2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 #include "xfs_types.h"
24 #include "xfs_trans.h"
28 #include "xfs_mount.h"
29 #include "xfs_bmap_btree.h"
30 #include "xfs_alloc_btree.h"
31 #include "xfs_ialloc_btree.h"
32 #include "xfs_dinode.h"
33 #include "xfs_inode.h"
34 #include "xfs_btree.h"
35 #include "xfs_ialloc.h"
36 #include "xfs_alloc.h"
37 #include "xfs_rtalloc.h"
39 #include "xfs_error.h"
41 #include "xfs_quota.h"
42 #include "xfs_fsops.h"
43 #include "xfs_utils.h"
44 #include "xfs_trace.h"
48 STATIC void xfs_icsb_balance_counter(xfs_mount_t *, xfs_sb_field_t,
50 STATIC void xfs_icsb_balance_counter_locked(xfs_mount_t *, xfs_sb_field_t,
52 STATIC void xfs_icsb_disable_counter(xfs_mount_t *, xfs_sb_field_t);
55 #define xfs_icsb_balance_counter(mp, a, b) do { } while (0)
56 #define xfs_icsb_balance_counter_locked(mp, a, b) do { } while (0)
61 short type; /* 0 = integer
62 * 1 = binary / string (no translation)
65 { offsetof(xfs_sb_t, sb_magicnum), 0 },
66 { offsetof(xfs_sb_t, sb_blocksize), 0 },
67 { offsetof(xfs_sb_t, sb_dblocks), 0 },
68 { offsetof(xfs_sb_t, sb_rblocks), 0 },
69 { offsetof(xfs_sb_t, sb_rextents), 0 },
70 { offsetof(xfs_sb_t, sb_uuid), 1 },
71 { offsetof(xfs_sb_t, sb_logstart), 0 },
72 { offsetof(xfs_sb_t, sb_rootino), 0 },
73 { offsetof(xfs_sb_t, sb_rbmino), 0 },
74 { offsetof(xfs_sb_t, sb_rsumino), 0 },
75 { offsetof(xfs_sb_t, sb_rextsize), 0 },
76 { offsetof(xfs_sb_t, sb_agblocks), 0 },
77 { offsetof(xfs_sb_t, sb_agcount), 0 },
78 { offsetof(xfs_sb_t, sb_rbmblocks), 0 },
79 { offsetof(xfs_sb_t, sb_logblocks), 0 },
80 { offsetof(xfs_sb_t, sb_versionnum), 0 },
81 { offsetof(xfs_sb_t, sb_sectsize), 0 },
82 { offsetof(xfs_sb_t, sb_inodesize), 0 },
83 { offsetof(xfs_sb_t, sb_inopblock), 0 },
84 { offsetof(xfs_sb_t, sb_fname[0]), 1 },
85 { offsetof(xfs_sb_t, sb_blocklog), 0 },
86 { offsetof(xfs_sb_t, sb_sectlog), 0 },
87 { offsetof(xfs_sb_t, sb_inodelog), 0 },
88 { offsetof(xfs_sb_t, sb_inopblog), 0 },
89 { offsetof(xfs_sb_t, sb_agblklog), 0 },
90 { offsetof(xfs_sb_t, sb_rextslog), 0 },
91 { offsetof(xfs_sb_t, sb_inprogress), 0 },
92 { offsetof(xfs_sb_t, sb_imax_pct), 0 },
93 { offsetof(xfs_sb_t, sb_icount), 0 },
94 { offsetof(xfs_sb_t, sb_ifree), 0 },
95 { offsetof(xfs_sb_t, sb_fdblocks), 0 },
96 { offsetof(xfs_sb_t, sb_frextents), 0 },
97 { offsetof(xfs_sb_t, sb_uquotino), 0 },
98 { offsetof(xfs_sb_t, sb_gquotino), 0 },
99 { offsetof(xfs_sb_t, sb_qflags), 0 },
100 { offsetof(xfs_sb_t, sb_flags), 0 },
101 { offsetof(xfs_sb_t, sb_shared_vn), 0 },
102 { offsetof(xfs_sb_t, sb_inoalignmt), 0 },
103 { offsetof(xfs_sb_t, sb_unit), 0 },
104 { offsetof(xfs_sb_t, sb_width), 0 },
105 { offsetof(xfs_sb_t, sb_dirblklog), 0 },
106 { offsetof(xfs_sb_t, sb_logsectlog), 0 },
107 { offsetof(xfs_sb_t, sb_logsectsize),0 },
108 { offsetof(xfs_sb_t, sb_logsunit), 0 },
109 { offsetof(xfs_sb_t, sb_features2), 0 },
110 { offsetof(xfs_sb_t, sb_bad_features2), 0 },
111 { sizeof(xfs_sb_t), 0 }
114 static DEFINE_MUTEX(xfs_uuid_table_mutex);
115 static int xfs_uuid_table_size;
116 static uuid_t *xfs_uuid_table;
119 * See if the UUID is unique among mounted XFS filesystems.
120 * Mount fails if UUID is nil or a FS with the same UUID is already mounted.
124 struct xfs_mount *mp)
126 uuid_t *uuid = &mp->m_sb.sb_uuid;
129 if (mp->m_flags & XFS_MOUNT_NOUUID)
132 if (uuid_is_nil(uuid)) {
133 xfs_warn(mp, "Filesystem has nil UUID - can't mount");
134 return XFS_ERROR(EINVAL);
137 mutex_lock(&xfs_uuid_table_mutex);
138 for (i = 0, hole = -1; i < xfs_uuid_table_size; i++) {
139 if (uuid_is_nil(&xfs_uuid_table[i])) {
143 if (uuid_equal(uuid, &xfs_uuid_table[i]))
148 xfs_uuid_table = kmem_realloc(xfs_uuid_table,
149 (xfs_uuid_table_size + 1) * sizeof(*xfs_uuid_table),
150 xfs_uuid_table_size * sizeof(*xfs_uuid_table),
152 hole = xfs_uuid_table_size++;
154 xfs_uuid_table[hole] = *uuid;
155 mutex_unlock(&xfs_uuid_table_mutex);
160 mutex_unlock(&xfs_uuid_table_mutex);
161 xfs_warn(mp, "Filesystem has duplicate UUID - can't mount");
162 return XFS_ERROR(EINVAL);
167 struct xfs_mount *mp)
169 uuid_t *uuid = &mp->m_sb.sb_uuid;
172 if (mp->m_flags & XFS_MOUNT_NOUUID)
175 mutex_lock(&xfs_uuid_table_mutex);
176 for (i = 0; i < xfs_uuid_table_size; i++) {
177 if (uuid_is_nil(&xfs_uuid_table[i]))
179 if (!uuid_equal(uuid, &xfs_uuid_table[i]))
181 memset(&xfs_uuid_table[i], 0, sizeof(uuid_t));
184 ASSERT(i < xfs_uuid_table_size);
185 mutex_unlock(&xfs_uuid_table_mutex);
190 * Reference counting access wrappers to the perag structures.
191 * Because we never free per-ag structures, the only thing we
192 * have to protect against changes is the tree structure itself.
195 xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno)
197 struct xfs_perag *pag;
201 pag = radix_tree_lookup(&mp->m_perag_tree, agno);
203 ASSERT(atomic_read(&pag->pag_ref) >= 0);
204 ref = atomic_inc_return(&pag->pag_ref);
207 trace_xfs_perag_get(mp, agno, ref, _RET_IP_);
212 * search from @first to find the next perag with the given tag set.
216 struct xfs_mount *mp,
217 xfs_agnumber_t first,
220 struct xfs_perag *pag;
225 found = radix_tree_gang_lookup_tag(&mp->m_perag_tree,
226 (void **)&pag, first, 1, tag);
231 ref = atomic_inc_return(&pag->pag_ref);
233 trace_xfs_perag_get_tag(mp, pag->pag_agno, ref, _RET_IP_);
238 xfs_perag_put(struct xfs_perag *pag)
242 ASSERT(atomic_read(&pag->pag_ref) > 0);
243 ref = atomic_dec_return(&pag->pag_ref);
244 trace_xfs_perag_put(pag->pag_mount, pag->pag_agno, ref, _RET_IP_);
249 struct rcu_head *head)
251 struct xfs_perag *pag = container_of(head, struct xfs_perag, rcu_head);
253 ASSERT(atomic_read(&pag->pag_ref) == 0);
258 * Free up the per-ag resources associated with the mount structure.
265 struct xfs_perag *pag;
267 for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
268 spin_lock(&mp->m_perag_lock);
269 pag = radix_tree_delete(&mp->m_perag_tree, agno);
270 spin_unlock(&mp->m_perag_lock);
272 ASSERT(atomic_read(&pag->pag_ref) == 0);
273 call_rcu(&pag->rcu_head, __xfs_free_perag);
278 * Check size of device based on the (data/realtime) block count.
279 * Note: this check is used by the growfs code as well as mount.
