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. 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 */))) {
373 xfs_warn(mp, "SB sanity check 1 failed");
374 return XFS_ERROR(EFSCORRUPTED);
378 * Sanity check AG count, size fields against data size field
381 sbp->sb_dblocks == 0 ||
383 (xfs_drfsbno_t)sbp->sb_agcount * sbp->sb_agblocks ||
384 sbp->sb_dblocks < (xfs_drfsbno_t)(sbp->sb_agcount - 1) *
385 sbp->sb_agblocks + XFS_MIN_AG_BLOCKS)) {
387 xfs_warn(mp, "SB sanity check 2 failed");
388 return XFS_ERROR(EFSCORRUPTED);
392 * Until this is fixed only page-sized or smaller data blocks work.
394 if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
397 "File system with blocksize %d bytes. "
398 "Only pagesize (%ld) or less will currently work.",
399 sbp->sb_blocksize, PAGE_SIZE);
401 return XFS_ERROR(ENOSYS);
405 * Currently only very few inode sizes are supported.
407 switch (sbp->sb_inodesize) {
415 xfs_warn(mp, "inode size of %d bytes not supported",
417 return XFS_ERROR(ENOSYS);
420 if (xfs_sb_validate_fsb_count(sbp, sbp->sb_dblocks) ||
421 xfs_sb_validate_fsb_count(sbp, sbp->sb_rblocks)) {
424 "file system too large to be mounted on this system.");
425 return XFS_ERROR(EFBIG);
428 if (unlikely(sbp->sb_inprogress)) {
430 xfs_warn(mp, "file system busy");
431 return XFS_ERROR(EFSCORRUPTED);
435 * Version 1 directory format has never worked on Linux.
437 if (unlikely(!xfs_sb_version_hasdirv2(sbp))) {
440 "file system using version 1 directory format");
441 return XFS_ERROR(ENOSYS);
448 xfs_initialize_perag(
450 xfs_agnumber_t agcount,
451 xfs_agnumber_t *maxagi)
453 xfs_agnumber_t index, max_metadata;
454 xfs_agnumber_t first_initialised = 0;
458 xfs_sb_t *sbp = &mp->m_sb;
462 * Walk the current per-ag tree so we don't try to initialise AGs
463 * that already exist (growfs case). Allocate and insert all the
464 * AGs we don't find ready for initialisation.
466 for (index = 0; index < agcount; index++) {
467 pag = xfs_perag_get(mp, index);
472 if (!first_initialised)
473 first_initialised = index;
475 pag = kmem_zalloc(sizeof(*pag), KM_MAYFAIL);
478 pag->pag_agno = index;
480 spin_lock_init(&pag->pag_ici_lock);
481 mutex_init(&pag->pag_ici_reclaim_lock);
482 INIT_RADIX_TREE(&pag->pag_ici_root, GFP_ATOMIC);
483 spin_lock_init(&pag->pag_buf_lock);
484 pag->pag_buf_tree = RB_ROOT;
486 if (radix_tree_preload(GFP_NOFS))
489 spin_lock(&mp->m_perag_lock);
490 if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
492 spin_unlock(&mp->m_perag_lock);
493 radix_tree_preload_end();
497 spin_unlock(&mp->m_perag_lock);
498 radix_tree_preload_end();
502 * If we mount with the inode64 option, or no inode overflows
503 * the legacy 32-bit address space clear the inode32 option.
505 agino = XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks - 1, 0);
506 ino = XFS_AGINO_TO_INO(mp, agcount - 1, agino);
508 if ((mp->m_flags & XFS_MOUNT_SMALL_INUMS) && ino > XFS_MAXINUMBER_32)
509 mp->m_flags |= XFS_MOUNT_32BITINODES;
511 mp->m_flags &= ~XFS_MOUNT_32BITINODES;
513 if (mp->m_flags & XFS_MOUNT_32BITINODES) {
515 * Calculate how much should be reserved for inodes to meet
516 * the max inode percentage.
518 if (mp->m_maxicount) {
521 icount = sbp->sb_dblocks * sbp->sb_imax_pct;
523 icount += sbp->sb_agblocks - 1;
524 do_div(icount, sbp->sb_agblocks);
525 max_metadata = icount;
527 max_metadata = agcount;
530 for (index = 0; index < agcount; index++) {
531 ino = XFS_AGINO_TO_INO(mp, index, agino);
532 if (ino > XFS_MAXINUMBER_32) {
537 pag = xfs_perag_get(mp, index);
538 pag->pagi_inodeok = 1;
539 if (index < max_metadata)
540 pag->pagf_metadata = 1;
544 for (index = 0; index < agcount; index++) {
545 pag = xfs_perag_get(mp, index);
546 pag->pagi_inodeok = 1;
557 for (; index > first_initialised; index--) {
558 pag = radix_tree_delete(&mp->m_perag_tree, index);
569 to->sb_magicnum = be32_to_cpu(from->sb_magicnum);
570 to->sb_blocksize = be32_to_cpu(from->sb_blocksize);
571 to->sb_dblocks = be64_to_cpu(from->sb_dblocks);
572 to->sb_rblocks = be64_to_cpu(from->sb_rblocks);
573 to->sb_rextents = be64_to_cpu(from->sb_rextents);
574 memcpy(&to->sb_uuid, &from->sb_uuid, sizeof(to->sb_uuid));
575 to->sb_logstart = be64_to_cpu(from->sb_logstart);
576 to->sb_rootino = be64_to_cpu(from->sb_rootino);
577 to->sb_rbmino = be64_to_cpu(from->sb_rbmino);
578 to->sb_rsumino = be64_to_cpu(from->sb_rsumino);
579 to->sb_rextsize = be32_to_cpu(from->sb_rextsize);
580 to->sb_agblocks = be32_to_cpu(from->sb_agblocks);
581 to->sb_agcount = be32_to_cpu(from->sb_agcount);
582 to->sb_rbmblocks = be32_to_cpu(from->sb_rbmblocks);
583 to->sb_logblocks = be32_to_cpu(from->sb_logblocks);
584 to->sb_versionnum = be16_to_cpu(from->sb_versionnum);
585 to->sb_sectsize = be16_to_cpu(from->sb_sectsize);
586 to->sb_inodesize = be16_to_cpu(from->sb_inodesize);
587 to->sb_inopblock = be16_to_cpu(from->sb_inopblock);
588 memcpy(&to->sb_fname, &from->sb_fname, sizeof(to->sb_fname));
589 to->sb_blocklog = from->sb_blocklog;
590 to->sb_sectlog = from->sb_sectlog;
591 to->sb_inodelog = from->sb_inodelog;
592 to->sb_inopblog = from->sb_inopblog;
593 to->sb_agblklog = from->sb_agblklog;
594 to->sb_rextslog = from->sb_rextslog;
595 to->sb_inprogress = from->sb_inprogress;
596 to->sb_imax_pct = from->sb_imax_pct;
597 to->sb_icount = be64_to_cpu(from->sb_icount);
598 to->sb_ifree = be64_to_cpu(from->sb_ifree);
599 to->sb_fdblocks = be64_to_cpu(from->sb_fdblocks);
600 to->sb_frextents = be64_to_cpu(from->sb_frextents);
601 to->sb_uquotino = be64_to_cpu(from->sb_uquotino);
602 to->sb_gquotino = be64_to_cpu(from->sb_gquotino);
603 to->sb_qflags = be16_to_cpu(from->sb_qflags);
604 to->sb_flags = from->sb_flags;
605 to->sb_shared_vn = from->sb_shared_vn;
606 to->sb_inoalignmt = be32_to_cpu(from->sb_inoalignmt);
607 to->sb_unit = be32_to_cpu(from->sb_unit);
608 to->sb_width = be32_to_cpu(from->sb_width);
609 to->sb_dirblklog = from->sb_dirblklog;
610 to->sb_logsectlog = from->sb_logsectlog;
611 to->sb_logsectsize = be16_to_cpu(from->sb_logsectsize);
612 to->sb_logsunit = be32_to_cpu(from->sb_logsunit);
613 to->sb_features2 = be32_to_cpu(from->sb_features2);
614 to->sb_bad_features2 = be32_to_cpu(from->sb_bad_features2);
618 * Copy in core superblock to ondisk one.
