1 /* Copyright 1996-2000 Hans Reiser, see reiserfs/README for licensing
2 * and copyright details */
4 #ifndef _LINUX_REISER_FS_SB
5 #define _LINUX_REISER_FS_SB
8 #include <linux/workqueue.h>
12 reiserfs_attrs_cleared = 0x00000001,
13 } reiserfs_super_block_flags;
15 /* struct reiserfs_super_block accessors/mutators
16 * since this is a disk structure, it will always be in
17 * little endian format. */
18 #define sb_block_count(sbp) (le32_to_cpu((sbp)->s_v1.s_block_count))
19 #define set_sb_block_count(sbp,v) ((sbp)->s_v1.s_block_count = cpu_to_le32(v))
20 #define sb_free_blocks(sbp) (le32_to_cpu((sbp)->s_v1.s_free_blocks))
21 #define set_sb_free_blocks(sbp,v) ((sbp)->s_v1.s_free_blocks = cpu_to_le32(v))
22 #define sb_root_block(sbp) (le32_to_cpu((sbp)->s_v1.s_root_block))
23 #define set_sb_root_block(sbp,v) ((sbp)->s_v1.s_root_block = cpu_to_le32(v))
25 #define sb_jp_journal_1st_block(sbp) \
26 (le32_to_cpu((sbp)->s_v1.s_journal.jp_journal_1st_block))
27 #define set_sb_jp_journal_1st_block(sbp,v) \
28 ((sbp)->s_v1.s_journal.jp_journal_1st_block = cpu_to_le32(v))
29 #define sb_jp_journal_dev(sbp) \
30 (le32_to_cpu((sbp)->s_v1.s_journal.jp_journal_dev))
31 #define set_sb_jp_journal_dev(sbp,v) \
32 ((sbp)->s_v1.s_journal.jp_journal_dev = cpu_to_le32(v))
33 #define sb_jp_journal_size(sbp) \
34 (le32_to_cpu((sbp)->s_v1.s_journal.jp_journal_size))
35 #define set_sb_jp_journal_size(sbp,v) \
36 ((sbp)->s_v1.s_journal.jp_journal_size = cpu_to_le32(v))
37 #define sb_jp_journal_trans_max(sbp) \
38 (le32_to_cpu((sbp)->s_v1.s_journal.jp_journal_trans_max))
39 #define set_sb_jp_journal_trans_max(sbp,v) \
40 ((sbp)->s_v1.s_journal.jp_journal_trans_max = cpu_to_le32(v))
41 #define sb_jp_journal_magic(sbp) \
42 (le32_to_cpu((sbp)->s_v1.s_journal.jp_journal_magic))
43 #define set_sb_jp_journal_magic(sbp,v) \
44 ((sbp)->s_v1.s_journal.jp_journal_magic = cpu_to_le32(v))
45 #define sb_jp_journal_max_batch(sbp) \
46 (le32_to_cpu((sbp)->s_v1.s_journal.jp_journal_max_batch))
47 #define set_sb_jp_journal_max_batch(sbp,v) \
48 ((sbp)->s_v1.s_journal.jp_journal_max_batch = cpu_to_le32(v))
49 #define sb_jp_jourmal_max_commit_age(sbp) \
50 (le32_to_cpu((sbp)->s_v1.s_journal.jp_journal_max_commit_age))
51 #define set_sb_jp_journal_max_commit_age(sbp,v) \
52 ((sbp)->s_v1.s_journal.jp_journal_max_commit_age = cpu_to_le32(v))
54 #define sb_blocksize(sbp) (le16_to_cpu((sbp)->s_v1.s_blocksize))
55 #define set_sb_blocksize(sbp,v) ((sbp)->s_v1.s_blocksize = cpu_to_le16(v))
56 #define sb_oid_maxsize(sbp) (le16_to_cpu((sbp)->s_v1.s_oid_maxsize))
57 #define set_sb_oid_maxsize(sbp,v) ((sbp)->s_v1.s_oid_maxsize = cpu_to_le16(v))
58 #define sb_oid_cursize(sbp) (le16_to_cpu((sbp)->s_v1.s_oid_cursize))
59 #define set_sb_oid_cursize(sbp,v) ((sbp)->s_v1.s_oid_cursize = cpu_to_le16(v))
60 #define sb_umount_state(sbp) (le16_to_cpu((sbp)->s_v1.s_umount_state))
61 #define set_sb_umount_state(sbp,v) ((sbp)->s_v1.s_umount_state = cpu_to_le16(v))
62 #define sb_fs_state(sbp) (le16_to_cpu((sbp)->s_v1.s_fs_state))
63 #define set_sb_fs_state(sbp,v) ((sbp)->s_v1.s_fs_state = cpu_to_le16(v))
64 #define sb_hash_function_code(sbp) \
65 (le32_to_cpu((sbp)->s_v1.s_hash_function_code))
66 #define set_sb_hash_function_code(sbp,v) \
67 ((sbp)->s_v1.s_hash_function_code = cpu_to_le32(v))
68 #define sb_tree_height(sbp) (le16_to_cpu((sbp)->s_v1.s_tree_height))
