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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-15 08:35:31 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-15 08:35:31 +0300 |
commit | 5cc60aeedf315a7513f92e98314e86d515b986d1 (patch) | |
tree | c83e252b8e2ad2cd42cbbb7974348290831dbb2a /fs/iomap.c | |
parent | 5c2992ee7fd8a29d04125dc0aa3522784c5fa5eb (diff) | |
parent | 9807b773dad4555665931d57065d7f8adab58e0f (diff) | |
download | linux-5cc60aeedf315a7513f92e98314e86d515b986d1.tar.xz |
Merge tag 'xfs-for-linus-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs
Pull xfs updates from Dave Chinner:
"There is quite a varied bunch of stuff in this update, and some of it
you will have already merged through the ext4 tree which imported the
dax-4.10-iomap-pmd topic branch from the XFS tree.
There is also a new direct IO implementation that uses the iomap
infrastructure. It's much simpler, faster, and has lower IO latency
than the existing direct IO infrastructure.
Summary:
- DAX PMD faults via iomap infrastructure
- Direct-io support in iomap infrastructure
- removal of now-redundant XFS inode iolock, replaced with VFS
i_rwsem
- synchronisation with fixes and changes in userspace libxfs code
- extent tree lookup helpers
- lots of little corruption detection improvements to verifiers
- optimised CRC calculations
- faster buffer cache lookups
- deprecation of barrier/nobarrier mount options - we always use
REQ_FUA/REQ_FLUSH where appropriate for data integrity now
- cleanups to speculative preallocation
- miscellaneous minor bug fixes and cleanups"
* tag 'xfs-for-linus-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (63 commits)
xfs: nuke unused tracepoint definitions
xfs: use GPF_NOFS when allocating btree cursors
xfs: use xfs_vn_setattr_size to check on new size
xfs: deprecate barrier/nobarrier mount option
xfs: Always flush caches when integrity is required
xfs: ignore leaf attr ichdr.count in verifier during log replay
xfs: use rhashtable to track buffer cache
xfs: optimise CRC updates
xfs: make xfs btree stats less huge
xfs: don't cap maximum dedupe request length
xfs: don't allow di_size with high bit set
xfs: error out if trying to add attrs and anextents > 0
xfs: don't crash if reading a directory results in an unexpected hole
xfs: complain if we don't get nextents bmap records
xfs: check for bogus values in btree block headers
xfs: forbid AG btrees with level == 0
xfs: several xattr functions can be void
xfs: handle cow fork in xfs_bmap_trace_exlist
xfs: pass state not whichfork to trace_xfs_extlist
xfs: Move AGI buffer type setting to xfs_read_agi
...
Diffstat (limited to 'fs/iomap.c')
-rw-r--r-- | fs/iomap.c | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/fs/iomap.c b/fs/iomap.c index 13dd413b2b9c..354a123f170e 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -24,6 +24,7 @@ #include <linux/uio.h> #include <linux/backing-dev.h> #include <linux/buffer_head.h> +#include <linux/task_io_accounting_ops.h> #include <linux/dax.h> #include "internal.h" @@ -584,3 +585,375 @@ int iomap_fiemap(struct inode *inode, struct fiemap_extent_info *fi, return 0; } EXPORT_SYMBOL_GPL(iomap_fiemap); + +/* + * Private flags for iomap_dio, must not overlap with the public ones in + * iomap.h: + */ +#define IOMAP_DIO_WRITE (1 << 30) +#define IOMAP_DIO_DIRTY (1 << 31) + +struct iomap_dio { + struct kiocb *iocb; + iomap_dio_end_io_t *end_io; + loff_t i_size; + loff_t size; + atomic_t ref; + unsigned flags; + int error; + + union { + /* used during submission and for synchronous completion: */ + struct { + struct iov_iter *iter; + struct task_struct *waiter; + struct request_queue *last_queue; + blk_qc_t cookie; + } submit; + + /* used for aio completion: */ + struct { + struct work_struct work; + } aio; + }; +}; + +static ssize_t iomap_dio_complete(struct iomap_dio *dio) +{ + struct kiocb *iocb = dio->iocb; + ssize_t ret; + + if (dio->end_io) { + ret = dio->end_io(iocb, + dio->error ? dio->error : dio->size, + dio->flags); + } else { + ret = dio->error; + } + + if (likely(!ret)) { + ret = dio->size; + /* check for short read */ + if (iocb->ki_pos + ret > dio->i_size && + !