192  *  blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
196  *  - new PA:				buddy += N; PA = N
197  *  - use inode PA:			on-disk += N; PA -= N
198  *  - discard inode PA			buddy -= on-disk - PA; PA = 0
199  *  - use locality group PA		on-disk += N; PA -= N
200  *  - discard locality group PA		buddy -= PA; PA = 0
201  *  note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
203  *        bits from PA, only from on-disk bitmap
213  *     bit set and PA claims same block, it's OK. IOW, one can set bit in
214  *     on-disk bitmap if buddy has same bit set or/and PA covers corresponded
219  *    - new PA
220  *      blocks for PA are allocated in the buddy, buddy must be referenced
221  *      until PA is linked to allocation group to avoid concurrent buddy init
222  *    - use inode PA
223  *      we need to make sure that either on-disk bitmap or PA has uptodate data
224  *      given (3) we care that PA-=N operation doesn't interfere with init
225  *    - discard inode PA
227  *    - use locality group PA
228  *      again PA-=N must be serialized with init
229  *    - discard locality group PA
231  *  - new PA vs.
232  *    - use inode PA
234  *    - discard inode PA
235  *      discard process must wait until PA isn't used by another process
236  *    - use locality group PA
238  *    - discard locality group PA
239  *      discard process must wait until PA isn't used by another process
240  *  - use inode PA
241  *    - use inode PA
243  *    - discard inode PA
244  *      discard process must wait until PA isn't used by another process
245  *    - use locality group PA
247  *    - discard locality group PA
248  *      discard process must wait until PA isn't used by another process
251  *  - PA is referenced and while it is no discard is possible
252  *  - PA is referenced until block isn't marked in on-disk bitmap
253  *  - PA changes only after on-disk bitmap
258  * a special case when we've used PA to emptiness. no need to modify buddy
273  *    find proper PA (per-inode or group)
277  *    release PA
289  *    remove PA from object (inode or locality group)
301  *  - per-pa lock		(pa)
304  *  - new pa
308  *  - find and use pa:
309  *    pa
311  *  - release consumed pa:
312  *    pa
318  *        pa
322  *        pa
327  *        pa
689 		struct ext4_prealloc_space *pa;  in __mb_check_buddy()  local
690 		pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);  in __mb_check_buddy()
691 		ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k);  in __mb_check_buddy()
693 		for (i = 0; i < pa->pa_len; i++)  in __mb_check_buddy()
2949 	struct ext4_prealloc_space *pa;  in ext4_mb_cleanup_pa()  local
2954 		pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);  in ext4_mb_cleanup_pa()
2955 		list_del(&pa->pa_group_list);  in ext4_mb_cleanup_pa()
2957 		kmem_cache_free(ext4_pspace_cachep, pa);  in ext4_mb_cleanup_pa()
3448 	struct ext4_prealloc_space *pa;  in ext4_mb_normalize_request()  local
3551 	list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {  in ext4_mb_normalize_request()
3554 		if (pa->pa_deleted)  in ext4_mb_normalize_request()
3556 		spin_lock(&pa->pa_lock);  in ext4_mb_normalize_request()
3557 		if (pa->pa_deleted) {  in ext4_mb_normalize_request()
3558 			spin_unlock(&pa->pa_lock);  in ext4_mb_normalize_request()
3562 		pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),  in ext4_mb_normalize_request()
3563 						  pa->pa_len);  in ext4_mb_normalize_request()
