c08782dacd
On ia64, powerpc64 and sparc64 the bitfield is modified through a RMW cycle and current gcc rewrites the adjacent 4B word, which in case of a spinlock or atomic has disaterous effect. https://lkml.org/lkml/2012/2/1/220 Signed-off-by: David Sterba <dsterba@suse.cz>
67 lines
1.8 KiB
C
67 lines
1.8 KiB
C
#ifndef __EXTENTMAP__
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#define __EXTENTMAP__
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#include <linux/rbtree.h>
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#define EXTENT_MAP_LAST_BYTE (u64)-4
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#define EXTENT_MAP_HOLE (u64)-3
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#define EXTENT_MAP_INLINE (u64)-2
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#define EXTENT_MAP_DELALLOC (u64)-1
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/* bits for the flags field */
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#define EXTENT_FLAG_PINNED 0 /* this entry not yet on disk, don't free it */
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#define EXTENT_FLAG_COMPRESSED 1
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#define EXTENT_FLAG_VACANCY 2 /* no file extent item found */
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#define EXTENT_FLAG_PREALLOC 3 /* pre-allocated extent */
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struct extent_map {
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struct rb_node rb_node;
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/* all of these are in bytes */
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u64 start;
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u64 len;
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u64 orig_start;
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u64 block_start;
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u64 block_len;
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unsigned long flags;
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struct block_device *bdev;
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atomic_t refs;
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unsigned int in_tree;
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unsigned int compress_type;
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};
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struct extent_map_tree {
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struct rb_root map;
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rwlock_t lock;
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};
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static inline u64 extent_map_end(struct extent_map *em)
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{
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if (em->start + em->len < em->start)
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return (u64)-1;
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return em->start + em->len;
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}
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static inline u64 extent_map_block_end(struct extent_map *em)
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{
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if (em->block_start + em->block_len < em->block_start)
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return (u64)-1;
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return em->block_start + em->block_len;
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}
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void extent_map_tree_init(struct extent_map_tree *tree);
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struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
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u64 start, u64 len);
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int add_extent_mapping(struct extent_map_tree *tree,
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struct extent_map *em);
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int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em);
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struct extent_map *alloc_extent_map(void);
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void free_extent_map(struct extent_map *em);
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int __init extent_map_init(void);
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void extent_map_exit(void);
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int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len);
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struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
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u64 start, u64 len);
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#endif
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