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e120e2b666
Define named bit-position constants for all CEPH_I_* inode flags and derive the bitmask values from them. This gives every flag a named _BIT constant usable with the test_bit/set_bit/clear_bit family. The intentionally unused bit position 1 is documented inline. Convert all flag modifications to use atomic bitops (set_bit, clear_bit, test_and_clear_bit). The previous code mixed lockless atomic ops on some flags (ERROR_WRITE, ODIRECT) with non-atomic read-modify-write (|= / &= ~) on other flags sharing the same unsigned long. A concurrent non-atomic RMW can clobber an adjacent lockless atomic update -- for example, a lockless clear_bit(ERROR_WRITE) could be silently resurrected by a concurrent ci->i_ceph_flags |= CEPH_I_FLUSH under the spinlock. Using atomic bitops for all modifications eliminates this class of race entirely. Flags whose only users are now the _BIT form (ERROR_WRITE, ASYNC_CHECK_CAPS) have their old mask defines removed to document that callers must use the _BIT constant with the set_bit/test_bit family. ERROR_FILELOCK and SHUTDOWN retain their mask defines because they are still used via bitmask tests in lockless readers (ceph_inode_is_shutdown, reconnect_caps_cb). The direct assignment in ceph_finish_async_create() is converted from i_ceph_flags = CEPH_I_ASYNC_CREATE to set_bit(). This inode is I_NEW at this point -- still invisible to other threads and guaranteed to have zero flags from alloc_inode -- so either form is safe, but set_bit() keeps the conversion uniform. Signed-off-by: Alex Markuze <amarkuze@redhat.com> Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> Signed-off-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
1343 lines
37 KiB
1343 lines
37 KiB