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_shared.h"
21 #include "xfs_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_trans_resv.h"
28 #include "xfs_mount.h"
29 #include "xfs_da_format.h"
30 #include "xfs_inode.h"
32 #include "xfs_ialloc.h"
33 #include "xfs_alloc.h"
34 #include "xfs_rtalloc.h"
36 #include "xfs_trans.h"
37 #include "xfs_trans_priv.h"
39 #include "xfs_error.h"
40 #include "xfs_quota.h"
41 #include "xfs_fsops.h"
42 #include "xfs_trace.h"
43 #include "xfs_icache.h"
44 #include "xfs_dinode.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)
59 static DEFINE_MUTEX(xfs_uuid_table_mutex);
60 static int xfs_uuid_table_size;
61 static uuid_t *xfs_uuid_table;
64 * See if the UUID is unique among mounted XFS filesystems.
65 * Mount fails if UUID is nil or a FS with the same UUID is already mounted.
71 uuid_t *uuid = &mp->m_sb.sb_uuid;
74 if (mp->m_flags & XFS_MOUNT_NOUUID)
77 if (uuid_is_nil(uuid)) {
78 xfs_warn(mp, "Filesystem has nil UUID - can't mount");
79 return XFS_ERROR(EINVAL);
82 mutex_lock(&xfs_uuid_table_mutex);
83 for (i = 0, hole = -1; i < xfs_uuid_table_size; i++) {
84 if (uuid_is_nil(&xfs_uuid_table[i])) {
88 if (uuid_equal(uuid, &xfs_uuid_table[i]))
93 xfs_uuid_table = kmem_realloc(xfs_uuid_table,
94 (xfs_uuid_table_size + 1) * sizeof(*xfs_uuid_table),
95 xfs_uuid_table_size * sizeof(*xfs_uuid_table),
97 hole = xfs_uuid_table_size++;
99 xfs_uuid_table[hole] = *uuid;
100 mutex_unlock(&xfs_uuid_table_mutex);
105 mutex_unlock(&xfs_uuid_table_mutex);
106 xfs_warn(mp, "Filesystem has duplicate UUID %pU - can't mount", uuid);
107 return XFS_ERROR(EINVAL);
112 struct xfs_mount *mp)
114 uuid_t *uuid = &mp->m_sb.sb_uuid;
117 if (mp->m_flags & XFS_MOUNT_NOUUID)
120 mutex_lock(&xfs_uuid_table_mutex);
121 for (i = 0; i < xfs_uuid_table_size; i++) {
122 if (uuid_is_nil(&xfs_uuid_table[i]))
124 if (!uuid_equal(uuid, &xfs_uuid_table[i]))
126 memset(&xfs_uuid_table[i], 0, sizeof(uuid_t));
129 ASSERT(i < xfs_uuid_table_size);
130 mutex_unlock(&xfs_uuid_table_mutex);
136 struct rcu_head *head)
138 struct xfs_perag *pag = container_of(head, struct xfs_perag, rcu_head);
140 ASSERT(atomic_read(&pag->pag_ref) == 0);
145 * Free up the per-ag resources associated with the mount structure.
152 struct xfs_perag *pag;
154 for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
155 spin_lock(&mp->m_perag_lock);
156 pag = radix_tree_delete(&mp->m_perag_tree, agno);
157 spin_unlock(&mp->m_perag_lock);
159 ASSERT(atomic_read(&pag->pag_ref) == 0);
160 call_rcu(&pag->rcu_head, __xfs_free_perag);
165 * Check size of device based on the (data/realtime) block count.
166 * Note: this check is used by the growfs code as well as mount.
169 xfs_sb_validate_fsb_count(
173 ASSERT(PAGE_SHIFT >= sbp->sb_blocklog);
174 ASSERT(sbp->sb_blocklog >= BBSHIFT);
176 #if XFS_BIG_BLKNOS /* Limited by ULONG_MAX of page cache index */
177 if (nblocks >> (PAGE_CACHE_SHIFT - sbp->sb_blocklog) > ULONG_MAX)
179 #else /* Limited by UINT_MAX of sectors */
180 if (nblocks << (sbp->sb_blocklog - BBSHIFT) > UINT_MAX)
187 xfs_initialize_perag(
189 xfs_agnumber_t agcount,
190 xfs_agnumber_t *maxagi)
192 xfs_agnumber_t index;
193 xfs_agnumber_t first_initialised = 0;
197 xfs_sb_t *sbp = &mp->m_sb;
201 * Walk the current per-ag tree so we don't try to initialise AGs
202 * that already exist (growfs case). Allocate and insert all the
203 * AGs we don't find ready for initialisation.
205 for (index = 0; index < agcount; index++) {
206 pag = xfs_perag_get(mp, index);
211 if (!first_initialised)
212 first_initialised = index;
214 pag = kmem_zalloc(sizeof(*pag), KM_MAYFAIL);
217 pag->pag_agno = index;
219 spin_lock_init(&pag->pag_ici_lock);
220 mutex_init(&pag->pag_ici_reclaim_lock);
221 INIT_RADIX_TREE(&pag->pag_ici_root, GFP_ATOMIC);
222 spin_lock_init(&pag->pag_buf_lock);
223 pag->pag_buf_tree = RB_ROOT;
225 if (radix_tree_preload(GFP_NOFS))
228 spin_lock(&mp->m_perag_lock);
229 if (radix_tree_insert(&mp->m_perag_tree, index, pag)) {
231 spin_unlock(&mp->m_perag_lock);
232 radix_tree_preload_end();
236 spin_unlock(&mp->m_perag_lock);
237 radix_tree_preload_end();
241 * If we mount with the inode64 option, or no inode overflows
242 * the legacy 32-bit address space clear the inode32 option.
244 agino = XFS_OFFBNO_TO_AGINO(mp, sbp->sb_agblocks - 1, 0);
245 ino = XFS_AGINO_TO_INO(mp, agcount - 1, agino);
247 if ((mp->m_flags & XFS_MOUNT_SMALL_INUMS) && ino > XFS_MAXINUMBER_32)
248 mp->m_flags |= XFS_MOUNT_32BITINODES;
250 mp->m_flags &= ~XFS_MOUNT_32BITINODES;
252 if (mp->m_flags & XFS_MOUNT_32BITINODES)
253 index = xfs_set_inode32(mp);
255 index = xfs_set_inode64(mp);
263 for (; index > first_initialised; index--) {
264 pag = radix_tree_delete(&mp->m_perag_tree, index);
273 * Does the initial read of the superblock.