3565 		/* PA must not overlap original request */  in ext4_mb_normalize_request()
3567 			ac->ac_o_ex.fe_logical < pa->pa_lstart));  in ext4_mb_normalize_request()
3570 		if (pa->pa_lstart >= end || pa_end <= start) {  in ext4_mb_normalize_request()
3571 			spin_unlock(&pa->pa_lock);  in ext4_mb_normalize_request()
3574 		BUG_ON(pa->pa_lstart <= start && pa_end >= end);  in ext4_mb_normalize_request()
3576 		/* adjust start or end to be adjacent to this pa */  in ext4_mb_normalize_request()
3580 		} else if (pa->pa_lstart > ac->ac_o_ex.fe_logical) {  in ext4_mb_normalize_request()
3581 			BUG_ON(pa->pa_lstart > end);  in ext4_mb_normalize_request()
3582 			end = pa->pa_lstart;  in ext4_mb_normalize_request()
3584 		spin_unlock(&pa->pa_lock);  in ext4_mb_normalize_request()
3591 	list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {  in ext4_mb_normalize_request()
3594 		spin_lock(&pa->pa_lock);  in ext4_mb_normalize_request()
3595 		if (pa->pa_deleted == 0) {  in ext4_mb_normalize_request()
3596 			pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),  in ext4_mb_normalize_request()
3597 							  pa->pa_len);  in ext4_mb_normalize_request()
3598 			BUG_ON(!(start >= pa_end || end <= pa->pa_lstart));  in ext4_mb_normalize_request()
3600 		spin_unlock(&pa->pa_lock);  in ext4_mb_normalize_request()
3665  * Called on failure; free up any blocks from the inode PA for this
3672 	struct ext4_prealloc_space *pa = ac->ac_pa;  in ext4_discard_allocated_blocks()  local
3676 	if (pa == NULL) {  in ext4_discard_allocated_blocks()
3696 	if (pa->pa_type == MB_INODE_PA)  in ext4_discard_allocated_blocks()
3697 		pa->pa_free += ac->ac_b_ex.fe_len;  in ext4_discard_allocated_blocks()
3704 				struct ext4_prealloc_space *pa)  in ext4_mb_use_inode_pa()  argument
3712 	start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);  in ext4_mb_use_inode_pa()
3713 	end = min(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len),  in ext4_mb_use_inode_pa()
3720 	ac->ac_pa = pa;  in ext4_mb_use_inode_pa()
3722 	BUG_ON(start < pa->pa_pstart);  in ext4_mb_use_inode_pa()
3723 	BUG_ON(end > pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len));  in ext4_mb_use_inode_pa()
3724 	BUG_ON(pa->pa_free < len);  in ext4_mb_use_inode_pa()
3725 	pa->pa_free -= len;  in ext4_mb_use_inode_pa()
3727 	mb_debug(ac->ac_sb, "use %llu/%d from inode pa %p\n", start, len, pa);  in ext4_mb_use_inode_pa()
3734 				struct ext4_prealloc_space *pa)  in ext4_mb_use_group_pa()  argument
3738 	ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,  in ext4_mb_use_group_pa()
3743 	ac->ac_pa = pa;  in ext4_mb_use_group_pa()
3747 	 * instead we correct pa later, after blocks are marked  in ext4_mb_use_group_pa()
3749 	 * Other CPUs are prevented from allocating from this pa by lg_mutex  in ext4_mb_use_group_pa()
3751 	mb_debug(ac->ac_sb, "use %u/%u from group pa %p\n",  in ext4_mb_use_group_pa()
3752 		 pa->pa_lstart-len, len, pa);  in ext4_mb_use_group_pa()
3763 			struct ext4_prealloc_space *pa,  in ext4_mb_check_group_pa()  argument
3769 		atomic_inc(&pa->pa_count);  in ext4_mb_check_group_pa()
3770 		return pa;  in ext4_mb_check_group_pa()
3773 	new_distance = abs(goal_block - pa->pa_pstart);  in ext4_mb_check_group_pa()
3780 	atomic_inc(&pa->pa_count);  in ext4_mb_check_group_pa()
3781 	return pa;  in ext4_mb_check_group_pa()
3794 	struct ext4_prealloc_space *pa, *cpa = NULL;  in ext4_mb_use_preallocated()  local
