From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
Switch from __blockdev_direct_IO() to iomap_dio_rw().
Rename btrfs_get_blocks_direct() to btrfs_dio_iomap_begin() and use it
as iomap_begin() for iomap direct I/O functions. This function
allocates and locks all the blocks required for the I/O.
btrfs_submit_direct() is used as the submit_io() hook for direct I/O
ops.
Since we need direct I/O reads to go through iomap_dio_rw(), we change
file_operations.read_iter() to a btrfs_file_read_iter() which calls
btrfs_direct_IO() for direct reads and falls back to
generic_file_buffered_read() for incomplete reads and buffered reads.
We don't need address_space.direct_IO() anymore so set it to noop.
Similarly, we don't need flags used in __blockdev_direct_IO(). iomap is
capable of direct I/O reads from a hole, so we don't need to return
-ENOENT.
BTRFS direct I/O is now done under i_rwsem, shared in case of reads and
exclusive in case of writes. This guards against simultaneous truncates.
Use iomap->iomap_end() to check for failed or incomplete direct I/O:
- for writes, call __endio_write_update_ordered()
- for reads, unlock extents
btrfs_dio_data is now hooked in iomap->private and not
current->journal_info. It carries the reservation variable and the
amount of data submitted, so we can calculate the amount of data to call
__endio_write_update_ordered in case of an error.
This patch removes last use of struct buffer_head from btrfs.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
---
fs/btrfs/Kconfig | 1 +
fs/btrfs/ctree.h | 1 +
fs/btrfs/file.c | 21 +++-
fs/btrfs/inode.c | 317 ++++++++++++++++++++++-------------------------
4 files changed, 170 insertions(+), 170 deletions(-)
diff --git a/fs/btrfs/Kconfig b/fs/btrfs/Kconfig
index 575636f6491e..68b95ad82126 100644
--- a/fs/btrfs/Kconfig
+++ b/fs/btrfs/Kconfig
@@ -14,6 +14,7 @@ config BTRFS_FS
select LZO_DECOMPRESS
select ZSTD_COMPRESS
select ZSTD_DECOMPRESS
+ select FS_IOMAP
select RAID6_PQ
select XOR_BLOCKS
select SRCU
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index d404cce8ae40..677f170434e3 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2935,6 +2935,7 @@ int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end);
void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start,
u64 end, int uptodate);
extern const struct dentry_operations btrfs_dentry_operations;
+ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter);
/* ioctl.c */
long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 2520605afc25..9d486350f1bf 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1835,7 +1835,7 @@ static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
loff_t endbyte;
int err;
- written = generic_file_direct_write(iocb, from);
+ written = btrfs_direct_IO(iocb, from);
if (written < 0 || !iov_iter_count(from))
return written;
@@ -3504,9 +3504,26 @@ static int btrfs_file_open(struct inode *inode, struct file *filp)
return generic_file_open(inode, filp);
}
+static ssize_t btrfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+ ssize_t ret = 0;
+
+ if (iocb->ki_flags & IOCB_DIRECT) {
+ struct inode *inode = file_inode(iocb->ki_filp);
+
+ inode_lock_shared(inode);
+ ret = btrfs_direct_IO(iocb, to);
+ inode_unlock_shared(inode);
+ if (ret < 0)
+ return ret;
+ }
+
+ return generic_file_buffered_read(iocb, to, ret);
+}
+
const struct file_operations btrfs_file_operations = {
.llseek = btrfs_file_llseek,
- .read_iter = generic_file_read_iter,
+ .read_iter = btrfs_file_read_iter,
.splice_read = generic_file_splice_read,
.write_iter = btrfs_file_write_iter,
.mmap = btrfs_file_mmap,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 18d384f4af54..0fa75af35a1f 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5,7 +5,6 @@
#include <linux/kernel.h>
#include <linux/bio.h>
-#include <linux/buffer_head.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
@@ -30,6 +29,7 @@
#include <linux/swap.h>