282 xfs_sb_validate_fsb_count(
286 ASSERT(PAGE_SHIFT >= sbp->sb_blocklog);
287 ASSERT(sbp->sb_blocklog >= BBSHIFT);
289 #if XFS_BIG_BLKNOS /* Limited by ULONG_MAX of page cache index */
290 if (nblocks >> (PAGE_CACHE_SHIFT - sbp->sb_blocklog) > ULONG_MAX)
292 #else /* Limited by UINT_MAX of sectors */
293 if (nblocks << (sbp->sb_blocklog - BBSHIFT) > UINT_MAX)
300 * Check the validity of the SB found.
303 xfs_mount_validate_sb(
308 int loud = !(flags & XFS_MFSI_QUIET);
311 * If the log device and data device have the
312 * same device number, the log is internal.
313 * Consequently, the sb_logstart should be non-zero. If
314 * we have a zero sb_logstart in this case, we may be trying to mount
315 * a volume filesystem in a non-volume manner.
317 if (sbp->sb_magicnum != XFS_SB_MAGIC) {
319 xfs_warn(mp, "bad magic number");
320 return XFS_ERROR(EWRONGFS);
323 if (!xfs_sb_good_version(sbp)) {
325 xfs_warn(mp, "bad version");
326 return XFS_ERROR(EWRONGFS);
330 sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
333 "filesystem is marked as having an external log; "
334 "specify logdev on the mount command line.");
335 return XFS_ERROR(EINVAL);
339 sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
342 "filesystem is marked as having an internal log; "
343 "do not specify logdev on the mount command line.");
344 return XFS_ERROR(EINVAL);
348 * More sanity checking. Most of these were stolen directly from
352 sbp->sb_agcount <= 0 ||
353 sbp->sb_sectsize < XFS_MIN_SECTORSIZE ||
354 sbp->sb_sectsize > XFS_MAX_SECTORSIZE ||
355 sbp->sb_sectlog < XFS_MIN_SECTORSIZE_LOG ||
356 sbp->sb_sectlog > XFS_MAX_SECTORSIZE_LOG ||
357 sbp->sb_sectsize != (1 << sbp->sb_sectlog) ||
358 sbp->sb_blocksize < XFS_MIN_BLOCKSIZE ||
359 sbp->sb_blocksize > XFS_MAX_BLOCKSIZE ||
360 sbp->sb_blocklog < XFS_MIN_BLOCKSIZE_LOG ||
361 sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG ||
362 sbp->sb_blocksize != (1 << sbp->sb_blocklog) ||
363 sbp->sb_inodesize < XFS_DINODE_MIN_SIZE ||
364 sbp->sb_inodesize > XFS_DINODE_MAX_SIZE ||
365 sbp->sb_inodelog < XFS_DINODE_MIN_LOG ||
366 sbp->sb_inodelog > XFS_DINODE_MAX_LOG ||
367 sbp->sb_inodesize != (1 << sbp->sb_inodelog) ||
368 (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog) ||
369 (sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE) ||
370 (sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE) ||
371 (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */) ||
372 sbp->sb_dblocks == 0 ||
373 sbp->sb_dblocks > XFS_MAX_DBLOCKS(sbp) ||
374 sbp->sb_dblocks < XFS_MIN_DBLOCKS(sbp))) {
376 XFS_CORRUPTION_ERROR("SB sanity check failed",
377 XFS_ERRLEVEL_LOW, mp, sbp);
378 return XFS_ERROR(EFSCORRUPTED);
382 * Until this is fixed only page-sized or smaller data blocks work.
384 if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
387 "File system with blocksize %d bytes. "
388 "Only pagesize (%ld) or less will currently work.",
389 sbp->sb_blocksize, PAGE_SIZE);
391 return XFS_ERROR(ENOSYS);
395 * Currently only very few inode sizes are supported.
397 switch (sbp->sb_inodesize) {
405 xfs_warn(mp, "inode size of %d bytes not supported",
407 return XFS_ERROR(ENOSYS);
410 if (xfs_sb_validate_fsb_count(sbp, sbp->sb_dblocks) ||
411 xfs_sb_validate_fsb_count(sbp, sbp->sb_rblocks)) {
414 "file system too large to be mounted on this system.");
415 return XFS_ERROR(EFBIG);
418 if (unlikely(sbp->sb_inprogress)) {
420 xfs_warn(mp, "file system busy");
421 return XFS_ERROR(EFSCORRUPTED);
425 * Version 1 directory format has never worked on Linux.
427 if (unlikely(!xfs_sb_version_hasdirv2(sbp))) {
430 "file system using version 1 directory format");
431 return XFS_ERROR(ENOSYS);
438 xfs_initialize_perag(
440 xfs_agnumber_t agcount,
441 xfs_agnumber_t *maxagi)
443 xfs_agnumber_t index, max_metadata;
444 xfs_agnumber_t first_initialised = 0;
448 xfs_sb_t *sbp = &mp->m_sb;
452 * Walk the current per-ag tree so we don't try to initialise AGs
453 * that already exist (growfs case). Allocate and insert all the
454 * AGs we don't find ready for initialisation.
456 for (index = 0; index < agcount; index++) {
457 pag = xfs_perag_get(mp, index);
462 if (!first_initialised)
463 first_initialised = index;
465 pag = kmem_zalloc(sizeof(*pag), KM_MAYFAIL);
468 pag->pag_agno = index;
470 spin_lock_init(&pag->pag_ici_lock);
471 mutex_init(&pag->pag_ici_reclaim_lock);
472 INIT_RADIX_TREE(&pag->pag_ici_root, GFP_ATOMIC);
473 spin_lock_init(&pag->pag_buf_lock);
474 pag->pag_buf_tree = RB_ROOT;
476 if (radix_tree_preload(GFP_NOFS))
479 spin_lock(&mp->m_perag_lock);
480 if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
482 spin_unlock(&mp->m_perag_lock);
483 radix_tree_preload_end();
487 spin_unlock(&mp->m_perag_lock);
488 radix_tree_preload_end();
492 * If we mount with the inode64 option, or no inode overflows
493 * the legacy 32-bit address space clear the inode32 option.
495 agino = XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks - 1, 0);
496 ino = XFS_AGINO_TO_INO(mp, agcount - 1, agino);
498 if ((mp->m_flags & XFS_MOUNT_SMALL_INUMS) && ino > XFS_MAXINUMBER_32)
499 mp->m_flags |= XFS_MOUNT_32BITINODES;
501 mp->m_flags &= ~XFS_MOUNT_32BITINODES;
503 if (mp->m_flags & XFS_MOUNT_32BITINODES) {
505 * Calculate how much should be reserved for inodes to meet
506 * the max inode percentage.
508 if (mp->m_maxicount) {
511 icount = sbp->sb_dblocks * sbp->sb_imax_pct;
513 icount += sbp->sb_agblocks - 1;
514 do_div(icount, sbp->sb_agblocks);
515 max_metadata = icount;
517 max_metadata = agcount;
520 for (index = 0; index < agcount; index++) {
521 ino = XFS_AGINO_TO_INO(mp, index, agino);
522 if (ino > XFS_MAXINUMBER_32) {
527 pag = xfs_perag_get(mp, index);
528 pag->pagi_inodeok = 1;
529 if (index < max_metadata)
530 pag->pagf_metadata = 1;
534 for (index = 0; index < agcount; index++) {
535 pag = xfs_perag_get(mp, index);
536 pag->pagi_inodeok = 1;
547 for (; index > first_initialised; index--) {
548 pag = radix_tree_delete(&mp->m_perag_tree, index);
559 to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
560 to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
561 to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
562 to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
563 to->sb_rextents = be64_to_cpu(from->sb_rextents);
564 memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
565 to->sb_logstart = be64_to_cpu(from->sb_logstart);
566 to->sb_rootino = be64_to_cpu(from->sb_rootino);
567 to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
568 to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
569 to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
570 to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
571 to->sb_agcount = be32_to_cpu(from->sb_agcount);
572 to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
573 to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
574 to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
575 to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
576 to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
577 to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
578 memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
579 to->sb_blocklog = from->sb_blocklog;
580 to->sb_sectlog = from->sb_sectlog;
581 to->sb_inodelog = from->sb_inodelog;
582 to->sb_inopblog = from->sb_inopblog;
583 to->sb_agblklog = from->sb_agblklog;
584 to->sb_rextslog = from->sb_rextslog;
585 to->sb_inprogress = from->sb_inprogress;
586 to->sb_imax_pct = from->sb_imax_pct;
587 to->sb_icount = be64_to_cpu(from->sb_icount);
588 to->sb_ifree = be64_to_cpu(from->sb_ifree);
589 to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
590 to->sb_frextents = be64_to_cpu(from->sb_frextents);
591 to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
592 to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
593 to->sb_qflags = be16_to_cpu(from->sb_qflags);
594 to->sb_flags = from->sb_flags;
595 to->sb_shared_vn = from->sb_shared_vn;
596 to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
597 to->sb_unit = be32_to_cpu(from->sb_unit);
598 to->sb_width = be32_to_cpu(from->sb_width);
599 to->sb_dirblklog = from->sb_dirblklog;
600 to->sb_logsectlog = from->sb_logsectlog;
601 to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
602 to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
603 to->sb_features2 = be32_to_cpu(from->sb_features2);
604 to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
608 * Copy in core superblock to ondisk one.
