From 491a6d01183dee9e95d55098752b5561ef93542e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 5 May 2022 15:11:12 -0500 Subject: [PATCH] btrfs: allocate dio_data on stack Make use of the new iomap_iter->private field to avoid a memory allocation per iomap range. Reviewed-by: Nikolay Borisov Signed-off-by: Christoph Hellwig Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/inode.c | 34 +++++++++++----------------------- 1 file changed, 11 insertions(+), 23 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 954e91b74d21..9848a5a0f980 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7546,10 +7546,11 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start, loff_t length, unsigned int flags, struct iomap *iomap, struct iomap *srcmap) { + struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap); 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; + struct btrfs_dio_data *dio_data = iter->private; u64 lockstart, lockend; const bool write = !!(flags & IOMAP_WRITE); int ret = 0; @@ -7595,17 +7596,7 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start, } } - if (flags & IOMAP_NOWAIT) { - dio_data = kzalloc(sizeof(*dio_data), GFP_NOWAIT); - if (!dio_data) - return -EAGAIN; - } else { - dio_data = kzalloc(sizeof(*dio_data), GFP_NOFS); - if (!dio_data) - return -ENOMEM; - } - - iomap->private = dio_data; + memset(dio_data, 0, sizeof(*dio_data)); /* * We always try to allocate data space and must do it before locking @@ -7769,23 +7760,22 @@ static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start, extent_changeset_free(dio_data->data_reserved); } - kfree(dio_data); - return ret; } static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length, ssize_t written, unsigned int flags, struct iomap *iomap) { - int ret = 0; - struct btrfs_dio_data *dio_data = iomap->private; + struct iomap_iter *iter = container_of(iomap, struct iomap_iter, iomap); + struct btrfs_dio_data *dio_data = iter->private; size_t submitted = dio_data->submitted; const bool write = !!(flags & IOMAP_WRITE); + int ret = 0; if (!write && (iomap->type == IOMAP_HOLE)) { /* If reading from a hole, unlock and return */ unlock_extent(&BTRFS_I(inode)->io_tree, pos, pos + length - 1); - goto out; + return 0; } if (submitted < length) { @@ -7802,10 +7792,6 @@ static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length, if (write) extent_changeset_free(dio_data->data_reserved); -out: - kfree(dio_data); - iomap->private = NULL; - return ret; } @@ -8041,7 +8027,7 @@ static void btrfs_submit_direct(const struct iomap_iter *iter, int ret; blk_status_t status; struct btrfs_io_geometry geom; - struct btrfs_dio_data *dio_data = iter->iomap.private; + struct btrfs_dio_data *dio_data = iter->private; struct extent_map *em = NULL; dip = btrfs_create_dio_private(dio_bio, inode, file_offset); @@ -8166,8 +8152,10 @@ static const struct iomap_dio_ops btrfs_dio_ops = { ssize_t btrfs_dio_rw(struct kiocb *iocb, struct iov_iter *iter, size_t done_before) { + struct btrfs_dio_data data; + return iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dio_ops, - IOMAP_DIO_PARTIAL, NULL, done_before); + IOMAP_DIO_PARTIAL, &data, done_before); } static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,