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 <kernel@pankajraghav.com>
Fixes: f078d4ea82 ("xfs: convert kmem_alloc() to kmalloc()")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20240822135018.1931258-8-kernel@pankajraghav.com
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Daniel Gomez <da.gomez@samsung.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Dave Chinner 2024-08-22 15:50:15 +02:00 committed by Christian Brauner
parent 10553a9165
commit de631e1a8b

View File

@ -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);