diff options
Diffstat (limited to 'include/linux/backing-dev.h')
| -rw-r--r-- | include/linux/backing-dev.h | 77 |
1 files changed, 57 insertions, 20 deletions
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index c49a2d045e11..13ab79d99268 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -12,6 +12,7 @@ #include <linux/log2.h> #include <linux/proportions.h> #include <linux/kernel.h> +#include <linux/fs.h> #include <asm/atomic.h> struct page; @@ -151,22 +152,43 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); /* * Flags in backing_dev_info::capability - * - 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 */ -#define BDI_CAP_NO_ACCT_DIRTY 0x00000001 /* Dirty pages shouldn't contribute to accounting */ -#define BDI_CAP_NO_WRITEBACK 0x00000002 /* Don't write pages back */ -#define BDI_CAP_MAP_COPY 0x00000004 /* Copy can be mapped (MAP_PRIVATE) */ -#define BDI_CAP_MAP_DIRECT 0x00000008 /* Can be mapped directly (MAP_SHARED) */ -#define BDI_CAP_READ_MAP 0x00000010 /* Can be mapped for reading */ -#define BDI_CAP_WRITE_MAP 0x00000020 /* Can be mapped for writing */ -#define BDI_CAP_EXEC_MAP 0x00000040 /* Can be mapped for execution */ +#define BDI_CAP_NO_ACCT_DIRTY 0x00000001 +#define BDI_CAP_NO_WRITEBACK 0x00000002 +#define BDI_CAP_MAP_COPY 0x00000004 +#define BDI_CAP_MAP_DIRECT 0x00000008 +#define BDI_CAP_READ_MAP 0x00000010 +#define BDI_CAP_WRITE_MAP 0x00000020 +#define BDI_CAP_EXEC_MAP 0x00000040 +#define BDI_CAP_NO_ACCT_WB 0x00000080 + #define BDI_CAP_VMFLAGS \ (BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP) +#define BDI_CAP_NO_ACCT_AND_WRITEBACK \ + (BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB) + #if defined(VM_MAYREAD) && \ (BDI_CAP_READ_MAP != VM_MAYREAD || \ BDI_CAP_WRITE_MAP != VM_MAYWRITE || \ @@ -206,17 +228,32 @@ void clear_bdi_congested(struct backing_dev_info *bdi, int rw); void set_bdi_congested(struct backing_dev_info *bdi, int rw); long congestion_wait(int rw, long timeout); -#define bdi_cap_writeback_dirty(bdi) \ - (!((bdi)->capabilities & BDI_CAP_NO_WRITEBACK)) -#define bdi_cap_account_dirty(bdi) \ - (!((bdi)->capabilities & BDI_CAP_NO_ACCT_DIRTY)) +static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi) +{ + return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK); +} + +static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi) +{ + return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY); +} -#define mapping_cap_writeback_dirty(mapping) \ - bdi_cap_writeback_dirty((mapping)->backing_dev_info) +static inline bool bdi_cap_account_writeback(struct backing_dev_info *bdi) +{ + /* Paranoia: BDI_CAP_NO_WRITEBACK implies BDI_CAP_NO_ACCT_WB */ + return !(bdi->capabilities & (BDI_CAP_NO_ACCT_WB | + BDI_CAP_NO_WRITEBACK)); +} -#define mapping_cap_account_dirty(mapping) \ - bdi_cap_account_dirty((mapping)->backing_dev_info) +static inline bool mapping_cap_writeback_dirty(struct address_space *mapping) +{ + return bdi_cap_writeback_dirty(mapping->backing_dev_info); +} +static inline bool mapping_cap_account_dirty(struct address_space *mapping) +{ + return bdi_cap_account_dirty(mapping->backing_dev_info); +} #endif /* _LINUX_BACKING_DEV_H */ |