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
  ...

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);