277 struct xfs_mount *mp,
280 unsigned int sector_size;
282 struct xfs_sb *sbp = &mp->m_sb;
284 int loud = !(flags & XFS_MFSI_QUIET);
286 ASSERT(mp->m_sb_bp == NULL);
287 ASSERT(mp->m_ddev_targp != NULL);
290 * Allocate a (locked) buffer to hold the superblock.
291 * This will be kept around at all times to optimize
292 * access to the superblock.
294 sector_size = xfs_getsize_buftarg(mp->m_ddev_targp);
297 bp = xfs_buf_read_uncached(mp->m_ddev_targp, XFS_SB_DADDR,
298 BTOBB(sector_size), 0,
299 loud ? &xfs_sb_buf_ops
300 : &xfs_sb_quiet_buf_ops);
303 xfs_warn(mp, "SB buffer read failed");
309 xfs_warn(mp, "SB validate failed with error %d.", error);
310 /* bad CRC means corrupted metadata */
311 if (error == EFSBADCRC)
312 error = EFSCORRUPTED;
317 * Initialize the mount structure from the superblock.
319 xfs_sb_from_disk(&mp->m_sb, XFS_BUF_TO_SBP(bp));
320 xfs_sb_quota_from_disk(&mp->m_sb);
323 * We must be able to do sector-sized and sector-aligned IO.
325 if (sector_size > sbp->sb_sectsize) {
327 xfs_warn(mp, "device supports %u byte sectors (not %u)",
328 sector_size, sbp->sb_sectsize);
334 * If device sector size is smaller than the superblock size,
335 * re-read the superblock so the buffer is correctly sized.
337 if (sector_size < sbp->sb_sectsize) {
339 sector_size = sbp->sb_sectsize;
343 /* Initialize per-cpu counters */
344 xfs_icsb_reinit_counters(mp);
346 /* no need to be quiet anymore, so reset the buf ops */
347 bp->b_ops = &xfs_sb_buf_ops;
359 * Update alignment values based on mount options and sb values
362 xfs_update_alignment(xfs_mount_t *mp)
364 xfs_sb_t *sbp = &(mp->m_sb);
368 * If stripe unit and stripe width are not multiples
369 * of the fs blocksize turn off alignment.
371 if ((BBTOB(mp->m_dalign) & mp->m_blockmask) ||
372 (BBTOB(mp->m_swidth) & mp->m_blockmask)) {
374 "alignment check failed: sunit/swidth vs. blocksize(%d)",
376 return XFS_ERROR(EINVAL);
379 * Convert the stripe unit and width to FSBs.
381 mp->m_dalign = XFS_BB_TO_FSBT(mp, mp->m_dalign);
382 if (mp->m_dalign && (sbp->sb_agblocks % mp->m_dalign)) {
384 "alignment check failed: sunit/swidth vs. agsize(%d)",
386 return XFS_ERROR(EINVAL);
387 } else if (mp->m_dalign) {
388 mp->m_swidth = XFS_BB_TO_FSBT(mp, mp->m_swidth);
391 "alignment check failed: sunit(%d) less than bsize(%d)",
392 mp->m_dalign, sbp->sb_blocksize);
393 return XFS_ERROR(EINVAL);
398 * Update superblock with new values
401 if (xfs_sb_version_hasdalign(sbp)) {
402 if (sbp->sb_unit != mp->m_dalign) {
403 sbp->sb_unit = mp->m_dalign;
404 mp->m_update_flags |= XFS_SB_UNIT;
406 if (sbp->sb_width != mp->m_swidth) {
407 sbp->sb_width = mp->m_swidth;
408 mp->m_update_flags |= XFS_SB_WIDTH;
412 "cannot change alignment: superblock does not support data alignment");
413 return XFS_ERROR(EINVAL);
415 } else if ((mp->m_flags & XFS_MOUNT_NOALIGN) != XFS_MOUNT_NOALIGN &&
416 xfs_sb_version_hasdalign(&mp->m_sb)) {
417 mp->m_dalign = sbp->sb_unit;
418 mp->m_swidth = sbp->sb_width;
425 * Set the maximum inode count for this filesystem
428 xfs_set_maxicount(xfs_mount_t *mp)
430 xfs_sb_t *sbp = &(mp->m_sb);
433 if (sbp->sb_imax_pct) {
435 * Make sure the maximum inode count is a multiple
436 * of the units we allocate inodes in.
438 icount = sbp->sb_dblocks * sbp->sb_imax_pct;
440 do_div(icount, mp->m_ialloc_blks);
441 mp->m_maxicount = (icount * mp->m_ialloc_blks) <<
449 * Set the default minimum read and write sizes unless
450 * already specified in a mount option.
451 * We use smaller I/O sizes when the file system
452 * is being used for NFS service (wsync mount option).
455 xfs_set_rw_sizes(xfs_mount_t *mp)
457 xfs_sb_t *sbp = &(mp->m_sb);
458 int readio_log, writeio_log;
460 if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE)) {
461 if (mp->m_flags & XFS_MOUNT_WSYNC) {
462 readio_log = XFS_WSYNC_READIO_LOG;
463 writeio_log = XFS_WSYNC_WRITEIO_LOG;
465 readio_log = XFS_READIO_LOG_LARGE;
466 writeio_log = XFS_WRITEIO_LOG_LARGE;
469 readio_log = mp->m_readio_log;
470 writeio_log = mp->m_writeio_log;
473 if (sbp->sb_blocklog > readio_log) {
474 mp->m_readio_log = sbp->sb_blocklog;
476 mp->m_readio_log = readio_log;
478 mp->m_readio_blocks = 1 << (mp->m_readio_log - sbp->sb_blocklog);
479 if (sbp->sb_blocklog > writeio_log) {
480 mp->m_writeio_log = sbp->sb_blocklog;
482 mp->m_writeio_log = writeio_log;
484 mp->m_writeio_blocks = 1 << (mp->m_writeio_log - sbp->sb_blocklog);
488 * precalculate the low space thresholds for dynamic speculative preallocation.
491 xfs_set_low_space_thresholds(
492 struct xfs_mount *mp)
496 for (i = 0; i < XFS_LOWSP_MAX; i++) {
497 __uint64_t space = mp->m_sb.sb_dblocks;
500 mp->m_low_space[i] = space * (i + 1);
506 * Set whether we're using inode alignment.
509 xfs_set_inoalignment(xfs_mount_t *mp)
511 if (xfs_sb_version_hasalign(&mp->m_sb) &&
512 mp->m_sb.sb_inoalignmt >=
513 XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size))
514 mp->m_inoalign_mask = mp->m_sb.sb_inoalignmt - 1;
516 mp->m_inoalign_mask = 0;
518 * If we are using stripe alignment, check whether
519 * the stripe unit is a multiple of the inode alignment
521 if (mp->m_dalign && mp->m_inoalign_mask &&
522 !(mp->m_dalign & mp->m_inoalign_mask))
523 mp->m_sinoalign = mp->m_dalign;
529 * Check that the data (and log if separate) is an ok size.
