From 68e41a43f18b681f83329c8ad83123571bb8db0d Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Tue, 19 Mar 2013 18:16:45 +0100 Subject: [PATCH] drbd: use the cached meta_dev_idx Now we have the cached meta_dev_idx member, we can get rid of a few rcu_read_lock() sections and rcu_dereference(). Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_int.h | 32 +++++--------------------------- drivers/block/drbd/drbd_nl.c | 7 +------ 2 files changed, 6 insertions(+), 33 deletions(-) diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index ee19ba2..6eecdec 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -1777,9 +1777,9 @@ static inline void drbd_chk_io_error_(struct drbd_conf *mdev, * BTW, for internal meta data, this happens to be the maximum capacity * we could agree upon with our peer node. */ -static inline sector_t _drbd_md_first_sector(int meta_dev_idx, struct drbd_backing_dev *bdev) +static inline sector_t drbd_md_first_sector(struct drbd_backing_dev *bdev) { - switch (meta_dev_idx) { + switch (bdev->md.meta_dev_idx) { case DRBD_MD_INDEX_INTERNAL: case DRBD_MD_INDEX_FLEX_INT: return bdev->md.md_offset + bdev->md.bm_offset; @@ -1789,30 +1789,13 @@ static inline sector_t _drbd_md_first_sector(int meta_dev_idx, struct drbd_backi } } -static inline sector_t drbd_md_first_sector(struct drbd_backing_dev *bdev) -{ - int meta_dev_idx; - - rcu_read_lock(); - meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx; - rcu_read_unlock(); - - return _drbd_md_first_sector(meta_dev_idx, bdev); -} - /** * drbd_md_last_sector() - Return the last sector number of the meta data area * @bdev: Meta data block device. */ static inline sector_t drbd_md_last_sector(struct drbd_backing_dev *bdev) { - int meta_dev_idx; - - rcu_read_lock(); - meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx; - rcu_read_unlock(); - - switch (meta_dev_idx) { + switch (bdev->md.meta_dev_idx) { case DRBD_MD_INDEX_INTERNAL: case DRBD_MD_INDEX_FLEX_INT: return bdev->md.md_offset + MD_4kB_SECT -1; @@ -1840,18 +1823,13 @@ static inline sector_t drbd_get_capacity(struct block_device *bdev) static inline sector_t drbd_get_max_capacity(struct drbd_backing_dev *bdev) { sector_t s; - int meta_dev_idx; - - rcu_read_lock(); - meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx; - rcu_read_unlock(); - switch (meta_dev_idx) { + switch (bdev->md.meta_dev_idx) { case DRBD_MD_INDEX_INTERNAL: case DRBD_MD_INDEX_FLEX_INT: s = drbd_get_capacity(bdev->backing_bdev) ? min_t(sector_t, DRBD_MAX_SECTORS_FLEX, - _drbd_md_first_sector(meta_dev_idx, bdev)) + drbd_md_first_sector(bdev)) : 0; break; case DRBD_MD_INDEX_FLEX_EXT: diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index 104b7ce..5621df8 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -722,14 +722,10 @@ static void drbd_md_set_sector_offsets(struct drbd_conf *mdev, { sector_t md_size_sect = 0; unsigned int al_size_sect = MD_32kB_SECT; - int meta_dev_idx; - - rcu_read_lock(); - meta_dev_idx = rcu_dereference(bdev->disk_conf)->meta_dev_idx; bdev->md.md_offset = drbd_md_ss(bdev); - switch (meta_dev_idx) { + switch (bdev->md.meta_dev_idx) { default: /* v07 style fixed size indexed meta data */ bdev->md.md_size_sect = MD_128MB_SECT; @@ -761,7 +757,6 @@ static void drbd_md_set_sector_offsets(struct drbd_conf *mdev, bdev->md.bm_offset = -md_size_sect + MD_4kB_SECT; break; } - rcu_read_unlock(); } /* input size is expected to be in KB */ -- 2.7.4