3803 	list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {  in ext4_mb_use_preallocated()
3807 		if (ac->ac_o_ex.fe_logical < pa->pa_lstart ||  in ext4_mb_use_preallocated()
3808 		    ac->ac_o_ex.fe_logical >= (pa->pa_lstart +  in ext4_mb_use_preallocated()
3809 					       EXT4_C2B(sbi, pa->pa_len)))  in ext4_mb_use_preallocated()
3814 		    (pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len) >  in ext4_mb_use_preallocated()
3819 		spin_lock(&pa->pa_lock);  in ext4_mb_use_preallocated()
3820 		if (pa->pa_deleted == 0 && pa->pa_free) {  in ext4_mb_use_preallocated()
3821 			atomic_inc(&pa->pa_count);  in ext4_mb_use_preallocated()
3822 			ext4_mb_use_inode_pa(ac, pa);  in ext4_mb_use_preallocated()
3823 			spin_unlock(&pa->pa_lock);  in ext4_mb_use_preallocated()
3828 		spin_unlock(&pa->pa_lock);  in ext4_mb_use_preallocated()
3852 		list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[i],  in ext4_mb_use_preallocated()
3854 			spin_lock(&pa->pa_lock);  in ext4_mb_use_preallocated()
3855 			if (pa->pa_deleted == 0 &&  in ext4_mb_use_preallocated()
3856 					pa->pa_free >= ac->ac_o_ex.fe_len) {  in ext4_mb_use_preallocated()
3859 								pa, cpa);  in ext4_mb_use_preallocated()
3861 			spin_unlock(&pa->pa_lock);  in ext4_mb_use_preallocated()
3907 	struct ext4_prealloc_space *pa;  in ext4_mb_generate_from_pa()  local
3923 		pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);  in ext4_mb_generate_from_pa()
3924 		spin_lock(&pa->pa_lock);  in ext4_mb_generate_from_pa()
3925 		ext4_get_group_no_and_offset(sb, pa->pa_pstart,  in ext4_mb_generate_from_pa()
3927 		len = pa->pa_len;  in ext4_mb_generate_from_pa()
3928 		spin_unlock(&pa->pa_lock);  in ext4_mb_generate_from_pa()
3939 				    struct ext4_prealloc_space *pa)  in ext4_mb_mark_pa_deleted()  argument
3943 	if (pa->pa_deleted) {  in ext4_mb_mark_pa_deleted()
3944 		ext4_warning(sb, "deleted pa, type:%d, pblk:%llu, lblk:%u, len:%d\n",  in ext4_mb_mark_pa_deleted()
3945 			     pa->pa_type, pa->pa_pstart, pa->pa_lstart,  in ext4_mb_mark_pa_deleted()
3946 			     pa->pa_len);  in ext4_mb_mark_pa_deleted()
3950 	pa->pa_deleted = 1;  in ext4_mb_mark_pa_deleted()
3952 	if (pa->pa_type == MB_INODE_PA) {  in ext4_mb_mark_pa_deleted()
3953 		ei = EXT4_I(pa->pa_inode);  in ext4_mb_mark_pa_deleted()
3960 	struct ext4_prealloc_space *pa;  in ext4_mb_pa_callback()  local
3961 	pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);  in ext4_mb_pa_callback()
3963 	BUG_ON(atomic_read(&pa->pa_count));  in ext4_mb_pa_callback()
3964 	BUG_ON(pa->pa_deleted == 0);  in ext4_mb_pa_callback()
3965 	kmem_cache_free(ext4_pspace_cachep, pa);  in ext4_mb_pa_callback()
3973 			struct super_block *sb, struct ext4_prealloc_space *pa)  in ext4_mb_put_pa()  argument
3979 	spin_lock(&pa->pa_lock);  in ext4_mb_put_pa()
3980 	if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0) {  in ext4_mb_put_pa()
3981 		spin_unlock(&pa->pa_lock);  in ext4_mb_put_pa()
3985 	if (pa->pa_deleted == 1) {  in ext4_mb_put_pa()
3986 		spin_unlock(&pa->pa_lock);  in ext4_mb_put_pa()
3990 	ext4_mb_mark_pa_deleted(sb, pa);  in ext4_mb_put_pa()
3991 	spin_unlock(&pa->pa_lock);  in ext4_mb_put_pa()
3993 	grp_blk = pa->pa_pstart;  in ext4_mb_put_pa()
3996 	 * next group when pa is used up  in ext4_mb_put_pa()
3998 	if (pa->pa_type == MB_GROUP_PA)  in ext4_mb_put_pa()
4007 	 *					find block B in PA  in ext4_mb_put_pa()
4010 	 *					drop PA from group  in ext4_mb_put_pa()