610 * The fields argument is mask of superblock fields to copy.
618 xfs_caddr_t to_ptr = (xfs_caddr_t)to;
619 xfs_caddr_t from_ptr = (xfs_caddr_t)from;
629 f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
630 first = xfs_sb_info[f].offset;
631 size = xfs_sb_info[f + 1].offset - first;
633 ASSERT(xfs_sb_info[f].type == 0 || xfs_sb_info[f].type == 1);
635 if (size == 1 || xfs_sb_info[f].type == 1) {
636 memcpy(to_ptr + first, from_ptr + first, size);
640 *(__be16 *)(to_ptr + first) =
641 cpu_to_be16(*(__u16 *)(from_ptr + first));
644 *(__be32 *)(to_ptr + first) =
645 cpu_to_be32(*(__u32 *)(from_ptr + first));
648 *(__be64 *)(to_ptr + first) =
649 cpu_to_be64(*(__u64 *)(from_ptr + first));
656 fields &= ~(1LL << f);
663 * Does the initial read of the superblock.
666 xfs_readsb(xfs_mount_t *mp, int flags)
668 unsigned int sector_size;
671 int loud = !(flags & XFS_MFSI_QUIET);
673 ASSERT(mp->m_sb_bp == NULL);
674 ASSERT(mp->m_ddev_targp != NULL);
677 * Allocate a (locked) buffer to hold the superblock.
678 * This will be kept around at all times to optimize
679 * access to the superblock.
681 sector_size = xfs_getsize_buftarg(mp->m_ddev_targp);
684 bp = xfs_buf_read_uncached(mp, mp->m_ddev_targp,
685 XFS_SB_DADDR, sector_size, 0);
688 xfs_warn(mp, "SB buffer read failed");
693 * Initialize the mount structure from the superblock.
694 * But first do some basic consistency checking.
696 xfs_sb_from_disk(&mp->m_sb, XFS_BUF_TO_SBP(bp));
697 error = xfs_mount_validate_sb(mp, &(mp->m_sb), flags);
700 xfs_warn(mp, "SB validate failed");
705 * We must be able to do sector-sized and sector-aligned IO.
707 if (sector_size > mp->m_sb.sb_sectsize) {
709 xfs_warn(mp, "device supports %u byte sectors (not %u)",
710 sector_size, mp->m_sb.sb_sectsize);
716 * If device sector size is smaller than the superblock size,
717 * re-read the superblock so the buffer is correctly sized.
719 if (sector_size < mp->m_sb.sb_sectsize) {
721 sector_size = mp->m_sb.sb_sectsize;
725 /* Initialize per-cpu counters */
726 xfs_icsb_reinit_counters(mp);
741 * Mount initialization code establishing various mount
742 * fields from the superblock associated with the given
746 xfs_mount_common(xfs_mount_t *mp, xfs_sb_t *sbp)
748 mp->m_agfrotor = mp->m_agirotor = 0;
749 spin_lock_init(&mp->m_agirotor_lock);
750 mp->m_maxagi = mp->m_sb.sb_agcount;
751 mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
752 mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
753 mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
754 mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
755 mp->m_agino_log = sbp->sb_inopblog + sbp->sb_agblklog;
756 mp->m_blockmask = sbp->sb_blocksize - 1;
757 mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
758 mp->m_blockwmask = mp->m_blockwsize - 1;
760 mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 1);
761 mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 0);
762 mp->m_alloc_mnr[0] = mp->m_alloc_mxr[0] / 2;
763 mp->m_alloc_mnr[1] = mp->m_alloc_mxr[1] / 2;
765 mp->m_inobt_mxr[0] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 1);
766 mp->m_inobt_mxr[1] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 0);
767 mp->m_inobt_mnr[0] = mp->m_inobt_mxr[0] / 2;
768 mp->m_inobt_mnr[1] = mp->m_inobt_mxr[1] / 2;
770 mp->m_bmap_dmxr[0] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 1);
771 mp->m_bmap_dmxr[1] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 0);
772 mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
773 mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
775 mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
776 mp->m_ialloc_inos = (int)MAX((__uint16_t)XFS_INODES_PER_CHUNK,
778 mp->m_ialloc_blks = mp->m_ialloc_inos >> sbp->sb_inopblog;
782 * xfs_initialize_perag_data
784 * Read in each per-ag structure so we can count up the number of
785 * allocated inodes, free inodes and used filesystem blocks as this
786 * information is no longer persistent in the superblock. Once we have
787 * this information, write it into the in-core superblock structure.
790 xfs_initialize_perag_data(xfs_mount_t *mp, xfs_agnumber_t agcount)
792 xfs_agnumber_t index;
794 xfs_sb_t *sbp = &mp->m_sb;
798 uint64_t bfreelst = 0;
802 for (index = 0; index < agcount; index++) {
804 * read the agf, then the agi. This gets us
805 * all the information we need and populates the
806 * per-ag structures for us.
808 error = xfs_alloc_pagf_init(mp, NULL, index, 0);
812 error = xfs_ialloc_pagi_init(mp, NULL, index);
815 pag = xfs_perag_get(mp, index);
816 ifree += pag->pagi_freecount;
817 ialloc += pag->pagi_count;
818 bfree += pag->pagf_freeblks;
819 bfreelst += pag->pagf_flcount;
820 btree += pag->pagf_btreeblks;
824 * Overwrite incore superblock counters with just-read data
826 spin_lock(&mp->m_sb_lock);
827 sbp->sb_ifree = ifree;
828 sbp->sb_icount = ialloc;
829 sbp->sb_fdblocks = bfree + bfreelst + btree;
830 spin_unlock(&mp->m_sb_lock);
832 /* Fixup the per-cpu counters as well. */
833 xfs_icsb_reinit_counters(mp);
839 * Update alignment values based on mount options and sb values
842 xfs_update_alignment(xfs_mount_t *mp)
844 xfs_sb_t *sbp = &(mp->m_sb);
848 * If stripe unit and stripe width are not multiples
849 * of the fs blocksize turn off alignment.
851 if ((BBTOB(mp->m_dalign) & mp->m_blockmask) ||
852 (BBTOB(mp->m_swidth) & mp->m_blockmask)) {
853 if (mp->m_flags & XFS_MOUNT_RETERR) {
854 xfs_warn(mp, "alignment check failed: "
855 "(sunit/swidth vs. blocksize)");
856 return XFS_ERROR(EINVAL);
858 mp->m_dalign = mp->m_swidth = 0;
861 * Convert the stripe unit and width to FSBs.
863 mp->m_dalign = XFS_BB_TO_FSBT(mp, mp->m_dalign);
864 if (mp->m_dalign && (sbp->sb_agblocks % mp->m_dalign)) {
865 if (mp->m_flags & XFS_MOUNT_RETERR) {
866 xfs_warn(mp, "alignment check failed: "
867 "(sunit/swidth vs. ag size)");
868 return XFS_ERROR(EINVAL);
871 "stripe alignment turned off: sunit(%d)/swidth(%d) "
872 "incompatible with agsize(%d)",
873 mp->m_dalign, mp->m_swidth,
878 } else if (mp->m_dalign) {
879 mp->m_swidth = XFS_BB_TO_FSBT(mp, mp->m_swidth);
881 if (mp->m_flags & XFS_MOUNT_RETERR) {
882 xfs_warn(mp, "alignment check failed: "
883 "sunit(%d) less than bsize(%d)",
886 return XFS_ERROR(EINVAL);
893 * Update superblock with new values
896 if (xfs_sb_version_hasdalign(sbp)) {
897 if (sbp->sb_unit != mp->m_dalign) {
898 sbp->sb_unit = mp->m_dalign;
899 mp->m_update_flags |= XFS_SB_UNIT;
901 if (sbp->sb_width != mp->m_swidth) {
902 sbp->sb_width = mp->m_swidth;
903 mp->m_update_flags |= XFS_SB_WIDTH;
906 } else if ((mp->m_flags & XFS_MOUNT_NOALIGN) != XFS_MOUNT_NOALIGN &&
907 xfs_sb_version_hasdalign(&mp->m_sb)) {
908 mp->m_dalign = sbp->sb_unit;
909 mp->m_swidth = sbp->sb_width;
916 * Set the maximum inode count for this filesystem
919 xfs_set_maxicount(xfs_mount_t *mp)
921 xfs_sb_t *sbp = &(mp->m_sb);
924 if (sbp->sb_imax_pct) {
926 * Make sure the maximum inode count is a multiple
927 * of the units we allocate inodes in.
929 icount = sbp->sb_dblocks * sbp->sb_imax_pct;
931 do_div(icount, mp->m_ialloc_blks);
932 mp->m_maxicount = (icount * mp->m_ialloc_blks) <<
940 * Set the default minimum read and write sizes unless
941 * already specified in a mount option.
942 * We use smaller I/O sizes when the file system
943 * is being used for NFS service (wsync mount option).
