From de631e1a8b71017b8a12b57d07db82e4052555af Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Thu, 22 Aug 2024 15:50:15 +0200 Subject: [PATCH] xfs: use kvmalloc for xattr buffers Pankaj Raghav reported that when filesystem block size is larger than page size, the xattr code can use kmalloc() for high order allocations. This triggers a useless warning in the allocator as it is a __GFP_NOFAIL allocation here: static inline struct page *rmqueue(struct zone *preferred_zone, struct zone *zone, unsigned int order, gfp_t gfp_flags, unsigned int alloc_flags, int migratetype) { struct page *page; /* * We most definitely don't want callers attempting to * allocate greater than order-1 page units with __GFP_NOFAIL. */ >>>> WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1)); ... Fix this by changing all these call sites to use kvmalloc(), which will strip the NOFAIL from the kmalloc attempt and if that fails will do a __GFP_NOFAIL vmalloc(). This is not an issue that productions systems will see as filesystems with block size > page size cannot be mounted by the kernel; Pankaj is developing this functionality right now. Reported-by: Pankaj Raghav Fixes: f078d4ea8276 ("xfs: convert kmem_alloc() to kmalloc()") Signed-off-by: Dave Chinner Link: https://lore.kernel.org/r/20240822135018.1931258-8-kernel@pankajraghav.com Reviewed-by: Darrick J. Wong Reviewed-by: Pankaj Raghav Reviewed-by: Hannes Reinecke Signed-off-by: Christoph Hellwig Acked-by: Darrick J. Wong Reviewed-by: Daniel Gomez Reviewed-by: Dave Chinner Reviewed-by: Matthew Wilcox (Oracle) Signed-off-by: Christian Brauner --- fs/xfs/libxfs/xfs_attr_leaf.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c index b9e98950eb3d..09f4cb061a6e 100644 --- a/fs/xfs/libxfs/xfs_attr_leaf.c +++ b/fs/xfs/libxfs/xfs_attr_leaf.c @@ -1138,10 +1138,7 @@ xfs_attr3_leaf_to_shortform( trace_xfs_attr_leaf_to_sf(args); - tmpbuffer = kmalloc(args->geo->blksize, GFP_KERNEL | __GFP_NOFAIL); - if (!tmpbuffer) - return -ENOMEM; - + tmpbuffer = kvmalloc(args->geo->blksize, GFP_KERNEL | __GFP_NOFAIL); memcpy(tmpbuffer, bp->b_addr, args->geo->blksize); leaf = (xfs_attr_leafblock_t *)tmpbuffer; @@ -1205,7 +1202,7 @@ xfs_attr3_leaf_to_shortform( error = 0; out: - kfree(tmpbuffer); + kvfree(tmpbuffer); return error; } @@ -1613,7 +1610,7 @@ xfs_attr3_leaf_compact( trace_xfs_attr_leaf_compact(args); - tmpbuffer = kmalloc(args->geo->blksize, GFP_KERNEL | __GFP_NOFAIL); + tmpbuffer = kvmalloc(args->geo->blksize, GFP_KERNEL | __GFP_NOFAIL); memcpy(tmpbuffer, bp->b_addr, args->geo->blksize); memset(bp->b_addr, 0, args->geo->blksize); leaf_src = (xfs_attr_leafblock_t *)tmpbuffer; @@ -1651,7 +1648,7 @@ xfs_attr3_leaf_compact( */ xfs_trans_log_buf(trans, bp, 0, args->geo->blksize - 1); - kfree(tmpbuffer); + kvfree(tmpbuffer); } /* @@ -2330,7 +2327,7 @@ xfs_attr3_leaf_unbalance( struct xfs_attr_leafblock *tmp_leaf; struct xfs_attr3_icleaf_hdr tmphdr; - tmp_leaf = kzalloc(state->args->geo->blksize, + tmp_leaf = kvzalloc(state->args->geo->blksize, GFP_KERNEL | __GFP_NOFAIL); /* @@ -2371,7 +2368,7 @@ xfs_attr3_leaf_unbalance( } memcpy(save_leaf, tmp_leaf, state->args->geo->blksize); savehdr = tmphdr; /* struct copy */ - kfree(tmp_leaf); + kvfree(tmp_leaf); } xfs_attr3_leaf_hdr_to_disk(state->args->geo, save_leaf, &savehdr);