diff options
Diffstat (limited to 'include/linux/maple_tree.h')
| -rw-r--r-- | include/linux/maple_tree.h | 87 |
1 files changed, 50 insertions, 37 deletions
diff --git a/include/linux/maple_tree.h b/include/linux/maple_tree.h index 0b82efe0cf1e..4dd668f7b111 100644 --- a/include/linux/maple_tree.h +++ b/include/linux/maple_tree.h @@ -350,6 +350,36 @@ static inline bool mtree_empty(const struct maple_tree *mt) /* Advanced API */ /* + * Maple State Status + * ma_active means the maple state is pointing to a node and offset and can + * continue operating on the tree. + * ma_start means we have not searched the tree. + * ma_root means we have searched the tree and the entry we found lives in + * the root of the tree (ie it has index 0, length 1 and is the only entry in + * the tree). + * ma_none means we have searched the tree and there is no node in the + * tree for this entry. For example, we searched for index 1 in an empty + * tree. Or we have a tree which points to a full leaf node and we + * searched for an entry which is larger than can be contained in that + * leaf node. + * ma_pause means the data within the maple state may be stale, restart the + * operation + * ma_overflow means the search has reached the upper limit of the search + * ma_underflow means the search has reached the lower limit of the search + * ma_error means there was an error, check the node for the error number. + */ +enum maple_status { + ma_active, + ma_start, + ma_root, + ma_none, + ma_pause, + ma_overflow, + ma_underflow, + ma_error, +}; + +/* * The maple state is defined in the struct ma_state and is used to keep track * of information during operations, and even between operations when using the * advanced API. @@ -381,6 +411,13 @@ static inline bool mtree_empty(const struct maple_tree *mt) * When returning a value the maple state index and last respectively contain * the start and end of the range for the entry. Ranges are inclusive in the * Maple Tree. + * + * The status of the state is used to determine how the next action should treat + * the state. For instance, if the status is ma_start then the next action + * should start at the root of the tree and walk down. If the status is + * ma_pause then the node may be stale data and should be discarded. If the + * status is ma_overflow, then the last action hit the upper limit. + * */ struct ma_state { struct maple_tree *tree; /* The tree we're operating in */ @@ -390,6 +427,7 @@ struct ma_state { unsigned long min; /* The minimum index of this node - implied pivot min */ unsigned long max; /* The maximum index of this node - implied pivot max */ struct maple_alloc *alloc; /* Allocated nodes for this operation */ + enum maple_status status; /* The status of the state (active, start, none, etc) */ unsigned char depth; /* depth of tree descent during write */ unsigned char offset; unsigned char mas_flags; @@ -416,28 +454,12 @@ struct ma_wr_state { spin_lock_nested(&((mas)->tree->ma_lock), subclass) #define mas_unlock(mas) spin_unlock(&((mas)->tree->ma_lock)) - /* * Special values for ma_state.node. - * MAS_START means we have not searched the tree. - * MAS_ROOT means we have searched the tree and the entry we found lives in - * the root of the tree (ie it has index 0, length 1 and is the only entry in - * the tree). - * MAS_NONE means we have searched the tree and there is no node in the - * tree for this entry. For example, we searched for index 1 in an empty - * tree. Or we have a tree which points to a full leaf node and we - * searched for an entry which is larger than can be contained in that - * leaf node. * MA_ERROR represents an errno. After dropping the lock and attempting * to resolve the error, the walk would have to be restarted from the * top of the tree as the tree may have been modified. */ -#define MAS_START ((struct maple_enode *)1UL) -#define MAS_ROOT ((struct maple_enode *)5UL) -#define MAS_NONE ((struct maple_enode *)9UL) -#define MAS_PAUSE ((struct maple_enode *)17UL) -#define MAS_OVERFLOW ((struct maple_enode *)33UL) -#define MAS_UNDERFLOW ((struct maple_enode *)65UL) #define MA_ERROR(err) \ ((struct maple_enode *)(((unsigned long)err << 2) | 2UL)) @@ -446,7 +468,8 @@ struct ma_wr_state { .tree = mt, \ .index = first, \ .last = end, \ - .node = MAS_START, \ + .node = NULL, \ + .status = ma_start, \ .min = 0, \ .max = ULONG_MAX, \ .alloc = NULL, \ @@ -477,7 +500,6 @@ void *mas_find_range(struct ma_state *mas, unsigned long max); void *mas_find_rev(struct ma_state *mas, unsigned long min); void *mas_find_range_rev(struct ma_state *mas, unsigned long max); int mas_preallocate(struct ma_state *mas, void *entry, gfp_t gfp); -bool mas_is_err(struct ma_state *mas); bool mas_nomem(struct ma_state *mas, gfp_t gfp); void mas_pause(struct ma_state *mas); @@ -506,28 +528,18 @@ static inline void mas_init(struct ma_state *mas, struct maple_tree *tree, mas->tree = tree; mas->index = mas->last = addr; mas->max = ULONG_MAX; - mas->node = MAS_START; + mas->status = ma_start; + mas->node = NULL; } -/* Checks if a mas has not found anything */ -static inline bool mas_is_none(const struct ma_state *mas) -{ - return mas->node == MAS_NONE; -} - -/* Checks if a mas has been paused */ -static inline bool mas_is_paused(const struct ma_state *mas) +static inline bool mas_is_active(struct ma_state *mas) { - return mas->node == MAS_PAUSE; + return mas->status == ma_active; } -/* Check if the mas is pointing to a node or not */ -static inline bool mas_is_active(struct ma_state *mas) +static inline bool mas_is_err(struct ma_state *mas) { - if ((unsigned long)mas->node >= MAPLE_RESERVED_RANGE) - return true; - - return false; + return mas->status == ma_error; } /** @@ -540,9 +552,10 @@ static inline bool mas_is_active(struct ma_state *mas) * * Context: Any context. */ -static inline void mas_reset(struct ma_state *mas) +static __always_inline void mas_reset(struct ma_state *mas) { - mas->node = MAS_START; + mas->status = ma_start; + mas->node = NULL; } /** @@ -716,7 +729,7 @@ static inline void __mas_set_range(struct ma_state *mas, unsigned long start, static inline void mas_set_range(struct ma_state *mas, unsigned long start, unsigned long last) { - mas->node = MAS_START; + mas_reset(mas); __mas_set_range(mas, start, last); } |