620 * The fields argument is mask of superblock fields to copy.
628 xfs_caddr_t to_ptr = (xfs_caddr_t)to;
629 xfs_caddr_t from_ptr = (xfs_caddr_t)from;
639 f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
640 first = xfs_sb_info[f].offset;
641 size = xfs_sb_info[f + 1].offset - first;
643 ASSERT(xfs_sb_info[f].type == 0 || xfs_sb_info[f].type == 1);
645 if (size == 1 || xfs_sb_info[f].type == 1) {
646 memcpy(to_ptr + first, from_ptr + first, size);
650 *(__be16 *)(to_ptr + first) =
651 cpu_to_be16(*(__u16 *)(from_ptr + first));
654 *(__be32 *)(to_ptr + first) =
655 cpu_to_be32(*(__u32 *)(from_ptr + first));
658 *(__be64 *)(to_ptr + first) =
659 cpu_to_be64(*(__u64 *)(from_ptr + first));
666 fields &= ~(1LL << f);
673 * Does the initial read of the superblock.
676 xfs_readsb(xfs_mount_t *mp, int flags)
678 unsigned int sector_size;
681 int loud = !(flags & XFS_MFSI_QUIET);
683 ASSERT(mp->m_sb_bp == NULL);
684 ASSERT(mp->m_ddev_targp != NULL);
687 * Allocate a (locked) buffer to hold the superblock.
688 * This will be kept around at all times to optimize
689 * access to the superblock.
691 sector_size = xfs_getsize_buftarg(mp->m_ddev_targp);
694 bp = xfs_buf_read_uncached(mp, mp->m_ddev_targp,
695 XFS_SB_DADDR, sector_size, 0);
698 xfs_warn(mp, "SB buffer read failed");
703 * Initialize the mount structure from the superblock.
704 * But first do some basic consistency checking.
706 xfs_sb_from_disk(&mp->m_sb, XFS_BUF_TO_SBP(bp));
707 error = xfs_mount_validate_sb(mp, &(mp->m_sb), flags);
710 xfs_warn(mp, "SB validate failed");
715 * We must be able to do sector-sized and sector-aligned IO.
717 if (sector_size > mp->m_sb.sb_sectsize) {
719 xfs_warn(mp, "device supports %u byte sectors (not %u)",
720 sector_size, mp->m_sb.sb_sectsize);
726 * If device sector size is smaller than the superblock size,
727 * re-read the superblock so the buffer is correctly sized.
729 if (sector_size < mp->m_sb.sb_sectsize) {
731 sector_size = mp->m_sb.sb_sectsize;
735 /* Initialize per-cpu counters */
736 xfs_icsb_reinit_counters(mp);
751 * Mount initialization code establishing various mount
752 * fields from the superblock associated with the given
756 xfs_mount_common(xfs_mount_t *mp, xfs_sb_t *sbp)
758 mp->m_agfrotor = mp->m_agirotor = 0;
759 spin_lock_init(&mp->m_agirotor_lock);
760 mp->m_maxagi = mp->m_sb.sb_agcount;
761 mp->m_blkbit_log = sbp->sb_blocklog + XFS_NBBYLOG;
762 mp->m_blkbb_log = sbp->sb_blocklog - BBSHIFT;
763 mp->m_sectbb_log = sbp->sb_sectlog - BBSHIFT;
764 mp->m_agno_log = xfs_highbit32(sbp->sb_agcount - 1) + 1;
765 mp->m_agino_log = sbp->sb_inopblog + sbp->sb_agblklog;
766 mp->m_blockmask = sbp->sb_blocksize - 1;
767 mp->m_blockwsize = sbp->sb_blocksize >> XFS_WORDLOG;
768 mp->m_blockwmask = mp->m_blockwsize - 1;
770 mp->m_alloc_mxr[0] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 1);
771 mp->m_alloc_mxr[1] = xfs_allocbt_maxrecs(mp, sbp->sb_blocksize, 0);
772 mp->m_alloc_mnr[0] = mp->m_alloc_mxr[0] / 2;
773 mp->m_alloc_mnr[1] = mp->m_alloc_mxr[1] / 2;
775 mp->m_inobt_mxr[0] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 1);
776 mp->m_inobt_mxr[1] = xfs_inobt_maxrecs(mp, sbp->sb_blocksize, 0);
777 mp->m_inobt_mnr[0] = mp->m_inobt_mxr[0] / 2;
778 mp->m_inobt_mnr[1] = mp->m_inobt_mxr[1] / 2;
780 mp->m_bmap_dmxr[0] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 1);
781 mp->m_bmap_dmxr[1] = xfs_bmbt_maxrecs(mp, sbp->sb_blocksize, 0);
782 mp->m_bmap_dmnr[0] = mp->m_bmap_dmxr[0] / 2;
783 mp->m_bmap_dmnr[1] = mp->m_bmap_dmxr[1] / 2;
785 mp->m_bsize = XFS_FSB_TO_BB(mp, 1);
786 mp->m_ialloc_inos = (int)MAX((__uint16_t)XFS_INODES_PER_CHUNK,
788 mp->m_ialloc_blks = mp->m_ialloc_inos >> sbp->sb_inopblog;
792 * xfs_initialize_perag_data
794 * Read in each per-ag structure so we can count up the number of
795 * allocated inodes, free inodes and used filesystem blocks as this
796 * information is no longer persistent in the superblock. Once we have
797 * this information, write it into the in-core superblock structure.
800 xfs_initialize_perag_data(xfs_mount_t *mp, xfs_agnumber_t agcount)
802 xfs_agnumber_t index;
804 xfs_sb_t *sbp = &mp->m_sb;
808 uint64_t bfreelst = 0;
812 for (index = 0; index < agcount; index++) {
814 * read the agf, then the agi. This gets us
815 * all the information we need and populates the
816 * per-ag structures for us.
818 error = xfs_alloc_pagf_init(mp, NULL, index, 0);
822 error = xfs_ialloc_pagi_init(mp, NULL, index);
825 pag = xfs_perag_get(mp, index);
826 ifree += pag->pagi_freecount;
827 ialloc += pag->pagi_count;
828 bfree += pag->pagf_freeblks;
829 bfreelst += pag->pagf_flcount;
830 btree += pag->pagf_btreeblks;
834 * Overwrite incore superblock counters with just-read data
836 spin_lock(&mp->m_sb_lock);
837 sbp->sb_ifree = ifree;
838 sbp->sb_icount = ialloc;
839 sbp->sb_fdblocks = bfree + bfreelst + btree;
840 spin_unlock(&mp->m_sb_lock);
842 /* Fixup the per-cpu counters as well. */
843 xfs_icsb_reinit_counters(mp);
849 * Update alignment values based on mount options and sb values
852 xfs_update_alignment(xfs_mount_t *mp)
854 xfs_sb_t *sbp = &(mp->m_sb);
858 * If stripe unit and stripe width are not multiples
859 * of the fs blocksize turn off alignment.
861 if ((BBTOB(mp->m_dalign) & mp->m_blockmask) ||
862 (BBTOB(mp->m_swidth) & mp->m_blockmask)) {
863 if (mp->m_flags & XFS_MOUNT_RETERR) {
864 xfs_warn(mp, "alignment check 1 failed");
865 return XFS_ERROR(EINVAL);
867 mp->m_dalign = mp->m_swidth = 0;
870 * Convert the stripe unit and width to FSBs.
