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1/* SPDX-License-Identifier: GPL-2.0+ */2/*3 * the_nilfs shared structure.4 *5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.6 *7 * Written by Ryusuke Konishi.8 *9 */10 11#ifndef _THE_NILFS_H12#define _THE_NILFS_H13 14#include <linux/types.h>15#include <linux/buffer_head.h>16#include <linux/rbtree.h>17#include <linux/fs.h>18#include <linux/blkdev.h>19#include <linux/backing-dev.h>20#include <linux/slab.h>21#include <linux/refcount.h>22 23struct nilfs_sc_info;24struct nilfs_sysfs_dev_subgroups;25 26/* the_nilfs struct */27enum {28 THE_NILFS_INIT = 0, /* Information from super_block is set */29 THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */30 THE_NILFS_GC_RUNNING, /* gc process is running */31 THE_NILFS_SB_DIRTY, /* super block is dirty */32 THE_NILFS_PURGING, /* disposing dirty files for cleanup */33};34 35/**36 * struct the_nilfs - struct to supervise multiple nilfs mount points37 * @ns_flags: flags38 * @ns_flushed_device: flag indicating if all volatile data was flushed39 * @ns_sb: back pointer to super block instance40 * @ns_bdev: block device41 * @ns_sem: semaphore for shared states42 * @ns_snapshot_mount_mutex: mutex to protect snapshot mounts43 * @ns_sbh: buffer heads of on-disk super blocks44 * @ns_sbp: pointers to super block data45 * @ns_sbwtime: previous write time of super block46 * @ns_sbwcount: write count of super block47 * @ns_sbsize: size of valid data in super block48 * @ns_mount_state: file system state49 * @ns_sb_update_freq: interval of periodical update of superblocks (in seconds)50 * @ns_seg_seq: segment sequence counter51 * @ns_segnum: index number of the latest full segment.52 * @ns_nextnum: index number of the full segment index to be used next53 * @ns_pseg_offset: offset of next partial segment in the current full segment54 * @ns_cno: next checkpoint number55 * @ns_ctime: write time of the last segment56 * @ns_nongc_ctime: write time of the last segment not for cleaner operation57 * @ns_ndirtyblks: Number of dirty data blocks58 * @ns_last_segment_lock: lock protecting fields for the latest segment59 * @ns_last_pseg: start block number of the latest segment60 * @ns_last_seq: sequence value of the latest segment61 * @ns_last_cno: checkpoint number of the latest segment62 * @ns_prot_seq: least sequence number of segments which must not be reclaimed63 * @ns_prev_seq: base sequence number used to decide if advance log cursor64 * @ns_writer: log writer65 * @ns_segctor_sem: semaphore protecting log write66 * @ns_dat: DAT file inode67 * @ns_cpfile: checkpoint file inode68 * @ns_sufile: segusage file inode69 * @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root)70 * @ns_cptree_lock: lock protecting @ns_cptree71 * @ns_dirty_files: list of dirty files72 * @ns_inode_lock: lock protecting @ns_dirty_files73 * @ns_gc_inodes: dummy inodes to keep live blocks74 * @ns_mount_opt: mount options75 * @ns_resuid: uid for reserved blocks76 * @ns_resgid: gid for reserved blocks77 * @ns_interval: checkpoint creation interval78 * @ns_watermark: watermark for the number of dirty buffers79 * @ns_blocksize_bits: bit length of block size80 * @ns_blocksize: block size81 * @ns_nsegments: number of segments in filesystem82 * @ns_blocks_per_segment: number of blocks per segment83 * @ns_r_segments_percentage: reserved segments percentage84 * @ns_nrsvsegs: number of reserved segments85 * @ns_first_data_block: block number of first data block86 * @ns_inode_size: size of on-disk inode87 * @ns_first_ino: first not-special inode number88 * @ns_crc_seed: seed value of CRC32 calculation89 * @ns_dev_kobj: /sys/fs/<nilfs>/<device>90 * @ns_dev_kobj_unregister: completion state91 * @ns_dev_subgroups: <device> subgroups pointer92 */93struct the_nilfs {94 unsigned long ns_flags;95 int ns_flushed_device;96 97 struct super_block *ns_sb;98 struct block_device *ns_bdev;99 struct