532 xfs_check_sizes(xfs_mount_t *mp)
537 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_dblocks);
538 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_dblocks) {
539 xfs_warn(mp, "filesystem size mismatch detected");
540 return XFS_ERROR(EFBIG);
542 bp = xfs_buf_read_uncached(mp->m_ddev_targp,
543 d - XFS_FSS_TO_BB(mp, 1),
544 XFS_FSS_TO_BB(mp, 1), 0, NULL);
546 xfs_warn(mp, "last sector read failed");
551 if (mp->m_logdev_targp != mp->m_ddev_targp) {
552 d = (xfs_daddr_t)XFS_FSB_TO_BB(mp, mp->m_sb.sb_logblocks);
553 if (XFS_BB_TO_FSB(mp, d) != mp->m_sb.sb_logblocks) {
554 xfs_warn(mp, "log size mismatch detected");
555 return XFS_ERROR(EFBIG);
557 bp = xfs_buf_read_uncached(mp->m_logdev_targp,
558 d - XFS_FSB_TO_BB(mp, 1),
559 XFS_FSB_TO_BB(mp, 1), 0, NULL);
561 xfs_warn(mp, "log device read failed");
570 * Clear the quotaflags in memory and in the superblock.
573 xfs_mount_reset_sbqflags(
574 struct xfs_mount *mp)
577 struct xfs_trans *tp;
582 * It is OK to look at sb_qflags here in mount path,
585 if (mp->m_sb.sb_qflags == 0)
587 spin_lock(&mp->m_sb_lock);
588 mp->m_sb.sb_qflags = 0;
589 spin_unlock(&mp->m_sb_lock);
592 * If the fs is readonly, let the incore superblock run
593 * with quotas off but don't flush the update out to disk
595 if (mp->m_flags & XFS_MOUNT_RDONLY)
598 tp = xfs_trans_alloc(mp, XFS_TRANS_QM_SBCHANGE);
599 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_qm_sbchange, 0, 0);
601 xfs_trans_cancel(tp, 0);
602 xfs_alert(mp, "%s: Superblock update failed!", __func__);
606 xfs_mod_sb(tp, XFS_SB_QFLAGS);
607 return xfs_trans_commit(tp, 0);
611 xfs_default_resblks(xfs_mount_t *mp)
616 * We default to 5% or 8192 fsbs of space reserved, whichever is
617 * smaller. This is intended to cover concurrent allocation
618 * transactions when we initially hit enospc. These each require a 4
619 * block reservation. Hence by default we cover roughly 2000 concurrent
620 * allocation reservations.
622 resblks = mp->m_sb.sb_dblocks;
624 resblks = min_t(__uint64_t, resblks, 8192);
629 * This function does the following on an initial mount of a file system:
630 * - reads the superblock from disk and init the mount struct
631 * - if we're a 32-bit kernel, do a size check on the superblock
632 * so we don't mount terabyte filesystems
633 * - init mount struct realtime fields
634 * - allocate inode hash table for fs
635 * - init directory manager
636 * - perform recovery and init the log manager
642 xfs_sb_t *sbp = &(mp->m_sb);
649 xfs_sb_mount_common(mp, sbp);
652 * Check for a mismatched features2 values. Older kernels
653 * read & wrote into the wrong sb offset for sb_features2
654 * on some platforms due to xfs_sb_t not being 64bit size aligned
655 * when sb_features2 was added, which made older superblock
656 * reading/writing routines swap it as a 64-bit value.
658 * For backwards compatibility, we make both slots equal.
660 * If we detect a mismatched field, we OR the set bits into the
661 * existing features2 field in case it has already been modified; we
662 * don't want to lose any features. We then update the bad location
663 * with the ORed value so that older kernels will see any features2
664 * flags, and mark the two fields as needing updates once the
665 * transaction subsystem is online.
667 if (xfs_sb_has_mismatched_features2(sbp)) {
668 xfs_warn(mp, "correcting sb_features alignment problem");
669 sbp->sb_features2 |= sbp->sb_bad_features2;
670 sbp->sb_bad_features2 = sbp->sb_features2;
671 mp->m_update_flags |= XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2;
674 * Re-check for ATTR2 in case it was found in bad_features2
677 if (xfs_sb_version_hasattr2(&mp->m_sb) &&
678 !(mp->m_flags & XFS_MOUNT_NOATTR2))
679 mp->m_flags |= XFS_MOUNT_ATTR2;
682 if (xfs_sb_version_hasattr2(&mp->m_sb) &&
683 (mp->m_flags & XFS_MOUNT_NOATTR2)) {
684 xfs_sb_version_removeattr2(&mp->m_sb);
685 mp->m_update_flags |= XFS_SB_FEATURES2;
687 /* update sb_versionnum for the clearing of the morebits */
688 if (!sbp->sb_features2)
689 mp->m_update_flags |= XFS_SB_VERSIONNUM;
693 * Check if sb_agblocks is aligned at stripe boundary
694 * If sb_agblocks is NOT aligned turn off m_dalign since
695 * allocator alignment is within an ag, therefore ag has
696 * to be aligned at stripe boundary.
698 error = xfs_update_alignment(mp);
702 xfs_alloc_compute_maxlevels(mp);
703 xfs_bmap_compute_maxlevels(mp, XFS_DATA_FORK);
704 xfs_bmap_compute_maxlevels(mp, XFS_ATTR_FORK);
705 xfs_ialloc_compute_maxlevels(mp);
707 xfs_set_maxicount(mp);
709 error = xfs_uuid_mount(mp);
714 * Set the minimum read and write sizes
716 xfs_set_rw_sizes(mp);
718 /* set the low space thresholds for dynamic preallocation */
719 xfs_set_low_space_thresholds(mp);
722 * Set the inode cluster size.
723 * This may still be overridden by the file system
724 * block size if it is larger than the chosen cluster size.
726 * For v5 filesystems, scale the cluster size with the inode size to
727 * keep a constant ratio of inode per cluster buffer, but only if mkfs
728 * has set the inode alignment value appropriately for larger cluster
731 mp->m_inode_cluster_size = XFS_INODE_BIG_CLUSTER_SIZE;
732 if (xfs_sb_version_hascrc(&mp->m_sb)) {
733 int new_size = mp->m_inode_cluster_size;
735 new_size *= mp->m_sb.sb_inodesize / XFS_DINODE_MIN_SIZE;
736 if (mp->m_sb.sb_inoalignmt >= XFS_B_TO_FSBT(mp, new_size))
737 mp->m_inode_cluster_size = new_size;
738 xfs_info(mp, "Using inode cluster size of %d bytes",
739 mp->m_inode_cluster_size);
743 * Set inode alignment fields
745 xfs_set_inoalignment(mp);
748 * Check that the data (and log if separate) is an ok size.