872 mp->m_dalign = XFS_BB_TO_FSBT(mp, mp->m_dalign);
873 if (mp->m_dalign && (sbp->sb_agblocks % mp->m_dalign)) {
874 if (mp->m_flags & XFS_MOUNT_RETERR) {
875 return XFS_ERROR(EINVAL);
878 "stripe alignment turned off: sunit(%d)/swidth(%d) "
879 "incompatible with agsize(%d)",
880 mp->m_dalign, mp->m_swidth,
885 } else if (mp->m_dalign) {
886 mp->m_swidth = XFS_BB_TO_FSBT(mp, mp->m_swidth);
888 if (mp->m_flags & XFS_MOUNT_RETERR) {
890 "stripe alignment turned off: sunit(%d) less than bsize(%d)",
893 return XFS_ERROR(EINVAL);
900 * Update superblock with new values
903 if (xfs_sb_version_hasdalign(sbp)) {
904 if (sbp->sb_unit != mp->m_dalign) {
905 sbp->sb_unit = mp->m_dalign;
906 mp->m_update_flags |= XFS_SB_UNIT;
908 if (sbp->sb_width != mp->m_swidth) {
909 sbp->sb_width = mp->m_swidth;
910 mp->m_update_flags |= XFS_SB_WIDTH;
913 } else if ((mp->m_flags & XFS_MOUNT_NOALIGN) != XFS_MOUNT_NOALIGN &&
914 xfs_sb_version_hasdalign(&mp->m_sb)) {
915 mp->m_dalign = sbp->sb_unit;
916 mp->m_swidth = sbp->sb_width;
923 * Set the maximum inode count for this filesystem
926 xfs_set_maxicount(xfs_mount_t *mp)
928 xfs_sb_t *sbp = &(mp->m_sb);
931 if (sbp->sb_imax_pct) {
933 * Make sure the maximum inode count is a multiple
934 * of the units we allocate inodes in.
936 icount = sbp->sb_dblocks * sbp->sb_imax_pct;
938 do_div(icount, mp->m_ialloc_blks);
939 mp->m_maxicount = (icount * mp->m_ialloc_blks) <<
947 * Set the default minimum read and write sizes unless
948 * already specified in a mount option.
949 * We use smaller I/O sizes when the file system
950 * is being used for NFS service (wsync mount option).
953 xfs_set_rw_sizes(xfs_mount_t *mp)
955 xfs_sb_t *sbp = &(mp->m_sb);
956 int readio_log, writeio_log;
958 if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) {
959 if (mp->m_flags & XFS_MOUNT_WSYNC) {
960 readio_log = XFS_WSYNC_READIO_LOG;
961 writeio_log = XFS_WSYNC_WRITEIO_LOG;
963 readio_log = XFS_READIO_LOG_LARGE;
964 writeio_log = XFS_WRITEIO_LOG_LARGE;
967 readio_log = mp->m_readio_log;
968 writeio_log = mp->m_writeio_log;
971 if (sbp->sb_blocklog > readio_log) {
972 mp->m_readio_log = sbp->sb_blocklog;
974 mp->m_readio_log = readio_log;
976 mp->m_readio_blocks = 1 << (mp->m_readio_log - sbp->sb_blocklog);
977 if (sbp->sb_blocklog > writeio_log) {
978 mp->m_writeio_log = sbp->sb_blocklog;
980 mp->m_writeio_log = writeio_log;
982 mp->m_writeio_blocks = 1 << (mp->m_writeio_log - sbp->sb_blocklog);
986 * precalculate the low space thresholds for dynamic speculative preallocation.
989 xfs_set_low_space_thresholds(
990 struct xfs_mount *mp)
994 for (i = 0; i < XFS_LOWSP_MAX; i++) {
995 __uint64_t space = mp->m_sb.sb_dblocks;
998 mp->m_low_space[i] = space * (i + 1);
1004 * Set whether we're using inode alignment.
1007 xfs_set_inoalignment(xfs_mount_t *mp)
1009 if (xfs_sb_version_hasalign(&mp->m_sb) &&
1010 mp->m_sb.sb_inoalignmt >=
1011 XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size))
1012 mp->m_inoalign_mask = mp->m_sb.sb_inoalignmt - 1;
1014 mp->m_inoalign_mask = 0;
1016 * If we are using stripe alignment, check whether
1017 * the stripe unit is a multiple of the inode alignment
1019 if (mp->m_dalign && mp->m_inoalign_mask &&
1020 !(mp->m_dalign & mp->m_inoalign_mask))
1021 mp->m_sinoalign = mp->m_dalign;
1023 mp->m_sinoalign = 0;
1027 * Check that the data (and log if separate) are an ok size.
1030 xfs_check_sizes(xfs_mount_t *mp)
1035 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
1036 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_dblocks) {
1037 xfs_warn(mp, "filesystem size mismatch detected");
1038 return XFS_ERROR(EFBIG);
1040 bp = xfs_buf_read_uncached(mp, mp->m_ddev_targp,
1041 d - XFS_FSS_TO_BB(mp, 1),
1042 BBTOB(XFS_FSS_TO_BB(mp, 1)), 0);
1044 xfs_warn(mp, "last sector read failed");
1049 if (mp->m_logdev_targp != mp->m_ddev_targp) {
1050 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks);
1051 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_logblocks) {
1052 xfs_warn(mp, "log size mismatch detected");
1053 return XFS_ERROR(EFBIG);
1055 bp = xfs_buf_read_uncached(mp, mp->m_logdev_targp,
1056 d - XFS_FSB_TO_BB(mp, 1),
1057 XFS_FSB_TO_B(mp, 1), 0);
1059 xfs_warn(mp, "log device read failed");
1068 * Clear the quotaflags in memory and in the superblock.
1071 xfs_mount_reset_sbqflags(
1072 struct xfs_mount *mp)
1075 struct xfs_trans *tp;
1080 * It is OK to look at sb_qflags here in mount path,
1081 * without m_sb_lock.
1083 if (mp->m_sb.sb_qflags == 0)
1085 spin_lock(&mp->m_sb_lock);
1086 mp->m_sb.sb_qflags = 0;
1087 spin_unlock(&mp->m_sb_lock);
1090 * If the fs is readonly, let the incore superblock run
1091 * with quotas off but don't flush the update out to disk
1093 if (mp->m_flags & XFS_MOUNT_RDONLY)
1097 xfs_notice(mp, "Writing superblock quota changes");
1100 tp = xfs_trans_alloc(mp, XFS_TRANS_QM_SBCHANGE);
1101 error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
1102 XFS_DEFAULT_LOG_COUNT);
1104 xfs_trans_cancel(tp, 0);
1105 xfs_alert(mp, "%s: Superblock update failed!", __func__);
1109 xfs_mod_sb(tp, XFS_SB_QFLAGS);
1110 return xfs_trans_commit(tp, 0);
1114 xfs_default_resblks(xfs_mount_t *mp)
1119 * We default to 5% or 8192 fsbs of space reserved, whichever is
1120 * smaller. This is intended to cover concurrent allocation
1121 * transactions when we initially hit enospc. These each require a 4
1122 * block reservation. Hence by default we cover roughly 2000 concurrent
1123 * allocation reservations.
1125 resblks = mp->m_sb.sb_dblocks;
1126 do_div(resblks, 20);
1127 resblks = min_t(__uint64_t, resblks, 8192);
1132 * This function does the following on an initial mount of a file system:
1133 * - reads the superblock from disk and init the mount struct
1134 * - if we're a 32-bit kernel, do a size check on the superblock
1135 * so we don't mount terabyte filesystems
1136 * - init mount struct realtime fields
1137 * - allocate inode hash table for fs
1138 * - init directory manager
1139 * - perform recovery and init the log manager
1145 xfs_sb_t *sbp = &(mp->m_sb);
1148 uint quotamount = 0;
1149 uint quotaflags = 0;
1152 xfs_mount_common(mp, sbp);
1155 * Check for a mismatched features2 values. Older kernels
1156 * read & wrote into the wrong sb offset for sb_features2
1157 * on some platforms due to xfs_sb_t not being 64bit size aligned
1158 * when sb_features2 was added, which made older superblock
1159 * reading/writing routines swap it as a 64-bit value.
1161 * For backwards compatibility, we make both slots equal.