4014 	 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"  in ext4_mb_put_pa()
4018 	list_del(&pa->pa_group_list);  in ext4_mb_put_pa()
4021 	spin_lock(pa->pa_obj_lock);  in ext4_mb_put_pa()
4022 	list_del_rcu(&pa->pa_inode_list);  in ext4_mb_put_pa()
4023 	spin_unlock(pa->pa_obj_lock);  in ext4_mb_put_pa()
4025 	call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);  in ext4_mb_put_pa()
4036 	struct ext4_prealloc_space *pa;  in ext4_mb_new_inode_pa()  local
4046 	pa = ac->ac_pa;  in ext4_mb_new_inode_pa()
4086 	pa->pa_lstart = ac->ac_b_ex.fe_logical;  in ext4_mb_new_inode_pa()
4087 	pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);  in ext4_mb_new_inode_pa()
4088 	pa->pa_len = ac->ac_b_ex.fe_len;  in ext4_mb_new_inode_pa()
4089 	pa->pa_free = pa->pa_len;  in ext4_mb_new_inode_pa()
4090 	spin_lock_init(&pa->pa_lock);  in ext4_mb_new_inode_pa()
4091 	INIT_LIST_HEAD(&pa->pa_inode_list);  in ext4_mb_new_inode_pa()
4092 	INIT_LIST_HEAD(&pa->pa_group_list);  in ext4_mb_new_inode_pa()
4093 	pa->pa_deleted = 0;  in ext4_mb_new_inode_pa()
4094 	pa->pa_type = MB_INODE_PA;  in ext4_mb_new_inode_pa()
4096 	mb_debug(sb, "new inode pa %p: %llu/%d for %u\n", pa, pa->pa_pstart,  in ext4_mb_new_inode_pa()
4097 		 pa->pa_len, pa->pa_lstart);  in ext4_mb_new_inode_pa()
4098 	trace_ext4_mb_new_inode_pa(ac, pa);  in ext4_mb_new_inode_pa()
4100 	ext4_mb_use_inode_pa(ac, pa);  in ext4_mb_new_inode_pa()
4101 	atomic_add(pa->pa_free, &sbi->s_mb_preallocated);  in ext4_mb_new_inode_pa()
4106 	pa->pa_obj_lock = &ei->i_prealloc_lock;  in ext4_mb_new_inode_pa()
4107 	pa->pa_inode = ac->ac_inode;  in ext4_mb_new_inode_pa()
4109 	list_add(&pa->pa_group_list, &grp->bb_prealloc_list);  in ext4_mb_new_inode_pa()
4111 	spin_lock(pa->pa_obj_lock);  in ext4_mb_new_inode_pa()
4112 	list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);  in ext4_mb_new_inode_pa()
4113 	spin_unlock(pa->pa_obj_lock);  in ext4_mb_new_inode_pa()
4125 	struct ext4_prealloc_space *pa;  in ext4_mb_new_group_pa()  local
4134 	pa = ac->ac_pa;  in ext4_mb_new_group_pa()
4140 	pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);  in ext4_mb_new_group_pa()
4141 	pa->pa_lstart = pa->pa_pstart;  in ext4_mb_new_group_pa()
4142 	pa->pa_len = ac->ac_b_ex.fe_len;  in ext4_mb_new_group_pa()
4143 	pa->pa_free = pa->pa_len;  in ext4_mb_new_group_pa()
4144 	spin_lock_init(&pa->pa_lock);  in ext4_mb_new_group_pa()
4145 	INIT_LIST_HEAD(&pa->pa_inode_list);  in ext4_mb_new_group_pa()
4146 	INIT_LIST_HEAD(&pa->pa_group_list);  in ext4_mb_new_group_pa()
4147 	pa->pa_deleted = 0;  in ext4_mb_new_group_pa()
4148 	pa->pa_type = MB_GROUP_PA;  in ext4_mb_new_group_pa()
4150 	mb_debug(sb, "new group pa %p: %llu/%d for %u\n", pa, pa->pa_pstart,  in ext4_mb_new_group_pa()
4151 		 pa->pa_len, pa->pa_lstart);  in ext4_mb_new_group_pa()
4152 	trace_ext4_mb_new_group_pa(ac, pa);  in ext4_mb_new_group_pa()
4154 	ext4_mb_use_group_pa(ac, pa);  in ext4_mb_new_group_pa()
4155 	atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);  in ext4_mb_new_group_pa()
4161 	pa->pa_obj_lock = &lg->lg_prealloc_lock;  in ext4_mb_new_group_pa()
4162 	pa->pa_inode = NULL;  in ext4_mb_new_group_pa()
4164 	list_add(&pa->pa_group_list, &grp->bb_prealloc_list);  in ext4_mb_new_group_pa()
4167 	 * We will later add the new pa to the right bucket  in ext4_mb_new_group_pa()
4183  * @pa must be unlinked from inode and group lists, so that