#include <linux/migrate.h>
#include <linux/sched/mm.h>
+#include <linux/iomap.h>
#include <asm/unaligned.h>
#include "misc.h"
#include "ctree.h"
@@ -58,9 +58,9 @@ struct btrfs_iget_args {
struct btrfs_dio_data {
u64 reserve;
- u64 unsubmitted_oe_range_start;
- u64 unsubmitted_oe_range_end;
- int overwrite;
+ loff_t length;
+ ssize_t submitted;
+ struct extent_changeset *data_reserved;
};
static const struct inode_operations btrfs_dir_inode_operations;
@@ -7069,7 +7069,7 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
}
static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
- struct extent_state **cached_state, int writing)
+ struct extent_state **cached_state, bool writing)
{
struct btrfs_ordered_extent *ordered;
int ret = 0;
@@ -7207,30 +7207,7 @@ static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
}
-static int btrfs_get_blocks_direct_read(struct extent_map *em,
- struct buffer_head *bh_result,
- struct inode *inode,
- u64 start, u64 len)
-{
- struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-
- if (em->block_start == EXTENT_MAP_HOLE ||
- test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
- return -ENOENT;
-
- len = min(len, em->len - (start - em->start));
-
- bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
- inode->i_blkbits;
- bh_result->b_size = len;
- bh_result->b_bdev = fs_info->fs_devices->latest_bdev;
- set_buffer_mapped(bh_result);
-
- return 0;
-}
-
static int btrfs_get_blocks_direct_write(struct extent_map **map,
- struct buffer_head *bh_result,
struct inode *inode,
struct btrfs_dio_data *dio_data,
u64 start, u64 len)
@@ -7292,7 +7269,6 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map,
}
/* this will cow the extent */
- len = bh_result->b_size;
free_extent_map(em);
*map = em = btrfs_new_extent_direct(inode, start, len);
if (IS_ERR(em)) {
@@ -7303,64 +7279,73 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map,
len = min(len, em->len - (start - em->start));
skip_cow:
- bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
- inode->i_blkbits;
- bh_result->b_size = len;
- bh_result->b_bdev = fs_info->fs_devices->latest_bdev;
- set_buffer_mapped(bh_result);
-
- if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
- set_buffer_new(bh_result);
-
/*
* Need to update the i_size under the extent lock so buffered
* readers will get the updated i_size when we unlock.
*/
- if (!dio_data->overwrite && start + len > i_size_read(inode))
+ if (start + len > i_size_read(inode))
i_size_write(inode, start + len);
- WARN_ON(dio_data->reserve < len);
dio_data->reserve -= len;
- dio_data->unsubmitted_oe_range_end = start + len;
- current->journal_info = dio_data;
out:
return ret;
}
-static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
- struct buffer_head *bh_result, int create)
+static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start,
+ loff_t length, unsigned int flags, struct iomap *iomap,
+ struct iomap *srcmap)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct extent_map *em;
struct extent_state *cached_state = NULL;
struct btrfs_dio_data *dio_data = NULL;
- u64 start = iblock << inode->i_blkbits;
u64 lockstart, lockend;
- u64 len = bh_result->b_size;
+ const bool write = !!(flags & IOMAP_WRITE);
int ret = 0;
+ u64 len = length;
+ bool unlock_extents = false;
- if (!create)
+ if (!write)
len = min_t(u64, len, fs_info->sectorsize);
lockstart = start;
lockend = start + len - 1;
- if (current->journal_info) {
- /*
- * Need to pull our outstanding extents and set journal_info to NULL so
- * that anything that needs to check if there's a transaction doesn't get
- * confused.
- */
- dio_data = current->journal_info;
- current->journal_info = NULL;
+ /*
+ * The generic stuff only does filemap_write_and_wait_range, which
+ * isn't enough if we've written compressed pages to this area, so we
+ * need to flush the dirty pages again to make absolutely sure that any
+ * outstanding dirty pages are on disk.