1163 * If we detect a mismatched field, we OR the set bits into the
1164 * existing features2 field in case it has already been modified; we
1165 * don't want to lose any features. We then update the bad location
1166 * with the ORed value so that older kernels will see any features2
1167 * flags, and mark the two fields as needing updates once the
1168 * transaction subsystem is online.
1170 if (xfs_sb_has_mismatched_features2(sbp)) {
1171 xfs_warn(mp, "correcting sb_features alignment problem");
1172 sbp->sb_features2 |= sbp->sb_bad_features2;
1173 sbp->sb_bad_features2 = sbp->sb_features2;
1174 mp->m_update_flags |= XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2;
1177 * Re-check for ATTR2 in case it was found in bad_features2
1180 if (xfs_sb_version_hasattr2(&mp->m_sb) &&
1181 !(mp->m_flags & XFS_MOUNT_NOATTR2))
1182 mp->m_flags |= XFS_MOUNT_ATTR2;
1185 if (xfs_sb_version_hasattr2(&mp->m_sb) &&
1186 (mp->m_flags & XFS_MOUNT_NOATTR2)) {
1187 xfs_sb_version_removeattr2(&mp->m_sb);
1188 mp->m_update_flags |= XFS_SB_FEATURES2;
1190 /* update sb_versionnum for the clearing of the morebits */
1191 if (!sbp->sb_features2)
1192 mp->m_update_flags |= XFS_SB_VERSIONNUM;
1196 * Check if sb_agblocks is aligned at stripe boundary
1197 * If sb_agblocks is NOT aligned turn off m_dalign since
1198 * allocator alignment is within an ag, therefore ag has
1199 * to be aligned at stripe boundary.
1201 error = xfs_update_alignment(mp);
1205 xfs_alloc_compute_maxlevels(mp);
1206 xfs_bmap_compute_maxlevels(mp, XFS_DATA_FORK);
1207 xfs_bmap_compute_maxlevels(mp, XFS_ATTR_FORK);
1208 xfs_ialloc_compute_maxlevels(mp);
1210 xfs_set_maxicount(mp);
1212 mp->m_maxioffset = xfs_max_file_offset(sbp->sb_blocklog);
1214 error = xfs_uuid_mount(mp);
1219 * Set the minimum read and write sizes
1221 xfs_set_rw_sizes(mp);
1223 /* set the low space thresholds for dynamic preallocation */
1224 xfs_set_low_space_thresholds(mp);
1227 * Set the inode cluster size.
1228 * This may still be overridden by the file system
1229 * block size if it is larger than the chosen cluster size.
1231 mp->m_inode_cluster_size = XFS_INODE_BIG_CLUSTER_SIZE;
1234 * Set inode alignment fields
1236 xfs_set_inoalignment(mp);
1239 * Check that the data (and log if separate) are an ok size.
1241 error = xfs_check_sizes(mp);
1243 goto out_remove_uuid;
1246 * Initialize realtime fields in the mount structure
1248 error = xfs_rtmount_init(mp);
1250 xfs_warn(mp, "RT mount failed");
1251 goto out_remove_uuid;
1255 * Copies the low order bits of the timestamp and the randomly
1256 * set "sequence" number out of a UUID.
1258 uuid_getnodeuniq(&sbp->sb_uuid, mp->m_fixedfsid);
1260 mp->m_dmevmask = 0; /* not persistent; set after each mount */
1265 * Initialize the attribute manager's entries.
1267 mp->m_attr_magicpct = (mp->m_sb.sb_blocksize * 37) / 100;
1270 * Initialize the precomputed transaction reservations values.
1275 * Allocate and initialize the per-ag data.
1277 spin_lock_init(&mp->m_perag_lock);
1278 INIT_RADIX_TREE(&mp->m_perag_tree, GFP_ATOMIC);
1279 error = xfs_initialize_perag(mp, sbp->sb_agcount, &mp->m_maxagi);
1281 xfs_warn(mp, "Failed per-ag init: %d", error);
1282 goto out_remove_uuid;
1285 if (!sbp->sb_logblocks) {
1286 xfs_warn(mp, "no log defined");
1287 XFS_ERROR_REPORT("xfs_mountfs", XFS_ERRLEVEL_LOW, mp);
1288 error = XFS_ERROR(EFSCORRUPTED);
1289 goto out_free_perag;
1293 * log's mount-time initialization. Perform 1st part recovery if needed
1295 error = xfs_log_mount(mp, mp->m_logdev_targp,
1296 XFS_FSB_TO_DADDR(mp, sbp->sb_logstart),
1297 XFS_FSB_TO_BB(mp, sbp->sb_logblocks));
1299 xfs_warn(mp, "log mount failed");
1300 goto out_free_perag;
1304 * Now the log is mounted, we know if it was an unclean shutdown or
1305 * not. If it was, with the first phase of recovery has completed, we
1306 * have consistent AG blocks on disk. We have not recovered EFIs yet,
1307 * but they are recovered transactionally in the second recovery phase
1310 * Hence we can safely re-initialise incore superblock counters from
1311 * the per-ag data. These may not be correct if the filesystem was not
1312 * cleanly unmounted, so we need to wait for recovery to finish before
1315 * If the filesystem was cleanly unmounted, then we can trust the
1316 * values in the superblock to be correct and we don't need to do
1319 * If we are currently making the filesystem, the initialisation will
1320 * fail as the perag data is in an undefined state.
1322 if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
1323 !XFS_LAST_UNMOUNT_WAS_CLEAN(mp) &&
1324 !mp->m_sb.sb_inprogress) {
1325 error = xfs_initialize_perag_data(mp, sbp->sb_agcount);
1327 goto out_free_perag;
1331 * Get and sanity-check the root inode.
1332 * Save the pointer to it in the mount structure.
1334 error = xfs_iget(mp, NULL, sbp->sb_rootino, 0, XFS_ILOCK_EXCL, &rip);
1336 xfs_warn(mp, "failed to read root inode");
1337 goto out_log_dealloc;
1340 ASSERT(rip != NULL);
1342 if (unlikely((rip->i_d.di_mode & S_IFMT) != S_IFDIR)) {
1343 xfs_warn(mp, "corrupted root inode %llu: not a directory",
1344 (unsigned long long)rip->i_ino);
1345 xfs_iunlock(rip, XFS_ILOCK_EXCL);
1346 XFS_ERROR_REPORT("xfs_mountfs_int(2)", XFS_ERRLEVEL_LOW,
1348 error = XFS_ERROR(EFSCORRUPTED);
1351 mp->m_rootip = rip; /* save it */
1353 xfs_iunlock(rip, XFS_ILOCK_EXCL);
1356 * Initialize realtime inode pointers in the mount structure
1358 error = xfs_rtmount_inodes(mp);
1361 * Free up the root inode.
1363 xfs_warn(mp, "failed to read RT inodes");
1368 * If this is a read-only mount defer the superblock updates until
1369 * the next remount into writeable mode. Otherwise we would never
1370 * perform the update e.g. for the root filesystem.
1372 if (mp->m_update_flags && !(mp->m_flags & XFS_MOUNT_RDONLY)) {
1373 error = xfs_mount_log_sb(mp, mp->m_update_flags);
1375 xfs_warn(mp, "failed to write sb changes");
1381 * Initialise the XFS quota management subsystem for this mount
1383 if (XFS_IS_QUOTA_RUNNING(mp)) {
1384 error = xfs_qm_newmount(mp, "amount, "aflags);
1388 ASSERT(!XFS_IS_QUOTA_ON(mp));
1391 * If a file system had quotas running earlier, but decided to
1392 * mount without -o uquota/pquota/gquota options, revoke the
1393 * quotachecked license.
1395 if (mp->m_sb.sb_qflags & XFS_ALL_QUOTA_ACCT) {
1396 xfs_notice(mp, "resetting quota flags");
1397 error = xfs_mount_reset_sbqflags(mp);
1404 * Finish recovering the file system. This part needed to be
1405 * delayed until after the root and real-time bitmap inodes
1406 * were consistently read in.
