logfs: handle powerfail on NAND flash

[sfrench/cifs-2.6.git] / fs / logfs / logfs.h

diff --git a/fs/logfs/logfs.h b/fs/logfs/logfs.h
index b84b0eec6024d87b17079229e249668f07418400..93b55f3372451b00fd03bad81424808ede0b1825 100644 (file)
--- a/fs/logfs/logfs.h
+++ b/fs/logfs/logfs.h
@@ -144,6 +144,7 @@ struct logfs_area_ops {
  * @erase:                     erase one segment
  * @read:                      read from the device
  * @erase:                     erase part of the device
+ * @can_write_buf:             decide whether wbuf can be written to ofs
  */
 struct logfs_device_ops {
        struct page *(*find_first_sb)(struct super_block *sb, u64 *ofs);
@@ -153,6 +154,7 @@ struct logfs_device_ops {
        void (*writeseg)(struct super_block *sb, u64 ofs, size_t len);
        int (*erase)(struct super_block *sb, loff_t ofs, size_t len,
                        int ensure_write);
+       int (*can_write_buf)(struct super_block *sb, u64 ofs);
        void (*sync)(struct super_block *sb);
        void (*put_device)(struct super_block *sb);
 };
@@ -257,10 +259,14 @@ struct logfs_shadow {
  * struct shadow_tree
  * @new:                       shadows where old_ofs==0, indexed by new_ofs
  * @old:                       shadows where old_ofs!=0, indexed by old_ofs
+ * @segment_map:               bitfield of segments containing shadows
+ * @no_shadowed_segment:       number of segments containing shadows
  */
 struct shadow_tree {
        struct btree_head64 new;
        struct btree_head64 old;
+       struct btree_head32 segment_map;
+       int no_shadowed_segments;
 };
 
 struct object_alias_item {
@@ -305,13 +311,14 @@ typedef int write_alias_t(struct super_block *sb, u64 ino, u64 bix,
                level_t level, int child_no, __be64 val);
 struct logfs_block_ops {
        void    (*write_block)(struct logfs_block *block);
-       gc_level_t      (*block_level)(struct logfs_block *block);
        void    (*free_block)(struct super_block *sb, struct logfs_block*block);
        int     (*write_alias)(struct super_block *sb,
                        struct logfs_block *block,
                        write_alias_t *write_one_alias);
 };
 
+#define MAX_JOURNAL_ENTRIES 256
+
 struct logfs_super {
        struct mtd_info *s_mtd;                 /* underlying device */
        struct block_device *s_bdev;            /* underlying device */
@@ -378,7 +385,7 @@ struct logfs_super {
        u32      s_journal_ec[LOGFS_JOURNAL_SEGS]; /* journal erasecounts */
        u64      s_last_version;
        struct logfs_area *s_journal_area;      /* open journal segment */
-       __be64  s_je_array[64];
+       __be64  s_je_array[MAX_JOURNAL_ENTRIES];
        int     s_no_je;
 
        int      s_sum_index;                   /* for the 12 summaries */
@@ -389,6 +396,7 @@ struct logfs_super {
        int      s_lock_count;
        mempool_t *s_block_pool;                /* struct logfs_block pool */
        mempool_t *s_shadow_pool;               /* struct logfs_shadow pool */
+       struct list_head s_writeback_list;      /* writeback pages */
        /*
         * Space accounting:
         * - s_used_bytes specifies space used to store valid data objects.
@@ -593,19 +601,19 @@ void freeseg(struct super_block *sb, u32 segno);
 int logfs_init_areas(struct super_block *sb);
 void logfs_cleanup_areas(struct super_block *sb);
 int logfs_open_area(struct logfs_area *area, size_t bytes);
-void __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len,
+int __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len,
                int use_filler);
 
-static inline void logfs_buf_write(struct logfs_area *area, u64 ofs,
+static inline int logfs_buf_write(struct logfs_area *area, u64 ofs,
                void *buf, size_t len)
 {
-       __logfs_buf_write(area, ofs, buf, len, 0);
+       return __logfs_buf_write(area, ofs, buf, len, 0);
 }
 
-static inline void logfs_buf_recover(struct logfs_area *area, u64 ofs,
+static inline int logfs_buf_recover(struct logfs_area *area, u64 ofs,
                void *buf, size_t len)
 {
-       __logfs_buf_write(area, ofs, buf, len, 1);
+       return __logfs_buf_write(area, ofs, buf, len, 1);
 }
 
 /* super.c */
@@ -722,4 +730,10 @@ static inline struct logfs_area *get_area(struct super_block *sb,
        return logfs_super(sb)->s_area[(__force u8)gc_level];
 }
 
+static inline void logfs_mempool_destroy(mempool_t *pool)
+{
+       if (pool)
+               mempool_destroy(pool);
+}
+
 #endif