4190 			struct ext4_prealloc_space *pa)  in ext4_mb_release_inode_pa()  argument
4201 	BUG_ON(pa->pa_deleted == 0);  in ext4_mb_release_inode_pa()
4202 	ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);  in ext4_mb_release_inode_pa()
4203 	grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit);  in ext4_mb_release_inode_pa()
4204 	BUG_ON(group != e4b->bd_group && pa->pa_len != 0);  in ext4_mb_release_inode_pa()
4205 	end = bit + pa->pa_len;  in ext4_mb_release_inode_pa()
4218 		trace_ext4_mb_release_inode_pa(pa, (grp_blk_start +  in ext4_mb_release_inode_pa()
4221 		mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);  in ext4_mb_release_inode_pa()
4224 	if (free != pa->pa_free) {  in ext4_mb_release_inode_pa()
4226 			 "pa %p: logic %lu, phys. %lu, len %d",  in ext4_mb_release_inode_pa()
4227 			 pa, (unsigned long) pa->pa_lstart,  in ext4_mb_release_inode_pa()
4228 			 (unsigned long) pa->pa_pstart,  in ext4_mb_release_inode_pa()
4229 			 pa->pa_len);  in ext4_mb_release_inode_pa()
4231 					free, pa->pa_free);  in ext4_mb_release_inode_pa()
4233 		 * pa is already deleted so we use the value obtained  in ext4_mb_release_inode_pa()
4244 				struct ext4_prealloc_space *pa)  in ext4_mb_release_group_pa()  argument
4250 	trace_ext4_mb_release_group_pa(sb, pa);  in ext4_mb_release_group_pa()
4251 	BUG_ON(pa->pa_deleted == 0);  in ext4_mb_release_group_pa()
4252 	ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);  in ext4_mb_release_group_pa()
4253 	BUG_ON(group != e4b->bd_group && pa->pa_len != 0);  in ext4_mb_release_group_pa()
4254 	mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);  in ext4_mb_release_group_pa()
4255 	atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);  in ext4_mb_release_group_pa()
4256 	trace_ext4_mballoc_discard(sb, NULL, group, bit, pa->pa_len);  in ext4_mb_release_group_pa()
4276 	struct ext4_prealloc_space *pa, *tmp;  in ext4_mb_discard_group_preallocations()  local
4305 	list_for_each_entry_safe(pa, tmp,  in ext4_mb_discard_group_preallocations()
4307 		spin_lock(&pa->pa_lock);  in ext4_mb_discard_group_preallocations()
4308 		if (atomic_read(&pa->pa_count)) {  in ext4_mb_discard_group_preallocations()
4309 			spin_unlock(&pa->pa_lock);  in ext4_mb_discard_group_preallocations()
4313 		if (pa->pa_deleted) {  in ext4_mb_discard_group_preallocations()
4314 			spin_unlock(&pa->pa_lock);  in ext4_mb_discard_group_preallocations()
4319 		ext4_mb_mark_pa_deleted(sb, pa);  in ext4_mb_discard_group_preallocations()
4325 		free += pa->pa_free;  in ext4_mb_discard_group_preallocations()
4327 		spin_unlock(&pa->pa_lock);  in ext4_mb_discard_group_preallocations()
4329 		list_del(&pa->pa_group_list);  in ext4_mb_discard_group_preallocations()
4330 		list_add(&pa->u.pa_tmp_list, &list);  in ext4_mb_discard_group_preallocations()
4334 	list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {  in ext4_mb_discard_group_preallocations()
4337 		spin_lock(pa->pa_obj_lock);  in ext4_mb_discard_group_preallocations()
4338 		list_del_rcu(&pa->pa_inode_list);  in ext4_mb_discard_group_preallocations()
4339 		spin_unlock(pa->pa_obj_lock);  in ext4_mb_discard_group_preallocations()
4341 		if (pa->pa_type == MB_GROUP_PA)  in ext4_mb_discard_group_preallocations()
4342 			ext4_mb_release_group_pa(&e4b, pa);  in ext4_mb_discard_group_preallocations()
4344 			ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);  in ext4_mb_discard_group_preallocations()