1408 error = xfs_log_mount_finish(mp);
1410 xfs_warn(mp, "log mount finish failed");
1415 * Complete the quota initialisation, post-log-replay component.
1418 ASSERT(mp->m_qflags == 0);
1419 mp->m_qflags = quotaflags;
1421 xfs_qm_mount_quotas(mp);
1425 * Now we are mounted, reserve a small amount of unused space for
1426 * privileged transactions. This is needed so that transaction
1427 * space required for critical operations can dip into this pool
1428 * when at ENOSPC. This is needed for operations like create with
1429 * attr, unwritten extent conversion at ENOSPC, etc. Data allocations
1430 * are not allowed to use this reserved space.
1432 * This may drive us straight to ENOSPC on mount, but that implies
1433 * we were already there on the last unmount. Warn if this occurs.
1435 if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
1436 resblks = xfs_default_resblks(mp);
1437 error = xfs_reserve_blocks(mp, &resblks, NULL);
1440 "Unable to allocate reserve blocks. Continuing without reserve pool.");
1446 xfs_rtunmount_inodes(mp);
1450 xfs_log_unmount(mp);
1454 xfs_uuid_unmount(mp);
1460 * This flushes out the inodes,dquots and the superblock, unmounts the
1461 * log and makes sure that incore structures are freed.
1465 struct xfs_mount *mp)
1470 xfs_qm_unmount_quotas(mp);
1471 xfs_rtunmount_inodes(mp);
1472 IRELE(mp->m_rootip);
1475 * We can potentially deadlock here if we have an inode cluster
1476 * that has been freed has its buffer still pinned in memory because
1477 * the transaction is still sitting in a iclog. The stale inodes
1478 * on that buffer will have their flush locks held until the
1479 * transaction hits the disk and the callbacks run. the inode
1480 * flush takes the flush lock unconditionally and with nothing to
1481 * push out the iclog we will never get that unlocked. hence we
1482 * need to force the log first.
1484 xfs_log_force(mp, XFS_LOG_SYNC);
1487 * Do a delwri reclaim pass first so that as many dirty inodes are
1488 * queued up for IO as possible. Then flush the buffers before making
1489 * a synchronous path to catch all the remaining inodes are reclaimed.
1490 * This makes the reclaim process as quick as possible by avoiding
1491 * synchronous writeout and blocking on inodes already in the delwri
1492 * state as much as possible.
1494 xfs_reclaim_inodes(mp, 0);
1495 XFS_bflush(mp->m_ddev_targp);
1496 xfs_reclaim_inodes(mp, SYNC_WAIT);
1501 * Flush out the log synchronously so that we know for sure
1502 * that nothing is pinned. This is important because bflush()
1503 * will skip pinned buffers.
1505 xfs_log_force(mp, XFS_LOG_SYNC);
1508 * Unreserve any blocks we have so that when we unmount we don't account
1509 * the reserved free space as used. This is really only necessary for
1510 * lazy superblock counting because it trusts the incore superblock
1511 * counters to be absolutely correct on clean unmount.
1513 * We don't bother correcting this elsewhere for lazy superblock
1514 * counting because on mount of an unclean filesystem we reconstruct the
1515 * correct counter value and this is irrelevant.
1517 * For non-lazy counter filesystems, this doesn't matter at all because
1518 * we only every apply deltas to the superblock and hence the incore
1519 * value does not matter....
1522 error = xfs_reserve_blocks(mp, &resblks, NULL);
1524 xfs_warn(mp, "Unable to free reserved block pool. "
1525 "Freespace may not be correct on next mount.");
1527 error = xfs_log_sbcount(mp, 1);
1529 xfs_warn(mp, "Unable to update superblock counters. "
1530 "Freespace may not be correct on next mount.");
1531 xfs_unmountfs_writesb(mp);
1534 * Make sure all buffers have been flushed and completed before
1535 * unmounting the log.
1537 error = xfs_flush_buftarg(mp->m_ddev_targp, 1);
1539 xfs_warn(mp, "%d busy buffers during unmount.", error);
1540 xfs_wait_buftarg(mp->m_ddev_targp);
1542 xfs_log_unmount_write(mp);
1543 xfs_log_unmount(mp);
1544 xfs_uuid_unmount(mp);
1547 xfs_errortag_clearall(mp, 0);
1553 xfs_fs_writable(xfs_mount_t *mp)
1555 return !(xfs_test_for_freeze(mp) || XFS_FORCED_SHUTDOWN(mp) ||
1556 (mp->m_flags & XFS_MOUNT_RDONLY));
1562 * Called either periodically to keep the on disk superblock values
1563 * roughly up to date or from unmount to make sure the values are
1564 * correct on a clean unmount.
1566 * Note this code can be called during the process of freezing, so
1567 * we may need to use the transaction allocator which does not not
1568 * block when the transaction subsystem is in its frozen state.
1578 if (!xfs_fs_writable(mp))
1581 xfs_icsb_sync_counters(mp, 0);
1584 * we don't need to do this if we are updating the superblock
1585 * counters on every modification.
1587 if (!xfs_sb_version_haslazysbcount(&mp->m_sb))
1590 tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT, KM_SLEEP);
1591 error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
1592 XFS_DEFAULT_LOG_COUNT);
1594 xfs_trans_cancel(tp, 0);
1598 xfs_mod_sb(tp, XFS_SB_IFREE | XFS_SB_ICOUNT | XFS_SB_FDBLOCKS);
1600 xfs_trans_set_sync(tp);
1601 error = xfs_trans_commit(tp, 0);
1606 xfs_unmountfs_writesb(xfs_mount_t *mp)
1612 * skip superblock write if fs is read-only, or
1613 * if we are doing a forced umount.
1615 if (!((mp->m_flags & XFS_MOUNT_RDONLY) ||
1616 XFS_FORCED_SHUTDOWN(mp))) {
1618 sbp = xfs_getsb(mp, 0);
1620 XFS_BUF_UNDONE(sbp);
1621 XFS_BUF_UNREAD(sbp);
1622 XFS_BUF_UNDELAYWRITE(sbp);
1624 XFS_BUF_UNASYNC(sbp);
1625 ASSERT(XFS_BUF_TARGET(sbp) == mp->m_ddev_targp);
1626 xfsbdstrat(mp, sbp);
1627 error = xfs_buf_iowait(sbp);
1629 xfs_ioerror_alert("xfs_unmountfs_writesb",
1630 mp, sbp, XFS_BUF_ADDR(sbp));
1637 * xfs_mod_sb() can be used to copy arbitrary changes to the
1638 * in-core superblock into the superblock buffer to be logged.
1639 * It does not provide the higher level of locking that is
1640 * needed to protect the in-core superblock from concurrent
1644 xfs_mod_sb(xfs_trans_t *tp, __int64_t fields)
1656 bp = xfs_trans_getsb(tp, mp, 0);
1657 first = sizeof(xfs_sb_t);
1660 /* translate/copy */
1662 xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb, fields);
1664 /* find modified range */
1665 f = (xfs_sb_field_t)xfs_highbit64((__uint64_t)fields);
1666 ASSERT((1LL << f) & XFS_SB_MOD_BITS);
1667 last = xfs_sb_info[f + 1].offset - 1;
1669 f = (xfs_sb_field_t)xfs_lowbit64((__uint64_t)fields);
1670 ASSERT((1LL << f) & XFS_SB_MOD_BITS);
1671 first = xfs_sb_info[f].offset;
1673 xfs_trans_log_buf(tp, bp, first, last);
1678 * xfs_mod_incore_sb_unlocked() is a utility routine common used to apply
1679 * a delta to a specified field in the in-core superblock. Simply
1680 * switch on the field indicated and apply the delta to that field.
1681 * Fields are not allowed to dip below zero, so if the delta would
1682 * do this do not apply it and return EINVAL.
1684 * The m_sb_lock must be held when this routine is called.