750 error = xfs_check_sizes(mp);
752 goto out_remove_uuid;
755 * Initialize realtime fields in the mount structure
757 error = xfs_rtmount_init(mp);
759 xfs_warn(mp, "RT mount failed");
760 goto out_remove_uuid;
764 * Copies the low order bits of the timestamp and the randomly
765 * set "sequence" number out of a UUID.
767 uuid_getnodeuniq(&sbp->sb_uuid, mp->m_fixedfsid);
769 mp->m_dmevmask = 0; /* not persistent; set after each mount */
774 * Initialize the attribute manager's entries.
776 mp->m_attr_magicpct = (mp->m_sb.sb_blocksize * 37) / 100;
779 * Initialize the precomputed transaction reservations values.
784 * Allocate and initialize the per-ag data.
786 spin_lock_init(&mp->m_perag_lock);
787 INIT_RADIX_TREE(&mp->m_perag_tree, GFP_ATOMIC);
788 error = xfs_initialize_perag(mp, sbp->sb_agcount, &mp->m_maxagi);
790 xfs_warn(mp, "Failed per-ag init: %d", error);
791 goto out_remove_uuid;
794 if (!sbp->sb_logblocks) {
795 xfs_warn(mp, "no log defined");
796 XFS_ERROR_REPORT("xfs_mountfs", XFS_ERRLEVEL_LOW, mp);
797 error = XFS_ERROR(EFSCORRUPTED);
802 * log's mount-time initialization. Perform 1st part recovery if needed
804 error = xfs_log_mount(mp, mp->m_logdev_targp,
805 XFS_FSB_TO_DADDR(mp, sbp->sb_logstart),
806 XFS_FSB_TO_BB(mp, sbp->sb_logblocks));
808 xfs_warn(mp, "log mount failed");
813 * Now the log is mounted, we know if it was an unclean shutdown or
814 * not. If it was, with the first phase of recovery has completed, we
815 * have consistent AG blocks on disk. We have not recovered EFIs yet,
816 * but they are recovered transactionally in the second recovery phase
819 * Hence we can safely re-initialise incore superblock counters from
820 * the per-ag data. These may not be correct if the filesystem was not
821 * cleanly unmounted, so we need to wait for recovery to finish before
824 * If the filesystem was cleanly unmounted, then we can trust the
825 * values in the superblock to be correct and we don't need to do
828 * If we are currently making the filesystem, the initialisation will
829 * fail as the perag data is in an undefined state.
831 if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
832 !XFS_LAST_UNMOUNT_WAS_CLEAN(mp) &&
833 !mp->m_sb.sb_inprogress) {
834 error = xfs_initialize_perag_data(mp, sbp->sb_agcount);
840 * Get and sanity-check the root inode.
841 * Save the pointer to it in the mount structure.
843 error = xfs_iget(mp, NULL, sbp->sb_rootino, 0, XFS_ILOCK_EXCL, &rip);
845 xfs_warn(mp, "failed to read root inode");
846 goto out_log_dealloc;
851 if (unlikely(!S_ISDIR(rip->i_d.di_mode))) {
852 xfs_warn(mp, "corrupted root inode %llu: not a directory",
853 (unsigned long long)rip->i_ino);
854 xfs_iunlock(rip, XFS_ILOCK_EXCL);
855 XFS_ERROR_REPORT("xfs_mountfs_int(2)", XFS_ERRLEVEL_LOW,
857 error = XFS_ERROR(EFSCORRUPTED);
860 mp->m_rootip = rip; /* save it */
862 xfs_iunlock(rip, XFS_ILOCK_EXCL);
865 * Initialize realtime inode pointers in the mount structure
867 error = xfs_rtmount_inodes(mp);
870 * Free up the root inode.
872 xfs_warn(mp, "failed to read RT inodes");
877 * If this is a read-only mount defer the superblock updates until
878 * the next remount into writeable mode. Otherwise we would never
879 * perform the update e.g. for the root filesystem.
881 if (mp->m_update_flags && !(mp->m_flags & XFS_MOUNT_RDONLY)) {
882 error = xfs_mount_log_sb(mp, mp->m_update_flags);
884 xfs_warn(mp, "failed to write sb changes");
890 * Initialise the XFS quota management subsystem for this mount
892 if (XFS_IS_QUOTA_RUNNING(mp)) {
893 error = xfs_qm_newmount(mp, "amount, "aflags);
897 ASSERT(!XFS_IS_QUOTA_ON(mp));
900 * If a file system had quotas running earlier, but decided to
901 * mount without -o uquota/pquota/gquota options, revoke the
902 * quotachecked license.
904 if (mp->m_sb.sb_qflags & XFS_ALL_QUOTA_ACCT) {
905 xfs_notice(mp, "resetting quota flags");
906 error = xfs_mount_reset_sbqflags(mp);
913 * Finish recovering the file system. This part needed to be
914 * delayed until after the root and real-time bitmap inodes
915 * were consistently read in.
917 error = xfs_log_mount_finish(mp);
919 xfs_warn(mp, "log mount finish failed");
924 * Complete the quota initialisation, post-log-replay component.
927 ASSERT(mp->m_qflags == 0);
928 mp->m_qflags = quotaflags;
930 xfs_qm_mount_quotas(mp);
934 * Now we are mounted, reserve a small amount of unused space for
935 * privileged transactions. This is needed so that transaction
936 * space required for critical operations can dip into this pool
937 * when at ENOSPC. This is needed for operations like create with
938 * attr, unwritten extent conversion at ENOSPC, etc. Data allocations
939 * are not allowed to use this reserved space.
941 * This may drive us straight to ENOSPC on mount, but that implies
942 * we were already there on the last unmount. Warn if this occurs.
944 if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
945 resblks = xfs_default_resblks(mp);
946 error = xfs_reserve_blocks(mp, &resblks, NULL);
949 "Unable to allocate reserve blocks. Continuing without reserve pool.");
955 xfs_rtunmount_inodes(mp);
961 if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp)
962 xfs_wait_buftarg(mp->m_logdev_targp);
963 xfs_wait_buftarg(mp->m_ddev_targp);
967 xfs_uuid_unmount(mp);
973 * This flushes out the inodes,dquots and the superblock, unmounts the
974 * log and makes sure that incore structures are freed.