4346 		list_del(&pa->u.pa_tmp_list);  in ext4_mb_discard_group_preallocations()
4347 		call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);  in ext4_mb_discard_group_preallocations()
4373 	struct ext4_prealloc_space *pa, *tmp;  in ext4_discard_preallocations()  local
4398 	/* first, collect all pa's in the inode */  in ext4_discard_preallocations()
4401 		pa = list_entry(ei->i_prealloc_list.prev,  in ext4_discard_preallocations()
4403 		BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock);  in ext4_discard_preallocations()
4404 		spin_lock(&pa->pa_lock);  in ext4_discard_preallocations()
4405 		if (atomic_read(&pa->pa_count)) {  in ext4_discard_preallocations()
4408 			spin_unlock(&pa->pa_lock);  in ext4_discard_preallocations()
4411 				 "uh-oh! used pa while discarding");  in ext4_discard_preallocations()
4417 		if (pa->pa_deleted == 0) {  in ext4_discard_preallocations()
4418 			ext4_mb_mark_pa_deleted(sb, pa);  in ext4_discard_preallocations()
4419 			spin_unlock(&pa->pa_lock);  in ext4_discard_preallocations()
4420 			list_del_rcu(&pa->pa_inode_list);  in ext4_discard_preallocations()
4421 			list_add(&pa->u.pa_tmp_list, &list);  in ext4_discard_preallocations()
4426 		/* someone is deleting pa right now */  in ext4_discard_preallocations()
4427 		spin_unlock(&pa->pa_lock);  in ext4_discard_preallocations()
4431 		 * doesn't mean pa is already unlinked from  in ext4_discard_preallocations()
4435 		 * pa from inode's list may access already  in ext4_discard_preallocations()
4447 	list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {  in ext4_discard_preallocations()
4448 		BUG_ON(pa->pa_type != MB_INODE_PA);  in ext4_discard_preallocations()
4449 		group = ext4_get_group_number(sb, pa->pa_pstart);  in ext4_discard_preallocations()
4469 		list_del(&pa->pa_group_list);  in ext4_discard_preallocations()
4470 		ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);  in ext4_discard_preallocations()
4476 		list_del(&pa->u.pa_tmp_list);  in ext4_discard_preallocations()
4477 		call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);  in ext4_discard_preallocations()
4483 	struct ext4_prealloc_space *pa;  in ext4_mb_pa_alloc()  local
4486 	pa = kmem_cache_zalloc(ext4_pspace_cachep, GFP_NOFS);  in ext4_mb_pa_alloc()
4487 	if (!pa)  in ext4_mb_pa_alloc()
4489 	atomic_set(&pa->pa_count, 1);  in ext4_mb_pa_alloc()
4490 	ac->ac_pa = pa;  in ext4_mb_pa_alloc()
4496 	struct ext4_prealloc_space *pa = ac->ac_pa;  in ext4_mb_pa_free()  local
4498 	BUG_ON(!pa);  in ext4_mb_pa_free()
4500 	WARN_ON(!atomic_dec_and_test(&pa->pa_count));  in ext4_mb_pa_free()
4501 	kmem_cache_free(ext4_pspace_cachep, pa);  in ext4_mb_pa_free()
4516 		struct ext4_prealloc_space *pa;  in ext4_mb_show_pa()  local
4521 			pa = list_entry(cur, struct ext4_prealloc_space,  in ext4_mb_show_pa()
4523 			spin_lock(&pa->pa_lock);  in ext4_mb_show_pa()
4524 			ext4_get_group_no_and_offset(sb, pa->pa_pstart,  in ext4_mb_show_pa()
4526 			spin_unlock(&pa->pa_lock);  in ext4_mb_show_pa()
4527 			mb_debug(sb, "PA:%u:%d:%d\n", i, start,  in ext4_mb_show_pa()
4528 				 pa->pa_len);  in ext4_mb_show_pa()
4695 	struct ext4_prealloc_space *pa, *tmp;  in ext4_mb_discard_lg_preallocations()  local
4702 	list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order],  in ext4_mb_discard_lg_preallocations()
4705 		spin_lock(&pa->pa_lock);  in ext4_mb_discard_lg_preallocations()
4706 		if (atomic_read(&pa->pa_count)) {  in ext4_mb_discard_lg_preallocations()
