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See http://www.infradead.org/rpr.html X-Rspam-User: X-Rspamd-Queue-Id: C21E7140008 X-Rspamd-Server: rspam12 X-Stat-Signature: h1575set18bcbiafte1sgz7poguoxxik X-HE-Tag: 1740581895-212070 X-HE-Meta: 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 E2INz+q6 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Feb 24, 2025 at 07:33:01PM -0500, Mike Snitzer wrote: > Add PF_KCOMPACTD flag and current_is_kcompactd() helper to check for > it so nfs_release_folio() can skip calling nfs_wb_folio() from > kcompactd. > > Otherwise NFS can deadlock waiting for kcompactd enduced writeback > which recurses back to NFS (which triggers writeback to NFSD via > NFS loopback mount on the same host, NFSD blocks waiting for XFS's > call to __filemap_get_folio): Having a flag for a specific kernel thread feels wrong. I'm not an expert in this area, but as fast as I can tell the problem is that kcompactd should be calling into ->release_folio without __GFP_IO set.