978 struct xfs_mount *mp)
983 cancel_delayed_work_sync(&mp->m_eofblocks_work);
985 xfs_qm_unmount_quotas(mp);
986 xfs_rtunmount_inodes(mp);
990 * We can potentially deadlock here if we have an inode cluster
991 * that has been freed has its buffer still pinned in memory because
992 * the transaction is still sitting in a iclog. The stale inodes
993 * on that buffer will have their flush locks held until the
994 * transaction hits the disk and the callbacks run. the inode
995 * flush takes the flush lock unconditionally and with nothing to
996 * push out the iclog we will never get that unlocked. hence we
997 * need to force the log first.
999 xfs_log_force(mp, XFS_LOG_SYNC);
1002 * Flush all pending changes from the AIL.
1004 xfs_ail_push_all_sync(mp->m_ail);
1007 * And reclaim all inodes. At this point there should be no dirty
1008 * inodes and none should be pinned or locked, but use synchronous
1009 * reclaim just to be sure. We can stop background inode reclaim
1010 * here as well if it is still running.
1012 cancel_delayed_work_sync(&mp->m_reclaim_work);
1013 xfs_reclaim_inodes(mp, SYNC_WAIT);
1018 * Unreserve any blocks we have so that when we unmount we don't account
1019 * the reserved free space as used. This is really only necessary for
1020 * lazy superblock counting because it trusts the incore superblock
1021 * counters to be absolutely correct on clean unmount.
1023 * We don't bother correcting this elsewhere for lazy superblock
1024 * counting because on mount of an unclean filesystem we reconstruct the
1025 * correct counter value and this is irrelevant.
1027 * For non-lazy counter filesystems, this doesn't matter at all because
1028 * we only every apply deltas to the superblock and hence the incore
1029 * value does not matter....
1032 error = xfs_reserve_blocks(mp, &resblks, NULL);
1034 xfs_warn(mp, "Unable to free reserved block pool. "
1035 "Freespace may not be correct on next mount.");
1037 error = xfs_log_sbcount(mp);
1039 xfs_warn(mp, "Unable to update superblock counters. "
1040 "Freespace may not be correct on next mount.");
1042 xfs_log_unmount(mp);
1043 xfs_uuid_unmount(mp);
1046 xfs_errortag_clearall(mp, 0);
1052 xfs_fs_writable(xfs_mount_t *mp)
1054 return !(mp->m_super->s_writers.frozen || XFS_FORCED_SHUTDOWN(mp) ||
1055 (mp->m_flags & XFS_MOUNT_RDONLY));
1061 * Sync the superblock counters to disk.
1063 * Note this code can be called during the process of freezing, so
1064 * we may need to use the transaction allocator which does not
1065 * block when the transaction subsystem is in its frozen state.
1068 xfs_log_sbcount(xfs_mount_t *mp)
1073 if (!xfs_fs_writable(mp))
1076 xfs_icsb_sync_counters(mp, 0);
1079 * we don't need to do this if we are updating the superblock
1080 * counters on every modification.
1082 if (!xfs_sb_version_haslazysbcount(&mp->m_sb))
1085 tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT, KM_SLEEP);
1086 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_sb, 0, 0);
1088 xfs_trans_cancel(tp, 0);
1092 xfs_mod_sb(tp, XFS_SB_IFREE | XFS_SB_ICOUNT | XFS_SB_FDBLOCKS);
1093 xfs_trans_set_sync(tp);
1094 error = xfs_trans_commit(tp, 0);
1099 * xfs_mod_incore_sb_unlocked() is a utility routine commonly used to apply
1100 * a delta to a specified field in the in-core superblock. Simply
1101 * switch on the field indicated and apply the delta to that field.
1102 * Fields are not allowed to dip below zero, so if the delta would
1103 * do this do not apply it and return EINVAL.
1105 * The m_sb_lock must be held when this routine is called.
1108 xfs_mod_incore_sb_unlocked(
1110 xfs_sb_field_t field,
1114 int scounter; /* short counter for 32 bit fields */
1115 long long lcounter; /* long counter for 64 bit fields */
1116 long long res_used, rem;
1119 * With the in-core superblock spin lock held, switch
1120 * on the indicated field. Apply the delta to the
1121 * proper field. If the fields value would dip below
1122 * 0, then do not apply the delta and return EINVAL.
1125 case XFS_SBS_ICOUNT:
1126 lcounter = (long long)mp->m_sb.sb_icount;
1130 return XFS_ERROR(EINVAL);
1132 mp->m_sb.sb_icount = lcounter;
1135 lcounter = (long long)mp->m_sb.sb_ifree;
1139 return XFS_ERROR(EINVAL);
1141 mp->m_sb.sb_ifree = lcounter;
1143 case XFS_SBS_FDBLOCKS:
1144 lcounter = (long long)
1145 mp->m_sb.sb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
1146 res_used = (long long)(mp->m_resblks - mp->m_resblks_avail);
1148 if (delta > 0) { /* Putting blocks back */
1149 if (res_used > delta) {
1150 mp->m_resblks_avail += delta;
1152 rem = delta - res_used;
1153 mp->m_resblks_avail = mp->m_resblks;
1156 } else { /* Taking blocks away */
1158 if (lcounter >= 0) {
1159 mp->m_sb.sb_fdblocks = lcounter +
1160 XFS_ALLOC_SET_ASIDE(mp);
1165 * We are out of blocks, use any available reserved
1166 * blocks if were allowed to.
