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author | Christoph Hellwig <hch@lst.de> | 2020-05-19 09:46:29 -0500 |
---|---|---|
committer | David Sterba <dsterba@suse.com> | 2020-05-28 14:01:52 +0200 |
commit | d8f3e73587ce574f7a9bc165e0db69b0b148f6f8 (patch) | |
tree | ccd7157c3beec52a1c74fc734c3bef5966d0c094 /fs/btrfs | |
parent | 5f008163a559d566a0ee1190a0a24f3eec6f1ea7 (diff) | |
download | linux-stable-d8f3e73587ce574f7a9bc165e0db69b0b148f6f8.tar.gz linux-stable-d8f3e73587ce574f7a9bc165e0db69b0b148f6f8.tar.bz2 linux-stable-d8f3e73587ce574f7a9bc165e0db69b0b148f6f8.zip |
btrfs: split btrfs_direct_IO to read and write part
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 <hch@lst.de>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r-- | fs/btrfs/ctree.h | 3 | ||||
-rw-r--r-- | fs/btrfs/file.c | 88 | ||||
-rw-r--r-- | fs/btrfs/inode.c | 82 |
3 files changed, 83 insertions, 90 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 47b8874eddff..161533040978 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -28,6 +28,7 @@ #include <linux/dynamic_debug.h> #include <linux/refcount.h> #include <linux/crc32c.h> +#include <linux/iomap.h> #include "extent-io-tree.h" #include "extent_io.h" #include "extent_map.h" @@ -2934,6 +2935,8 @@ 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); +extern const struct iomap_ops btrfs_dio_iomap_ops; +extern const struct iomap_dio_ops btrfs_dops; /* 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 dff89d04fd16..fde125616687 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1809,21 +1809,61 @@ again: return num_written ? num_written : ret; } -static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from) +static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info, + const struct iov_iter *iter, loff_t offset) +{ + const unsigned int blocksize_mask = fs_info->sectorsize - 1; + + if (offset & blocksize_mask) + return -EINVAL; + + if (iov_iter_alignment(iter) & blocksize_mask) + return -EINVAL; + + return 0; +} + +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; - ssize_t written; + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + loff_t pos = iocb->ki_pos; + ssize_t written = 0; ssize_t written_buffered; loff_t endbyte; int err; + size_t count = 0; + bool relock = false; - written = btrfs_direct_IO(iocb, from); + if (check_direct_IO(fs_info, from, pos)) + goto buffered; + + count = iov_iter_count(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 at this + * case. + */ + if (pos + count <= inode->i_size) { + inode_unlock(inode); + relock = true; + } else if (iocb->ki_flags & IOCB_NOWAIT) { + return -EAGAIN; + } + + down_read(&BTRFS_I(inode)->dio_sem); + written = iomap_dio_rw(iocb, from, &btrfs_dio_iomap_ops, &btrfs_dops, + is_sync_kiocb(iocb)); + up_read(&BTRFS_I(inode)->dio_sem); + + if (relock) + inode_lock(inode); if (written < 0 || !iov_iter_count(from)) return written; +buffered: pos = iocb->ki_pos; written_buffered = btrfs_buffered_write(iocb, from); if (written_buffered < 0) { @@ -1962,7 +2002,7 @@ 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) @@ -3476,16 +3516,44 @@ static int btrfs_file_open(struct inode *inode, struct file *filp) return generic_file_open(inode, filp); } +static int check_direct_read(struct btrfs_fs_info *fs_info, + const struct iov_iter *iter, loff_t offset) +{ + int ret; + int i, seg; + + ret = check_direct_IO(fs_info, iter, offset); + if (ret < 0) + return ret; + + for (seg = 0; seg < iter->nr_segs; seg++) + for (i = seg + 1; i < iter->nr_segs; i++) + if (iter->iov[seg].iov_base == iter->iov[i].iov_base) + return -EINVAL; + return 0; +} + +static ssize_t btrfs_direct_read(struct kiocb *iocb, struct iov_iter *to) +{ + struct inode *inode = file_inode(iocb->ki_filp); + ssize_t ret; + + if (check_direct_read(btrfs_sb(inode->i_sb), to, iocb->ki_pos)) + return 0; + + inode_lock_shared(inode); + ret = iomap_dio_rw(iocb, to, &btrfs_dio_iomap_ops, &btrfs_dops, + is_sync_kiocb(iocb)); + inode_unlock_shared(inode); + return ret; +} + 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); + ret = btrfs_direct_read(iocb, to); if (ret < 0) return ret; } diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 0c47f79da2e1..4583f0763571 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -29,7 +29,6 @@ #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" @@ -7759,92 +7758,15 @@ out_err: return BLK_QC_T_NONE; } -static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info, - const struct iov_iter *iter, loff_t offset) -{ - int seg; - int i; - unsigned int blocksize_mask = fs_info->sectorsize - 1; - ssize_t retval = -EINVAL; - - if (offset & blocksize_mask) - goto out; - - if (iov_iter_alignment(iter) & blocksize_mask) - goto out; - - /* If this is a write we don't need to check anymore */ - if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter)) - return 0; - /* - * Check to make sure we don't have duplicate iov_base's in this - * iovec, if so return EINVAL, otherwise we'll get csum errors - * when reading back. - */ - for (seg = 0; seg < iter->nr_segs; seg++) { - for (i = seg + 1; i < iter->nr_segs; i++) { - if (iter->iov[seg].iov_base == iter->iov[i].iov_base) - goto out; - } - } - retval = 0; -out: - return retval; -} - -static const struct iomap_ops btrfs_dio_iomap_ops = { +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_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 extent_changeset *data_reserved = NULL; - loff_t offset = iocb->ki_pos; - size_t count = 0; - bool relock = false; - ssize_t ret; - - if (check_direct_IO(fs_info, iter, offset)) - return 0; - - 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; - } - 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); - } -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, |