1687 xfs_mod_incore_sb_unlocked(
1689 xfs_sb_field_t field,
1693 int scounter; /* short counter for 32 bit fields */
1694 long long lcounter; /* long counter for 64 bit fields */
1695 long long res_used, rem;
1698 * With the in-core superblock spin lock held, switch
1699 * on the indicated field. Apply the delta to the
1700 * proper field. If the fields value would dip below
1701 * 0, then do not apply the delta and return EINVAL.
1704 case XFS_SBS_ICOUNT:
1705 lcounter = (long long)mp->m_sb.sb_icount;
1709 return XFS_ERROR(EINVAL);
1711 mp->m_sb.sb_icount = lcounter;
1714 lcounter = (long long)mp->m_sb.sb_ifree;
1718 return XFS_ERROR(EINVAL);
1720 mp->m_sb.sb_ifree = lcounter;
1722 case XFS_SBS_FDBLOCKS:
1723 lcounter = (long long)
1724 mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
1725 res_used = (long long)(mp->m_resblks - mp->m_resblks_avail);
1727 if (delta > 0) { /* Putting blocks back */
1728 if (res_used > delta) {
1729 mp->m_resblks_avail += delta;
1731 rem = delta - res_used;
1732 mp->m_resblks_avail = mp->m_resblks;
1735 } else { /* Taking blocks away */
1737 if (lcounter >= 0) {
1738 mp->m_sb.sb_fdblocks = lcounter +
1739 XFS_ALLOC_SET_ASIDE(mp);
1744 * We are out of blocks, use any available reserved
1745 * blocks if were allowed to.
1748 return XFS_ERROR(ENOSPC);
1750 lcounter = (long long)mp->m_resblks_avail + delta;
1751 if (lcounter >= 0) {
1752 mp->m_resblks_avail = lcounter;
1755 printk_once(KERN_WARNING
1756 "Filesystem \"%s\": reserve blocks depleted! "
1757 "Consider increasing reserve pool size.",
1759 return XFS_ERROR(ENOSPC);
1762 mp->m_sb.sb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
1764 case XFS_SBS_FREXTENTS:
1765 lcounter = (long long)mp->m_sb.sb_frextents;
1768 return XFS_ERROR(ENOSPC);
1770 mp->m_sb.sb_frextents = lcounter;
1772 case XFS_SBS_DBLOCKS:
1773 lcounter = (long long)mp->m_sb.sb_dblocks;
1777 return XFS_ERROR(EINVAL);
1779 mp->m_sb.sb_dblocks = lcounter;
1781 case XFS_SBS_AGCOUNT:
1782 scounter = mp->m_sb.sb_agcount;
1786 return XFS_ERROR(EINVAL);
1788 mp->m_sb.sb_agcount = scounter;
1790 case XFS_SBS_IMAX_PCT:
1791 scounter = mp->m_sb.sb_imax_pct;
1795 return XFS_ERROR(EINVAL);
1797 mp->m_sb.sb_imax_pct = scounter;
1799 case XFS_SBS_REXTSIZE:
1800 scounter = mp->m_sb.sb_rextsize;
1804 return XFS_ERROR(EINVAL);
1806 mp->m_sb.sb_rextsize = scounter;
1808 case XFS_SBS_RBMBLOCKS:
1809 scounter = mp->m_sb.sb_rbmblocks;
1813 return XFS_ERROR(EINVAL);
1815 mp->m_sb.sb_rbmblocks = scounter;
1817 case XFS_SBS_RBLOCKS:
1818 lcounter = (long long)mp->m_sb.sb_rblocks;
1822 return XFS_ERROR(EINVAL);
1824 mp->m_sb.sb_rblocks = lcounter;
1826 case XFS_SBS_REXTENTS:
1827 lcounter = (long long)mp->m_sb.sb_rextents;
1831 return XFS_ERROR(EINVAL);
1833 mp->m_sb.sb_rextents = lcounter;
1835 case XFS_SBS_REXTSLOG:
1836 scounter = mp->m_sb.sb_rextslog;
1840 return XFS_ERROR(EINVAL);
1842 mp->m_sb.sb_rextslog = scounter;
1846 return XFS_ERROR(EINVAL);
1851 * xfs_mod_incore_sb() is used to change a field in the in-core
1852 * superblock structure by the specified delta. This modification
1853 * is protected by the m_sb_lock. Just use the xfs_mod_incore_sb_unlocked()
1854 * routine to do the work.
1858 struct xfs_mount *mp,
1859 xfs_sb_field_t field,
1865 #ifdef HAVE_PERCPU_SB
1866 ASSERT(field < XFS_SBS_ICOUNT || field > XFS_SBS_FDBLOCKS);
1868 spin_lock(&mp->m_sb_lock);
1869 status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
1870 spin_unlock(&mp->m_sb_lock);
1876 * Change more than one field in the in-core superblock structure at a time.
1878 * The fields and changes to those fields are specified in the array of
1879 * xfs_mod_sb structures passed in. Either all of the specified deltas
1880 * will be applied or none of them will. If any modified field dips below 0,
1881 * then all modifications will be backed out and EINVAL will be returned.
1883 * Note that this function may not be used for the superblock values that
1884 * are tracked with the in-memory per-cpu counters - a direct call to
1885 * xfs_icsb_modify_counters is required for these.
1888 xfs_mod_incore_sb_batch(
1889 struct xfs_mount *mp,
1898 * Loop through the array of mod structures and apply each individually.
1899 * If any fail, then back out all those which have already been applied.
1900 * Do all of this within the scope of the m_sb_lock so that all of the
1901 * changes will be atomic.
1903 spin_lock(&mp->m_sb_lock);
1904 for (msbp = msb; msbp < (msb + nmsb); msbp++) {
1905 ASSERT(msbp->msb_field < XFS_SBS_ICOUNT ||
1906 msbp->msb_field > XFS_SBS_FDBLOCKS);
1908 error = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
1909 msbp->msb_delta, rsvd);
1913 spin_unlock(&mp->m_sb_lock);
1917 while (--msbp >= msb) {
1918 error = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
1919 -msbp->msb_delta, rsvd);
1922 spin_unlock(&mp->m_sb_lock);
1927 * xfs_getsb() is called to obtain the buffer for the superblock.
1928 * The buffer is returned locked and read in from disk.
1929 * The buffer should be released with a call to xfs_brelse().
1931 * If the flags parameter is BUF_TRYLOCK, then we'll only return
1932 * the superblock buffer if it can be locked without sleeping.
1933 * If it can't then we'll return NULL.
1942 ASSERT(mp->m_sb_bp != NULL);
1944 if (flags & XBF_TRYLOCK) {
1945 if (!XFS_BUF_CPSEMA(bp)) {
1949 XFS_BUF_PSEMA(bp, PRIBIO);
1952 ASSERT(XFS_BUF_ISDONE(bp));
1957 * Used to free the superblock along various error paths.
1961 struct xfs_mount *mp)
1963 struct xfs_buf *bp = mp->m_sb_bp;
1971 * Used to log changes to the superblock unit and width fields which could
1972 * be altered by the mount options, as well as any potential sb_features2
1973 * fixup. Only the first superblock is updated.
1983 ASSERT(fields & (XFS_SB_UNIT | XFS_SB_WIDTH | XFS_SB_UUID |
1984 XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2 |
1985 XFS_SB_VERSIONNUM));
1987 tp = xfs_trans_alloc(mp, XFS_TRANS_SB_UNIT);
1988 error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,
1989 XFS_DEFAULT_LOG_COUNT);
1991 xfs_trans_cancel(tp, 0);
1994 xfs_mod_sb(tp, fields);
1995 error = xfs_trans_commit(tp, 0);
2000 * If the underlying (data/log/rt) device is readonly, there are some
2001 * operations that cannot proceed.
2004 xfs_dev_is_read_only(
2005 struct xfs_mount *mp,
2008 if (xfs_readonly_buftarg(mp->m_ddev_targp) ||
2009 xfs_readonly_buftarg(mp->m_logdev_targp) ||
2010 (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp))) {
2011 xfs_notice(mp, "%s required on read-only device.", message);
2012 xfs_notice(mp, "write access unavailable, cannot proceed.");
2018 #ifdef HAVE_PERCPU_SB
2020 * Per-cpu incore superblock counters
2022 * Simple concept, difficult implementation
2024 * Basically, replace the incore superblock counters with a distributed per cpu
2025 * counter for contended fields (e.g. free block count).
