| Message ID | 150412224334.10177.12994820445044936627.stgit@dwillia2-desk3.amr.corp.intel.com |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | fs, dax: lookup dax_device at mount time | expand |
On Wed 30-08-17 12:44:03, Dan Williams wrote: > 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" <tytso@mit.edu> > Cc: Andreas Dilger <adilger.kernel@dilger.ca> > Cc: Jan Kara <jack@suse.cz> > Reported-by: Christoph Hellwig <hch@lst.de> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> Looks good to me (and it looks even cleaner than your previous approach). Just one nit below. You can add: Reviewed-by: Jan Kara <jack@suse.cz> > diff --git a/fs/ext2/super.c b/fs/ext2/super.c > index 7b1bc9059863..d9dd999568c2 100644 > --- a/fs/ext2/super.c > +++ b/fs/ext2/super.c > @@ -144,6 +144,7 @@ static void ext2_put_super (struct super_block * sb) > int db_count; > int i; > struct ext2_sb_info *sbi = EXT2_SB(sb); > + struct dax_device *dax_dev = sbi->s_daxdev; > > ext2_quota_off_umount(sb); > > @@ -172,6 +173,7 @@ static void ext2_put_super (struct super_block * sb) > sb->s_fs_info = NULL; > kfree(sbi->s_blockgroup_lock); > kfree(sbi); > + fs_put_dax(dax_dev); The local variable looks superfluous here. I'd just do fs_put_dax(sbi->s_daxdev); Honza
On Thu, Aug 31, 2017 at 1:22 AM, Jan Kara <jack@suse.cz> wrote: > On Wed 30-08-17 12:44:03, Dan Williams wrote: >> 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" <tytso@mit.edu> >> Cc: Andreas Dilger <adilger.kernel@dilger.ca> >> Cc: Jan Kara <jack@suse.cz> >> Reported-by: Christoph Hellwig <hch@lst.de> >> Signed-off-by: Dan Williams <dan.j.williams@intel.com> > > Looks good to me (and it looks even cleaner than your previous approach). > Just one nit below. You can add: > > Reviewed-by: Jan Kara <jack@suse.cz> > >> diff --git a/fs/ext2/super.c b/fs/ext2/super.c >> index 7b1bc9059863..d9dd999568c2 100644 >> --- a/fs/ext2/super.c >> +++ b/fs/ext2/super.c >> @@ -144,6 +144,7 @@ static void ext2_put_super (struct super_block * sb) >> int db_count; >> int i; >> struct ext2_sb_info *sbi = EXT2_SB(sb); >> + struct dax_device *dax_dev = sbi->s_daxdev; >> >> ext2_quota_off_umount(sb); >> >> @@ -172,6 +173,7 @@ static void ext2_put_super (struct super_block * sb) >> sb->s_fs_info = NULL; >> kfree(sbi->s_blockgroup_lock); >> kfree(sbi); >> + fs_put_dax(dax_dev); > > The local variable looks superfluous here. I'd just do > fs_put_dax(sbi->s_daxdev); Ok... and move that before the kfree(sbi).
diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h index 23ebb92484c6..28de3edd4f4d 100644 --- a/fs/ext2/ext2.h +++ b/fs/ext2/ext2.h @@ -114,6 +114,7 @@ struct ext2_sb_info { */ spinlock_t s_lock; struct mb_cache *s_ea_block_cache; + struct dax_device *s_daxdev; }; static inline spinlock_t * 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)) diff --git a/fs/ext2/super.c b/fs/ext2/super.c index 7b1bc9059863..d9dd999568c2 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -144,6 +144,7 @@ static void ext2_put_super (struct super_block * sb) int db_count; int i; struct ext2_sb_info *sbi = EXT2_SB(sb); + struct dax_device *dax_dev = sbi->s_daxdev; ext2_quota_off_umount(sb); @@ -172,6 +173,7 @@ static void ext2_put_super (struct super_block * sb) sb->s_fs_info = NULL; kfree(sbi->s_blockgroup_lock); kfree(sbi); + fs_put_dax(dax_dev); } static struct kmem_cache * ext2_inode_cachep; @@ -813,6 +815,7 @@ static unsigned long descriptor_loc(struct super_block *sb, static int ext2_fill_super(struct super_block *sb, void *data, int silent) { + struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev); struct buffer_head * bh; struct ext2_sb_info * sbi; struct ext2_super_block * es; @@ -842,6 +845,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent) } sb->s_fs_info = sbi; sbi->s_sb_block = sb_block; + sbi->s_daxdev = dax_dev; spin_lock_init(&sbi->s_lock); @@ -1200,6 +1204,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent) kfree(sbi->s_blockgroup_lock); kfree(sbi); failed: + fs_put_dax(dax_dev); return ret; }
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" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jan Kara <jack@suse.cz> Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- fs/ext2/ext2.h | 1 + fs/ext2/inode.c | 11 +++-------- fs/ext2/super.c | 5 +++++ 3 files changed, 9 insertions(+), 8 deletions(-)