4708 			 * This is the pa that we just used  in ext4_mb_discard_lg_preallocations()
4712 			spin_unlock(&pa->pa_lock);  in ext4_mb_discard_lg_preallocations()
4715 		if (pa->pa_deleted) {  in ext4_mb_discard_lg_preallocations()
4716 			spin_unlock(&pa->pa_lock);  in ext4_mb_discard_lg_preallocations()
4720 		BUG_ON(pa->pa_type != MB_GROUP_PA);  in ext4_mb_discard_lg_preallocations()
4723 		ext4_mb_mark_pa_deleted(sb, pa);  in ext4_mb_discard_lg_preallocations()
4724 		spin_unlock(&pa->pa_lock);  in ext4_mb_discard_lg_preallocations()
4726 		list_del_rcu(&pa->pa_inode_list);  in ext4_mb_discard_lg_preallocations()
4727 		list_add(&pa->u.pa_tmp_list, &discard_list);  in ext4_mb_discard_lg_preallocations()
4742 	list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) {  in ext4_mb_discard_lg_preallocations()
4745 		group = ext4_get_group_number(sb, pa->pa_pstart);  in ext4_mb_discard_lg_preallocations()
4754 		list_del(&pa->pa_group_list);  in ext4_mb_discard_lg_preallocations()
4755 		ext4_mb_release_group_pa(&e4b, pa);  in ext4_mb_discard_lg_preallocations()
4759 		list_del(&pa->u.pa_tmp_list);  in ext4_mb_discard_lg_preallocations()
4760 		call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);  in ext4_mb_discard_lg_preallocations()
4778 	struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa;  in ext4_mb_add_n_trim()  local
4780 	order = fls(pa->pa_free) - 1;  in ext4_mb_add_n_trim()
4794 		if (!added && pa->pa_free < tmp_pa->pa_free) {  in ext4_mb_add_n_trim()
4796 			list_add_tail_rcu(&pa->pa_inode_list,  in ext4_mb_add_n_trim()
4808 		list_add_tail_rcu(&pa->pa_inode_list,  in ext4_mb_add_n_trim()
4822  * if per-inode prealloc list is too long, trim some PA
4846 	struct ext4_prealloc_space *pa = ac->ac_pa;  in ext4_mb_release_context()  local
4847 	if (pa) {  in ext4_mb_release_context()
4848 		if (pa->pa_type == MB_GROUP_PA) {  in ext4_mb_release_context()
4850 			spin_lock(&pa->pa_lock);  in ext4_mb_release_context()
4851 			pa->pa_pstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);  in ext4_mb_release_context()
4852 			pa->pa_lstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len);  in ext4_mb_release_context()
4853 			pa->pa_free -= ac->ac_b_ex.fe_len;  in ext4_mb_release_context()
4854 			pa->pa_len -= ac->ac_b_ex.fe_len;  in ext4_mb_release_context()
4855 			spin_unlock(&pa->pa_lock);  in ext4_mb_release_context()
4858 			 * We want to add the pa to the right bucket.  in ext4_mb_release_context()
4863 			if (likely(pa->pa_free)) {  in ext4_mb_release_context()
4864 				spin_lock(pa->pa_obj_lock);  in ext4_mb_release_context()
4865 				list_del_rcu(&pa->pa_inode_list);  in ext4_mb_release_context()
4866 				spin_unlock(pa->pa_obj_lock);  in ext4_mb_release_context()
4871 		if (pa->pa_type == MB_INODE_PA) {  in ext4_mb_release_context()
4874 			 * to trim the least recently used PA.  in ext4_mb_release_context()
4876 			spin_lock(pa->pa_obj_lock);  in ext4_mb_release_context()
4877 			list_move(&pa->pa_inode_list, &ei->i_prealloc_list);  in ext4_mb_release_context()
4878 			spin_unlock(pa->pa_obj_lock);  in ext4_mb_release_context()
4881 		ext4_mb_put_pa(ac, ac->ac_sb, pa);  in ext4_mb_release_context()
5040 		 * pa allocated above is added to grp->bb_prealloc_list only  in ext4_mb_new_blocks()
5044 		 * So we have to free this pa here itself.  in ext4_mb_new_blocks()
5069 		 * If block allocation fails then the pa allocated above  in ext4_mb_new_blocks()