69 #define set_sb_tree_height(sbp,v) ((sbp)->s_v1.s_tree_height = cpu_to_le16(v))
70 #define sb_bmap_nr(sbp) (le16_to_cpu((sbp)->s_v1.s_bmap_nr))
71 #define set_sb_bmap_nr(sbp,v) ((sbp)->s_v1.s_bmap_nr = cpu_to_le16(v))
72 #define sb_version(sbp) (le16_to_cpu((sbp)->s_v1.s_version))
73 #define set_sb_version(sbp,v) ((sbp)->s_v1.s_version = cpu_to_le16(v))
75 #define sb_reserved_for_journal(sbp) \
76 (le16_to_cpu((sbp)->s_v1.s_reserved_for_journal))
77 #define set_sb_reserved_for_journal(sbp,v) \
78 ((sbp)->s_v1.s_reserved_for_journal = cpu_to_le16(v))
82 /* These all interelate for performance.
84 ** If the journal block count is smaller than n transactions, you lose speed.
85 ** I don't know what n is yet, I'm guessing 8-16.
87 ** typical transaction size depends on the application, how often fsync is
88 ** called, and how many metadata blocks you dirty in a 30 second period.
89 ** The more small files (<16k) you use, the larger your transactions will
92 ** If your journal fills faster than dirty buffers get flushed to disk, it must flush them before allowing the journal
93 ** to wrap, which slows things down. If you need high speed meta data updates, the journal should be big enough
94 ** to prevent wrapping before dirty meta blocks get to disk.
96 ** If the batch max is smaller than the transaction max, you'll waste space at the end of the journal
97 ** because journal_end sets the next transaction to start at 0 if the next transaction has any chance of wrapping.
99 ** The large the batch max age, the better the speed, and the more meta data changes you'll lose after a crash.
103 /* don't mess with these for a while */
104 /* we have a node size define somewhere in reiserfs_fs.h. -Hans */
105 #define JOURNAL_BLOCK_SIZE 4096 /* BUG gotta get rid of this */
106 #define JOURNAL_MAX_CNODE 1500 /* max cnodes to allocate. */
107 #define JOURNAL_HASH_SIZE 8192
108 #define JOURNAL_NUM_BITMAPS 5 /* number of copies of the bitmaps to have floating. Must be >= 2 */
110 /* One of these for every block in every transaction
111 ** Each one is in two hash tables. First, a hash of the current transaction, and after journal_end, a
112 ** hash of all the in memory transactions.
113 ** next and prev are used by the current transaction (journal_hash).
114 ** hnext and hprev are used by journal_list_hash. If a block is in more than one transaction, the journal_list_hash
115 ** links it in multiple times. This allows flush_journal_list to remove just the cnode belonging
116 ** to a given transaction.
118 struct reiserfs_journal_cnode {
119 struct buffer_head *bh ; /* real buffer head */
120 struct super_block *sb ; /* dev of real buffer head */
121 __u32 blocknr ; /* block number of real buffer head, == 0 when buffer on disk */
123 struct reiserfs_journal_list *jlist ; /* journal list this cnode lives in */
124 struct reiserfs_journal_cnode *next ; /* next in transaction list */
125 struct reiserfs_journal_cnode *prev ; /* prev in transaction list */
126 struct reiserfs_journal_cnode *hprev ; /* prev in hash list */
127 struct reiserfs_journal_cnode *hnext ; /* next in hash list */
130 struct reiserfs_bitmap_node {
133 struct list_head list ;
136 struct reiserfs_list_bitmap {
137 struct reiserfs_journal_list *journal_list ;
138 struct reiserfs_bitmap_node **bitmaps ;
142 ** one of these for each transaction. The most important part here is the j_realblock.