946 xfs_set_rw_sizes(xfs_mount_t *mp)
948 xfs_sb_t *sbp = &(mp->m_sb);
949 int readio_log, writeio_log;
951 if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) {
952 if (mp->m_flags & XFS_MOUNT_WSYNC) {
953 readio_log = XFS_WSYNC_READIO_LOG;
954 writeio_log = XFS_WSYNC_WRITEIO_LOG;
956 readio_log = XFS_READIO_LOG_LARGE;
957 writeio_log = XFS_WRITEIO_LOG_LARGE;
960 readio_log = mp->m_readio_log;
961 writeio_log = mp->m_writeio_log;
964 if (sbp->sb_blocklog > readio_log) {
965 mp->m_readio_log = sbp->sb_blocklog;
967 mp->m_readio_log = readio_log;
969 mp->m_readio_blocks = 1 << (mp->m_readio_log - sbp->sb_blocklog);
970 if (sbp->sb_blocklog > writeio_log) {
971 mp->m_writeio_log = sbp->sb_blocklog;
973 mp->m_writeio_log = writeio_log;
975 mp->m_writeio_blocks = 1 << (mp->m_writeio_log - sbp->sb_blocklog);
979 * precalculate the low space thresholds for dynamic speculative preallocation.
982 xfs_set_low_space_thresholds(
983 struct xfs_mount *mp)
987 for (i = 0; i < XFS_LOWSP_MAX; i++) {
988 __uint64_t space = mp->m_sb.sb_dblocks;
991 mp->m_low_space[i] = space * (i + 1);
997 * Set whether we're using inode alignment.
1000 xfs_set_inoalignment(xfs_mount_t *mp)
1002 if (xfs_sb_version_hasalign(&mp->m_sb) &&
1003 mp->m_sb.sb_inoalignmt >=
1004 XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size))
1005 mp->m_inoalign_mask = mp->m_sb.sb_inoalignmt - 1;
1007 mp->m_inoalign_mask = 0;
1009 * If we are using stripe alignment, check whether
1010 * the stripe unit is a multiple of the inode alignment
1012 if (mp->m_dalign && mp->m_inoalign_mask &&
1013 !(mp->m_dalign & mp->m_inoalign_mask))
1014 mp->m_sinoalign = mp->m_dalign;
1016 mp->m_sinoalign = 0;
1020 * Check that the data (and log if separate) are an ok size.
1023 xfs_check_sizes(xfs_mount_t *mp)
1028 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
1029 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_dblocks) {
1030 xfs_warn(mp, "filesystem size mismatch detected");
1031 return XFS_ERROR(EFBIG);
1033 bp = xfs_buf_read_uncached(mp, mp->m_ddev_targp,
1034 d - XFS_FSS_TO_BB(mp, 1),
1035 BBTOB(XFS_FSS_TO_BB(mp, 1)), 0);
1037 xfs_warn(mp, "last sector read failed");
1042 if (mp->m_logdev_targp != mp->m_ddev_targp) {
1043 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks);
1044 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_logblocks) {
1045 xfs_warn(mp, "log size mismatch detected");
1046 return XFS_ERROR(EFBIG);
1048 bp = xfs_buf_read_uncached(mp, mp->m_logdev_targp,
1049 d - XFS_FSB_TO_BB(mp, 1),
1050 XFS_FSB_TO_B(mp, 1), 0);
1052 xfs_warn(mp, "log device read failed");
1061 * Clear the quotaflags in memory and in the superblock.
1064 xfs_mount_reset_sbqflags(
1065 struct xfs_mount *mp)
1068 struct xfs_trans *tp;
1073 * It is OK to look at sb_qflags here in mount path,
1074 * without m_sb_lock.
1076 if (mp->m_sb.sb_qflags == 0)
1078 spin_lock(&mp->m_sb_lock);
1079 mp->m_sb.sb_qflags = 0;
1080 spin_unlock(&mp->m_sb_lock);
1083 * If the fs is readonly, let the incore superblock run
1084 * with quotas off but don't flush the update out to disk
1086 if (mp->m_flags & XFS_MOUNT_RDONLY)
1089 tp = xfs_trans_alloc(mp, XFS_TRANS_QM_SBCHANGE);
1090 error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
1091 XFS_DEFAULT_LOG_COUNT);
1093 xfs_trans_cancel(tp, 0);
1094 xfs_alert(mp, "%s: Superblock update failed!", __func__);
1098 xfs_mod_sb(tp, XFS_SB_QFLAGS);
1099 return xfs_trans_commit(tp, 0);
1103 xfs_default_resblks(xfs_mount_t *mp)
1108 * We default to 5% or 8192 fsbs of space reserved, whichever is
1109 * smaller. This is intended to cover concurrent allocation
1110 * transactions when we initially hit enospc. These each require a 4
1111 * block reservation. Hence by default we cover roughly 2000 concurrent
1112 * allocation reservations.
1114 resblks = mp->m_sb.sb_dblocks;
1115 do_div(resblks, 20);
1116 resblks = min_t(__uint64_t, resblks, 8192);
1121 * This function does the following on an initial mount of a file system:
1122 * - reads the superblock from disk and init the mount struct
1123 * - if we're a 32-bit kernel, do a size check on the superblock
1124 * so we don't mount terabyte filesystems
1125 * - init mount struct realtime fields
1126 * - allocate inode hash table for fs
1127 * - init directory manager
1128 * - perform recovery and init the log manager
1134 xfs_sb_t *sbp = &(mp->m_sb);
1137 uint quotamount = 0;
1138 uint quotaflags = 0;
1141 xfs_mount_common(mp, sbp);
1144 * Check for a mismatched features2 values. Older kernels
1145 * read & wrote into the wrong sb offset for sb_features2
1146 * on some platforms due to xfs_sb_t not being 64bit size aligned
1147 * when sb_features2 was added, which made older superblock
1148 * reading/writing routines swap it as a 64-bit value.
1150 * For backwards compatibility, we make both slots equal.
1152 * If we detect a mismatched field, we OR the set bits into the
1153 * existing features2 field in case it has already been modified; we
1154 * don't want to lose any features. We then update the bad location
1155 * with the ORed value so that older kernels will see any features2
1156 * flags, and mark the two fields as needing updates once the
1157 * transaction subsystem is online.
1159 if (xfs_sb_has_mismatched_features2(sbp)) {
1160 xfs_warn(mp, "correcting sb_features alignment problem");
1161 sbp->sb_features2 |= sbp->sb_bad_features2;
1162 sbp->sb_bad_features2 = sbp->sb_features2;
1163 mp->m_update_flags |= XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2;
1166 * Re-check for ATTR2 in case it was found in bad_features2
1169 if (xfs_sb_version_hasattr2(&mp->m_sb) &&
1170 !(mp->m_flags & XFS_MOUNT_NOATTR2))
1171 mp->m_flags |= XFS_MOUNT_ATTR2;
1174 if (xfs_sb_version_hasattr2(&mp->m_sb) &&
1175 (mp->m_flags & XFS_MOUNT_NOATTR2)) {
1176 xfs_sb_version_removeattr2(&mp->m_sb);
1177 mp->m_update_flags |= XFS_SB_FEATURES2;
1179 /* update sb_versionnum for the clearing of the morebits */
1180 if (!sbp->sb_features2)
1181 mp->m_update_flags |= XFS_SB_VERSIONNUM;
1185 * Check if sb_agblocks is aligned at stripe boundary
1186 * If sb_agblocks is NOT aligned turn off m_dalign since
1187 * allocator alignment is within an ag, therefore ag has
1188 * to be aligned at stripe boundary.
1190 error = xfs_update_alignment(mp);
1194 xfs_alloc_compute_maxlevels(mp);
1195 xfs_bmap_compute_maxlevels(mp, XFS_DATA_FORK);
1196 xfs_bmap_compute_maxlevels(mp, XFS_ATTR_FORK);
1197 xfs_ialloc_compute_maxlevels(mp);
1199 xfs_set_maxicount(mp);
1201 mp->m_maxioffset = xfs_max_file_offset(sbp->sb_blocklog);
1203 error = xfs_uuid_mount(mp);
1208 * Set the minimum read and write sizes
1210 xfs_set_rw_sizes(mp);
1212 /* set the low space thresholds for dynamic preallocation */
1213 xfs_set_low_space_thresholds(mp);
1216 * Set the inode cluster size.
1217 * This may still be overridden by the file system
1218 * block size if it is larger than the chosen cluster size.
1220 mp->m_inode_cluster_size = XFS_INODE_BIG_CLUSTER_SIZE;
1223 * Set inode alignment fields
1225 xfs_set_inoalignment(mp);
1228 * Check that the data (and log if separate) are an ok size.
1230 error = xfs_check_sizes(mp);
1232 goto out_remove_uuid;
1235 * Initialize realtime fields in the mount structure
1237 error = xfs_rtmount_init(mp);
1239 xfs_warn(mp, "RT mount failed");
1240 goto out_remove_uuid;
1244 * Copies the low order bits of the timestamp and the randomly
1245 * set "sequence" number out of a UUID.
1247 uuid_getnodeuniq(&sbp->sb_uuid, mp->m_fixedfsid);
1249 mp->m_dmevmask = 0; /* not persistent; set after each mount */
1254 * Initialize the attribute manager's entries.
