uapi/linux/btrfs_tree.h

1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
20 /* holds pointers to all of the tree roots */
27  * chunk tree stores translations from logical -> physical block numbering
28  * the super block points to the chunk tree
33  * stores information about which areas of a given device are in use.
34  * one per device.  The tree of tree roots points to the device tree
41 /* directory objectid inside the root tree */
56 /* device stats in the device tree */
59 /* for storing balance parameters in the root tree */
60 #define BTRFS_BALANCE_OBJECTID -4ULL
63 #define BTRFS_ORPHAN_OBJECTID -5ULL
66 #define BTRFS_TREE_LOG_OBJECTID -6ULL
67 #define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL
70 #define BTRFS_TREE_RELOC_OBJECTID -8ULL
71 #define BTRFS_DATA_RELOC_TREE_OBJECTID -9ULL
75  * this allows them to share the logging tree
78 #define BTRFS_EXTENT_CSUM_OBJECTID -10ULL
81 #define BTRFS_FREE_SPACE_OBJECTID -11ULL
87 #define BTRFS_FREE_INO_OBJECTID -12ULL
90 #define BTRFS_MULTIPLE_OBJECTIDS -255ULL
96 #define BTRFS_LAST_FREE_OBJECTID -256ULL
101  * the device items go into the chunk tree.  The key is in the form
122 /* reserve 2-15 close to the inode for later flexibility */
125  * dir items are the name -> inode pointers in a directory.  There is one
138  * extent csums are stored in a separate tree and hold csums for
144  * root items point to tree roots.  They are typically in the root
145  * tree used by the super block to find all the other trees
163  * extent items are in the extent map tree.  These record which blocks
170  * the length, so we save the level in key->offset instead of the length.
191  * Every block group is represented in the free space tree by a free space info
232  * Records the child-parent relationship of qgroups. For
245  * The key type for tree items that are stored persistently, but do not need to
246  * exist for extended period of time. The items can exist in any tree.
252  * - balance status item
263  * The key type for tree items that are stored persistently and usually exist
265  * information, stats or preference values. The item can exist in any tree.
271  * - device statistics, store IO stats in the device tree, one key for all
278  * Persistantly stores the device replace state in the device tree.
285  * These items are part of the filesystem UUID tree.
335  * The key defines the order in the tree, and so it also defines (optimal)
364 	/* the internal btrfs device id */
367 	/* size of the device */
373 	/* optimal io alignment for this device */
376 	/* optimal io width for this device */
379 	/* minimal io size for this device */
382 	/* type and info about this device */
385 	/* expected generation for this device */
389 	 * starting byte of this partition on the device,
397 	/* seek speed 0-100 where 100 is fastest */
400 	/* bandwidth 0-100 where 100 is fastest */
403 	/* btrfs generated uuid for this device */
406 	/* uuid of FS who owns this device */
495 /* following flags only apply to tree blocks */
528  * field points back to the chunk allocation mapping tree that allocated
529  * the extent.  The chunk tree uuid field is a way to double check the owner
602  * Internal in-memory flag that a subvolume has been marked for deletion but
643 	__le64 stransid; /* trans when sent. non-zero for received subvol */
644 	__le64 rtransid; /* trans when received. non-zero for received subvol */
680 	 * BTRFS_BALANCE_ARGS_USAGE_RANGE - range syntax, min..max
712 	 * BTRFS_BALANCE_ARGS_LIMIT_RANGE - the extend version can use minimum
889  * fs_info->avail_*_alloc_bits (in-memory) and balance item fields
890  * (on-disk).  The corresponding on-disk bit in chunk.type is reserved
947  * with a non-qgroup-aware version.