143 ** this list of cnodes is used to hash all the blocks in all the commits, to mark all the
144 ** real buffer heads dirty once all the commits hit the disk,
145 ** and to make sure every real block in a transaction is on disk before allowing the log area
146 ** to be overwritten */
147 struct reiserfs_journal_list {
148 unsigned long j_start ;
149 unsigned long j_state;
150 unsigned long j_len ;
151 atomic_t j_nonzerolen ;
152 atomic_t j_commit_left ;
153 atomic_t j_older_commits_done ; /* all commits older than this on disk*/
154 struct semaphore j_commit_lock;
155 unsigned long j_trans_id ;
157 struct reiserfs_list_bitmap *j_list_bitmap ;
158 struct buffer_head *j_commit_bh ; /* commit buffer head */
159 struct reiserfs_journal_cnode *j_realblock ;
160 struct reiserfs_journal_cnode *j_freedlist ; /* list of buffers that were freed during this trans. free each of these on flush */
161 /* time ordered list of all active transactions */
162 struct list_head j_list;
164 /* time ordered list of all transactions we haven't tried to flush yet */
165 struct list_head j_working_list;
167 /* list of tail conversion targets in need of flush before commit */
168 struct list_head j_tail_bh_list;
169 /* list of data=ordered buffers in need of flush before commit */
170 struct list_head j_bh_list;
174 struct reiserfs_journal {
175 struct buffer_head ** j_ap_blocks ; /* journal blocks on disk */
176 struct reiserfs_journal_cnode *j_last ; /* newest journal block */
177 struct reiserfs_journal_cnode *j_first ; /* oldest journal block. start here for traverse */
179 struct file *j_dev_file;
180 struct block_device *j_dev_bd;
181 int j_1st_reserved_block; /* first block on s_dev of reserved area journal */
184 unsigned long j_trans_id ;
185 unsigned long j_mount_id ;
186 unsigned long j_start ; /* start of current waiting commit (index into j_ap_blocks) */
187 unsigned long j_len ; /* lenght of current waiting commit */
188 unsigned long j_len_alloc ; /* number of buffers requested by journal_begin() */
189 atomic_t j_wcount ; /* count of writers for current commit */
190 unsigned long j_bcount ; /* batch count. allows turning X transactions into 1 */
191 unsigned long j_first_unflushed_offset ; /* first unflushed transactions offset */
192 unsigned long j_last_flush_trans_id ; /* last fully flushed journal timestamp */
193 struct buffer_head *j_header_bh ;
195 time_t j_trans_start_time ; /* time this transaction started */
196 struct semaphore j_lock;
197 struct semaphore j_flush_sem;
198 wait_queue_head_t j_join_wait ; /* wait for current transaction to finish before starting new one */
199 atomic_t j_jlock ; /* lock for j_join_wait */
200 int j_list_bitmap_index ; /* number of next list bitmap to use */
201 int j_must_wait ; /* no more journal begins allowed. MUST sleep on j_join_wait */
202 int j_next_full_flush ; /* next journal_end will flush all journal list */
203 int j_next_async_flush ; /* next journal_end will flush all async commits */
205 int j_cnode_used ; /* number of cnodes on the used list */
206 int j_cnode_free ; /* number of cnodes on the free list */
208 unsigned int s_journal_trans_max ; /* max number of blocks in a transaction. */
209 unsigned int s_journal_max_batch ; /* max number of blocks to batch into a trans */
210 unsigned int s_journal_max_commit_age ; /* in seconds, how old can an async commit be */
211 unsigned int s_journal_default_max_commit_age ; /* the default for the max commit age */
212 unsigned int s_journal_max_trans_age ; /* in seconds, how old can a transaction be */