1256 mp->m_attr_magicpct = (mp->m_sb.sb_blocksize * 37) / 100;
1259 * Initialize the precomputed transaction reservations values.
1264 * Allocate and initialize the per-ag data.
1266 spin_lock_init(&mp->m_perag_lock);
1267 INIT_RADIX_TREE(&mp->m_perag_tree, GFP_ATOMIC);
1268 error = xfs_initialize_perag(mp, sbp->sb_agcount, &mp->m_maxagi);
1270 xfs_warn(mp, "Failed per-ag init: %d", error);
1271 goto out_remove_uuid;
1274 if (!sbp->sb_logblocks) {
1275 xfs_warn(mp, "no log defined");
1276 XFS_ERROR_REPORT("xfs_mountfs", XFS_ERRLEVEL_LOW, mp);
1277 error = XFS_ERROR(EFSCORRUPTED);
1278 goto out_free_perag;
1282 * log's mount-time initialization. Perform 1st part recovery if needed
1284 error = xfs_log_mount(mp, mp->m_logdev_targp,
1285 XFS_FSB_TO_DADDR(mp, sbp->sb_logstart),
1286 XFS_FSB_TO_BB(mp, sbp->sb_logblocks));
1288 xfs_warn(mp, "log mount failed");
1289 goto out_free_perag;
1293 * Now the log is mounted, we know if it was an unclean shutdown or
1294 * not. If it was, with the first phase of recovery has completed, we
1295 * have consistent AG blocks on disk. We have not recovered EFIs yet,
1296 * but they are recovered transactionally in the second recovery phase
1299 * Hence we can safely re-initialise incore superblock counters from
1300 * the per-ag data. These may not be correct if the filesystem was not
1301 * cleanly unmounted, so we need to wait for recovery to finish before
1304 * If the filesystem was cleanly unmounted, then we can trust the
1305 * values in the superblock to be correct and we don't need to do
1308 * If we are currently making the filesystem, the initialisation will
1309 * fail as the perag data is in an undefined state.
1311 if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
1312 !XFS_LAST_UNMOUNT_WAS_CLEAN(mp) &&
1313 !mp->m_sb.sb_inprogress) {
1314 error = xfs_initialize_perag_data(mp, sbp->sb_agcount);
1316 goto out_free_perag;
1320 * Get and sanity-check the root inode.
1321 * Save the pointer to it in the mount structure.
1323 error = xfs_iget(mp, NULL, sbp->sb_rootino, 0, XFS_ILOCK_EXCL, &rip);
1325 xfs_warn(mp, "failed to read root inode");
1326 goto out_log_dealloc;
1329 ASSERT(rip != NULL);
1331 if (unlikely(!S_ISDIR(rip->i_d.di_mode))) {
1332 xfs_warn(mp, "corrupted root inode %llu: not a directory",
1333 (unsigned long long)rip->i_ino);
1334 xfs_iunlock(rip, XFS_ILOCK_EXCL);
1335 XFS_ERROR_REPORT("xfs_mountfs_int(2)", XFS_ERRLEVEL_LOW,
1337 error = XFS_ERROR(EFSCORRUPTED);
1340 mp->m_rootip = rip; /* save it */
1342 xfs_iunlock(rip, XFS_ILOCK_EXCL);
1345 * Initialize realtime inode pointers in the mount structure
1347 error = xfs_rtmount_inodes(mp);
1350 * Free up the root inode.
1352 xfs_warn(mp, "failed to read RT inodes");
1357 * If this is a read-only mount defer the superblock updates until
1358 * the next remount into writeable mode. Otherwise we would never
1359 * perform the update e.g. for the root filesystem.
1361 if (mp->m_update_flags && !(mp->m_flags & XFS_MOUNT_RDONLY)) {
1362 error = xfs_mount_log_sb(mp, mp->m_update_flags);
1364 xfs_warn(mp, "failed to write sb changes");
1370 * Initialise the XFS quota management subsystem for this mount
1372 if (XFS_IS_QUOTA_RUNNING(mp)) {
1373 error = xfs_qm_newmount(mp, "amount, "aflags);
1377 ASSERT(!XFS_IS_QUOTA_ON(mp));
1380 * If a file system had quotas running earlier, but decided to
1381 * mount without -o uquota/pquota/gquota options, revoke the
1382 * quotachecked license.
1384 if (mp->m_sb.sb_qflags & XFS_ALL_QUOTA_ACCT) {
1385 xfs_notice(mp, "resetting quota flags");
1386 error = xfs_mount_reset_sbqflags(mp);
1393 * Finish recovering the file system. This part needed to be
1394 * delayed until after the root and real-time bitmap inodes
1395 * were consistently read in.
1397 error = xfs_log_mount_finish(mp);
1399 xfs_warn(mp, "log mount finish failed");
1404 * Complete the quota initialisation, post-log-replay component.
1407 ASSERT(mp->m_qflags == 0);
1408 mp->m_qflags = quotaflags;
1410 xfs_qm_mount_quotas(mp);
1414 * Now we are mounted, reserve a small amount of unused space for
1415 * privileged transactions. This is needed so that transaction
1416 * space required for critical operations can dip into this pool
1417 * when at ENOSPC. This is needed for operations like create with
1418 * attr, unwritten extent conversion at ENOSPC, etc. Data allocations
1419 * are not allowed to use this reserved space.
1421 * This may drive us straight to ENOSPC on mount, but that implies
1422 * we were already there on the last unmount. Warn if this occurs.
1424 if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
1425 resblks = xfs_default_resblks(mp);
1426 error = xfs_reserve_blocks(mp, &resblks, NULL);
1429 "Unable to allocate reserve blocks. Continuing without reserve pool.");
1435 xfs_rtunmount_inodes(mp);
1439 xfs_log_unmount(mp);
1443 xfs_uuid_unmount(mp);
1449 * This flushes out the inodes,dquots and the superblock, unmounts the
1450 * log and makes sure that incore structures are freed.
1454 struct xfs_mount *mp)
1459 xfs_qm_unmount_quotas(mp);
1460 xfs_rtunmount_inodes(mp);
1461 IRELE(mp->m_rootip);
1464 * We can potentially deadlock here if we have an inode cluster
1465 * that has been freed has its buffer still pinned in memory because
1466 * the transaction is still sitting in a iclog. The stale inodes
1467 * on that buffer will have their flush locks held until the
1468 * transaction hits the disk and the callbacks run. the inode
1469 * flush takes the flush lock unconditionally and with nothing to
1470 * push out the iclog we will never get that unlocked. hence we
1471 * need to force the log first.
1473 xfs_log_force(mp, XFS_LOG_SYNC);
1476 * Do a delwri reclaim pass first so that as many dirty inodes are
1477 * queued up for IO as possible. Then flush the buffers before making
1478 * a synchronous path to catch all the remaining inodes are reclaimed.
1479 * This makes the reclaim process as quick as possible by avoiding
1480 * synchronous writeout and blocking on inodes already in the delwri
1481 * state as much as possible.
1483 xfs_reclaim_inodes(mp, 0);
1484 xfs_flush_buftarg(mp->m_ddev_targp, 1);
1485 xfs_reclaim_inodes(mp, SYNC_WAIT);
1490 * Flush out the log synchronously so that we know for sure
1491 * that nothing is pinned. This is important because bflush()
1492 * will skip pinned buffers.
1494 xfs_log_force(mp, XFS_LOG_SYNC);
1497 * Unreserve any blocks we have so that when we unmount we don't account
1498 * the reserved free space as used. This is really only necessary for
1499 * lazy superblock counting because it trusts the incore superblock
1500 * counters to be absolutely correct on clean unmount.
1502 * We don't bother correcting this elsewhere for lazy superblock
1503 * counting because on mount of an unclean filesystem we reconstruct the
1504 * correct counter value and this is irrelevant.
1506 * For non-lazy counter filesystems, this doesn't matter at all because
1507 * we only every apply deltas to the superblock and hence the incore
1508 * value does not matter....
1511 error = xfs_reserve_blocks(mp, &resblks, NULL);
1513 xfs_warn(mp, "Unable to free reserved block pool. "
1514 "Freespace may not be correct on next mount.");
1516 error = xfs_log_sbcount(mp);
1518 xfs_warn(mp, "Unable to update superblock counters. "
1519 "Freespace may not be correct on next mount.");
1520 xfs_unmountfs_writesb(mp);
1523 * Make sure all buffers have been flushed and completed before
1524 * unmounting the log.
1526 error = xfs_flush_buftarg(mp->m_ddev_targp, 1);
1528 xfs_warn(mp, "%d busy buffers during unmount.", error);
1529 xfs_wait_buftarg(mp->m_ddev_targp);
1531 xfs_log_unmount_write(mp);
1532 xfs_log_unmount(mp);
1533 xfs_uuid_unmount(mp);
1536 xfs_errortag_clearall(mp, 0);
1542 xfs_fs_writable(xfs_mount_t *mp)
1544 return !(xfs_test_for_freeze(mp) || XFS_FORCED_SHUTDOWN(mp) ||
1545 (mp->m_flags & XFS_MOUNT_RDONLY));
1551 * Sync the superblock counters to disk.
