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To avoid this, handle the case separately in grow_dev_folio(). This ensures that buffer_head-based filesystems will not encounter the warning when using __GFP_NOFAIL to read metadata after BS > PS support is enabled. Signed-off-by: Baokun Li Reviewed-by: Zhang Yi --- fs/buffer.c | 33 +++++++++++++++++++++++++++++++-- 1 file changed, 31 insertions(+), 2 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index 6a8752f7bbed..2f5a7dd199b2 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1031,6 +1031,35 @@ static sector_t folio_init_buffers(struct folio *folio, return end_block; } +static struct folio *blkdev_get_folio(struct address_space *mapping, + pgoff_t index, fgf_t fgp_flags, gfp_t gfp) +{ + struct folio *folio; + unsigned int min_order = mapping_min_folio_order(mapping); + + /* + * Allocating page units greater than order-1 with __GFP_NOFAIL in + * __alloc_pages_slowpath() can trigger an unexpected WARN_ON. + * Handle this case separately to suppress the warning. + */ + if (min_order <= 1) + return __filemap_get_folio(mapping, index, fgp_flags, gfp); + + while (1) { + folio = __filemap_get_folio(mapping, index, fgp_flags, + gfp & ~__GFP_NOFAIL); + if (!IS_ERR(folio) || !(gfp & __GFP_NOFAIL)) + return folio; + + if (PTR_ERR(folio) != -ENOMEM && PTR_ERR(folio) != -EAGAIN) + return folio; + + memalloc_retry_wait(gfp); + } + + return folio; +} + /* * Create the page-cache folio that contains the requested block. * @@ -1047,8 +1076,8 @@ static bool grow_dev_folio(struct block_device *bdev, sector_t block, struct buffer_head *bh; sector_t end_block = 0; - folio = __filemap_get_folio(mapping, index, - FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp); + folio = blkdev_get_folio(mapping, index, + FGP_LOCK | FGP_ACCESSED | FGP_CREAT, gfp); if (IS_ERR(folio)) return false; -- 2.46.1