214 struct reiserfs_journal_cnode *j_cnode_free_list ;
215 struct reiserfs_journal_cnode *j_cnode_free_orig ; /* orig pointer returned from vmalloc */
217 struct reiserfs_journal_list *j_current_jl;
218 int j_free_bitmap_nodes ;
219 int j_used_bitmap_nodes ;
221 int j_num_lists; /* total number of active transactions */
222 int j_num_work_lists; /* number that need attention from kreiserfsd */
224 /* debugging to make sure things are flushed in order */
227 /* debugging to make sure things are committed in order */
228 int j_last_commit_id;
230 struct list_head j_bitmap_nodes ;
231 struct list_head j_dirty_buffers ;
232 spinlock_t j_dirty_buffers_lock ; /* protects j_dirty_buffers */
234 /* list of all active transactions */
235 struct list_head j_journal_list;
236 /* lists that haven't been touched by writeback attempts */
237 struct list_head j_working_list;
239 struct reiserfs_list_bitmap j_list_bitmap[JOURNAL_NUM_BITMAPS] ; /* array of bitmaps to record the deleted blocks */
240 struct reiserfs_journal_cnode *j_hash_table[JOURNAL_HASH_SIZE] ; /* hash table for real buffer heads in current trans */
241 struct reiserfs_journal_cnode *j_list_hash_table[JOURNAL_HASH_SIZE] ; /* hash table for all the real buffer heads in all
243 struct list_head j_prealloc_list; /* list of inodes which have preallocated blocks */
244 unsigned long j_max_trans_size ;
245 unsigned long j_max_batch_size ;
247 /* when flushing ordered buffers, throttle new ordered writers */
248 struct work_struct j_work;
249 atomic_t j_async_throttle;
252 #define JOURNAL_DESC_MAGIC "ReIsErLB" /* ick. magic string to find desc blocks in the journal */
255 typedef __u32 (*hashf_t) (const signed char *, int);
257 struct reiserfs_bitmap_info
259 // FIXME: Won't work with block sizes > 8K
260 __u16 first_zero_hint;
262 struct buffer_head *bh; /* the actual bitmap */
265 struct proc_dir_entry;
267 #if defined( CONFIG_PROC_FS ) && defined( CONFIG_REISERFS_PROC_INFO )
268 typedef unsigned long int stat_cnt_t;
269 typedef struct reiserfs_proc_info_data
273 int max_hash_collisions;
276 stat_cnt_t bread_miss;
277 stat_cnt_t search_by_key;
278 stat_cnt_t search_by_key_fs_changed;
279 stat_cnt_t search_by_key_restarted;
281 stat_cnt_t insert_item_restarted;
282 stat_cnt_t paste_into_item_restarted;
283 stat_cnt_t cut_from_item_restarted;
284 stat_cnt_t delete_solid_item_restarted;
285 stat_cnt_t delete_item_restarted;
287 stat_cnt_t leaked_oid;
288 stat_cnt_t leaves_removable;
290 /* balances per level. Use explicit 5 as MAX_HEIGHT is not visible yet. */
291 stat_cnt_t balance_at[ 5 ]; /* XXX */
292 /* sbk == search_by_key */
293 stat_cnt_t sbk_read_at[ 5 ]; /* XXX */
294 stat_cnt_t sbk_fs_changed[ 5 ];
295 stat_cnt_t sbk_restarted[ 5 ];
296 stat_cnt_t items_at[ 5 ]; /* XXX */
297 stat_cnt_t free_at[ 5 ]; /* XXX */
298 stat_cnt_t can_node_be_removed[ 5 ]; /* XXX */
299 long int lnum[ 5 ]; /* XXX */
300 long int rnum[ 5 ]; /* XXX */
301 long int lbytes[ 5 ]; /* XXX */
302 long int rbytes[ 5 ]; /* XXX */
303 stat_cnt_t get_neighbors[ 5 ];
304 stat_cnt_t get_neighbors_restart[ 5 ];
305 stat_cnt_t need_l_neighbor[ 5 ];
306 stat_cnt_t need_r_neighbor[ 5 ];
308 stat_cnt_t free_block;
309 struct __scan_bitmap_stats {
314 stat_cnt_t in_journal_hint;
315 stat_cnt_t in_journal_nohint;
318 struct __journal_stats {
319 stat_cnt_t in_journal;
320 stat_cnt_t in_journal_bitmap;
321 stat_cnt_t in_journal_reusable;
322 stat_cnt_t lock_journal;
323 stat_cnt_t lock_journal_wait;
324 stat_cnt_t journal_being;
325 stat_cnt_t journal_relock_writers;
326 stat_cnt_t journal_relock_wcount;
