From 8cf037a8b22f71c6659bd0246bfaba9e79766f64 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 30 Aug 2017 09:43:34 -0700 Subject: ext2: perform dax_device lookup at mount The ->iomap_begin() operation is a hot path, so cache the fs_dax_get_by_host() result at mount time to avoid the incurring the hash lookup overhead on a per-i/o basis. Cc: "Theodore Ts'o" Cc: Andreas Dilger Reviewed-by: Jan Kara Reported-by: Christoph Hellwig Signed-off-by: Dan Williams --- fs/ext2/inode.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) (limited to 'fs/ext2/inode.c') diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 30163d007b2f..4dca6f348714 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -800,10 +800,10 @@ int ext2_get_block(struct inode *inode, sector_t iblock, static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length, unsigned flags, struct iomap *iomap) { - struct block_device *bdev; unsigned int blkbits = inode->i_blkbits; unsigned long first_block = offset >> blkbits; unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits; + struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb); bool new = false, boundary = false; u32 bno; int ret; @@ -814,13 +814,9 @@ static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length, return ret; iomap->flags = 0; - bdev = inode->i_sb->s_bdev; - iomap->bdev = bdev; + iomap->bdev = inode->i_sb->s_bdev; iomap->offset = (u64)first_block << blkbits; - if (blk_queue_dax(bdev->bd_queue)) - iomap->dax_dev = fs_dax_get_by_host(bdev->bd_disk->disk_name); - else - iomap->dax_dev = NULL; + iomap->dax_dev = sbi->s_daxdev; if (ret == 0) { iomap->type = IOMAP_HOLE; @@ -842,7 +838,6 @@ static int ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length, ssize_t written, unsigned flags, struct iomap *iomap) { - fs_put_dax(iomap->dax_dev); if (iomap->type == IOMAP_MAPPED && written < length && (flags & IOMAP_WRITE)) -- cgit v1.2.3