1553 * Note this code can be called during the process of freezing, so
1554 * we may need to use the transaction allocator which does not
1555 * block when the transaction subsystem is in its frozen state.
1558 xfs_log_sbcount(xfs_mount_t *mp)
1563 if (!xfs_fs_writable(mp))
1566 xfs_icsb_sync_counters(mp, 0);
1569 * we don't need to do this if we are updating the superblock
1570 * counters on every modification.
1572 if (!xfs_sb_version_haslazysbcount(&mp->m_sb))
1575 tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT, KM_SLEEP);
1576 error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
1577 XFS_DEFAULT_LOG_COUNT);
1579 xfs_trans_cancel(tp, 0);
1583 xfs_mod_sb(tp, XFS_SB_IFREE | XFS_SB_ICOUNT | XFS_SB_FDBLOCKS);
1584 xfs_trans_set_sync(tp);
1585 error = xfs_trans_commit(tp, 0);
1590 xfs_unmountfs_writesb(xfs_mount_t *mp)
1596 * skip superblock write if fs is read-only, or
1597 * if we are doing a forced umount.
1599 if (!((mp->m_flags & XFS_MOUNT_RDONLY) ||
1600 XFS_FORCED_SHUTDOWN(mp))) {
1602 sbp = xfs_getsb(mp, 0);
1604 XFS_BUF_UNDONE(sbp);
1605 XFS_BUF_UNREAD(sbp);
1606 xfs_buf_delwri_dequeue(sbp);
1608 XFS_BUF_UNASYNC(sbp);
1609 ASSERT(sbp->b_target == mp->m_ddev_targp);
1610 xfsbdstrat(mp, sbp);
1611 error = xfs_buf_iowait(sbp);
1613 xfs_buf_ioerror_alert(sbp, __func__);
1620 * xfs_mod_sb() can be used to copy arbitrary changes to the
1621 * in-core superblock into the superblock buffer to be logged.
1622 * It does not provide the higher level of locking that is
1623 * needed to protect the in-core superblock from concurrent
1627 xfs_mod_sb(xfs_trans_t *tp, __int64_t fields)
1639 bp = xfs_trans_getsb(tp, mp, 0);
1640 first = sizeof(xfs_sb_t);
1643 /* translate/copy */
1645 xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, fields);
1647 /* find modified range */
1648 f = (xfs_sb_field_t)xfs_highbit64((__uint64_t)fields);
1649 ASSERT((1LL << f) & XFS_SB_MOD_BITS);
1650 last = xfs_sb_info[f + 1].offset - 1;
1652 f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
1653 ASSERT((1LL << f) & XFS_SB_MOD_BITS);
1654 first = xfs_sb_info[f].offset;
1656 xfs_trans_log_buf(tp, bp, first, last);
1661 * xfs_mod_incore_sb_unlocked() is a utility routine common used to apply
1662 * a delta to a specified field in the in-core superblock. Simply
1663 * switch on the field indicated and apply the delta to that field.
1664 * Fields are not allowed to dip below zero, so if the delta would
1665 * do this do not apply it and return EINVAL.
1667 * The m_sb_lock must be held when this routine is called.
1670 xfs_mod_incore_sb_unlocked(
1672 xfs_sb_field_t field,
1676 int scounter; /* short counter for 32 bit fields */
1677 long long lcounter; /* long counter for 64 bit fields */
1678 long long res_used, rem;
1681 * With the in-core superblock spin lock held, switch
1682 * on the indicated field. Apply the delta to the
1683 * proper field. If the fields value would dip below
1684 * 0, then do not apply the delta and return EINVAL.
1687 case XFS_SBS_ICOUNT:
1688 lcounter = (long long)mp->m_sb.sb_icount;
1692 return XFS_ERROR(EINVAL);
1694 mp->m_sb.sb_icount = lcounter;
1697 lcounter = (long long)mp->m_sb.sb_ifree;
1701 return XFS_ERROR(EINVAL);
1703 mp->m_sb.sb_ifree = lcounter;
1705 case XFS_SBS_FDBLOCKS:
1706 lcounter = (long long)
1707 mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
1708 res_used = (long long)(mp->m_resblks - mp->m_resblks_avail);
1710 if (delta > 0) { /* Putting blocks back */
1711 if (res_used > delta) {
1712 mp->m_resblks_avail += delta;
1714 rem = delta - res_used;
1715 mp->m_resblks_avail = mp->m_resblks;
1718 } else { /* Taking blocks away */
1720 if (lcounter >= 0) {
1721 mp->m_sb.sb_fdblocks = lcounter +
1722 XFS_ALLOC_SET_ASIDE(mp);
1727 * We are out of blocks, use any available reserved
1728 * blocks if were allowed to.
1731 return XFS_ERROR(ENOSPC);
1733 lcounter = (long long)mp->m_resblks_avail + delta;
1734 if (lcounter >= 0) {
1735 mp->m_resblks_avail = lcounter;
1738 printk_once(KERN_WARNING
1739 "Filesystem \"%s\": reserve blocks depleted! "
1740 "Consider increasing reserve pool size.",
1742 return XFS_ERROR(ENOSPC);
1745 mp->m_sb.sb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
1747 case XFS_SBS_FREXTENTS:
1748 lcounter = (long long)mp->m_sb.sb_frextents;
1751 return XFS_ERROR(ENOSPC);
1753 mp->m_sb.sb_frextents = lcounter;
1755 case XFS_SBS_DBLOCKS:
1756 lcounter = (long long)mp->m_sb.sb_dblocks;
1760 return XFS_ERROR(EINVAL);
1762 mp->m_sb.sb_dblocks = lcounter;
1764 case XFS_SBS_AGCOUNT:
1765 scounter = mp->m_sb.sb_agcount;
1769 return XFS_ERROR(EINVAL);
1771 mp->m_sb.sb_agcount = scounter;
1773 case XFS_SBS_IMAX_PCT:
1774 scounter = mp->m_sb.sb_imax_pct;
1778 return XFS_ERROR(EINVAL);
1780 mp->m_sb.sb_imax_pct = scounter;
1782 case XFS_SBS_REXTSIZE:
1783 scounter = mp->m_sb.sb_rextsize;
1787 return XFS_ERROR(EINVAL);
1789 mp->m_sb.sb_rextsize = scounter;
1791 case XFS_SBS_RBMBLOCKS:
1792 scounter = mp->m_sb.sb_rbmblocks;
1796 return XFS_ERROR(EINVAL);
1798 mp->m_sb.sb_rbmblocks = scounter;
1800 case XFS_SBS_RBLOCKS:
1801 lcounter = (long long)mp->m_sb.sb_rblocks;
1805 return XFS_ERROR(EINVAL);
1807 mp->m_sb.sb_rblocks = lcounter;
1809 case XFS_SBS_REXTENTS:
1810 lcounter = (long long)mp->m_sb.sb_rextents;
1814 return XFS_ERROR(EINVAL);
1816 mp->m_sb.sb_rextents = lcounter;
1818 case XFS_SBS_REXTSLOG:
1819 scounter = mp->m_sb.sb_rextslog;
1823 return XFS_ERROR(EINVAL);
1825 mp->m_sb.sb_rextslog = scounter;
1829 return XFS_ERROR(EINVAL);
1834 * xfs_mod_incore_sb() is used to change a field in the in-core
1835 * superblock structure by the specified delta. This modification
1836 * is protected by the m_sb_lock. Just use the xfs_mod_incore_sb_unlocked()
1837 * routine to do the work.
1841 struct xfs_mount *mp,
1842 xfs_sb_field_t field,
1848 #ifdef HAVE_PERCPU_SB
1849 ASSERT(field < XFS_SBS_ICOUNT || field > XFS_SBS_FDBLOCKS);
1851 spin_lock(&mp->m_sb_lock);
1852 status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
1853 spin_unlock(&mp->m_sb_lock);
1859 * Change more than one field in the in-core superblock structure at a time.
1861 * The fields and changes to those fields are specified in the array of
1862 * xfs_mod_sb structures passed in. Either all of the specified deltas
1863 * will be applied or none of them will. If any modified field dips below 0,
1864 * then all modifications will be backed out and EINVAL will be returned.
1866 * Note that this function may not be used for the superblock values that
1867 * are tracked with the in-memory per-cpu counters - a direct call to
1868 * xfs_icsb_modify_counters is required for these.
1871 xfs_mod_incore_sb_batch(
1872 struct xfs_mount *mp,
1881 * Loop through the array of mod structures and apply each individually.
1882 * If any fail, then back out all those which have already been applied.
1883 * Do all of this within the scope of the m_sb_lock so that all of the
1884 * changes will be atomic.
1886 spin_lock(&mp->m_sb_lock);
1887 for (msbp = msb; msbp < (msb + nmsb); msbp++) {
1888 ASSERT(msbp->msb_field < XFS_SBS_ICOUNT ||
1889 msbp->msb_field > XFS_SBS_FDBLOCKS);
1891 error = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
1892 msbp->msb_delta, rsvd);
1896 spin_unlock(&mp->m_sb_lock);
1900 while (--msbp >= msb) {
1901 error = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
1902 -msbp->msb_delta, rsvd);
1905 spin_unlock(&mp->m_sb_lock);
1910 * xfs_getsb() is called to obtain the buffer for the superblock.