+ */
+ if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
+ &BTRFS_I(inode)->runtime_flags))
+ ret = filemap_fdatawrite_range(inode->i_mapping, start,
+ start + length - 1);
+
+ dio_data = kzalloc(sizeof(*dio_data), GFP_NOFS);
+ if (!dio_data)
+ return -ENOMEM;
+
+ dio_data->length = length;
+ if (write) {
+ dio_data->reserve = round_up(length, fs_info->sectorsize);
+ ret = btrfs_delalloc_reserve_space(inode,
+ &dio_data->data_reserved,
+ start, dio_data->reserve);
+ if (ret) {
+ extent_changeset_free(dio_data->data_reserved);
+ kfree(dio_data);
+ return ret;
+ }
}
+ iomap->private = dio_data;
+
/*
* If this errors out it's because we couldn't invalidate pagecache for
* this range and we need to fallback to buffered.
*/
- if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
- create)) {
+ if (lock_extent_direct(inode, lockstart, lockend, &cached_state, write)) {
ret = -ENOTBLK;
goto err;
}
@@ -7392,36 +7377,48 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
goto unlock_err;
}
- if (create) {
- ret = btrfs_get_blocks_direct_write(&em, bh_result, inode,
- dio_data, start, len);
+ len = min(len, em->len - (start - em->start));
+ if (write) {
+ ret = btrfs_get_blocks_direct_write(&em, inode, dio_data,
+ start, len);
if (ret < 0)
goto unlock_err;
-
- unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
- lockend, &cached_state);
+ unlock_extents = true;
+ /* Recalc len in case the new em is smaller than requested */
+ len = min(len, em->len - (start - em->start));
} else {
- ret = btrfs_get_blocks_direct_read(em, bh_result, inode,
- start, len);
- /* Can be negative only if we read from a hole */
- if (ret < 0) {
- ret = 0;
- free_extent_map(em);
- goto unlock_err;
- }
/*
* We need to unlock only the end area that we aren't using.
* The rest is going to be unlocked by the endio routine.
*/
- lockstart = start + bh_result->b_size;
- if (lockstart < lockend) {
- unlock_extent_cached(&BTRFS_I(inode)->io_tree,
- lockstart, lockend, &cached_state);
- } else {
- free_extent_state(cached_state);
- }
+ lockstart = start + len;
+ if (lockstart < lockend)
+ unlock_extents = true;
}
+ if (unlock_extents)
+ unlock_extent_cached(&BTRFS_I(inode)->io_tree,
+ lockstart, lockend, &cached_state);
+ else
+ free_extent_state(cached_state);
+
+ /*
+ * Translate extent map information to iomap.
+ * We trim the extents (and move the addr) even though iomap code does
+ * that, since we have locked only the parts we are performing I/O in.
+ */
+ if ((em->block_start == EXTENT_MAP_HOLE) ||
+ (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) && !write)) {
+ iomap->addr = IOMAP_NULL_ADDR;
+ iomap->type = IOMAP_HOLE;
+ } else {
+ iomap->addr = em->block_start + (start - em->start);
+ iomap->type = IOMAP_MAPPED;
+ }
+ iomap->offset = start;
+ iomap->bdev = fs_info->fs_devices->latest_bdev;
+ iomap->length = len;
+
free_extent_map(em);
return 0;
@@ -7430,8 +7427,53 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
&cached_state);
err:
- if (dio_data)
- current->journal_info = dio_data;
+ if (dio_data) {
+ btrfs_delalloc_release_space(inode, dio_data->data_reserved,
+ start, dio_data->reserve, true);
+ btrfs_delalloc_release_extents(BTRFS_I(inode), dio_data->reserve);
+ extent_changeset_free(dio_data->data_reserved);
+ kfree(dio_data);
+ }
+ return ret;
+}
+
+static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length,
+ ssize_t written, unsigned int flags, struct iomap *iomap)
+{
+ int ret = 0;
+ struct btrfs_dio_data *dio_data = iomap->private;
+ size_t submitted = dio_data->submitted;
+ const bool write = !!(flags & IOMAP_WRITE);
+
+ if (!write && (iomap->type == IOMAP_HOLE)) {
+ /* If reading from a hole, unlock and return */
+ unlock_extent(&BTRFS_I(inode)->io_tree, pos, pos + length - 1);
