Re: [PATCH 4/5] xfs: Remove kmem_realloc

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Wed, Nov 20, 2019 at 11:44:24AM +0100, Carlos Maiolino wrote:
> We can use krealloc() with __GFP_NOFAIL directly
> 
> Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>

Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

--D

> ---
> V2:
> 	- Fix small conflict in kmem.h due removal of kmem_free()
> 	- Small comment update on xfs_iroot_realloc()
> 
>  fs/xfs/kmem.c                  | 22 ----------------------
>  fs/xfs/kmem.h                  |  1 -
>  fs/xfs/libxfs/xfs_iext_tree.c  |  2 +-
>  fs/xfs/libxfs/xfs_inode_fork.c | 10 +++++-----
>  fs/xfs/xfs_log_recover.c       |  2 +-
>  fs/xfs/xfs_mount.c             |  4 ++--
>  6 files changed, 9 insertions(+), 32 deletions(-)
> 
> diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c
> index 2644fdaa0549..6e10e565632c 100644
> --- a/fs/xfs/kmem.c
> +++ b/fs/xfs/kmem.c
> @@ -93,25 +93,3 @@ kmem_alloc_large(size_t size, xfs_km_flags_t flags)
>  		return ptr;
>  	return __kmem_vmalloc(size, flags);
>  }
> -
> -void *
> -kmem_realloc(const void *old, size_t newsize, xfs_km_flags_t flags)
> -{
> -	int	retries = 0;
> -	gfp_t	lflags = kmem_flags_convert(flags);
> -	void	*ptr;
> -
> -	trace_kmem_realloc(newsize, flags, _RET_IP_);
> -
> -	do {
> -		ptr = krealloc(old, newsize, lflags);
> -		if (ptr || (flags & KM_MAYFAIL))
> -			return ptr;
> -		if (!(++retries % 100))
> -			xfs_err(NULL,
> -	"%s(%u) possible memory allocation deadlock size %zu in %s (mode:0x%x)",
> -				current->comm, current->pid,
> -				newsize, __func__, lflags);
> -		congestion_wait(BLK_RW_ASYNC, HZ/50);
> -	} while (1);
> -}
> diff --git a/fs/xfs/kmem.h b/fs/xfs/kmem.h
> index b9ee67fa747b..a18c27c99721 100644
> --- a/fs/xfs/kmem.h
> +++ b/fs/xfs/kmem.h
> @@ -55,7 +55,6 @@ kmem_flags_convert(xfs_km_flags_t flags)
>  extern void *kmem_alloc(size_t, xfs_km_flags_t);
>  extern void *kmem_alloc_io(size_t size, int align_mask, xfs_km_flags_t flags);
>  extern void *kmem_alloc_large(size_t size, xfs_km_flags_t);
> -extern void *kmem_realloc(const void *, size_t, xfs_km_flags_t);
>  
>  static inline void *
>  kmem_zalloc_large(size_t size, xfs_km_flags_t flags)
> diff --git a/fs/xfs/libxfs/xfs_iext_tree.c b/fs/xfs/libxfs/xfs_iext_tree.c
> index e75e7c021187..78c9f6c7a36a 100644
> --- a/fs/xfs/libxfs/xfs_iext_tree.c
> +++ b/fs/xfs/libxfs/xfs_iext_tree.c
> @@ -607,7 +607,7 @@ xfs_iext_realloc_root(
>  	if (new_size / sizeof(struct xfs_iext_rec) == RECS_PER_LEAF)
>  		new_size = NODE_SIZE;
>  
> -	new = kmem_realloc(ifp->if_u1.if_root, new_size, KM_NOFS);
> +	new = krealloc(ifp->if_u1.if_root, new_size, GFP_NOFS | __GFP_NOFAIL);
>  	memset(new + ifp->if_bytes, 0, new_size - ifp->if_bytes);
>  	ifp->if_u1.if_root = new;
>  	cur->leaf = new;
> diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c
> index ceb322c7105e..82799dddf97d 100644
> --- a/fs/xfs/libxfs/xfs_inode_fork.c
> +++ b/fs/xfs/libxfs/xfs_inode_fork.c
> @@ -380,15 +380,15 @@ xfs_iroot_realloc(
>  
>  		/*
>  		 * If there is already an existing if_broot, then we need
> -		 * to realloc() it and shift the pointers to their new
> +		 * to krealloc() it and shift the pointers to their new
>  		 * location.  The records don't change location because
>  		 * they are kept butted up against the btree block header.
>  		 */
>  		cur_max = xfs_bmbt_maxrecs(mp, ifp->if_broot_bytes, 0);
>  		new_max = cur_max + rec_diff;
>  		new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, new_max);
> -		ifp->if_broot = kmem_realloc(ifp->if_broot, new_size,
> -				KM_NOFS);
> +		ifp->if_broot = krealloc(ifp->if_broot, new_size,
> +				GFP_NOFS | __GFP_NOFAIL);
>  		op = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
>  						     ifp->if_broot_bytes);
>  		np = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
> @@ -497,8 +497,8 @@ xfs_idata_realloc(
>  	 * in size so that it can be logged and stay on word boundaries.
>  	 * We enforce that here.
>  	 */
> -	ifp->if_u1.if_data = kmem_realloc(ifp->if_u1.if_data,
> -			roundup(new_size, 4), KM_NOFS);
> +	ifp->if_u1.if_data = krealloc(ifp->if_u1.if_data, roundup(new_size, 4),
> +				      GFP_NOFS | __GFP_NOFAIL);
>  	ifp->if_bytes = new_size;
>  }
>  
> diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
> index cb02deb5dedc..5423171e0b7d 100644
> --- a/fs/xfs/xfs_log_recover.c
> +++ b/fs/xfs/xfs_log_recover.c
> @@ -4211,7 +4211,7 @@ xlog_recover_add_to_cont_trans(
>  	old_ptr = item->ri_buf[item->ri_cnt-1].i_addr;
>  	old_len = item->ri_buf[item->ri_cnt-1].i_len;
>  
> -	ptr = kmem_realloc(old_ptr, len + old_len, 0);
> +	ptr = krealloc(old_ptr, len + old_len, GFP_KERNEL | __GFP_NOFAIL);
>  	memcpy(&ptr[old_len], dp, len);
>  	item->ri_buf[item->ri_cnt-1].i_len += len;
>  	item->ri_buf[item->ri_cnt-1].i_addr = ptr;
> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> index c352567c8ef5..12a1cdf8e292 100644
> --- a/fs/xfs/xfs_mount.c
> +++ b/fs/xfs/xfs_mount.c
> @@ -80,9 +80,9 @@ xfs_uuid_mount(
>  	}
>  
>  	if (hole < 0) {
> -		xfs_uuid_table = kmem_realloc(xfs_uuid_table,
> +		xfs_uuid_table = krealloc(xfs_uuid_table,
>  			(xfs_uuid_table_size + 1) * sizeof(*xfs_uuid_table),
> -			0);
> +			GFP_KERNEL | __GFP_NOFAIL);
>  		hole = xfs_uuid_table_size++;
>  	}
>  	xfs_uuid_table[hole] = *uuid;
> -- 
> 2.23.0
>