1911 * The buffer is returned locked and read in from disk.
1912 * The buffer should be released with a call to xfs_brelse().
1914 * If the flags parameter is BUF_TRYLOCK, then we'll only return
1915 * the superblock buffer if it can be locked without sleeping.
1916 * If it can't then we'll return NULL.
1920 struct xfs_mount *mp,
1923 struct xfs_buf *bp = mp->m_sb_bp;
1925 if (!xfs_buf_trylock(bp)) {
1926 if (flags & XBF_TRYLOCK)
1932 ASSERT(XFS_BUF_ISDONE(bp));
1937 * Used to free the superblock along various error paths.
1941 struct xfs_mount *mp)
1943 struct xfs_buf *bp = mp->m_sb_bp;
1951 * Used to log changes to the superblock unit and width fields which could
1952 * be altered by the mount options, as well as any potential sb_features2
1953 * fixup. Only the first superblock is updated.
1963 ASSERT(fields & (XFS_SB_UNIT | XFS_SB_WIDTH | XFS_SB_UUID |
1964 XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2 |
1965 XFS_SB_VERSIONNUM));
1967 tp = xfs_trans_alloc(mp, XFS_TRANS_SB_UNIT);
1968 error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
1969 XFS_DEFAULT_LOG_COUNT);
1971 xfs_trans_cancel(tp, 0);
1974 xfs_mod_sb(tp, fields);
1975 error = xfs_trans_commit(tp, 0);
1980 * If the underlying (data/log/rt) device is readonly, there are some
1981 * operations that cannot proceed.
1984 xfs_dev_is_read_only(
1985 struct xfs_mount *mp,
1988 if (xfs_readonly_buftarg(mp->m_ddev_targp) ||
1989 xfs_readonly_buftarg(mp->m_logdev_targp) ||
1990 (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp))) {
1991 xfs_notice(mp, "%s required on read-only device.", message);
1992 xfs_notice(mp, "write access unavailable, cannot proceed.");
1998 #ifdef HAVE_PERCPU_SB
2000 * Per-cpu incore superblock counters
2002 * Simple concept, difficult implementation
2004 * Basically, replace the incore superblock counters with a distributed per cpu
2005 * counter for contended fields (e.g. free block count).
2007 * Difficulties arise in that the incore sb is used for ENOSPC checking, and
2008 * hence needs to be accurately read when we are running low on space. Hence
2009 * there is a method to enable and disable the per-cpu counters based on how
2010 * much "stuff" is available in them.
2012 * Basically, a counter is enabled if there is enough free resource to justify
2013 * running a per-cpu fast-path. If the per-cpu counter runs out (i.e. a local
2014 * ENOSPC), then we disable the counters to synchronise all callers and
2015 * re-distribute the available resources.
2017 * If, once we redistributed the available resources, we still get a failure,
2018 * we disable the per-cpu counter and go through the slow path.
2020 * The slow path is the current xfs_mod_incore_sb() function. This means that
2021 * when we disable a per-cpu counter, we need to drain its resources back to
2022 * the global superblock. We do this after disabling the counter to prevent
2023 * more threads from queueing up on the counter.
2025 * Essentially, this means that we still need a lock in the fast path to enable
2026 * synchronisation between the global counters and the per-cpu counters. This
2027 * is not a problem because the lock will be local to a CPU almost all the time
2028 * and have little contention except when we get to ENOSPC conditions.
2030 * Basically, this lock becomes a barrier that enables us to lock out the fast
2031 * path while we do things like enabling and disabling counters and
2032 * synchronising the counters.
2036 * 1. m_sb_lock before picking up per-cpu locks
2037 * 2. per-cpu locks always picked up via for_each_online_cpu() order
2038 * 3. accurate counter sync requires m_sb_lock + per cpu locks
2039 * 4. modifying per-cpu counters requires holding per-cpu lock
2040 * 5. modifying global counters requires holding m_sb_lock
2041 * 6. enabling or disabling a counter requires holding the m_sb_lock
2042 * and _none_ of the per-cpu locks.
2044 * Disabled counters are only ever re-enabled by a balance operation
2045 * that results in more free resources per CPU than a given threshold.
2046 * To ensure counters don't remain disabled, they are rebalanced when
2047 * the global resource goes above a higher threshold (i.e. some hysteresis
2048 * is present to prevent thrashing).
2051 #ifdef CONFIG_HOTPLUG_CPU
2053 * hot-plug CPU notifier support.
2055 * We need a notifier per filesystem as we need to be able to identify
2056 * the filesystem to balance the counters out. This is achieved by
2057 * having a notifier block embedded in the xfs_mount_t and doing pointer
2058 * magic to get the mount pointer from the notifier block address.
2061 xfs_icsb_cpu_notify(
2062 struct notifier_block *nfb,
2063 unsigned long action,
2066 xfs_icsb_cnts_t *cntp;
2069 mp = (xfs_mount_t *)container_of(nfb, xfs_mount_t, m_icsb_notifier);
2070 cntp = (xfs_icsb_cnts_t *)
2071 per_cpu_ptr(mp->m_sb_cnts, (unsigned long)hcpu);
2073 case CPU_UP_PREPARE:
2074 case CPU_UP_PREPARE_FROZEN:
2075 /* Easy Case - initialize the area and locks, and
2076 * then rebalance when online does everything else for us. */
2077 memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
2080 case CPU_ONLINE_FROZEN:
2082 xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
2083 xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
2084 xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
2085 xfs_icsb_unlock(mp);
2088 case CPU_DEAD_FROZEN:
2089 /* Disable all the counters, then fold the dead cpu's
2090 * count into the total on the global superblock and
2091 * re-enable the counters. */
2093 spin_lock(&mp->m_sb_lock);
2094 xfs_icsb_disable_counter(mp, XFS_SBS_ICOUNT);
2095 xfs_icsb_disable_counter(mp, XFS_SBS_IFREE);
2096 xfs_icsb_disable_counter(mp, XFS_SBS_FDBLOCKS);
2098 mp->m_sb.sb_icount += cntp->icsb_icount;
2099 mp->m_sb.sb_ifree += cntp->icsb_ifree;
2100 mp->m_sb.sb_fdblocks += cntp->icsb_fdblocks;
2102 memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
2104 xfs_icsb_balance_counter_locked(mp, XFS_SBS_ICOUNT, 0);
2105 xfs_icsb_balance_counter_locked(mp, XFS_SBS_IFREE, 0);
2106 xfs_icsb_balance_counter_locked(mp, XFS_SBS_FDBLOCKS, 0);
2107 spin_unlock(&mp->m_sb_lock);
2108 xfs_icsb_unlock(mp);
2114 #endif /* CONFIG_HOTPLUG_CPU */
2117 xfs_icsb_init_counters(
2120 xfs_icsb_cnts_t *cntp;
2123 mp->m_sb_cnts = alloc_percpu(xfs_icsb_cnts_t);
2124 if (mp->m_sb_cnts == NULL)
2127 #ifdef CONFIG_HOTPLUG_CPU
2128 mp->m_icsb_notifier.notifier_call = xfs_icsb_cpu_notify;
2129 mp->m_icsb_notifier.priority = 0;
2130 register_hotcpu_notifier(&mp->m_icsb_notifier);
2131 #endif /* CONFIG_HOTPLUG_CPU */
2133 for_each_online_cpu(i) {
2134 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2135 memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
2138 mutex_init(&mp->m_icsb_mutex);
2141 * start with all counters disabled so that the
2142 * initial balance kicks us off correctly
2144 mp->m_icsb_counters = -1;
2149 xfs_icsb_reinit_counters(
2154 * start with all counters disabled so that the
2155 * initial balance kicks us off correctly
2157 mp->m_icsb_counters = -1;
2158 xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
2159 xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
2160 xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
2161 xfs_icsb_unlock(mp);
2165 xfs_icsb_destroy_counters(
2168 if (mp->m_sb_cnts) {
2169 unregister_hotcpu_notifier(&mp->m_icsb_notifier);
2170 free_percpu(mp->m_sb_cnts);
2172 mutex_destroy(&mp->m_icsb_mutex);
2177 xfs_icsb_cnts_t *icsbp)
2179 while (test_and_set_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags)) {
2185 xfs_icsb_unlock_cntr(
2186 xfs_icsb_cnts_t *icsbp)
2188 clear_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags);
2193 xfs_icsb_lock_all_counters(
2196 xfs_icsb_cnts_t *cntp;
2199 for_each_online_cpu(i) {
2200 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2201 xfs_icsb_lock_cntr(cntp);