+ goto out;
+ }
+
+ if (submitted < length) {
+ pos += submitted;
+ length -= submitted;
+ if (write)
+ __endio_write_update_ordered(inode, pos, length, false);
+ else
+ unlock_extent(&BTRFS_I(inode)->io_tree, pos,
+ pos + length - 1);
+ ret = -ENOTBLK;
+ }
+
+ if (write) {
+ if (dio_data->reserve)
+ btrfs_delalloc_release_space(inode,
+ dio_data->data_reserved, pos,
+ dio_data->reserve, true);
+ btrfs_delalloc_release_extents(BTRFS_I(inode), dio_data->length);
+ extent_changeset_free(dio_data->data_reserved);
+ }
+out:
+ kfree(dio_data);
+ iomap->private = NULL;
+
return ret;
}
@@ -7454,7 +7496,7 @@ static void btrfs_dio_private_put(struct btrfs_dio_private *dip)
dip->logical_offset + dip->bytes - 1);
}
- dio_end_io(dip->dio_bio);
+ bio_endio(dip->dio_bio);
kfree(dip);
}
@@ -7690,24 +7732,11 @@ static struct btrfs_dio_private *btrfs_create_dio_private(struct bio *dio_bio,
dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
dip->dio_bio = dio_bio;
refcount_set(&dip->refs, 1);
-
- if (write) {
- struct btrfs_dio_data *dio_data = current->journal_info;
-
- /*
- * Setting range start and end to the same value means that
- * no cleanup will happen in btrfs_direct_IO
- */
- dio_data->unsubmitted_oe_range_end = dip->logical_offset +
- dip->bytes;
- dio_data->unsubmitted_oe_range_start =
- dio_data->unsubmitted_oe_range_end;
- }
return dip;
}
-static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
- loff_t file_offset)
+static blk_qc_t btrfs_submit_direct(struct inode *inode, struct iomap *iomap,
+ struct bio *dio_bio, loff_t file_offset)
{
const bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
const bool csum = !(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM);
@@ -7724,6 +7753,7 @@ static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
int ret;
blk_status_t status;
struct btrfs_io_geometry geom;
+ struct btrfs_dio_data *dio_data = iomap->private;
dip = btrfs_create_dio_private(dio_bio, inode, file_offset);
if (!dip) {
@@ -7732,8 +7762,8 @@ static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
file_offset + dio_bio->bi_iter.bi_size - 1);
}
dio_bio->bi_status = BLK_STS_RESOURCE;
- dio_end_io(dio_bio);
- return;
+ bio_endio(dio_bio);
+ return BLK_QC_T_NONE;
}
if (!write && csum) {
@@ -7804,15 +7834,17 @@ static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
goto out_err;
}
+ dio_data->submitted += clone_len;
clone_offset += clone_len;
start_sector += clone_len >> 9;
file_offset += clone_len;
} while (submit_len > 0);
- return;
+ return BLK_QC_T_NONE;
out_err:
dip->dio_bio->bi_status = status;
btrfs_dio_private_put(dip);
+ return BLK_QC_T_NONE;
}
static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
@@ -7848,37 +7880,31 @@ static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
return retval;
}
-static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
+static const struct iomap_ops btrfs_dio_iomap_ops = {
+ .iomap_begin = btrfs_dio_iomap_begin,
+ .iomap_end = btrfs_dio_iomap_end,
+};
+
+static const struct iomap_dio_ops btrfs_dops = {
+ .submit_io = btrfs_submit_direct,
+};
+
+ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
- struct btrfs_dio_data dio_data = { 0 };
struct extent_changeset *data_reserved = NULL;
loff_t offset = iocb->ki_pos;
size_t count = 0;
- int flags = 0;
- bool wakeup = true;
bool relock = false;
ssize_t ret;
+ int flags = IOMAP_DIO_RWF_NO_STALE_PAGECACHE;
if (check_direct_IO(fs_info, iter, offset))
return 0;
- inode_dio_begin(inode);
-
- /*
- * The generic stuff only does filemap_write_and_wait_range, which
- * isn't enough if we've written compressed pages to this area, so
- * we need to flush the dirty pages again to make absolutely sure
- * that any outstanding dirty pages are on disk.