327 stat_cnt_t mark_dirty;
328 stat_cnt_t mark_dirty_already;
329 stat_cnt_t mark_dirty_notjournal;
330 stat_cnt_t restore_prepared;
332 stat_cnt_t prepare_retry;
334 } reiserfs_proc_info_data_t;
336 typedef struct reiserfs_proc_info_data
337 {} reiserfs_proc_info_data_t;
340 /* reiserfs union of in-core super block data */
341 struct reiserfs_sb_info
343 struct buffer_head * s_sbh; /* Buffer containing the super block */
344 /* both the comment and the choice of
345 name are unclear for s_rs -Hans */
346 struct reiserfs_super_block * s_rs; /* Pointer to the super block in the buffer */
347 struct reiserfs_bitmap_info * s_ap_bitmap;
348 struct reiserfs_journal *s_journal ; /* pointer to journal information */
349 unsigned short s_mount_state; /* reiserfs state (valid, invalid) */
352 void (*end_io_handler)(struct buffer_head *, int);
353 hashf_t s_hash_function; /* pointer to function which is used
354 to sort names in directory. Set on
356 unsigned long s_mount_opt; /* reiserfs's mount options are set
357 here (currently - NOTAIL, NOLOG,
360 struct { /* This is a structure that describes block allocator options */
361 unsigned long bits; /* Bitfield for enable/disable kind of options */
362 unsigned long large_file_size; /* size started from which we consider file to be a large one(in blocks) */
363 int border; /* percentage of disk, border takes */
364 int preallocmin; /* Minimal file size (in blocks) starting from which we do preallocations */
365 int preallocsize; /* Number of blocks we try to prealloc when file
366 reaches preallocmin size (in blocks) or
367 prealloc_list is empty. */
371 wait_queue_head_t s_wait;
372 /* To be obsoleted soon by per buffer seals.. -Hans */
373 atomic_t s_generation_counter; // increased by one every time the
374 // tree gets re-balanced
375 unsigned long s_properties; /* File system properties. Currently holds
378 /* session statistics */
384 int s_unneeded_left_neighbor;
385 int s_good_search_by_key_reada;
387 int s_bmaps_without_search;
388 int s_direct2indirect;
389 int s_indirect2direct;
390 /* set up when it's ok for reiserfs_read_inode2() to read from
391 disk inode with nlink==0. Currently this is only used during
392 finish_unfinished() processing at mount time */
393 int s_is_unlinked_ok;
394 reiserfs_proc_info_data_t s_proc_info_data;
395 struct proc_dir_entry *procdir;
396 int reserved_blocks; /* amount of blocks reserved for further allocations */
397 spinlock_t bitmap_lock; /* this lock on now only used to protect reserved_blocks variable */
400 /* Definitions of reiserfs on-disk properties: */
401 #define REISERFS_3_5 0
402 #define REISERFS_3_6 1
404 enum reiserfs_mount_options {
406 REISERFS_LARGETAIL, /* large tails will be created in a session */
407 REISERFS_SMALLTAIL, /* small (for files less than block size) tails will be created in a session */
408 REPLAYONLY, /* replay journal and return 0. Use by fsck */
409 REISERFS_CONVERT, /* -o conv: causes conversion of old
410 format super block to the new
411 format. If not specified - old
412 partition will be dealt with in a
415 /* -o hash={tea, rupasov, r5, detect} is meant for properly mounting
416 ** reiserfs disks from 3.5.19 or earlier. 99% of the time, this option
417 ** is not required. If the normal autodection code can't determine which
418 ** hash to use (because both hases had the same value for a file)
419 ** use this option to force a specific hash. It won't allow you to override
420 ** the existing hash on the FS, so if you have a tea hash disk, and mount
421 ** with -o hash=rupasov, the mount will fail.