2206 xfs_icsb_unlock_all_counters(
2209 xfs_icsb_cnts_t *cntp;
2212 for_each_online_cpu(i) {
2213 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2214 xfs_icsb_unlock_cntr(cntp);
2221 xfs_icsb_cnts_t *cnt,
2224 xfs_icsb_cnts_t *cntp;
2227 memset(cnt, 0, sizeof(xfs_icsb_cnts_t));
2229 if (!(flags & XFS_ICSB_LAZY_COUNT))
2230 xfs_icsb_lock_all_counters(mp);
2232 for_each_online_cpu(i) {
2233 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2234 cnt->icsb_icount += cntp->icsb_icount;
2235 cnt->icsb_ifree += cntp->icsb_ifree;
2236 cnt->icsb_fdblocks += cntp->icsb_fdblocks;
2239 if (!(flags & XFS_ICSB_LAZY_COUNT))
2240 xfs_icsb_unlock_all_counters(mp);
2244 xfs_icsb_counter_disabled(
2246 xfs_sb_field_t field)
2248 ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
2249 return test_bit(field, &mp->m_icsb_counters);
2253 xfs_icsb_disable_counter(
2255 xfs_sb_field_t field)
2257 xfs_icsb_cnts_t cnt;
2259 ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
2262 * If we are already disabled, then there is nothing to do
2263 * here. We check before locking all the counters to avoid
2264 * the expensive lock operation when being called in the
2265 * slow path and the counter is already disabled. This is
2266 * safe because the only time we set or clear this state is under
2269 if (xfs_icsb_counter_disabled(mp, field))
2272 xfs_icsb_lock_all_counters(mp);
2273 if (!test_and_set_bit(field, &mp->m_icsb_counters)) {
2274 /* drain back to superblock */
2276 xfs_icsb_count(mp, &cnt, XFS_ICSB_LAZY_COUNT);
2278 case XFS_SBS_ICOUNT:
2279 mp->m_sb.sb_icount = cnt.icsb_icount;
2282 mp->m_sb.sb_ifree = cnt.icsb_ifree;
2284 case XFS_SBS_FDBLOCKS:
2285 mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
2292 xfs_icsb_unlock_all_counters(mp);
2296 xfs_icsb_enable_counter(
2298 xfs_sb_field_t field,
2302 xfs_icsb_cnts_t *cntp;
2305 ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
2307 xfs_icsb_lock_all_counters(mp);
2308 for_each_online_cpu(i) {
2309 cntp = per_cpu_ptr(mp->m_sb_cnts, i);
2311 case XFS_SBS_ICOUNT:
2312 cntp->icsb_icount = count + resid;
2315 cntp->icsb_ifree = count + resid;
2317 case XFS_SBS_FDBLOCKS:
2318 cntp->icsb_fdblocks = count + resid;
2326 clear_bit(field, &mp->m_icsb_counters);
2327 xfs_icsb_unlock_all_counters(mp);
2331 xfs_icsb_sync_counters_locked(
2335 xfs_icsb_cnts_t cnt;
2337 xfs_icsb_count(mp, &cnt, flags);
2339 if (!xfs_icsb_counter_disabled(mp, XFS_SBS_ICOUNT))
2340 mp->m_sb.sb_icount = cnt.icsb_icount;
2341 if (!xfs_icsb_counter_disabled(mp, XFS_SBS_IFREE))
2342 mp->m_sb.sb_ifree = cnt.icsb_ifree;
2343 if (!xfs_icsb_counter_disabled(mp, XFS_SBS_FDBLOCKS))
2344 mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
2348 * Accurate update of per-cpu counters to incore superblock
2351 xfs_icsb_sync_counters(
2355 spin_lock(&mp->m_sb_lock);
2356 xfs_icsb_sync_counters_locked(mp, flags);
2357 spin_unlock(&mp->m_sb_lock);
2361 * Balance and enable/disable counters as necessary.
2363 * Thresholds for re-enabling counters are somewhat magic. inode counts are
2364 * chosen to be the same number as single on disk allocation chunk per CPU, and
2365 * free blocks is something far enough zero that we aren't going thrash when we
2366 * get near ENOSPC. We also need to supply a minimum we require per cpu to
2367 * prevent looping endlessly when xfs_alloc_space asks for more than will
2368 * be distributed to a single CPU but each CPU has enough blocks to be
2371 * Note that we can be called when counters are already disabled.
2372 * xfs_icsb_disable_counter() optimises the counter locking in this case to
2373 * prevent locking every per-cpu counter needlessly.
2376 #define XFS_ICSB_INO_CNTR_REENABLE (uint64_t)64
2377 #define XFS_ICSB_FDBLK_CNTR_REENABLE(mp) \
2378 (uint64_t)(512 + XFS_ALLOC_SET_ASIDE(mp))
2380 xfs_icsb_balance_counter_locked(
2382 xfs_sb_field_t field,
2385 uint64_t count, resid;
2386 int weight = num_online_cpus();
2387 uint64_t min = (uint64_t)min_per_cpu;
2389 /* disable counter and sync counter */
2390 xfs_icsb_disable_counter(mp, field);
2392 /* update counters - first CPU gets residual*/
2394 case XFS_SBS_ICOUNT:
2395 count = mp->m_sb.sb_icount;
2396 resid = do_div(count, weight);
2397 if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE))
2401 count = mp->m_sb.sb_ifree;
2402 resid = do_div(count, weight);
2403 if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE))
2406 case XFS_SBS_FDBLOCKS:
2407 count = mp->m_sb.sb_fdblocks;
2408 resid = do_div(count, weight);
2409 if (count < max(min, XFS_ICSB_FDBLK_CNTR_REENABLE(mp)))
2414 count = resid = 0; /* quiet, gcc */
2418 xfs_icsb_enable_counter(mp, field, count, resid);
2422 xfs_icsb_balance_counter(
2424 xfs_sb_field_t fields,
2427 spin_lock(&mp->m_sb_lock);
2428 xfs_icsb_balance_counter_locked(mp, fields, min_per_cpu);
2429 spin_unlock(&mp->m_sb_lock);
2433 xfs_icsb_modify_counters(
2435 xfs_sb_field_t field,
2439 xfs_icsb_cnts_t *icsbp;
2440 long long lcounter; /* long counter for 64 bit fields */
2446 icsbp = this_cpu_ptr(mp->m_sb_cnts);
2449 * if the counter is disabled, go to slow path
2451 if (unlikely(xfs_icsb_counter_disabled(mp, field)))
2453 xfs_icsb_lock_cntr(icsbp);
2454 if (unlikely(xfs_icsb_counter_disabled(mp, field))) {
2455 xfs_icsb_unlock_cntr(icsbp);
2460 case XFS_SBS_ICOUNT:
2461 lcounter = icsbp->icsb_icount;
2463 if (unlikely(lcounter < 0))
2464 goto balance_counter;
2465 icsbp->icsb_icount = lcounter;
2469 lcounter = icsbp->icsb_ifree;
2471 if (unlikely(lcounter < 0))
2472 goto balance_counter;
2473 icsbp->icsb_ifree = lcounter;
2476 case XFS_SBS_FDBLOCKS:
2477 BUG_ON((mp->m_resblks - mp->m_resblks_avail) != 0);
2479 lcounter = icsbp->icsb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
2481 if (unlikely(lcounter < 0))
2482 goto balance_counter;
2483 icsbp->icsb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
2489 xfs_icsb_unlock_cntr(icsbp);
2497 * serialise with a mutex so we don't burn lots of cpu on
2498 * the superblock lock. We still need to hold the superblock
2499 * lock, however, when we modify the global structures.
2504 * Now running atomically.
2506 * If the counter is enabled, someone has beaten us to rebalancing.
2507 * Drop the lock and try again in the fast path....
2509 if (!(xfs_icsb_counter_disabled(mp, field))) {
2510 xfs_icsb_unlock(mp);
2515 * The counter is currently disabled. Because we are
2516 * running atomically here, we know a rebalance cannot
2517 * be in progress. Hence we can go straight to operating
2518 * on the global superblock. We do not call xfs_mod_incore_sb()
2519 * here even though we need to get the m_sb_lock. Doing so
2520 * will cause us to re-enter this function and deadlock.
2521 * Hence we get the m_sb_lock ourselves and then call
2522 * xfs_mod_incore_sb_unlocked() as the unlocked path operates
2523 * directly on the global counters.
2525 spin_lock(&mp->m_sb_lock);
2526 ret = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
2527 spin_unlock(&mp->m_sb_lock);
2530 * Now that we've modified the global superblock, we
2531 * may be able to re-enable the distributed counters
2532 * (e.g. lots of space just got freed). After that
2536 xfs_icsb_balance_counter(mp, field, 0);
2537 xfs_icsb_unlock(mp);
2541 xfs_icsb_unlock_cntr(icsbp);
2545 * We may have multiple threads here if multiple per-cpu
2546 * counters run dry at the same time. This will mean we can
2547 * do more balances than strictly necessary but it is not
2548 * the common slowpath case.
2553 * running atomically.
2555 * This will leave the counter in the correct state for future
2556 * accesses. After the rebalance, we simply try again and our retry
2557 * will either succeed through the fast path or slow path without
2558 * another balance operation being required.
2560 xfs_icsb_balance_counter(mp, field, delta);
2561 xfs_icsb_unlock(mp);