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[46.135.89.171]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4873cd7d039sm9776805e9.15.2026.03.29.10.20.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 29 Mar 2026 10:20:16 -0700 (PDT) From: Mateusz Guzik To: brauner@kernel.org Cc: viro@zeniv.linux.org.uk, jack@suse.cz, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Mateusz Guzik Subject: [PATCH v3 3/7] fs: enforce locking in icount_read(), add some commentary Date: Sun, 29 Mar 2026 19:19:58 +0200 Message-ID: <20260329172002.3557801-4-mjguzik@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260329172002.3557801-1-mjguzik@gmail.com> References: <20260329172002.3557801-1-mjguzik@gmail.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Signed-off-by: Mateusz Guzik --- include/linux/fs.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/include/linux/fs.h b/include/linux/fs.h index 0cf27085a579..07363fce4406 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2225,13 +2225,21 @@ static inline void mark_inode_dirty_sync(struct inode *inode) __mark_inode_dirty(inode, I_DIRTY_SYNC); } +/* + * returns the refcount on the inode. it can change arbitrarily. + */ static inline int icount_read_once(const struct inode *inode) { return atomic_read(&inode->i_count); } +/* + * returns the refcount on the inode. The lock guarantees no new references + * are added, but references can be dropped as long as the result is > 0. + */ static inline int icount_read(const struct inode *inode) { + lockdep_assert_held(&inode->i_lock); return atomic_read(&inode->i_count); } -- 2.48.1