diff options
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/fs.h | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 75dd16efc9b6..9a5f562abc77 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h | |||
@@ -695,6 +695,10 @@ struct fown_struct { | |||
695 | 695 | ||
696 | /* | 696 | /* |
697 | * Track a single file's readahead state | 697 | * Track a single file's readahead state |
698 | * | ||
699 | * ================#============|==================#==================| | ||
700 | * ^ ^ ^ ^ | ||
701 | * file_ra_state.la_index .ra_index .lookahead_index .readahead_index | ||
698 | */ | 702 | */ |
699 | struct file_ra_state { | 703 | struct file_ra_state { |
700 | unsigned long start; /* Current window */ | 704 | unsigned long start; /* Current window */ |
@@ -704,6 +708,12 @@ struct file_ra_state { | |||
704 | unsigned long prev_index; /* Cache last read() position */ | 708 | unsigned long prev_index; /* Cache last read() position */ |
705 | unsigned long ahead_start; /* Ahead window */ | 709 | unsigned long ahead_start; /* Ahead window */ |
706 | unsigned long ahead_size; | 710 | unsigned long ahead_size; |
711 | |||
712 | pgoff_t la_index; /* enqueue time */ | ||
713 | pgoff_t ra_index; /* begin offset */ | ||
714 | pgoff_t lookahead_index; /* time to do next readahead */ | ||
715 | pgoff_t readahead_index; /* end offset */ | ||
716 | |||
707 | unsigned long ra_pages; /* Maximum readahead window */ | 717 | unsigned long ra_pages; /* Maximum readahead window */ |
708 | unsigned long mmap_hit; /* Cache hit stat for mmap accesses */ | 718 | unsigned long mmap_hit; /* Cache hit stat for mmap accesses */ |
709 | unsigned long mmap_miss; /* Cache miss stat for mmap accesses */ | 719 | unsigned long mmap_miss; /* Cache miss stat for mmap accesses */ |
@@ -712,6 +722,60 @@ struct file_ra_state { | |||
712 | #define RA_FLAG_MISS 0x01 /* a cache miss occured against this file */ | 722 | #define RA_FLAG_MISS 0x01 /* a cache miss occured against this file */ |
713 | #define RA_FLAG_INCACHE 0x02 /* file is already in cache */ | 723 | #define RA_FLAG_INCACHE 0x02 /* file is already in cache */ |
714 | 724 | ||
725 | /* | ||
726 | * Measuring read-ahead sizes. | ||
727 | * | ||
728 | * |----------- readahead size ------------>| | ||
729 | * ===#============|==================#=====================| | ||
730 | * |------- invoke interval ------>|-- lookahead size -->| | ||
731 | */ | ||
732 | static inline unsigned long ra_readahead_size(struct file_ra_state *ra) | ||
733 | { | ||
734 | return ra->readahead_index - ra->ra_index; | ||
735 | } | ||
736 | |||
737 | static inline unsigned long ra_lookahead_size(struct file_ra_state *ra) | ||
738 | { | ||
739 | return ra->readahead_index - ra->lookahead_index; | ||
740 | } | ||
741 | |||
742 | static inline unsigned long ra_invoke_interval(struct file_ra_state *ra) | ||
743 | { | ||
744 | return ra->lookahead_index - ra->la_index; | ||
745 | } | ||
746 | |||
747 | /* | ||
748 | * Check if @index falls in the readahead windows. | ||
749 | */ | ||
750 | static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index) | ||
751 | { | ||
752 | return (index >= ra->la_index && | ||
753 | index < ra->readahead_index); | ||
754 | } | ||
755 | |||
756 | /* | ||
757 | * Where is the old read-ahead and look-ahead? | ||
758 | */ | ||
759 | static inline void ra_set_index(struct file_ra_state *ra, | ||
760 | pgoff_t la_index, pgoff_t ra_index) | ||
761 | { | ||
762 | ra->la_index = la_index; | ||
763 | ra->ra_index = ra_index; | ||
764 | } | ||
765 | |||
766 | /* | ||
767 | * Where is the new read-ahead and look-ahead? | ||
768 | */ | ||
769 | static inline void ra_set_size(struct file_ra_state *ra, | ||
770 | unsigned long ra_size, unsigned long la_size) | ||
771 | { | ||
772 | ra->readahead_index = ra->ra_index + ra_size; | ||
773 | ra->lookahead_index = ra->ra_index + ra_size - la_size; | ||
774 | } | ||
775 | |||
776 | unsigned long ra_submit(struct file_ra_state *ra, | ||
777 | struct address_space *mapping, struct file *filp); | ||
778 | |||
715 | struct file { | 779 | struct file { |
716 | /* | 780 | /* |
717 | * fu_list becomes invalid after file_free is called and queued via | 781 | * fu_list becomes invalid after file_free is called and queued via |