1169 return XFS_ERROR(ENOSPC);
1171 lcounter = (long long)mp->m_resblks_avail + delta;
1172 if (lcounter >= 0) {
1173 mp->m_resblks_avail = lcounter;
1176 printk_once(KERN_WARNING
1177 "Filesystem \"%s\": reserve blocks depleted! "
1178 "Consider increasing reserve pool size.",
1180 return XFS_ERROR(ENOSPC);
1183 mp->m_sb.sb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
1185 case XFS_SBS_FREXTENTS:
1186 lcounter = (long long)mp->m_sb.sb_frextents;
1189 return XFS_ERROR(ENOSPC);
1191 mp->m_sb.sb_frextents = lcounter;
1193 case XFS_SBS_DBLOCKS:
1194 lcounter = (long long)mp->m_sb.sb_dblocks;
1198 return XFS_ERROR(EINVAL);
1200 mp->m_sb.sb_dblocks = lcounter;
1202 case XFS_SBS_AGCOUNT:
1203 scounter = mp->m_sb.sb_agcount;
1207 return XFS_ERROR(EINVAL);
1209 mp->m_sb.sb_agcount = scounter;
1211 case XFS_SBS_IMAX_PCT:
1212 scounter = mp->m_sb.sb_imax_pct;
1216 return XFS_ERROR(EINVAL);
1218 mp->m_sb.sb_imax_pct = scounter;
1220 case XFS_SBS_REXTSIZE:
1221 scounter = mp->m_sb.sb_rextsize;
1225 return XFS_ERROR(EINVAL);
1227 mp->m_sb.sb_rextsize = scounter;
1229 case XFS_SBS_RBMBLOCKS:
1230 scounter = mp->m_sb.sb_rbmblocks;
1234 return XFS_ERROR(EINVAL);
1236 mp->m_sb.sb_rbmblocks = scounter;
1238 case XFS_SBS_RBLOCKS:
1239 lcounter = (long long)mp->m_sb.sb_rblocks;
1243 return XFS_ERROR(EINVAL);
1245 mp->m_sb.sb_rblocks = lcounter;
1247 case XFS_SBS_REXTENTS:
1248 lcounter = (long long)mp->m_sb.sb_rextents;
1252 return XFS_ERROR(EINVAL);
1254 mp->m_sb.sb_rextents = lcounter;
1256 case XFS_SBS_REXTSLOG:
1257 scounter = mp->m_sb.sb_rextslog;
1261 return XFS_ERROR(EINVAL);
1263 mp->m_sb.sb_rextslog = scounter;
1267 return XFS_ERROR(EINVAL);
1272 * xfs_mod_incore_sb() is used to change a field in the in-core
1273 * superblock structure by the specified delta. This modification
1274 * is protected by the m_sb_lock. Just use the xfs_mod_incore_sb_unlocked()
1275 * routine to do the work.
1279 struct xfs_mount *mp,
1280 xfs_sb_field_t field,
1286 #ifdef HAVE_PERCPU_SB
1287 ASSERT(field < XFS_SBS_ICOUNT || field > XFS_SBS_FDBLOCKS);
1289 spin_lock(&mp->m_sb_lock);
1290 status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
1291 spin_unlock(&mp->m_sb_lock);
1297 * Change more than one field in the in-core superblock structure at a time.
1299 * The fields and changes to those fields are specified in the array of
1300 * xfs_mod_sb structures passed in. Either all of the specified deltas
1301 * will be applied or none of them will. If any modified field dips below 0,
1302 * then all modifications will be backed out and EINVAL will be returned.
1304 * Note that this function may not be used for the superblock values that
1305 * are tracked with the in-memory per-cpu counters - a direct call to
1306 * xfs_icsb_modify_counters is required for these.
1309 xfs_mod_incore_sb_batch(
1310 struct xfs_mount *mp,
1319 * Loop through the array of mod structures and apply each individually.
1320 * If any fail, then back out all those which have already been applied.
1321 * Do all of this within the scope of the m_sb_lock so that all of the
1322 * changes will be atomic.
1324 spin_lock(&mp->m_sb_lock);
1325 for (msbp = msb; msbp < (msb + nmsb); msbp++) {
1326 ASSERT(msbp->msb_field < XFS_SBS_ICOUNT ||
1327 msbp->msb_field > XFS_SBS_FDBLOCKS);
1329 error = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
1330 msbp->msb_delta, rsvd);
1334 spin_unlock(&mp->m_sb_lock);
1338 while (--msbp >= msb) {
1339 error = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
1340 -msbp->msb_delta, rsvd);
1343 spin_unlock(&mp->m_sb_lock);
1348 * xfs_getsb() is called to obtain the buffer for the superblock.
1349 * The buffer is returned locked and read in from disk.
1350 * The buffer should be released with a call to xfs_brelse().
1352 * If the flags parameter is BUF_TRYLOCK, then we'll only return
1353 * the superblock buffer if it can be locked without sleeping.
1354 * If it can't then we'll return NULL.
1358 struct xfs_mount *mp,
1361 struct xfs_buf *bp = mp->m_sb_bp;
1363 if (!xfs_buf_trylock(bp)) {
1364 if (flags & XBF_TRYLOCK)
1370 ASSERT(XFS_BUF_ISDONE(bp));
1375 * Used to free the superblock along various error paths.
1379 struct xfs_mount *mp)
1381 struct xfs_buf *bp = mp->m_sb_bp;
1389 * Used to log changes to the superblock unit and width fields which could
1390 * be altered by the mount options, as well as any potential sb_features2
1391 * fixup. Only the first superblock is updated.
1401 ASSERT(fields & (XFS_SB_UNIT | XFS_SB_WIDTH | XFS_SB_UUID |
1402 XFS_SB_FEATURES2 | XFS_SB_BAD_FEATURES2 |
1403 XFS_SB_VERSIONNUM));
1405 tp = xfs_trans_alloc(mp, XFS_TRANS_SB_UNIT);
1406 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_sb, 0, 0);
1408 xfs_trans_cancel(tp, 0);
1411 xfs_mod_sb(tp, fields);
1412 error = xfs_trans_commit(tp, 0);
1417 * If the underlying (data/log/rt) device is readonly, there are some
1418 * operations that cannot proceed.
1421 xfs_dev_is_read_only(
1422 struct xfs_mount *mp,
1425 if (xfs_readonly_buftarg(mp->m_ddev_targp) ||
1426 xfs_readonly_buftarg(mp->m_logdev_targp) ||
1427 (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp))) {
1428 xfs_notice(mp, "%s required on read-only device.", message);
1429 xfs_notice(mp, "write access unavailable, cannot proceed.");
1435 #ifdef HAVE_PERCPU_SB
1437 * Per-cpu incore superblock counters
1439 * Simple concept, difficult implementation
1441 * Basically, replace the incore superblock counters with a distributed per cpu
1442 * counter for contended fields (e.g. free block count).
1444 * Difficulties arise in that the incore sb is used for ENOSPC checking, and
1445 * hence needs to be accurately read when we are running low on space. Hence
1446 * there is a method to enable and disable the per-cpu counters based on how
1447 * much "stuff" is available in them.
1449 * Basically, a counter is enabled if there is enough free resource to justify
1450 * running a per-cpu fast-path. If the per-cpu counter runs out (i.e. a local
1451 * ENOSPC), then we disable the counters to synchronise all callers and
1452 * re-distribute the available resources.
1454 * If, once we redistributed the available resources, we still get a failure,
1455 * we disable the per-cpu counter and go through the slow path.
1457 * The slow path is the current xfs_mod_incore_sb() function. This means that
1458 * when we disable a per-cpu counter, we need to drain its resources back to
1459 * the global superblock. We do this after disabling the counter to prevent
1460 * more threads from queueing up on the counter.
1462 * Essentially, this means that we still need a lock in the fast path to enable
1463 * synchronisation between the global counters and the per-cpu counters. This
1464 * is not a problem because the lock will be local to a CPU almost all the time
1465 * and have little contention except when we get to ENOSPC conditions.
