/* SPDX-License-Identifier: GPL-2.0+ */ /* * the_nilfs.h - the_nilfs shared structure. * * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. * * Written by Ryusuke Konishi. * */ #ifndef _THE_NILFS_H #define _THE_NILFS_H #include #include #include #include #include #include #include #include struct nilfs_sc_info; struct nilfs_sysfs_dev_subgroups; /* the_nilfs struct */ enum { THE_NILFS_INIT = 0, /* Information from super_block is set */ THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */ THE_NILFS_GC_RUNNING, /* gc process is running */ THE_NILFS_SB_DIRTY, /* super block is dirty */ THE_NILFS_PURGING, /* disposing dirty files for cleanup */ }; /** * struct the_nilfs - struct to supervise multiple nilfs mount points * @ns_flags: flags * @ns_flushed_device: flag indicating if all volatile data was flushed * @ns_sb: back pointer to super block instance * @ns_bdev: block device * @ns_sem: semaphore for shared states * @ns_snapshot_mount_mutex: mutex to protect snapshot mounts * @ns_sbh: buffer heads of on-disk super blocks * @ns_sbp: pointers to super block data * @ns_sbwtime: previous write time of super block * @ns_sbwcount: write count of super block * @ns_sbsize: size of valid data in super block * @ns_mount_state: file system state * @ns_sb_update_freq: interval of periodical update of superblocks (in seconds) * @ns_seg_seq: segment sequence counter * @ns_segnum: index number of the latest full segment. * @ns_nextnum: index number of the full segment index to be used next * @ns_pseg_offset: offset of next partial segment in the current full segment * @ns_cno: next checkpoint number * @ns_ctime: write time of the last segment * @ns_nongc_ctime: write time of the last segment not for cleaner operation * @ns_ndirtyblks: Number of dirty data blocks * @ns_last_segment_lock: lock protecting fields for the latest segment * @ns_last_pseg: start block number of the latest segment * @ns_last_seq: sequence value of the latest segment * @ns_last_cno: checkpoint number of the latest segment * @ns_prot_seq: least sequence number of segments which must not be reclaimed * @ns_prev_seq: base sequence number used to decide if advance log cursor * @ns_writer: log writer * @ns_segctor_sem: semaphore protecting log write * @ns_dat: DAT file inode * @ns_cpfile: checkpoint file inode * @ns_sufile: segusage file inode * @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root) * @ns_cptree_lock: lock protecting @ns_cptree * @ns_dirty_files: list of dirty files * @ns_inode_lock: lock protecting @ns_dirty_files * @ns_gc_inodes: dummy inodes to keep live blocks * @ns_next_generation: next generation number for inodes * @ns_next_gen_lock: lock protecting @ns_next_generation * @ns_mount_opt: mount options * @ns_resuid: uid for reserved blocks * @ns_resgid: gid for reserved blocks * @ns_interval: checkpoint creation interval * @ns_watermark: watermark for the number of dirty buffers * @ns_blocksize_bits: bit length of block size * @ns_blocksize: block size * @ns_nsegments: number of segments in filesystem * @ns_blocks_per_segment: number of blocks per segment * @ns_r_segments_percentage: reserved segments percentage * @ns_nrsvsegs: number of reserved segments * @ns_first_data_block: block number of first data block * @ns_inode_size: size of on-disk inode * @ns_first_ino: first not-special inode number * @ns_crc_seed: seed value of CRC32 calculation * @ns_dev_kobj: /sys/fs// * @ns_dev_kobj_unregister: completion state * @ns_dev_subgroups: subgroups pointer */ struct the_nilfs { unsigned long ns_flags; int ns_flushed_device; struct super_block *ns_sb; struct block_device *ns_bdev; struct rw_semaphore ns_sem; struct mutex ns_snapshot_mount_mutex; /* * used for * - loading the latest checkpoint exclusively. * - allocating a new full segment. */ struct buffer_head *ns_sbh[2]; struct nilfs_super_block *ns_sbp[2]; time64_t ns_sbwtime; unsigned int ns_sbwcount; unsigned int ns_sbsize; unsigned int ns_mount_state; unsigned int ns_sb_update_freq; /* * The following fields are updated by a writable FS-instance. * These fields are protected by ns_segctor_sem outside load_nilfs(). */ u64 ns_seg_seq; __u64 ns_segnum; __u64 ns_nextnum; unsigned long ns_pseg_offset; __u64 ns_cno; time64_t ns_ctime; time64_t ns_nongc_ctime; atomic_t ns_ndirtyblks; /* * The following fields hold information on the latest partial segment * written to disk with a super root. These fields are protected by * ns_last_segment_lock. */ spinlock_t ns_last_segment_lock; sector_t ns_last_pseg; u64 ns_last_seq; __u64 ns_last_cno; u64 ns_prot_seq; u64 ns_prev_seq; struct nilfs_sc_info *ns_writer; struct rw_semaphore ns_segctor_sem; /* * Following fields are lock free except for the period before * the_nilfs is initialized. */ struct inode *ns_dat; struct inode *ns_cpfile; struct inode *ns_sufile; /* Checkpoint tree */ struct rb_root ns_cptree; spinlock_t ns_cptree_lock; /* Dirty inode list */ struct list_head ns_dirty_files; spinlock_t ns_inode_lock; /* GC inode list */ struct list_head ns_gc_inodes; /* Inode allocator */ u32 ns_next_generation; spinlock_t ns_next_gen_lock; /* Mount options */ unsigned long ns_mount_opt; uid_t ns_resuid; gid_t ns_resgid; unsigned long ns_interval; unsigned long ns_watermark; /* Disk layout information (static) */ unsigned int ns_blocksize_bits; unsigned int ns_blocksize; unsigned long ns_nsegments; unsigned long