rw_semaphore ns_sem;100 struct mutex ns_snapshot_mount_mutex;101 102 /*103 * used for104 * - loading the latest checkpoint exclusively.105 * - allocating a new full segment.106 */107 struct buffer_head *ns_sbh[2];108 struct nilfs_super_block *ns_sbp[2];109 time64_t ns_sbwtime;110 unsigned int ns_sbwcount;111 unsigned int ns_sbsize;112 unsigned int ns_mount_state;113 unsigned int ns_sb_update_freq;114 115 /*116 * The following fields are updated by a writable FS-instance.117 * These fields are protected by ns_segctor_sem outside load_nilfs().118 */119 u64 ns_seg_seq;120 __u64 ns_segnum;121 __u64 ns_nextnum;122 unsigned long ns_pseg_offset;123 __u64 ns_cno;124 time64_t ns_ctime;125 time64_t ns_nongc_ctime;126 atomic_t ns_ndirtyblks;127 128 /*129 * The following fields hold information on the latest partial segment130 * written to disk with a super root. These fields are protected by131 * ns_last_segment_lock.132 */133 spinlock_t ns_last_segment_lock;134 sector_t ns_last_pseg;135 u64 ns_last_seq;136 __u64 ns_last_cno;137 u64 ns_prot_seq;138 u64 ns_prev_seq;139 140 struct nilfs_sc_info *ns_writer;141 struct rw_semaphore ns_segctor_sem;142 143 /*144 * Following fields are lock free except for the period before145 * the_nilfs is initialized.146 */147 struct inode *ns_dat;148 struct inode *ns_cpfile;149 struct inode *ns_sufile;150 151 /* Checkpoint tree */152 struct rb_root ns_cptree;153 spinlock_t ns_cptree_lock;154 155 /* Dirty inode list */156 struct list_head ns_dirty_files;157 spinlock_t ns_inode_lock;158 159 /* GC inode list */160 struct list_head ns_gc_inodes;161 162 /* Mount options */163 unsigned long ns_mount_opt;164 165 uid_t ns_resuid;166 gid_t ns_resgid;167 unsigned long ns_interval;168 unsigned long ns_watermark;169 170 /* Disk layout information (static) */171 unsigned int ns_blocksize_bits;172 unsigned int ns_blocksize;173 unsigned long ns_nsegments;174 unsigned long ns_blocks_per_segment;175 unsigned long ns_r_segments_percentage;176 unsigned long ns_nrsvsegs;177 unsigned long ns_first_data_block;178 int ns_inode_size;179 unsigned int ns_first_ino;180 u32 ns_crc_seed;181 182 /* /sys/fs/<nilfs>/<device> */183 struct kobject ns_dev_kobj;184 struct completion ns_dev_kobj_unregister;185 struct nilfs_sysfs_dev_subgroups *ns_dev_subgroups;186};187 188#define THE_NILFS_FNS(bit, name) \189static inline void set_nilfs_##name(struct the_nilfs *nilfs) \190{ \191 set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \192} \193static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \194{ \195 clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \196} \197static inline int nilfs_##name(struct the_nilfs *nilfs) \198{ \199 return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \200}201 202THE_NILFS_FNS(INIT, init)203THE_NILFS_FNS(DISCONTINUED, discontinued)204THE_NILFS_FNS(GC_RUNNING, gc_running)205THE_NILFS_FNS(SB_DIRTY, sb_dirty)206THE_NILFS_FNS(PURGING, purging)207 208/*209 * Mount option operations210 */211#define nilfs_clear_opt(nilfs, opt) \212 ((nilfs)->ns_mount_opt &= ~NILFS_MOUNT_##opt)213#define nilfs_set_opt(nilfs, opt) \214 ((nilfs)->ns_mount_opt |= NILFS_MOUNT_##opt)215#define nilfs_test_opt(nilfs, opt) ((nilfs)->ns_mount_opt & NILFS_MOUNT_##opt)216 217/**218 * struct nilfs_root - nilfs root object219 * @cno: checkpoint number220 * @rb_node: red-black tree node221 * @count: refcount of this structure222 * @nilfs: nilfs object223 * @ifile: inode file224 * @inodes_count: number of inodes225 * @blocks_count: number of blocks226 * @snapshot_kobj: /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot>227 * @snapshot_kobj_unregister: completion state for kernel object228 */229struct nilfs_root {230 __u64 cno;231 struct rb_node rb_node;232 233 refcount_t count;234 struct the_nilfs *nilfs;235 struct inode *ifile;236 237 atomic64_t inodes_count;238 atomic64_t blocks_count;239 240 /* /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> */241 