| Message ID | 20191210230155.22688-5-rgoldwyn@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs direct-io using iomap | expand |
On Tue, Dec 10, 2019 at 11:02 PM Goldwyn Rodrigues <rgoldwyn@suse.de> wrote: > > From: Goldwyn Rodrigues <rgoldwyn@suse.com> > > 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. > > Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> > --- > fs/btrfs/ctree.h | 1 + > fs/btrfs/file.c | 21 ++++++- > fs/btrfs/inode.c | 184 ++++++++++++++++++++++++++----------------------------- > 3 files changed, 107 insertions(+), 99 deletions(-) > > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h > index b2e8fd8a8e59..113dcd1a11cd 100644 > --- a/fs/btrfs/ctree.h > +++ b/fs/btrfs/ctree.h > @@ -2904,6 +2904,7 @@ 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 0cb43b682789..7010dd7beccc 100644 > --- a/fs/btrfs/file.c > +++ b/fs/btrfs/file.c > @@ -1832,7 +1832,7 @@ 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; > @@ -3444,9 +3444,26 @@ 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 56032c518b26..86730f2f2bf6 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -29,6 +29,7 @@ > #include <linux/iversion.h> > #include <linux/swap.h> > #include <linux/sched/mm.h> > +#include <linux/iomap.h> > #include <asm/unaligned.h> > #include "misc.h" > #include "ctree.h" > @@ -7510,7 +7511,7 @@ 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; > @@ -7648,30 +7649,7 @@ 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) > @@ -7733,7 +7711,6 @@ 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)) { > @@ -7744,15 +7721,6 @@ 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. > @@ -7768,24 +7736,37 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map, > 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 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; > + 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; > > + /* > + * 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); > + > if (current->journal_info) { > /* > * Need to pull our outstanding extents and set journal_info to NULL so > @@ -7801,7 +7782,7 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, > * this range and we need to fallback to buffered. > */ > if (lock_extent_direct(inode, lockstart, lockend, &cached_state, > - create)) { > + write)) { > ret = -ENOTBLK; > goto err; > } > @@ -7833,36 +7814,53 @@ 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, > + 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 if (em->block_start == EXTENT_MAP_HOLE || > + test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) { > + /* Unlock in case of direct reading from a hole */ > + unlock_extents = true; > } 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; > @@ -8230,9 +8228,8 @@ static void btrfs_endio_direct_read(struct bio *bio) > kfree(dip); > > dio_bio->bi_status = err; > - dio_end_io(dio_bio); > + bio_endio(dio_bio); > btrfs_io_bio_free_csum(io_bio); > - bio_put(bio); > } > > static void __endio_write_update_ordered(struct inode *inode, > @@ -8289,8 +8286,7 @@ static void btrfs_endio_direct_write(struct bio *bio) > kfree(dip); > > dio_bio->bi_status = bio->bi_status; > - dio_end_io(dio_bio); > - bio_put(bio); > + bio_endio(dio_bio); > } > > static blk_status_t btrfs_submit_bio_start_direct_io(void *private_data, > @@ -8522,9 +8518,10 @@ static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip) > return 0; > } > > -static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode, > +static blk_qc_t btrfs_submit_direct(struct bio *dio_bio, struct file *file, > loff_t file_offset) > { > + struct inode *inode = file_inode(file); > struct btrfs_dio_private *dip = NULL; > struct bio *bio = NULL; > struct btrfs_io_bio *io_bio; > @@ -8575,7 +8572,7 @@ static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode, > > ret = btrfs_submit_direct_hook(dip); > if (!ret) > - return; > + return BLK_QC_T_NONE; > > btrfs_io_bio_free_csum(io_bio); > > @@ -8594,7 +8591,7 @@ static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode, > /* > * The end io callbacks free our dip, do the final put on bio > * and all the cleanup and final put for dio_bio (through > - * dio_end_io()). > + * end_io()). > */ > dip = NULL; > bio = NULL; > @@ -8613,11 +8610,12 @@ static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode, > * Releases and cleans up our dio_bio, no need to bio_put() > * nor bio_endio()/bio_io_error() against dio_bio. > */ > - dio_end_io(dio_bio); > + bio_endio(dio_bio); Same as before, the