- */
count = iov_iter_count(iter);
- if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
- &BTRFS_I(inode)->runtime_flags))
- filemap_fdatawrite_range(inode->i_mapping, offset,
- offset + count - 1);
-
if (iov_iter_rw(iter) == WRITE) {
/*
* If the write DIO is beyond the EOF, we need update
@@ -7886,68 +7912,23 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
* not unlock the i_mutex at this case.
*/
if (offset + count <= inode->i_size) {
- dio_data.overwrite = 1;
inode_unlock(inode);
relock = true;
}
- ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
- offset, count);
- if (ret)
- goto out;
-
- /*
- * We need to know how many extents we reserved so that we can
- * do the accounting properly if we go over the number we
- * originally calculated. Abuse current->journal_info for this.
- */
- dio_data.reserve = round_up(count,
- fs_info->sectorsize);
- dio_data.unsubmitted_oe_range_start = (u64)offset;
- dio_data.unsubmitted_oe_range_end = (u64)offset;
- current->journal_info = &dio_data;
down_read(&BTRFS_I(inode)->dio_sem);
- } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
- &BTRFS_I(inode)->runtime_flags)) {
- inode_dio_end(inode);
- flags = DIO_LOCKING | DIO_SKIP_HOLES;
- wakeup = false;
}
- ret = __blockdev_direct_IO(iocb, inode,
- fs_info->fs_devices->latest_bdev,
- iter, btrfs_get_blocks_direct, NULL,
- btrfs_submit_direct, flags);
+ if (is_sync_kiocb(iocb))
+ flags |= IOMAP_DIO_RWF_SYNCIO;
+
+ ret = iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dops,
+ flags);
+
if (iov_iter_rw(iter) == WRITE) {
up_read(&BTRFS_I(inode)->dio_sem);
- current->journal_info = NULL;
- if (ret < 0 && ret != -EIOCBQUEUED) {
- if (dio_data.reserve)
- btrfs_delalloc_release_space(inode, data_reserved,
- offset, dio_data.reserve, true);
- /*
- * On error we might have left some ordered extents
- * without submitting corresponding bios for them, so
- * cleanup them up to avoid other tasks getting them
- * and waiting for them to complete forever.
- */
- if (dio_data.unsubmitted_oe_range_start <
- dio_data.unsubmitted_oe_range_end)
- __endio_write_update_ordered(inode,
- dio_data.unsubmitted_oe_range_start,
- dio_data.unsubmitted_oe_range_end -
- dio_data.unsubmitted_oe_range_start,
- false);
- } else if (ret >= 0 && (size_t)ret < count)
- btrfs_delalloc_release_space(inode, data_reserved,
- offset, count - (size_t)ret, true);
- btrfs_delalloc_release_extents(BTRFS_I(inode), count);
}
-out:
- if (wakeup)
- inode_dio_end(inode);
if (relock)
inode_lock(inode);
-
extent_changeset_free(data_reserved);
return ret;
}
@@ -10246,7 +10227,7 @@ static const struct address_space_operations btrfs_aops = {
.writepage = btrfs_writepage,
.writepages = btrfs_writepages,
.readahead = btrfs_readahead,
- .direct_IO = btrfs_direct_IO,
+ .direct_IO = noop_direct_IO,
.invalidatepage = btrfs_invalidatepage,
.releasepage = btrfs_releasepage,
#ifdef CONFIG_MIGRATION
--
2.26.2