423 FORCE_TEA_HASH, /* try to force tea hash on mount */
424 FORCE_RUPASOV_HASH, /* try to force rupasov hash on mount */
425 FORCE_R5_HASH, /* try to force rupasov hash on mount */
426 FORCE_HASH_DETECT, /* try to detect hash function on mount */
429 REISERFS_DATA_ORDERED,
430 REISERFS_DATA_WRITEBACK,
432 /* used for testing experimental features, makes benchmarking new
433 features with and without more convenient, should never be used by
434 users in any code shipped to users (ideally) */
437 REISERFS_NO_UNHASHED_RELOCATION,
438 REISERFS_HASHED_RELOCATION,
447 #define reiserfs_r5_hash(s) (REISERFS_SB(s)->s_mount_opt & (1 << FORCE_R5_HASH))
448 #define reiserfs_rupasov_hash(s) (REISERFS_SB(s)->s_mount_opt & (1 << FORCE_RUPASOV_HASH))
449 #define reiserfs_tea_hash(s) (REISERFS_SB(s)->s_mount_opt & (1 << FORCE_TEA_HASH))
450 #define reiserfs_hash_detect(s) (REISERFS_SB(s)->s_mount_opt & (1 << FORCE_HASH_DETECT))
451 #define reiserfs_no_border(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_NO_BORDER))
452 #define reiserfs_no_unhashed_relocation(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_NO_UNHASHED_RELOCATION))
453 #define reiserfs_hashed_relocation(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_HASHED_RELOCATION))
454 #define reiserfs_test4(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_TEST4))
456 #define have_large_tails(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_LARGETAIL))
457 #define have_small_tails(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_SMALLTAIL))
458 #define replay_only(s) (REISERFS_SB(s)->s_mount_opt & (1 << REPLAYONLY))
459 #define reiserfs_attrs(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_ATTRS))
460 #define old_format_only(s) (REISERFS_SB(s)->s_properties & (1 << REISERFS_3_5))
461 #define convert_reiserfs(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_CONVERT))
462 #define reiserfs_data_log(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_DATA_LOG))
463 #define reiserfs_data_ordered(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_DATA_ORDERED))
464 #define reiserfs_data_writeback(s) (REISERFS_SB(s)->s_mount_opt & (1 << REISERFS_DATA_WRITEBACK))
466 void reiserfs_file_buffer (struct buffer_head * bh, int list);
467 extern struct file_system_type reiserfs_fs_type;
468 int reiserfs_resize(struct super_block *, unsigned long) ;
471 #define SCHEDULE_OCCURRED 1
474 #define SB_BUFFER_WITH_SB(s) (REISERFS_SB(s)->s_sbh)
475 #define SB_JOURNAL(s) (REISERFS_SB(s)->s_journal)
476 #define SB_JOURNAL_1st_RESERVED_BLOCK(s) (SB_JOURNAL(s)->j_1st_reserved_block)
477 #define SB_JOURNAL_LEN_FREE(s) (SB_JOURNAL(s)->j_journal_len_free)
478 #define SB_AP_BITMAP(s) (REISERFS_SB(s)->s_ap_bitmap)
480 #define SB_DISK_JOURNAL_HEAD(s) (SB_JOURNAL(s)->j_header_bh->)
482 #define SB_JOURNAL_TRANS_MAX(s) (SB_JOURNAL(s)->s_journal_trans_max)
483 #define SB_JOURNAL_MAX_BATCH(s) (SB_JOURNAL(s)->s_journal_max_batch)
484 #define SB_JOURNAL_MAX_COMMIT_AGE(s) (SB_JOURNAL(s)->s_journal_max_commit_age)
485 #define SB_JOURNAL_DEFAULT_MAX_COMMIT_AGE(s) (SB_JOURNAL(s)->s_journal_default_max_commit_age)
486 #define SB_JOURNAL_MAX_TRANS_AGE(s) (SB_JOURNAL(s)->s_journal_max_trans_age)
488 /* A safe version of the "bdevname", which returns the "s_id" field of
489 * a superblock or else "Null superblock" if the super block is NULL.
491 static inline char *reiserfs_bdevname(struct super_block *s)
493 return (s == NULL) ? "Null superblock" : s -> s_id;
496 #endif /* _LINUX_REISER_FS_SB */