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_H 12 #define _THE_NILFS_H 13 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 23 struct nilfs_sc_info; 24 struct nilfs_sysfs_dev_subgroups; 25 26 /* the_nilfs struct */ 27 enum { 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 points 37 * @ns_flags: flags 38 * @ns_flushed_device: flag indicating if all volatile data was flushed 39 * @ns_sb: back pointer to super block instance 40 * @ns_bdev: block device 41 * @ns_sem: semaphore for shared states 42 * @ns_snapshot_mount_mutex: mutex to protect snapshot mounts 43 * @ns_sbh: buffer heads of on-disk super blocks 44 * @ns_sbp: pointers to super block data 45 * @ns_sbwtime: previous write time of super block 46 * @ns_sbwcount: write count of super block 47 * @ns_sbsize: size of valid data in super block 48 * @ns_mount_state: file system state 49 * @ns_sb_update_freq: interval of periodical update of superblocks (in seconds) 50 * @ns_seg_seq: segment sequence counter 51 * @ns_segnum: index number of the latest full segment. 52 * @ns_nextnum: index number of the full segment index to be used next 53 * @ns_pseg_offset: offset of next partial segment in the current full segment 54 * @ns_cno: next checkpoint number 55 * @ns_ctime: write time of the last segment 56 * @ns_nongc_ctime: write time of the last segment not for cleaner operation 57 * @ns_ndirtyblks: Number of dirty data blocks 58 * @ns_last_segment_lock: lock protecting fields for the latest segment 59 * @ns_last_pseg: start block number of the latest segment 60 * @ns_last_seq: sequence value of the latest segment 61 * @ns_last_cno: checkpoint number of the latest segment 62 * @ns_prot_seq: least sequence number of segments which must not be reclaimed 63 * @ns_prev_seq: base sequence number used to decide if advance log cursor 64 * @ns_writer: log writer 65 * @ns_segctor_sem: semaphore protecting log write 66 * @ns_dat: DAT file inode 67 * @ns_cpfile: checkpoint file inode 68 * @ns_sufile: segusage file inode 69 * @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root) 70 * @ns_cptree_lock: lock protecting @ns_cptree 71 * @ns_dirty_files: list of dirty files 72 * @ns_inode_lock: lock protecting @ns_dirty_files 73 * @ns_gc_inodes: dummy inodes to keep live blocks 74 * @ns_mount_opt: mount options 75 * @ns_resuid: uid for reserved blocks 76 * @ns_resgid: gid for reserved blocks 77 * @ns_interval: checkpoint creation interval 78 * @ns_watermark: watermark for the number of dirty buffers 79 * @ns_blocksize_bits: bit length of block size 80 * @ns_blocksize: block size 81 * @ns_nsegments: number of segments in filesystem 82 * @ns_blocks_per_segment: number of blocks per segment 83 * @ns_r_segments_percentage: reserved segments percentage 84 * @ns_nrsvsegs: number of reserved segments 85 * @ns_first_data_block: block number of first data block 86 * @ns_inode_size: size of on-disk inode 87 * @ns_first_ino: first not-special inode number 88 * @ns_crc_seed: seed value of CRC32 calculation 89 * @ns_dev_kobj: /sys/fs/<nilfs>/<device> 90 * @ns_dev_kobj_unregister: completion state 91 * @ns_dev_subgroups: <device> subgroups pointer 92 */ 93 struct 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 for 104 * - 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 segment 130 * written to disk with a super root. These fields are protected by 131 * 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 before 145 * 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) \ 189 static inline void set_nilfs_##name(struct the_nilfs *nilfs) \ 190 { \ 191 set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ 192 } \ 193 static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \ 194 { \ 195 clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ 196 } \ 197 static inline int nilfs_##name(struct the_nilfs *nilfs) \ 198 { \ 199 return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ 200 } 201 202 THE_NILFS_FNS(INIT, init) 203 THE_NILFS_FNS(DISCONTINUED, discontinued) 204 THE_NILFS_FNS(GC_RUNNING, gc_running) 205 THE_NILFS_FNS(SB_DIRTY, sb_dirty) 206 THE_NILFS_FNS(PURGING, purging) 207 208 /* 209 * Mount option operations 210 */ 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 object 219 * @cno: checkpoint number 220 * @rb_node: red-black tree node 221 * @count: refcount of this structure 222 * @nilfs: nilfs object 223 * @ifile: inode file 224 * @inodes_count: number of inodes 225 * @blocks_count: number of blocks 226 * @snapshot_kobj: /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> 227 * @snapshot_kobj_unregister: completion state for kernel object 228 */ 229 struct 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 0 247 248 /* Minimum interval of periodical update of superblocks (in seconds) */ 249 #define NILFS_SB_FREQ 10 250 nilfs_sb_need_update(struct the_nilfs * nilfs)251 static 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 nilfs_sb_will_flip(struct the_nilfs * nilfs)259 static 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 } 265 266 void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64); 267 struct the_nilfs *alloc_nilfs(struct super_block *sb); 268 void destroy_nilfs(struct the_nilfs *nilfs); 269 int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb); 270 int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb); 271 unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs); 272 void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs); 273 int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t); 274 int nilfs_count_free_blocks(struct the_nilfs *, sector_t *); 275 struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno); 276 struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs, 277 __u64 cno); 278 void nilfs_put_root(struct nilfs_root *root); 279 int nilfs_near_disk_full(struct the_nilfs *); 280 void nilfs_fall_back_super_block(struct the_nilfs *); 281 void nilfs_swap_super_block(struct the_nilfs *); 282 283 nilfs_get_root(struct nilfs_root * root)284 static inline void nilfs_get_root(struct nilfs_root *root) 285 { 286 refcount_inc(&root->count); 287 } 288 nilfs_valid_fs(struct the_nilfs * nilfs)289 static 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 } 298 299 static inline void nilfs_get_segment_range(struct the_nilfs * nilfs,__u64 segnum,sector_t * seg_start,sector_t * seg_end)300 nilfs_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 } 308 309 static inline sector_t nilfs_get_segment_start_blocknr(struct the_nilfs * nilfs,__u64 segnum)310 nilfs_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 } 315 316 static inline __u64 nilfs_get_segnum_of_block(struct the_nilfs * nilfs,sector_t blocknr)317 nilfs_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 } 324 325 static inline void nilfs_terminate_segment(struct the_nilfs * nilfs,sector_t seg_start,sector_t seg_end)326 nilfs_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 nilfs_shift_to_next_segment(struct the_nilfs * nilfs)333 static 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 nilfs_last_cno(struct the_nilfs * nilfs)341 static 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 nilfs_segment_is_active(struct the_nilfs * nilfs,__u64 n)351 static 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 nilfs_flush_device(struct the_nilfs * nilfs)356 static 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 after 366 * 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