(bd_inode);
struct blk_plug plug;
size_t shorted = 0;
ssize_t ret;
- if (bdev_read_only(I_BDEV(bd_inode)))
+ if (bdev_read_only(bdev))
return -EPERM;
if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev))
@@ -525,24 +564,26 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
- struct file *file = iocb->ki_filp;
- struct inode *bd_inode = bdev_file_inode(file);
- loff_t size = i_size_read(bd_inode);
+ struct block_device *bdev = iocb->ki_filp->private_data;
+ loff_t size = i_size_read(bdev->bd_inode);
loff_t pos = iocb->ki_pos;
size_t shorted = 0;
ssize_t ret;
- if (pos >= size)
- return 0;
-
- size -= pos;
- if (iov_iter_count(to) > size) {
- shorted = iov_iter_count(to) - size;
- iov_iter_truncate(to, size);
+ if (unlikely(pos + iov_iter_count(to) > size)) {
+ if (pos >= size)
+ return 0;
+ size -= pos;
+ if (iov_iter_count(to) > size) {
+ shorted = iov_iter_count(to) - size;
+ iov_iter_truncate(to, size);
+ }
}
ret = generic_file_read_iter(iocb, to);
- iov_iter_reexpand(to, iov_iter_count(to) + shorted);
+
+ if (unlikely(shorted))
+ iov_iter_reexpand(to, iov_iter_count(to) + shorted);
return ret;
}
@@ -553,7 +594,8 @@ static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
static long blkdev_fallocate(struct file *file, int mode, loff_t start,
loff_t len)
{
- struct block_device *bdev = I_BDEV(bdev_file_inode(file));
+ struct inode *inode = bdev_file_inode(file);
+ struct block_device *bdev = I_BDEV(inode);
loff_t end = start + len - 1;
loff_t isize;
int error;
@@ -563,7 +605,7 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start,
return -EOPNOTSUPP;
/* Don't go off the end of the device. */
- isize = i_size_read(bdev->bd_inode);
+ isize = bdev_nr_bytes(bdev);
if (start >= isize)
return -EINVAL;
if (end >= isize) {
@@ -580,37 +622,36 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start,
if ((start | len) & (bdev_logical_block_size(bdev) - 1))
return -EINVAL;
+ filemap_invalidate_lock(inode->i_mapping);
+
/* Invalidate the page cache, including dirty pages. */
error = truncate_bdev_range(bdev, file->f_mode, start, end);
if (error)
- return error;
+ goto fail;
switch (mode) {
case FALLOC_FL_ZERO_RANGE:
case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE:
- error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
- GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
+ error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT,
+ len >> SECTOR_SHIFT, GFP_KERNEL,
+ BLKDEV_ZERO_NOUNMAP);
break;
case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE:
- error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
- GFP_KERNEL, BLKDEV_ZERO_NOFALLBACK);
+ error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT,
+ len >> SECTOR_SHIFT, GFP_KERNEL,
+ BLKDEV_ZERO_NOFALLBACK);
break;
case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE:
- error = blkdev_issue_discard(bdev, start >> 9, len >> 9,
- GFP_KERNEL, 0);
+ error = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT,
+ len >> SECTOR_SHIFT, GFP_KERNEL, 0);
break;
default:
- return -EOPNOTSUPP;
+ error = -EOPNOTSUPP;
}
- if (error)
- return error;
- /*
- * Invalidate the page cache again; if someone wandered in and dirtied
- * a page, we just discard it - userspace has no way of knowing whether
- * the write happened before or after discard completing...
- */
- return truncate_bdev_range(bdev, file->f_mode, start, end);
+ fail:
+ filemap_invalidate_unlock(inode->i_mapping);
+ return error;
}
const struct file_operations def_blk_fops = {
@@ -619,10 +660,10 @@ const struct file_operations def_blk_fops = {
.llseek = blkdev_llseek,
.read_iter = blkdev_read_iter,
.write_iter = blkdev_write_iter,
- .iopoll = blkdev_iopoll,
+ .iopoll = iocb_bio_iopoll,
.mmap = generic_file_mmap,
.fsync = blkdev_fsync,
- .unlocked_ioctl = block_ioctl,
+ .unlocked_ioctl = blkdev_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = compat_blkdev_ioctl,
#endif
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.