(dio->flags & IOMAP_DIO_WRITE)) + ret = dio->i_size - iocb->ki_pos; + iocb->ki_pos += ret; + } + + inode_dio_end(file_inode(iocb->ki_filp)); + kfree(dio); + + return ret; +} + +static void iomap_dio_complete_work(struct work_struct *work) +{ + struct iomap_dio *dio = container_of(work, struct iomap_dio, aio.work); + struct kiocb *iocb = dio->iocb; + bool is_write = (dio->flags & IOMAP_DIO_WRITE); + ssize_t ret; + + ret = iomap_dio_complete(dio); + if (is_write && ret > 0) + ret = generic_write_sync(iocb, ret); + iocb->ki_complete(iocb, ret, 0); +} + +/* + * Set an error in the dio if none is set yet. We have to use cmpxchg + * as the submission context and the completion context(s) can race to + * update the error. + */ +static inline void iomap_dio_set_error(struct iomap_dio *dio, int ret) +{ + cmpxchg(&dio->error, 0, ret); +} + +static void iomap_dio_bio_end_io(struct bio *bio) +{ + struct iomap_dio *dio = bio->bi_private; + bool should_dirty = (dio->flags & IOMAP_DIO_DIRTY); + + if (bio->bi_error) + iomap_dio_set_error(dio, bio->bi_error); + + if (atomic_dec_and_test(&dio->ref)) { + if (is_sync_kiocb(dio->iocb)) { + struct task_struct *waiter = dio->submit.waiter; + + WRITE_ONCE(dio->submit.waiter, NULL); + wake_up_process(waiter); + } else if (dio->flags & IOMAP_DIO_WRITE) { + struct inode *inode = file_inode(dio->iocb->ki_filp); + + INIT_WORK(&dio->aio.work, iomap_dio_complete_work); + queue_work(inode->i_sb->s_dio_done_wq, &dio->aio.work); + } else { + iomap_dio_complete_work(&dio->aio.work); + } + } + + if (should_dirty) { + bio_check_pages_dirty(bio); + } else { + struct bio_vec *bvec; + int i; + + bio_for_each_segment_all(bvec, bio, i) + put_page(bvec->bv_page); + bio_put(bio); + } +} + +static blk_qc_t +iomap_dio_zero(struct iomap_dio *dio, struct iomap *iomap, loff_t pos, + unsigned len) +{ + struct page *page = ZERO_PAGE(0); + struct bio *bio; + + bio = bio_alloc(GFP_KERNEL, 1); + bio->bi_bdev = iomap->bdev; + bio->bi_iter.bi_sector = + iomap->blkno + ((pos - iomap->offset) >> 9); + bio->bi_private = dio; + bio->bi_end_io = iomap_dio_bio_end_io; + + get_page(page); + if (bio_add_page(bio, page, len, 0) != len) + BUG(); + bio_set_op_attrs(bio, REQ_OP_WRITE, REQ_SYNC | REQ_IDLE); + + atomic_inc(&dio->ref); + return submit_bio(bio); +} + +static loff_t +iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length, + void *data, struct iomap *iomap) +{ + struct iomap_dio *dio = data; + unsigned blkbits = blksize_bits(bdev_logical_block_size(iomap->bdev)); + unsigned fs_block_size = (1 << inode->i_blkbits), pad; + unsigned align = iov_iter_alignment(dio->submit.iter); + struct iov_iter iter; + struct bio *bio; + bool need_zeroout = false; + int nr_pages, ret; + + if ((pos | length | align) & ((1 << blkbits) - 1)) + return -EINVAL; + + switch (iomap->type) { + case IOMAP_HOLE: + if (WARN_ON_ONCE(dio->flags & IOMAP_DIO_WRITE)) + return -EIO; + /*FALLTHRU*/ + case IOMAP_UNWRITTEN: + if (!(dio->flags & IOMAP_DIO_WRITE)) { + iov_iter_zero(length, dio->submit.iter); + dio->size += length; + return length; + } + dio->flags |= IOMAP_DIO_UNWRITTEN; + need_zeroout = true; + break; + case IOMAP_MAPPED: + if (iomap->flags & IOMAP_F_SHARED) + dio->flags |= IOMAP_DIO_COW; + if (iomap->flags & IOMAP_F_NEW) + need_zeroout = true; + break; + default: + WARN_ON_ONCE(1); + return -EIO; + } + + /* + * Operate on a partial iter trimmed to the extent we were called for. + * We'll update the iter in the dio once we're done with this extent. + */ + iter = *dio->submit.iter; + iov_iter_truncate(&iter, length); + + nr_pages = iov_iter_npages(&iter, BIO_MAX_PAGES); + if (nr_pages <= 0) + return nr_pages; + + if (need_zeroout) { + /* zero out from the start of the block to the write offset */ + pad = pos & (fs_block_size - 1); + if (pad) + iomap_dio_zero(dio, iomap, pos - pad, pad); + } + + do { + if (dio->error) + return 0; + + bio = bio_alloc(GFP_KERNEL, nr_pages); + bio->bi_bdev = iomap->bdev; + bio->bi_iter.bi_sector = + iomap->blkno + ((pos - iomap->offset) >> 9); + bio->bi_private = dio; + bio->bi_end_io = iomap_dio_bio_end_io; + + ret = bio_iov_iter_get_pages(bio, &iter); + if (unlikely(ret)) { + bio_put(bio); + return ret; + } + + if (dio->flags & IOMAP_DIO_WRITE) { + bio_set_op_attrs(bio, REQ_OP_WRITE, REQ_SYNC | REQ_IDLE); + task_io_account_write(bio->bi_iter.bi_size); + } else { + bio_set_op_attrs(bio, REQ_OP_READ, 0); + if (dio->flags & IOMAP_DIO_DIRTY) + bio_set_pages_dirty(bio); + } + + dio->size += bio->bi_iter.bi_size; + pos += bio->bi_iter.bi_size; + + nr_pages = iov_iter_npages(&iter, BIO_MAX_PAGES); + + atomic_inc(&dio->ref); + + dio->submit.last_queue = bdev_get_queue(iomap->bdev); + dio->submit.cookie = submit_bio(bio); + } while (nr_pages); + + if (need_zeroout) { + /* zero out from the end of the write to the end of the block */ + pad = pos & (fs_block_size - 1); + if (pad) + iomap_dio_zero(dio, iomap, pos, fs_block_size - pad); + } + + iov_iter_advance(dio->submit.iter, length); + return length; +} + +ssize_t +iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, struct iomap_ops *ops, + iomap_dio_end_io_t end_io) +{ + struct address_space *mapping = iocb->ki_filp->f_mapping; + struct inode *inode = file_inode(iocb->ki_filp); + size_t count = iov_iter_count(iter); + loff_t pos = iocb->ki_pos, end = iocb->ki_pos + count - 1, ret = 0; + unsigned int flags = IOMAP_DIRECT; + struct blk_plug plug; + struct iomap_dio *dio; + + lockdep_assert_held(&inode->i_rwsem); + + if (!count) + return 0; + + dio = kmalloc(sizeof(*dio), GFP_KERNEL); + if (!dio) + return -ENOMEM; + + dio->iocb = iocb; + atomic_set(&dio->ref, 1); + dio->size = 0; + dio->i_size = i_size_read(inode); + dio->end_io = end_io; + dio->error = 0; + dio->flags = 0; + + dio->submit.iter = iter; + if (is_sync_kiocb(iocb)) { + dio->submit.waiter = current; + dio->submit.cookie = BLK_QC_T_NONE; + dio->submit.last_queue = NULL; + } + + if (iov_iter_rw(iter) == READ) { + if (pos >= dio->i_size) + goto out_free_dio; + + if (iter->type == ITER_IOVEC) + dio->flags |= IOMAP_DIO_DIRTY; + } else { + dio->flags |= IOMAP_DIO_WRITE; + flags |= IOMAP_WRITE; + } + + if (mapping->nrpages) { + ret = filemap_write_and_wait_range(mapping, iocb->ki_pos, end); + if (ret) + goto out_free_dio; + + ret = invalidate_inode_pages2_range(mapping, + iocb->ki_pos >> PAGE_SHIFT, end >> PAGE_SHIFT); + WARN_ON_ONCE(ret); + ret = 0; + } + + inode_dio_begin(inode); + + blk_start_plug(&plug); + do { + ret = iomap_apply(inode, pos, count, flags, ops, dio, + iomap_dio_actor); + if (ret <= 0) { + /* magic error code to fall back to buffered I/O */ + if (ret == -ENOTBLK) + ret = 0; + break; + } + pos += ret; + } while ((count = iov_iter_count(iter)) > 0); + blk_finish_plug(&plug); + + if (ret < 0) + iomap_dio_set_error(dio, ret); + + if (ret >= 0 && iov_iter_rw(iter) == WRITE && !is_sync_kiocb(iocb) && + !inode->i_sb->s_dio_done_wq) { + ret = sb_init_dio_done_wq(inode->i_sb); + if (ret < 0) + iomap_dio_set_error(dio, ret); + } + + if (!atomic_dec_and_test(&dio->ref)) { + if (!is_sync_kiocb(iocb)) + return -EIOCBQUEUED; + + for (;;) { + set_current_state(TASK_UNINTERRUPTIBLE); + if (!READ_ONCE(dio->submit.waiter)) + break; + + if (!(iocb->ki_flags & IOCB_HIPRI) || + !dio->submit.last_queue || + !blk_mq_poll(dio->submit.last_queue, + dio->submit.cookie)) + io_schedule(); + } + __set_current_state(TASK_RUNNING); + } + + /* + * Try again to invalidate clean pages which might have been cached by + * non-direct readahead, or faulted in by get_user_pages() if the source + * of the write was an mmap'ed region of the file we're writing. Either + * one is a pretty crazy thing to do, so we don't support it 100%. If + * this invalidation fails, tough, the write still worked... + */ + if (iov_iter_rw(iter) == WRITE && mapping->nrpages) { + ret = invalidate_inode_pages2_range(mapping, + iocb->ki_pos >> PAGE_SHIFT, end >> PAGE_SHIFT); + WARN_ON_ONCE(ret); + } + + return iomap_dio_complete(dio); + +out_free_dio: + kfree(dio); + return ret; +} +EXPORT_SYMBOL_GPL(iomap_dio_rw); |