X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=include%2Flinux%2Fbacking-dev.h;h=bd0e3c6f323f3fd1e5ea8b60ac8f1a4fdd7785d8;hb=3374cd1abd478f767aaedf2c21d109596ff0fe72;hp=ad3271d1e90a4061caf159acbd6e60d3479acd05;hpb=a42dde04152750426cc620fd277e80fffae2f65a;p=safe%2Fjmp%2Flinux-2.6 diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index ad3271d..bd0e3c6 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -12,18 +12,24 @@ #include #include #include +#include +#include +#include #include struct page; struct device; +struct dentry; /* * Bits in backing_dev_info.state */ enum bdi_state { - BDI_pdflush, /* A pdflush thread is working this device */ - BDI_write_congested, /* The write queue is getting full */ - BDI_read_congested, /* The read queue is getting full */ + BDI_pending, /* On its way to being activated */ + BDI_wb_alloc, /* Default embedded wb allocated */ + BDI_async_congested, /* The async (write) queue is getting full */ + BDI_sync_congested, /* The sync queue is getting full */ + BDI_registered, /* bdi_register() was done */ BDI_unused, /* Available bits start here */ }; @@ -37,7 +43,23 @@ enum bdi_stat_item { #define BDI_STAT_BATCH (8*(1+ilog2(nr_cpu_ids))) +struct bdi_writeback { + struct list_head list; /* hangs off the bdi */ + + struct backing_dev_info *bdi; /* our parent bdi */ + unsigned int nr; + + unsigned long last_old_flush; /* last old data flush */ + + struct task_struct *task; /* writeback task */ + struct list_head b_dirty; /* dirty inodes */ + struct list_head b_io; /* parked for writeback */ + struct list_head b_more_io; /* parked for more writeback */ +}; + struct backing_dev_info { + struct list_head bdi_list; + struct rcu_head rcu_head; unsigned long ra_pages; /* max readahead in PAGE_CACHE_SIZE units */ unsigned long state; /* Always use atomic bitops on this */ unsigned int capabilities; /* Device capabilities */ @@ -46,6 +68,8 @@ struct backing_dev_info { void (*unplug_io_fn)(struct backing_dev_info *, struct page *); void *unplug_io_data; + char *name; + struct percpu_counter bdi_stat[NR_BDI_STAT_ITEMS]; struct prop_local_percpu completions; @@ -54,7 +78,20 @@ struct backing_dev_info { unsigned int min_ratio; unsigned int max_ratio, max_prop_frac; + struct bdi_writeback wb; /* default writeback info for this bdi */ + spinlock_t wb_lock; /* protects update side of wb_list */ + struct list_head wb_list; /* the flusher threads hanging off this bdi */ + unsigned long wb_mask; /* bitmask of registered tasks */ + unsigned int wb_cnt; /* number of registered tasks */ + + struct list_head work_list; + struct device *dev; + +#ifdef CONFIG_DEBUG_FS + struct dentry *debug_dir; + struct dentry *debug_stats; +#endif }; int bdi_init(struct backing_dev_info *bdi); @@ -64,6 +101,21 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent, const char *fmt, ...); int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev); void bdi_unregister(struct backing_dev_info *bdi); +int bdi_setup_and_register(struct backing_dev_info *, char *, unsigned int); +void bdi_start_writeback(struct backing_dev_info *bdi, struct super_block *sb, + long nr_pages); +int bdi_writeback_task(struct bdi_writeback *wb); +int bdi_has_dirty_io(struct backing_dev_info *bdi); + +extern spinlock_t bdi_lock; +extern struct list_head bdi_list; + +static inline int wb_has_dirty_io(struct bdi_writeback *wb) +{ + return !list_empty(&wb->b_dirty) || + !list_empty(&wb->b_io) || + !list_empty(&wb->b_more_io); +} static inline void __add_bdi_stat(struct backing_dev_info *bdi, enum bdi_stat_item item, s64 amount) @@ -128,6 +180,8 @@ static inline s64 bdi_stat_sum(struct backing_dev_info *bdi, return sum; } +extern void bdi_writeout_inc(struct backing_dev_info *bdi); + /* * maximal error of a stat counter. */ @@ -145,22 +199,46 @@ 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 + * + * BDI_CAP_SWAP_BACKED: Count shmem/tmpfs objects as swap-backed. */ -#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_SWAP_BACKED 0x00000100 + #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 || \ @@ -169,6 +247,7 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio); #endif extern struct backing_dev_info default_backing_dev_info; +extern struct backing_dev_info noop_backing_dev_info; void default_unplug_io_fn(struct backing_dev_info *bdi, struct page *page); int writeback_in_progress(struct backing_dev_info *bdi); @@ -182,35 +261,89 @@ static inline int bdi_congested(struct backing_dev_info *bdi, int bdi_bits) static inline int bdi_read_congested(struct backing_dev_info *bdi) { - return bdi_congested(bdi, 1 << BDI_read_congested); + return bdi_congested(bdi, 1 << BDI_sync_congested); } static inline int bdi_write_congested(struct backing_dev_info *bdi) { - return bdi_congested(bdi, 1 << BDI_write_congested); + return bdi_congested(bdi, 1 << BDI_async_congested); } static inline int bdi_rw_congested(struct backing_dev_info *bdi) { - return bdi_congested(bdi, (1 << BDI_read_congested)| - (1 << BDI_write_congested)); + return bdi_congested(bdi, (1 << BDI_sync_congested) | + (1 << BDI_async_congested)); +} + +enum { + BLK_RW_ASYNC = 0, + BLK_RW_SYNC = 1, +}; + +void clear_bdi_congested(struct backing_dev_info *bdi, int sync); +void set_bdi_congested(struct backing_dev_info *bdi, int sync); +long congestion_wait(int sync, long timeout); + + +static inline bool bdi_cap_writeback_dirty(struct backing_dev_info *bdi) +{ + return !(bdi->capabilities & BDI_CAP_NO_WRITEBACK); } -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); +static inline bool bdi_cap_account_dirty(struct backing_dev_info *bdi) +{ + return !(bdi->capabilities & BDI_CAP_NO_ACCT_DIRTY); +} -#define bdi_cap_writeback_dirty(bdi) \ - (!((bdi)->capabilities & BDI_CAP_NO_WRITEBACK)) +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 bdi_cap_account_dirty(bdi) \ - (!((bdi)->capabilities & BDI_CAP_NO_ACCT_DIRTY)) +static inline bool bdi_cap_swap_backed(struct backing_dev_info *bdi) +{ + return bdi->capabilities & BDI_CAP_SWAP_BACKED; +} -#define mapping_cap_writeback_dirty(mapping) \ - bdi_cap_writeback_dirty((mapping)->backing_dev_info) +static inline bool bdi_cap_flush_forker(struct backing_dev_info *bdi) +{ + return bdi == &default_backing_dev_info; +} -#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); +} + +static inline bool mapping_cap_swap_backed(struct address_space *mapping) +{ + return bdi_cap_swap_backed(mapping->backing_dev_info); +} + +static inline int bdi_sched_wait(void *word) +{ + schedule(); + return 0; +} + +static inline void blk_run_backing_dev(struct backing_dev_info *bdi, + struct page *page) +{ + if (bdi && bdi->unplug_io_fn) + bdi->unplug_io_fn(bdi, page); +} + +static inline void blk_run_address_space(struct address_space *mapping) +{ + if (mapping) + blk_run_backing_dev(mapping->backing_dev_info, NULL); +} #endif /* _LINUX_BACKING_DEV_H */