comment is now stale. It mentions no need to call bio_endio(), yet the change makes it call bio_endio(). thanks > } > if (bio) > bio_put(bio); > kfree(dip); > + return BLK_QC_T_NONE; > } > > static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info, > @@ -8653,7 +8651,23 @@ 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, > +}; > + > +static const struct iomap_dio_ops btrfs_dops = { > + .submit_io = btrfs_submit_direct, > +}; > + > + > +/* > + * btrfs_direct_IO - perform direct I/O > + * inode->i_rwsem must be locked before calling this function, shared or exclusive. > + * @iocb - kernel iocb > + * @iter - iter to/from data is copied > + */ > + > +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; > @@ -8662,28 +8676,13 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) > 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; > > 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 > @@ -8714,17 +8713,11 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) > 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); > + ret = iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dops, > + is_sync_kiocb(iocb)); > + > if (iov_iter_rw(iter) == WRITE) { > up_read(&BTRFS_I(inode)->dio_sem); > current->journal_info = NULL; > @@ -8751,11 +8744,8 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) > 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; > } > @@ -11045,7 +11035,7 @@ static const struct address_space_operations btrfs_aops = { > .writepage = btrfs_writepage, > .writepages = btrfs_writepages, > .readpages = btrfs_readpages, > - .direct_IO = btrfs_direct_IO, > + .direct_IO = noop_direct_IO, > .invalidatepage = btrfs_invalidatepage, > .releasepage = btrfs_releasepage, > .set_page_dirty = btrfs_set_page_dirty, > -- > 2.16.4 >
On 11.12.19 г. 1:01 ч., Goldwyn Rodrigues wrote: > From: Goldwyn Rodrigues <rgoldwyn@suse.com> > > 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. > > Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> > --- > fs/btrfs/ctree.h | 1 + > fs/btrfs/file.c | 21 ++++++- > fs/btrfs/inode.c | 184 ++++++++++++++++++++++++++----------------------------- > 3 files changed, 107 insertions(+), 99 deletions(-) > <snip> > + > +/* > + * btrfs_direct_IO - perform direct I/O > + * inode->i_rwsem must be locked before calling this function, shared or exclusive. Instead of having this as a comment which cannot easily be checked automatically I'd rather it gets codified via lockdep_assert_held. I believe this is in line with Dave's comment comment on patch 3. > + * @iocb - kernel iocb > + * @iter - iter to/from data is copied > + */ > + > +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; > @@ -8662,28 +8676,13 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) > 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; > > 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 > @@ -8714,17 +8713,11 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) > 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); > + ret = iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dops, > + is_sync_kiocb(iocb)); > + > if (iov_iter_rw(iter) == WRITE) { > up_read(&BTRFS_I(inode)->dio_sem); > current->journal_info = NULL; > @@ -8751,11 +8744,8 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) > 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; > } > @@ -11045,7 +11035,7 @@ static const struct address_space_operations btrfs_aops = { > .writepage = btrfs_writepage, > .writepages = btrfs_writepages, > .readpages = btrfs_readpages, > - .direct_IO = btrfs_direct_IO, > + .direct_IO = noop_direct_IO, > .invalidatepage = btrfs_invalidatepage, > .releasepage = btrfs_releasepage, > .set_page_dirty = btrfs_set_page_dirty, >
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index b2e8fd8a8e59..113dcd1a11cd 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -2904,6 +2904,7 @@ 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 0cb43b682789..7010dd7beccc 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1832,7 +1832,7 @@ 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; @@ -3444,9 +3444,26 @@ 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 56032c518b26..86730f2f2bf6 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -29,6 +29,7 @@ #include <linux/iversion.h> #include <linux/swap.h> #include <linux/sched/mm.h> +#include <linux/iomap.h> #include <asm/unaligned.h> #include "misc.h" #include "ctree.h" @@ -7510,7 +7511,7 @@ 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; @@ -7648,30 +7649,7 @@ 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) @@ -7733,7 +7711,6 @@ 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)) { @@ -7744,15 +7721,6 @@ 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. @@ -7768,24 +7736,37 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map, 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 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; + 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; + /* + * 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); + if (current->journal_info) { /* * Need to pull our outstanding extents and set journal_info to NULL so @@ -7801,7 +7782,7 @@ static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock, * this range and we need to fallback to buffered. */ if (lock_extent_direct(inode, lockstart, lockend, &cached_state, - create)) { + write)) { ret = -ENOTBLK; goto err; } @@ -7833,36 +7814,53 @@ 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, + 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 if (em->block_start == EXTENT_MAP_HOLE || + test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) { + /* Unlock in case of direct reading from a hole */ + unlock_extents = true; } 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; @@ -8230,9 +8228,8 @@ static void btrfs_endio_direct_read(struct bio *bio) kfree(dip); dio_bio->bi_status = err; - dio_end_io(dio_bio); + bio_endio(dio_bio); btrfs_io_bio_free_csum(io_bio); - bio_put(bio); } static void __endio_write_update_ordered(struct inode *inode, @@ -8289,8 +8286,7 @@ static void btrfs_endio_direct_write(struct bio *bio) kfree(dip); dio_bio->bi_status = bio->bi_status; - dio_end_io(dio_bio); - bio_put(bio); + bio_endio(dio_bio); } static blk_status_t btrfs_submit_bio_start_direct_io(void *private_data, @@ -8522,9 +8518,10 @@ static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip) return 0; } -static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode, +static blk_qc_t btrfs_submit_direct(struct bio *dio_bio, struct file *file, loff_t file_offset) { + struct inode *inode = file_inode(file); struct btrfs_dio_private *dip = NULL; struct bio *bio = NULL; struct btrfs_io_bio *io_bio; @@ -8575,7 +8572,7 @@ static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode, ret = btrfs_submit_direct_hook(dip); if (!ret) - return; + return BLK_QC_T_NONE; btrfs_io_bio_free_csum(io_bio); @@ -8594,7 +8591,7 @@ static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode, /* * The end io callbacks free our dip, do the final put on bio * and all the cleanup and final put for dio_bio (through - * dio_end_io()). + * end_io()). */ dip = NULL; bio = NULL; @@ -8613,11 +8610,12 @@ static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode, * Releases and cleans up our dio_bio, no need to bio_put() * nor bio_endio()/bio_io_error() against dio_bio. */ - dio_end_io(dio_bio); + bio_endio(dio_bio); } if (bio) bio_put(bio); kfree(dip); + return BLK_QC_T_NONE; } static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info, @@ -8653,7 +8651,23 @@ 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, +}; + +static const struct iomap_dio_ops btrfs_dops = { + .submit_io = btrfs_submit_direct, +}; + + +/* + * btrfs_direct_IO - perform direct I/O + * inode->i_rwsem must be locked before calling this function, shared or exclusive. + * @iocb - kernel iocb + * @iter - iter to/from data is copied + */ + +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; @@ -8662,28 +8676,13 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 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; 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 @@ -8714,17 +8713,11 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 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); + ret = iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dops, + is_sync_kiocb(iocb)); + if (iov_iter_rw(iter) == WRITE) { up_read(&BTRFS_I(inode)->dio_sem); current->journal_info = NULL; @@ -8751,11 +8744,8 @@ static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) 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; } @@ -11045,7 +11035,7 @@ static const struct address_space_operations btrfs_aops = { .writepage = btrfs_writepage, .writepages = btrfs_writepages, .readpages = btrfs_readpages, - .direct_IO = btrfs_direct_IO, + .direct_IO = noop_direct_IO, .invalidatepage = btrfs_invalidatepage, .releasepage = btrfs_releasepage, .set_page_dirty = btrfs_set_page_dirty,