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b78b728e21Commit1d78d56c43("netfs: Fix folio_queue ENOMEM in writeback by adding a mempool") added a mempool for the folio_queues and made the request, subrequest and folio_queue allocations distinguish between writeback and everything else. Writeback is part of memory reclaim and must not fail due to ENOMEM, so it allocates under GFP_NOFS through mempool_alloc(), which may dip into the pool's reserve and, if that runs empty, wait for elements to be returned. The GFP_KERNEL paths, which can return -ENOMEM to their callers, invoke the pool's ->alloc() callback directly instead. The direct call, however, skips the alloc_hooks() wrapper that the mempool_alloc() macro provides. The pool callbacks, mempool_alloc_slab() and mempool_kmalloc(), call kmem_cache_alloc_noprof() and kmalloc_noprof() and rely on current->alloc_tag having been set by the caller. With CONFIG_MEM_ALLOC_PROFILING_DEBUG=y this leads to current->alloc_tag not set WARNING: ./include/linux/alloc_tag.h:161 at __alloc_tagging_slab_alloc_hook alloc_tag was not set WARNING: ./include/linux/alloc_tag.h:166 at __alloc_tagging_slab_free_hook at allocation and free time respectively, as reported when reading files on a CIFS mount. The allocations are also missing from /proc/allocinfo. Wrap the direct ->alloc() invocations in alloc_hooks() with a new mempool_alloc_noreserve() helper in include/linux/mempool.h, next to the other alloc_hooks()-wrapped macros such as mempool_alloc(). The GFP_KERNEL paths keep their failable allocation semantics, they just get tagged now. Fixes:1d78d56c43("netfs: Fix folio_queue ENOMEM in writeback by adding a mempool") Reported-by: Erhard Furtner <erhard_f@mailbox.org> Closes: https://lore.kernel.org/all/0b004319-9ef7-437c-a4dd-174d6a9a83db@mailbox.org/ Tested-by: Erhard Furtner <erhard_f@mailbox.org> Suggested-by: Suren Baghdasaryan <surenb@google.com> Cc: stable@vger.kernel.org Signed-off-by: Hao Ge <hao.ge@linux.dev> Link: https://patch.msgid.link/20260923063759.34667-1-hao.ge@linux.dev Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
268 lines
7.5 KiB
268 lines
7.5 KiB