1467 * Basically, this lock becomes a barrier that enables us to lock out the fast
1468 * path while we do things like enabling and disabling counters and
1469 * synchronising the counters.
1473 * 1. m_sb_lock before picking up per-cpu locks
1474 * 2. per-cpu locks always picked up via for_each_online_cpu() order
1475 * 3. accurate counter sync requires m_sb_lock + per cpu locks
1476 * 4. modifying per-cpu counters requires holding per-cpu lock
1477 * 5. modifying global counters requires holding m_sb_lock
1478 * 6. enabling or disabling a counter requires holding the m_sb_lock
1479 * and _none_ of the per-cpu locks.
1481 * Disabled counters are only ever re-enabled by a balance operation
1482 * that results in more free resources per CPU than a given threshold.
1483 * To ensure counters don't remain disabled, they are rebalanced when
1484 * the global resource goes above a higher threshold (i.e. some hysteresis
1485 * is present to prevent thrashing).
1488 #ifdef CONFIG_HOTPLUG_CPU
1490 * hot-plug CPU notifier support.
1492 * We need a notifier per filesystem as we need to be able to identify
1493 * the filesystem to balance the counters out. This is achieved by
1494 * having a notifier block embedded in the xfs_mount_t and doing pointer
1495 * magic to get the mount pointer from the notifier block address.
1498 xfs_icsb_cpu_notify(
1499 struct notifier_block *nfb,
1500 unsigned long action,
1503 xfs_icsb_cnts_t *cntp;
1506 mp = (xfs_mount_t *)container_of(nfb, xfs_mount_t, m_icsb_notifier);
1507 cntp = (xfs_icsb_cnts_t *)
1508 per_cpu_ptr(mp->m_sb_cnts, (unsigned long)hcpu);
1510 case CPU_UP_PREPARE:
1511 case CPU_UP_PREPARE_FROZEN:
1512 /* Easy Case - initialize the area and locks, and
1513 * then rebalance when online does everything else for us. */
1514 memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
1517 case CPU_ONLINE_FROZEN:
1519 xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
1520 xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
1521 xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
1522 xfs_icsb_unlock(mp);
1525 case CPU_DEAD_FROZEN:
1526 /* Disable all the counters, then fold the dead cpu's
1527 * count into the total on the global superblock and
1528 * re-enable the counters. */
1530 spin_lock(&mp->m_sb_lock);
1531 xfs_icsb_disable_counter(mp, XFS_SBS_ICOUNT);
1532 xfs_icsb_disable_counter(mp, XFS_SBS_IFREE);
1533 xfs_icsb_disable_counter(mp, XFS_SBS_FDBLOCKS);
1535 mp->m_sb.sb_icount += cntp->icsb_icount;
1536 mp->m_sb.sb_ifree += cntp->icsb_ifree;
1537 mp->m_sb.sb_fdblocks += cntp->icsb_fdblocks;
1539 memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
1541 xfs_icsb_balance_counter_locked(mp, XFS_SBS_ICOUNT, 0);
1542 xfs_icsb_balance_counter_locked(mp, XFS_SBS_IFREE, 0);
1543 xfs_icsb_balance_counter_locked(mp, XFS_SBS_FDBLOCKS, 0);
1544 spin_unlock(&mp->m_sb_lock);
1545 xfs_icsb_unlock(mp);
1551 #endif /* CONFIG_HOTPLUG_CPU */
1554 xfs_icsb_init_counters(
1557 xfs_icsb_cnts_t *cntp;
1560 mp->m_sb_cnts = alloc_percpu(xfs_icsb_cnts_t);
1561 if (mp->m_sb_cnts == NULL)
1564 for_each_online_cpu(i) {
1565 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
1566 memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
1569 mutex_init(&mp->m_icsb_mutex);
1572 * start with all counters disabled so that the
1573 * initial balance kicks us off correctly
1575 mp->m_icsb_counters = -1;
1577 #ifdef CONFIG_HOTPLUG_CPU
1578 mp->m_icsb_notifier.notifier_call = xfs_icsb_cpu_notify;
1579 mp->m_icsb_notifier.priority = 0;
1580 register_hotcpu_notifier(&mp->m_icsb_notifier);
1581 #endif /* CONFIG_HOTPLUG_CPU */
1587 xfs_icsb_reinit_counters(
1592 * start with all counters disabled so that the
1593 * initial balance kicks us off correctly
1595 mp->m_icsb_counters = -1;
1596 xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
1597 xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
1598 xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
1599 xfs_icsb_unlock(mp);
1603 xfs_icsb_destroy_counters(
1606 if (mp->m_sb_cnts) {
1607 unregister_hotcpu_notifier(&mp->m_icsb_notifier);
1608 free_percpu(mp->m_sb_cnts);
1610 mutex_destroy(&mp->m_icsb_mutex);
1615 xfs_icsb_cnts_t *icsbp)
1617 while (test_and_set_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags)) {
1623 xfs_icsb_unlock_cntr(
1624 xfs_icsb_cnts_t *icsbp)
1626 clear_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags);
1631 xfs_icsb_lock_all_counters(
1634 xfs_icsb_cnts_t *cntp;
1637 for_each_online_cpu(i) {
1638 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
1639 xfs_icsb_lock_cntr(cntp);
1644 xfs_icsb_unlock_all_counters(
1647 xfs_icsb_cnts_t *cntp;
1650 for_each_online_cpu(i) {
1651 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
1652 xfs_icsb_unlock_cntr(cntp);
1659 xfs_icsb_cnts_t *cnt,
1662 xfs_icsb_cnts_t *cntp;
1665 memset(cnt, 0, sizeof(xfs_icsb_cnts_t));
1667 if (!(flags & XFS_ICSB_LAZY_COUNT))
1668 xfs_icsb_lock_all_counters(mp);
1670 for_each_online_cpu(i) {
1671 cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
1672 cnt->icsb_icount += cntp->icsb_icount;
1673 cnt->icsb_ifree += cntp->icsb_ifree;
1674 cnt->icsb_fdblocks += cntp->icsb_fdblocks;
1677 if (!(flags & XFS_ICSB_LAZY_COUNT))
1678 xfs_icsb_unlock_all_counters(mp);
1682 xfs_icsb_counter_disabled(
1684 xfs_sb_field_t field)
1686 ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
