- * - The first two flags control whether dirty pages will contribute to the
- * VM's accounting and whether writepages() should be called for dirty pages
- * (something that would not, for example, be appropriate for ramfs)
- * - These flags let !MMU mmap() govern direct device mapping vs immediate
- * copying more easily for MAP_PRIVATE, especially for ROM filesystems
+ *
+ * The first three flags control whether dirty pages will contribute to the
+ * VM's accounting and whether writepages() should be called for dirty pages
+ * (something that would not, for example, be appropriate for ramfs)
+ *
+ * WARNING: these flags are closely related and should not normally be
+ * used separately. The BDI_CAP_NO_ACCT_AND_WRITEBACK combines these
+ * three flags into a single convenience macro.
+ *
+ * BDI_CAP_NO_ACCT_DIRTY: Dirty pages shouldn't contribute to accounting
+ * BDI_CAP_NO_WRITEBACK: Don't write pages back
+ * BDI_CAP_NO_ACCT_WB: Don't automatically account writeback pages
+ *
+ * These flags let !MMU mmap() govern direct device mapping vs immediate
+ * copying more easily for MAP_PRIVATE, especially for ROM filesystems.
+ *
+ * BDI_CAP_MAP_COPY: Copy can be mapped (MAP_PRIVATE)
+ * BDI_CAP_MAP_DIRECT: Can be mapped directly (MAP_SHARED)
+ * BDI_CAP_READ_MAP: Can be mapped for reading
+ * BDI_CAP_WRITE_MAP: Can be mapped for writing
+ * BDI_CAP_EXEC_MAP: Can be mapped for execution