struct kobject snapshot_kobj;242 struct completion snapshot_kobj_unregister;243};244 245/* Special checkpoint number */246#define NILFS_CPTREE_CURRENT_CNO 0247 248/* Minimum interval of periodical update of superblocks (in seconds) */249#define NILFS_SB_FREQ 10250 251static inline int nilfs_sb_need_update(struct the_nilfs *nilfs)252{253 u64 t = ktime_get_real_seconds();254 255 return t < nilfs->ns_sbwtime ||256 t > nilfs->ns_sbwtime + nilfs->ns_sb_update_freq;257}258 259static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs)260{261 int flip_bits = nilfs->ns_sbwcount & 0x0FL;262 263 return (flip_bits != 0x08 && flip_bits != 0x0F);264}265 266void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64);267struct the_nilfs *alloc_nilfs(struct super_block *sb);268void destroy_nilfs(struct the_nilfs *nilfs);269int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb);270int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb);271unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs);272void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs);273int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t);274int nilfs_count_free_blocks(struct the_nilfs *, sector_t *);275struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno);276struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs,277 __u64 cno);278void nilfs_put_root(struct nilfs_root *root);279int nilfs_near_disk_full(struct the_nilfs *);280void nilfs_fall_back_super_block(struct the_nilfs *);281void nilfs_swap_super_block(struct the_nilfs *);282 283 284static inline void nilfs_get_root(struct nilfs_root *root)285{286 refcount_inc(&root->count);287}288 289static inline int nilfs_valid_fs(struct the_nilfs *nilfs)290{291 unsigned int valid_fs;292 293 down_read(&nilfs->ns_sem);294 valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS);295 up_read(&nilfs->ns_sem);296 return valid_fs;297}298 299static inline void300nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum,301 sector_t *seg_start, sector_t *seg_end)302{303 *seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum;304 *seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1;305 if (segnum == 0)306 *seg_start = nilfs->ns_first_data_block;307}308 309static inline sector_t310nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum)311{312 return (segnum == 0) ? nilfs->ns_first_data_block :313 (sector_t)nilfs->ns_blocks_per_segment * segnum;314}315 316static inline __u64317nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr)318{319 sector_t segnum = blocknr;320 321 sector_div(segnum, nilfs->ns_blocks_per_segment);322 return segnum;323}324 325static inline void326nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start,327 sector_t seg_end)328{329 /* terminate the current full segment (used in case of I/O-error) */330 nilfs->ns_pseg_offset = seg_end - seg_start + 1;331}332 333static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs)334{335 /* move forward with a full segment */336 nilfs->ns_segnum = nilfs->ns_nextnum;337 nilfs->ns_pseg_offset = 0;338 nilfs->ns_seg_seq++;339}340 341static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs)342{343 __u64 cno;344 345 spin_lock(&nilfs->ns_last_segment_lock);346 cno = nilfs->ns_last_cno;347 spin_unlock(&nilfs->ns_last_segment_lock);348 return cno;349}350 351static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n)352{353 return n == nilfs->ns_segnum || n == nilfs->ns_nextnum;354}355 356static inline int nilfs_flush_device(struct the_nilfs *nilfs)357{358 int err;359 360 if (!nilfs_test_opt(nilfs, BARRIER) || nilfs->ns_flushed_device)361 return 0;362 363 nilfs->ns_flushed_device = 1;364 /*365 * the store to ns_flushed_device must not be reordered after366 * blkdev_issue_flush().367 */368 smp_wmb();369 370 err = blkdev_issue_flush(nilfs->ns_bdev);371 if (err != -EIO)372 err = 0;373 return err;374}375 376#endif /* _THE_NILFS_H */377