2027 * Difficulties arise in that the incore sb is used for ENOSPC checking, and
2028 * hence needs to be accurately read when we are running low on space. Hence
2029 * there is a method to enable and disable the per-cpu counters based on how
2030 * much "stuff" is available in them.
2032 * Basically, a counter is enabled if there is enough free resource to justify
2033 * running a per-cpu fast-path. If the per-cpu counter runs out (i.e. a local
2034 * ENOSPC), then we disable the counters to synchronise all callers and
2035 * re-distribute the available resources.
2037 * If, once we redistributed the available resources, we still get a failure,
2038 * we disable the per-cpu counter and go through the slow path.
2040 * The slow path is the current xfs_mod_incore_sb() function. This means that
2041 * when we disable a per-cpu counter, we need to drain its resources back to
2042 * the global superblock. We do this after disabling the counter to prevent
2043 * more threads from queueing up on the counter.
2045 * Essentially, this means that we still need a lock in the fast path to enable
2046 * synchronisation between the global counters and the per-cpu counters. This
2047 * is not a problem because the lock will be local to a CPU almost all the time
2048 * and have little contention except when we get to ENOSPC conditions.
2050 * Basically, this lock becomes a barrier that enables us to lock out the fast
2051 * path while we do things like enabling and disabling counters and
2052 * synchronising the counters.
2056 * 1. m_sb_lock before picking up per-cpu locks
2057 * 2. per-cpu locks always picked up via for_each_online_cpu() order
2058 * 3. accurate counter sync requires m_sb_lock + per cpu locks
2059 * 4. modifying per-cpu counters requires holding per-cpu lock
2060 * 5. modifying global counters requires holding m_sb_lock
2061 * 6. enabling or disabling a counter requires holding the m_sb_lock
2062 * and _none_ of the per-cpu locks.
2064 * Disabled counters are only ever re-enabled by a balance operation
2065 * that results in more free resources per CPU than a given threshold.
2066 * To ensure counters don't remain disabled, they are rebalanced when
2067 * the global resource goes above a higher threshold (i.e. some hysteresis
2068 * is present to prevent thrashing).
2071 #ifdef CONFIG_HOTPLUG_CPU
2073 * hot-plug CPU notifier support.
2075 * We need a notifier per filesystem as we need to be able to identify
2076 * the filesystem to balance the counters out. This is achieved by
2077 * having a notifier block embedded in the xfs_mount_t and doing pointer
2078 * magic to get the mount pointer from the notifier block address.
2081 xfs_icsb_cpu_notify(
2082 struct notifier_block *nfb,
2083 unsigned long action,
2086 xfs_icsb_cnts_t *cntp;
2089 mp = (xfs_mount_t *)container_of(nfb, xfs_mount_t, m_icsb_notifier);
2090 cntp = (xfs_icsb_cnts_t *)
2091 per_cpu_ptr(mp->m_sb_cnts, (unsigned long)hcpu);
2093 case CPU_UP_PREPARE:
2094 case CPU_UP_PREPARE_FROZEN:
2095 /* Easy Case - initialize the area and locks, and
2096 * then rebalance when online does everything else for us. */
2097 memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
2100 case CPU_ONLINE_FROZEN:
2102 xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
2103 xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
2104 xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
2105 xfs_icsb_unlock(mp);
2108 case CPU_DEAD_FROZEN:
2109 /* Disable all the counters, then fold the dead cpu's
2110 * count into the total on the global superblock and
2111 * re-enable the counters. */
2113 spin_lock(&mp->m_sb_lock);
2114 xfs_icsb_disable_counter(mp, XFS_SBS_ICOUNT);
2115 xfs_icsb_disable_counter(mp, XFS_SBS_IFREE);
2116 xfs_icsb_disable_counter(mp, XFS_SBS_FDBLOCKS);
2118 mp->m_sb.sb_icount += cntp->icsb_icount;
2119 mp->m_sb.sb_ifree += cntp->icsb_ifree;
2120 mp->m_sb.sb_fdblocks += cntp->icsb_fdblocks;
2122 memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
2124 xfs_icsb_balance_counter_locked(mp, XFS_SBS_ICOUNT, 0);
2125 xfs_icsb_balance_counter_locked(mp, XFS_SBS_IFREE, 0);
2126 xfs_icsb_balance_counter_locked(mp, XFS_SBS_FDBLOCKS, 0);
2127 spin_unlock(&mp->m_sb_lock);
2128 xfs_icsb_unlock(mp);
2134 #endif /* CONFIG_HOTPLUG_CPU */
2137 xfs_icsb_init_counters(
2140 xfs_icsb_cnts_t *cntp;
2143 mp->m_sb_cnts = alloc_percpu(xfs_icsb_cnts_t);
2144 if (mp->m_sb_cnts == NULL)
2147 #ifdef CONFIG_HOTPLUG_CPU
2148 mp->m_icsb_notifier.notifier_call = xfs_icsb_cpu_notify;
2149 mp->m_icsb_notifier.priority = 0;
2150 register_hotcpu_notifier(&mp->m_icsb_notifier);
2151 #endif /* CONFIG_HOTPLUG_CPU */
2153 for_each_online_cpu(i) {
2154 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2155 memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
2158 mutex_init(&mp->m_icsb_mutex);
2161 * start with all counters disabled so that the
2162 * initial balance kicks us off correctly
2164 mp->m_icsb_counters = -1;
2169 xfs_icsb_reinit_counters(
2174 * start with all counters disabled so that the
2175 * initial balance kicks us off correctly
2177 mp->m_icsb_counters = -1;
2178 xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
2179 xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
2180 xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
2181 xfs_icsb_unlock(mp);
2185 xfs_icsb_destroy_counters(
2188 if (mp->m_sb_cnts) {
2189 unregister_hotcpu_notifier(&mp->m_icsb_notifier);
2190 free_percpu(mp->m_sb_cnts);
2192 mutex_destroy(&mp->m_icsb_mutex);
2197 xfs_icsb_cnts_t *icsbp)
2199 while (test_and_set_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags)) {
2205 xfs_icsb_unlock_cntr(
2206 xfs_icsb_cnts_t *icsbp)
2208 clear_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags);
2213 xfs_icsb_lock_all_counters(
2216 xfs_icsb_cnts_t *cntp;
2219 for_each_online_cpu(i) {
2220 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2221 xfs_icsb_lock_cntr(cntp);
2226 xfs_icsb_unlock_all_counters(
2229 xfs_icsb_cnts_t *cntp;
2232 for_each_online_cpu(i) {
2233 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2234 xfs_icsb_unlock_cntr(cntp);
2241 xfs_icsb_cnts_t *cnt,
2244 xfs_icsb_cnts_t *cntp;
2247 memset(cnt, 0, sizeof(xfs_icsb_cnts_t));
2249 if (!(flags & XFS_ICSB_LAZY_COUNT))
2250 xfs_icsb_lock_all_counters(mp);
2252 for_each_online_cpu(i) {
2253 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
2254 cnt->icsb_icount += cntp->icsb_icount;
2255 cnt->icsb_ifree += cntp->icsb_ifree;
2256 cnt->icsb_fdblocks += cntp->icsb_fdblocks;
2259 if (!(flags & XFS_ICSB_LAZY_COUNT))
2260 xfs_icsb_unlock_all_counters(mp);
2264 xfs_icsb_counter_disabled(
2266 xfs_sb_field_t field)
2268 ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
2269 return test_bit(field, &mp->m_icsb_counters);
2273 xfs_icsb_disable_counter(
2275 xfs_sb_field_t field)
2277 xfs_icsb_cnts_t cnt;
2279 ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