ns_blocks_per_segment; unsigned long ns_r_segments_percentage; unsigned long ns_nrsvsegs; unsigned long ns_first_data_block; int ns_inode_size; int ns_first_ino; u32 ns_crc_seed; /* /sys/fs// */ struct kobject ns_dev_kobj; struct completion ns_dev_kobj_unregister; struct nilfs_sysfs_dev_subgroups *ns_dev_subgroups; }; #define THE_NILFS_FNS(bit, name) \ static inline void set_nilfs_##name(struct the_nilfs *nilfs) \ { \ set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ } \ static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \ { \ clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ } \ static inline int nilfs_##name(struct the_nilfs *nilfs) \ { \ return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ } THE_NILFS_FNS(INIT, init) THE_NILFS_FNS(DISCONTINUED, discontinued) THE_NILFS_FNS(GC_RUNNING, gc_running) THE_NILFS_FNS(SB_DIRTY, sb_dirty) THE_NILFS_FNS(PURGING, purging) /* * Mount option operations */ #define nilfs_clear_opt(nilfs, opt) \ ((nilfs)->ns_mount_opt &= ~NILFS_MOUNT_##opt) #define nilfs_set_opt(nilfs, opt) \ ((nilfs)->ns_mount_opt |= NILFS_MOUNT_##opt) #define nilfs_test_opt(nilfs, opt) ((nilfs)->ns_mount_opt & NILFS_MOUNT_##opt) #define nilfs_write_opt(nilfs, mask, opt) \ ((nilfs)->ns_mount_opt = \ (((nilfs)->ns_mount_opt & ~NILFS_MOUNT_##mask) | \ NILFS_MOUNT_##opt)) \ /** * struct nilfs_root - nilfs root object * @cno: checkpoint number * @rb_node: red-black tree node * @count: refcount of this structure * @nilfs: nilfs object * @ifile: inode file * @inodes_count: number of inodes * @blocks_count: number of blocks * @snapshot_kobj: /sys/fs///mounted_snapshots/ * @snapshot_kobj_unregister: completion state for kernel object */ struct nilfs_root { __u64 cno; struct rb_node rb_node; refcount_t count; struct the_nilfs *nilfs; struct inode *ifile; atomic64_t inodes_count; atomic64_t blocks_count; /* /sys/fs///mounted_snapshots/ */ struct kobject snapshot_kobj; struct completion snapshot_kobj_unregister; }; /* Special checkpoint number */ #define NILFS_CPTREE_CURRENT_CNO 0 /* Minimum interval of periodical update of superblocks (in seconds) */ #define NILFS_SB_FREQ 10 static inline int nilfs_sb_need_update(struct the_nilfs *nilfs) { u64 t = ktime_get_real_seconds(); return t < nilfs->ns_sbwtime || t > nilfs->ns_sbwtime + nilfs->ns_sb_update_freq; } static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs) { int flip_bits = nilfs->ns_sbwcount & 0x0FL; return (flip_bits != 0x08 && flip_bits != 0x0F); } void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64); struct the_nilfs *alloc_nilfs(struct super_block *sb); void destroy_nilfs(struct the_nilfs *nilfs); int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data); int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb); unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs); void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs); int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t); int nilfs_count_free_blocks(struct the_nilfs *, sector_t *); struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno); struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno); void nilfs_put_root(struct nilfs_root *root); int nilfs_near_disk_full(struct the_nilfs *); void nilfs_fall_back_super_block(struct the_nilfs *); void nilfs_swap_super_block(struct the_nilfs *); static inline void nilfs_get_root(struct nilfs_root *root) { refcount_inc(&root->count); } static inline int nilfs_valid_fs(struct the_nilfs *nilfs) { unsigned int valid_fs; down_read(&nilfs->ns_sem); valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS); up_read(&nilfs->ns_sem); return valid_fs; } static inline void nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum, sector_t *seg_start, sector_t *seg_end) { *seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum; *seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1; if (segnum == 0) *seg_start = nilfs->ns_first_data_block; } static inline sector_t nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum) { return (segnum == 0) ? nilfs->ns_first_data_block : (sector_t)nilfs->ns_blocks_per_segment * segnum; } static inline __u64 nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr) { sector_t segnum = blocknr; sector_div(segnum, nilfs->ns_blocks_per_segment); return segnum; } static inline void nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start, sector_t seg_end) { /* terminate the current full segment (used in case of I/O-error) */ nilfs->ns_pseg_offset = seg_end - seg_start + 1; } static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs) { /* move forward with a full segment */ nilfs->ns_segnum = nilfs->ns_nextnum; nilfs->ns_pseg_offset = 0; nilfs->ns_seg_seq++; } static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs) { __u64 cno; spin_lock(&nilfs->ns_last_segment_lock); cno = nilfs->ns_last_cno; spin_unlock(&nilfs->ns_last_segment_lock); return cno; } static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n) { return n == nilfs->ns_segnum || n == nilfs->ns_nextnum; } static inline int nilfs_flush_device(struct the_nilfs *nilfs) { int err; if (!nilfs_test_opt(nilfs, BARRIER) || nilfs->ns_flushed_device) return 0; nilfs->ns_flushed_device = 1; /* * the store to ns_flushed_device must not be reordered after * blkdev_issue_flush(). */ smp_wmb(); err = blkdev_issue_flush(nilfs->ns_bdev, GFP_KERNEL); if (err != -EIO) err = 0; return err; } #endif /* _THE_NILFS_H */