From 7194fa1986a48af46d2b01457865066cdbd14e35 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 21 Dec 2019 15:23:41 +0100 Subject: btrfs: split btrfs_direct_IO The read and write versions don't have anything in common except for the call to iomap_dio_rw. So split this function, and merge each half into its only caller. Signed-off-by: Christoph Hellwig --- fs/btrfs/ctree.h | 4 ++- fs/btrfs/file.c | 44 +++++++++++++++++++++++++---- fs/btrfs/inode.c | 72 ++++-------------------------------------------- 3 files changed, 48 insertions(+), 72 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 8faa069b0a73..fccbbfebdf88 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -28,6 +28,7 @@ #include #include #include +#include #include "extent-io-tree.h" #include "extent_io.h" #include "extent_map.h" @@ -2904,7 +2905,8 @@ 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); +const struct iomap_ops btrfs_dio_iomap_ops; +const struct iomap_dio_ops btrfs_dio_ops; /* 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 0522f6d45a98..ed0b2e015d8d 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1822,17 +1822,50 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, return num_written ? num_written : ret; } -static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from) +static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from) { struct file *file = iocb->ki_filp; struct inode *inode = file_inode(file); - loff_t pos; + size_t count = iov_iter_count(from); + struct extent_changeset *data_reserved = NULL; + loff_t pos = iocb->ki_pos; ssize_t written; ssize_t written_buffered; loff_t endbyte; + bool relock = false; int err; - written = btrfs_direct_IO(iocb, from); + /* + * If the write DIO is beyond the EOF, we need update the isize, but + * it is protected by i_mutex. So we can not unlock the i_mutex in + * this case. + */ + if (pos + count <= inode->i_size) { + inode_unlock(inode); + relock = true; + } else { + if (iocb->ki_flags & IOCB_NOWAIT) + return -EAGAIN; + } + + err = btrfs_delalloc_reserve_space(inode, &data_reserved, pos, count); + if (err) { + if (relock) + inode_lock(inode); + return err; + } + + down_read(&BTRFS_I(inode)->dio_sem); + written = iomap_dio_rw(iocb, from, &btrfs_dio_iomap_ops, &btrfs_dio_ops, + is_sync_kiocb(iocb)); + up_read(&BTRFS_I(inode)->dio_sem); + if (written >= 0 && (size_t)written < count) + btrfs_delalloc_release_space(inode, data_reserved, + pos, count - (size_t)written, true); + btrfs_delalloc_release_extents(BTRFS_I(inode), count); + if (relock) + inode_lock(inode); + extent_changeset_free(data_reserved); if (written < 0 || !iov_iter_count(from)) return written; @@ -1975,7 +2008,7 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, atomic_inc(&BTRFS_I(inode)->sync_writers); if (iocb->ki_flags & IOCB_DIRECT) { - num_written = __btrfs_direct_write(iocb, from); + num_written = btrfs_direct_write(iocb, from); } else { num_written = btrfs_buffered_write(iocb, from); if (num_written > 0) @@ -3473,7 +3506,8 @@ static ssize_t btrfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to) ssize_t ret; inode_lock_shared(inode); - ret = btrfs_direct_IO(iocb, to); + ret = iomap_dio_rw(iocb, to, &btrfs_dio_iomap_ops, + &btrfs_dio_ops, is_sync_kiocb(iocb)); inode_unlock_shared(inode); return ret; diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 18d153a62655..7b747270ec40 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -29,7 +29,6 @@ #include #include #include -#include #include #include "misc.h" #include "ctree.h" @@ -7856,6 +7855,11 @@ static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length, return 0; } +const struct iomap_ops btrfs_dio_iomap_ops = { + .iomap_begin = btrfs_dio_iomap_begin, + .iomap_end = btrfs_dio_iomap_end, +}; + static inline blk_status_t submit_dio_repair_bio(struct inode *inode, struct bio *bio, int mirror_num) @@ -8581,74 +8585,10 @@ static blk_qc_t btrfs_submit_direct(struct bio *dio_bio, struct file *file, return BLK_QC_T_NONE; } -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 = { +const struct iomap_dio_ops btrfs_dio_ops = { .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; - struct extent_changeset *data_reserved = NULL; - loff_t offset = iocb->ki_pos; - size_t count = 0; - bool relock = false; - ssize_t ret; - - lockdep_assert_held(&inode->i_rwsem); - - count = iov_iter_count(iter); - if (iov_iter_rw(iter) == WRITE) { - /* - * If the write DIO is beyond the EOF, we need update - * the isize, but it is protected by i_mutex. So we can - * not unlock the i_mutex at this case. - */ - if (offset + count <= inode->i_size) { - inode_unlock(inode); - relock = true; - } else if (iocb->ki_flags & IOCB_NOWAIT) { - ret = -EAGAIN; - goto out; - } - ret = btrfs_delalloc_reserve_space(inode, &data_reserved, - offset, count); - if (ret) - goto out; - - down_read(&BTRFS_I(inode)->dio_sem); - } - - 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); - 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 (relock) - inode_lock(inode); - extent_changeset_free(data_reserved); - return ret; -} - #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC) static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, -- 2.24.0