2282 * If we are already disabled, then there is nothing to do
2283 * here. We check before locking all the counters to avoid
2284 * the expensive lock operation when being called in the
2285 * slow path and the counter is already disabled. This is
2286 * safe because the only time we set or clear this state is under
2289 if (xfs_icsb_counter_disabled(mp, field))
2292 xfs_icsb_lock_all_counters(mp);
2293 if (!test_and_set_bit(field, &mp->m_icsb_counters)) {
2294 /* drain back to superblock */
2296 xfs_icsb_count(mp, &cnt, XFS_ICSB_LAZY_COUNT);
2298 case XFS_SBS_ICOUNT:
2299 mp->m_sb.sb_icount = cnt.icsb_icount;
2302 mp->m_sb.sb_ifree = cnt.icsb_ifree;
2304 case XFS_SBS_FDBLOCKS:
2305 mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
2312 xfs_icsb_unlock_all_counters(mp);
2316 xfs_icsb_enable_counter(
2318 xfs_sb_field_t field,
2322 xfs_icsb_cnts_t *cntp;
2325 ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
2327 xfs_icsb_lock_all_counters(mp);
2328 for_each_online_cpu(i) {
2329 cntp = per_cpu_ptr(mp->m_sb_cnts, i);
2331 case XFS_SBS_ICOUNT:
2332 cntp->icsb_icount = count + resid;
2335 cntp->icsb_ifree = count + resid;
2337 case XFS_SBS_FDBLOCKS:
2338 cntp->icsb_fdblocks = count + resid;
2346 clear_bit(field, &mp->m_icsb_counters);
2347 xfs_icsb_unlock_all_counters(mp);
2351 xfs_icsb_sync_counters_locked(
2355 xfs_icsb_cnts_t cnt;
2357 xfs_icsb_count(mp, &cnt, flags);
2359 if (!xfs_icsb_counter_disabled(mp, XFS_SBS_ICOUNT))
2360 mp->m_sb.sb_icount = cnt.icsb_icount;
2361 if (!xfs_icsb_counter_disabled(mp, XFS_SBS_IFREE))
2362 mp->m_sb.sb_ifree = cnt.icsb_ifree;
2363 if (!xfs_icsb_counter_disabled(mp, XFS_SBS_FDBLOCKS))
2364 mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
2368 * Accurate update of per-cpu counters to incore superblock
2371 xfs_icsb_sync_counters(
2375 spin_lock(&mp->m_sb_lock);
2376 xfs_icsb_sync_counters_locked(mp, flags);
2377 spin_unlock(&mp->m_sb_lock);
2381 * Balance and enable/disable counters as necessary.
2383 * Thresholds for re-enabling counters are somewhat magic. inode counts are
2384 * chosen to be the same number as single on disk allocation chunk per CPU, and
2385 * free blocks is something far enough zero that we aren't going thrash when we
2386 * get near ENOSPC. We also need to supply a minimum we require per cpu to
2387 * prevent looping endlessly when xfs_alloc_space asks for more than will
2388 * be distributed to a single CPU but each CPU has enough blocks to be
2391 * Note that we can be called when counters are already disabled.
2392 * xfs_icsb_disable_counter() optimises the counter locking in this case to
2393 * prevent locking every per-cpu counter needlessly.
2396 #define XFS_ICSB_INO_CNTR_REENABLE (uint64_t)64
2397 #define XFS_ICSB_FDBLK_CNTR_REENABLE(mp) \
2398 (uint64_t)(512 + XFS_ALLOC_SET_ASIDE(mp))
2400 xfs_icsb_balance_counter_locked(
2402 xfs_sb_field_t field,
2405 uint64_t count, resid;
2406 int weight = num_online_cpus();
2407 uint64_t min = (uint64_t)min_per_cpu;
2409 /* disable counter and sync counter */
2410 xfs_icsb_disable_counter(mp, field);
2412 /* update counters - first CPU gets residual*/
2414 case XFS_SBS_ICOUNT:
2415 count = mp->m_sb.sb_icount;
2416 resid = do_div(count, weight);
2417 if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE))
2421 count = mp->m_sb.sb_ifree;
2422 resid = do_div(count, weight);
2423 if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE))
2426 case XFS_SBS_FDBLOCKS:
2427 count = mp->m_sb.sb_fdblocks;
2428 resid = do_div(count, weight);
2429 if (count < max(min, XFS_ICSB_FDBLK_CNTR_REENABLE(mp)))
2434 count = resid = 0; /* quiet, gcc */
2438 xfs_icsb_enable_counter(mp, field, count, resid);
2442 xfs_icsb_balance_counter(
2444 xfs_sb_field_t fields,
2447 spin_lock(&mp->m_sb_lock);
2448 xfs_icsb_balance_counter_locked(mp, fields, min_per_cpu);
2449 spin_unlock(&mp->m_sb_lock);
2453 xfs_icsb_modify_counters(
2455 xfs_sb_field_t field,
2459 xfs_icsb_cnts_t *icsbp;
2460 long long lcounter; /* long counter for 64 bit fields */
2466 icsbp = this_cpu_ptr(mp->m_sb_cnts);
2469 * if the counter is disabled, go to slow path
2471 if (unlikely(xfs_icsb_counter_disabled(mp, field)))
2473 xfs_icsb_lock_cntr(icsbp);
2474 if (unlikely(xfs_icsb_counter_disabled(mp, field))) {
2475 xfs_icsb_unlock_cntr(icsbp);
2480 case XFS_SBS_ICOUNT:
2481 lcounter = icsbp->icsb_icount;
2483 if (unlikely(lcounter < 0))
2484 goto balance_counter;
2485 icsbp->icsb_icount = lcounter;
2489 lcounter = icsbp->icsb_ifree;
2491 if (unlikely(lcounter < 0))
2492 goto balance_counter;
2493 icsbp->icsb_ifree = lcounter;
2496 case XFS_SBS_FDBLOCKS:
2497 BUG_ON((mp->m_resblks - mp->m_resblks_avail) != 0);
2499 lcounter = icsbp->icsb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
2501 if (unlikely(lcounter < 0))
2502 goto balance_counter;
2503 icsbp->icsb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
2509 xfs_icsb_unlock_cntr(icsbp);
2517 * serialise with a mutex so we don't burn lots of cpu on
2518 * the superblock lock. We still need to hold the superblock
2519 * lock, however, when we modify the global structures.
2524 * Now running atomically.
2526 * If the counter is enabled, someone has beaten us to rebalancing.
2527 * Drop the lock and try again in the fast path....
2529 if (!(xfs_icsb_counter_disabled(mp, field))) {
2530 xfs_icsb_unlock(mp);
2535 * The counter is currently disabled. Because we are
2536 * running atomically here, we know a rebalance cannot
2537 * be in progress. Hence we can go straight to operating
2538 * on the global superblock. We do not call xfs_mod_incore_sb()
2539 * here even though we need to get the m_sb_lock. Doing so
2540 * will cause us to re-enter this function and deadlock.
2541 * Hence we get the m_sb_lock ourselves and then call
2542 * xfs_mod_incore_sb_unlocked() as the unlocked path operates
2543 * directly on the global counters.
2545 spin_lock(&mp->m_sb_lock);
2546 ret = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
2547 spin_unlock(&mp->m_sb_lock);
2550 * Now that we've modified the global superblock, we
2551 * may be able to re-enable the distributed counters
2552 * (e.g. lots of space just got freed). After that
2556 xfs_icsb_balance_counter(mp, field, 0);
2557 xfs_icsb_unlock(mp);
2561 xfs_icsb_unlock_cntr(icsbp);
2565 * We may have multiple threads here if multiple per-cpu
2566 * counters run dry at the same time. This will mean we can
2567 * do more balances than strictly necessary but it is not
2568 * the common slowpath case.
2573 * running atomically.
2575 * This will leave the counter in the correct state for future
2576 * accesses. After the rebalance, we simply try again and our retry
2577 * will either succeed through the fast path or slow path without
2578 * another balance operation being required.
2580 xfs_icsb_balance_counter(mp, field, delta);
2581 xfs_icsb_unlock(mp);