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748f553c3c
KCSAN reports that there's unlocked access mixed with locked access, which is technically correct but is not a bug. To avoid false alerts at least from KCSAN, add annotation and use a wrapper whenever ->full is accessed for read outside of lock. It is used as a fast check and only advisory. In the worst case the block reserve is found !full and becomes full in the meantime, but properly handled. Depending on the value of ->full, btrfs_block_rsv_release decides where to return the reservation, and block_rsv_release_bytes handles a NULL pointer for block_rsv and if it's not NULL then it double checks the full status under a lock. Link: https://lore.kernel.org/linux-btrfs/CAAwBoOJDjei5Hnem155N_cJwiEkVwJYvgN-tQrwWbZQGhFU=cA@mail.gmail.com/ Link: https://lore.kernel.org/linux-btrfs/YvHU/vsXd7uz5V6j@hungrycats.org Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Signed-off-by: David Sterba <dsterba@suse.com>
104 lines
3.5 KiB
C
104 lines
3.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef BTRFS_BLOCK_RSV_H
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#define BTRFS_BLOCK_RSV_H
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struct btrfs_trans_handle;
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enum btrfs_reserve_flush_enum;
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/*
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* Types of block reserves
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*/
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enum btrfs_rsv_type {
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BTRFS_BLOCK_RSV_GLOBAL,
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BTRFS_BLOCK_RSV_DELALLOC,
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BTRFS_BLOCK_RSV_TRANS,
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BTRFS_BLOCK_RSV_CHUNK,
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BTRFS_BLOCK_RSV_DELOPS,
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BTRFS_BLOCK_RSV_DELREFS,
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BTRFS_BLOCK_RSV_EMPTY,
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BTRFS_BLOCK_RSV_TEMP,
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};
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struct btrfs_block_rsv {
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u64 size;
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u64 reserved;
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struct btrfs_space_info *space_info;
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spinlock_t lock;
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bool full;
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bool failfast;
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/* Block reserve type, one of BTRFS_BLOCK_RSV_* */
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enum btrfs_rsv_type type:8;
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/*
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* Qgroup equivalent for @size @reserved
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*
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* Unlike normal @size/@reserved for inode rsv, qgroup doesn't care
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* about things like csum size nor how many tree blocks it will need to
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* reserve.
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*
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* Qgroup cares more about net change of the extent usage.
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*
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* So for one newly inserted file extent, in worst case it will cause
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* leaf split and level increase, nodesize for each file extent is
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* already too much.
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*
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* In short, qgroup_size/reserved is the upper limit of possible needed
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* qgroup metadata reservation.
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*/
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u64 qgroup_rsv_size;
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u64 qgroup_rsv_reserved;
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};
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void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, enum btrfs_rsv_type type);
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void btrfs_init_root_block_rsv(struct btrfs_root *root);
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struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_fs_info *fs_info,
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enum btrfs_rsv_type type);
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void btrfs_init_metadata_block_rsv(struct btrfs_fs_info *fs_info,
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struct btrfs_block_rsv *rsv,
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enum btrfs_rsv_type type);
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void btrfs_free_block_rsv(struct btrfs_fs_info *fs_info,
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struct btrfs_block_rsv *rsv);
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int btrfs_block_rsv_add(struct btrfs_fs_info *fs_info,
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struct btrfs_block_rsv *block_rsv, u64 num_bytes,
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enum btrfs_reserve_flush_enum flush);
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int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_factor);
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int btrfs_block_rsv_refill(struct btrfs_fs_info *fs_info,
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struct btrfs_block_rsv *block_rsv, u64 min_reserved,
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enum btrfs_reserve_flush_enum flush);
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int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
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struct btrfs_block_rsv *dst_rsv, u64 num_bytes,
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bool update_size);
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int btrfs_block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv, u64 num_bytes);
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int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info,
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struct btrfs_block_rsv *dest, u64 num_bytes,
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int min_factor);
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void btrfs_block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
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u64 num_bytes, bool update_size);
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u64 btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
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struct btrfs_block_rsv *block_rsv,
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u64 num_bytes, u64 *qgroup_to_release);
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void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info);
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void btrfs_init_global_block_rsv(struct btrfs_fs_info *fs_info);
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void btrfs_release_global_block_rsv(struct btrfs_fs_info *fs_info);
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struct btrfs_block_rsv *btrfs_use_block_rsv(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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u32 blocksize);
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static inline void btrfs_unuse_block_rsv(struct btrfs_fs_info *fs_info,
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struct btrfs_block_rsv *block_rsv,
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u32 blocksize)
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{
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btrfs_block_rsv_add_bytes(block_rsv, blocksize, false);
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btrfs_block_rsv_release(fs_info, block_rsv, 0, NULL);
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}
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/*
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* Fast path to check if the reserve is full, may be carefully used outside of
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* locks.
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*/
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static inline bool btrfs_block_rsv_full(const struct btrfs_block_rsv *rsv)
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{
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return data_race(rsv->full);
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}
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#endif /* BTRFS_BLOCK_RSV_H */
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