Re: [patch 17/35] btrfs: split extent_state ops

[Liu Bo <liubo2009@cn.fujitsu.com>]

On 03/22/2012 09:11 AM, Jeff Mahoney wrote:
>  set_extent_bit can do exclusive locking but only when called by lock_extent*,
> 
>  Drop the exclusive bits argument except when called by lock_extent.
> 

Hi Jeff,

I have to say this is not a good cleanup, any benefits?

thanks,
liubo

> Signed-off-by: Jeff Mahoney <jeffm@suse.com>
> ---
>  fs/btrfs/extent_io.c |   36 +++++++++++++++++++++++-------------
>  fs/btrfs/extent_io.h |    2 +-
>  fs/btrfs/inode.c     |    2 +-
>  3 files changed, 25 insertions(+), 15 deletions(-)
> 
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 0112c02..ffa7cc3 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -721,9 +721,10 @@ static void uncache_state(struct extent_state **cached_ptr)
>   * [start, end] is inclusive This takes the tree lock.
>   */
>  
> -int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
> -		   int bits, int exclusive_bits, u64 *failed_start,
> -		   struct extent_state **cached_state, gfp_t mask)
> +static int __must_check
> +__set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
> +		 int bits, int exclusive_bits, u64 *failed_start,
> +		 struct extent_state **cached_state, gfp_t mask)
>  {
>  	struct extent_state *state;
>  	struct extent_state *prealloc = NULL;
> @@ -917,6 +918,15 @@ search_again:
>  	goto again;
>  }
>  
> +int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits,
> +		   u64 *failed_start, struct extent_state **cached_state,
> +		   gfp_t mask)
> +{
> +	return __set_extent_bit(tree, start, end, bits, 0, failed_start,
> +				cached_state, mask);
> +}
> +
> +
>  /**
>   * convert_extent - convert all bits in a given range from one bit to another
>   * @tree:	the io tree to search
> @@ -1111,14 +1121,14 @@ search_again:
>  int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
>  		     gfp_t mask)
>  {
> -	return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL,
> +	return set_extent_bit(tree, start, end, EXTENT_DIRTY, NULL,
>  			      NULL, mask);
>  }
>  
>  int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
>  		    int bits, gfp_t mask)
>  {
> -	return set_extent_bit(tree, start, end, bits, 0, NULL,
> +	return set_extent_bit(tree, start, end, bits, NULL,
>  			      NULL, mask);
>  }
>  
> @@ -1133,7 +1143,7 @@ int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end,
>  {
>  	return set_extent_bit(tree, start, end,
>  			      EXTENT_DELALLOC | EXTENT_UPTODATE,
> -			      0, NULL, cached_state, mask);
> +			      NULL, cached_state, mask);
>  }
>  
>  int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
> @@ -1147,7 +1157,7 @@ int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end,
>  int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end,
>  		     gfp_t mask)
>  {
> -	return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL,
> +	return set_extent_bit(tree, start, end, EXTENT_NEW, NULL,
>  			      NULL, mask);
>  }
>  
> @@ -1155,7 +1165,7 @@ int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
>  			struct extent_state **cached_state, gfp_t mask)
>  {
>  	return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0,
> -			      NULL, cached_state, mask);
> +			      cached_state, mask);
>  }
>  
>  static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start,
> @@ -1176,9 +1186,9 @@ int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
>  	int err;
>  	u64 failed_start;
>  	while (1) {
> -		err = set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
> -				     EXTENT_LOCKED, &failed_start,
> -				     cached_state, GFP_NOFS);
> +		err = __set_extent_bit(tree, start, end, EXTENT_LOCKED | bits,
> +				       EXTENT_LOCKED, &failed_start,
> +				       cached_state, GFP_NOFS);
>  		if (err == -EEXIST) {
>  			wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED);
>  			start = failed_start;
> @@ -1199,8 +1209,8 @@ int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
>  	int err;
>  	u64 failed_start;
>  
> -	err = set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
> -			     &failed_start, NULL, GFP_NOFS);
> +	err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED,
> +			       &failed_start, NULL, GFP_NOFS);
>  	if (err == -EEXIST) {
>  		if (failed_start > start)
>  			clear_extent_bit(tree, start, failed_start - 1,
> diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
> index 439e183..3a171c2 100644
> --- a/fs/btrfs/extent_io.h
> +++ b/fs/btrfs/extent_io.h
> @@ -209,7 +209,7 @@ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
>  int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end,
>  		    int bits, gfp_t mask);
>  int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
> -		   int bits, int exclusive_bits, u64 *failed_start,
> +		   int bits, u64 *failed_start,
>  		   struct extent_state **cached_state, gfp_t mask);
>  int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end,
>  			struct extent_state **cached_state, gfp_t mask);
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index d16bf3f..593a2c3 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -6233,7 +6233,7 @@ static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
>  	if (writing) {
>  		write_bits = EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING;
>  		ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
> -				     EXTENT_DELALLOC, 0, NULL, &cached_state,
> +				     EXTENT_DELALLOC, NULL, &cached_state,
>  				     GFP_NOFS);
>  		if (ret) {
>  			clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,