1687 return test_bit(field, &mp->m_icsb_counters);
1691 xfs_icsb_disable_counter(
1693 xfs_sb_field_t field)
1695 xfs_icsb_cnts_t cnt;
1697 ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
1700 * If we are already disabled, then there is nothing to do
1701 * here. We check before locking all the counters to avoid
1702 * the expensive lock operation when being called in the
1703 * slow path and the counter is already disabled. This is
1704 * safe because the only time we set or clear this state is under
1707 if (xfs_icsb_counter_disabled(mp, field))
1710 xfs_icsb_lock_all_counters(mp);
1711 if (!test_and_set_bit(field, &mp->m_icsb_counters)) {
1712 /* drain back to superblock */
1714 xfs_icsb_count(mp, &cnt, XFS_ICSB_LAZY_COUNT);
1716 case XFS_SBS_ICOUNT:
1717 mp->m_sb.sb_icount = cnt.icsb_icount;
1720 mp->m_sb.sb_ifree = cnt.icsb_ifree;
1722 case XFS_SBS_FDBLOCKS:
1723 mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
1730 xfs_icsb_unlock_all_counters(mp);
1734 xfs_icsb_enable_counter(
1736 xfs_sb_field_t field,
1740 xfs_icsb_cnts_t *cntp;
1743 ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
1745 xfs_icsb_lock_all_counters(mp);
1746 for_each_online_cpu(i) {
1747 cntp = per_cpu_ptr(mp->m_sb_cnts, i);
1749 case XFS_SBS_ICOUNT:
1750 cntp->icsb_icount = count + resid;
1753 cntp->icsb_ifree = count + resid;
1755 case XFS_SBS_FDBLOCKS:
1756 cntp->icsb_fdblocks = count + resid;
1764 clear_bit(field, &mp->m_icsb_counters);
1765 xfs_icsb_unlock_all_counters(mp);
1769 xfs_icsb_sync_counters_locked(
1773 xfs_icsb_cnts_t cnt;
1775 xfs_icsb_count(mp, &cnt, flags);
1777 if (!xfs_icsb_counter_disabled(mp, XFS_SBS_ICOUNT))
1778 mp->m_sb.sb_icount = cnt.icsb_icount;
1779 if (!xfs_icsb_counter_disabled(mp, XFS_SBS_IFREE))
1780 mp->m_sb.sb_ifree = cnt.icsb_ifree;
1781 if (!xfs_icsb_counter_disabled(mp, XFS_SBS_FDBLOCKS))
1782 mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
1786 * Accurate update of per-cpu counters to incore superblock
1789 xfs_icsb_sync_counters(
1793 spin_lock(&mp->m_sb_lock);
1794 xfs_icsb_sync_counters_locked(mp, flags);
1795 spin_unlock(&mp->m_sb_lock);
1799 * Balance and enable/disable counters as necessary.
1801 * Thresholds for re-enabling counters are somewhat magic. inode counts are
1802 * chosen to be the same number as single on disk allocation chunk per CPU, and
1803 * free blocks is something far enough zero that we aren't going thrash when we
1804 * get near ENOSPC. We also need to supply a minimum we require per cpu to
1805 * prevent looping endlessly when xfs_alloc_space asks for more than will
1806 * be distributed to a single CPU but each CPU has enough blocks to be
1809 * Note that we can be called when counters are already disabled.
1810 * xfs_icsb_disable_counter() optimises the counter locking in this case to
1811 * prevent locking every per-cpu counter needlessly.
1814 #define XFS_ICSB_INO_CNTR_REENABLE (uint64_t)64
1815 #define XFS_ICSB_FDBLK_CNTR_REENABLE(mp) \
1816 (uint64_t)(512 + XFS_ALLOC_SET_ASIDE(mp))
1818 xfs_icsb_balance_counter_locked(
1820 xfs_sb_field_t field,
1823 uint64_t count, resid;
1824 int weight = num_online_cpus();
1825 uint64_t min = (uint64_t)min_per_cpu;
1827 /* disable counter and sync counter */
1828 xfs_icsb_disable_counter(mp, field);
1830 /* update counters - first CPU gets residual*/
1832 case XFS_SBS_ICOUNT:
1833 count = mp->m_sb.sb_icount;
1834 resid = do_div(count, weight);
1835 if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE))
1839 count = mp->m_sb.sb_ifree;
1840 resid = do_div(count, weight);
1841 if (count < max(min, XFS_ICSB_INO_CNTR_REENABLE))
1844 case XFS_SBS_FDBLOCKS:
1845 count = mp->m_sb.sb_fdblocks;
1846 resid = do_div(count, weight);
1847 if (count < max(min, XFS_ICSB_FDBLK_CNTR_REENABLE(mp)))
1852 count = resid = 0; /* quiet, gcc */
1856 xfs_icsb_enable_counter(mp, field, count, resid);
1860 xfs_icsb_balance_counter(
1862 xfs_sb_field_t fields,
1865 spin_lock(&mp->m_sb_lock);
1866 xfs_icsb_balance_counter_locked(mp, fields, min_per_cpu);
1867 spin_unlock(&mp->m_sb_lock);
1871 xfs_icsb_modify_counters(
1873 xfs_sb_field_t field,
1877 xfs_icsb_cnts_t *icsbp;
1878 long long lcounter; /* long counter for 64 bit fields */
1884 icsbp = this_cpu_ptr(mp->m_sb_cnts);
1887 * if the counter is disabled, go to slow path
1889 if (unlikely(xfs_icsb_counter_disabled(mp, field)))
1891 xfs_icsb_lock_cntr(icsbp);
1892 if (unlikely(xfs_icsb_counter_disabled(mp, field))) {
1893 xfs_icsb_unlock_cntr(icsbp);
1898 case XFS_SBS_ICOUNT:
1899 lcounter = icsbp->icsb_icount;
1901 if (unlikely(lcounter < 0))
1902 goto balance_counter;
1903 icsbp->icsb_icount = lcounter;
1907 lcounter = icsbp->icsb_ifree;
1909 if (unlikely(lcounter < 0))
1910 goto balance_counter;
1911 icsbp->icsb_ifree = lcounter;
1914 case XFS_SBS_FDBLOCKS:
1915 BUG_ON((mp->m_resblks - mp->m_resblks_avail) != 0);
1917 lcounter = icsbp->icsb_fdblocks - XFS_ALLOC_SET_ASIDE(mp);
1919 if (unlikely(lcounter < 0))
1920 goto balance_counter;
1921 icsbp->icsb_fdblocks = lcounter + XFS_ALLOC_SET_ASIDE(mp);
1927 xfs_icsb_unlock_cntr(icsbp);
1935 * serialise with a mutex so we don't burn lots of cpu on
1936 * the superblock lock. We still need to hold the superblock
1937 * lock, however, when we modify the global structures.
1942 * Now running atomically.
1944 * If the counter is enabled, someone has beaten us to rebalancing.
1945 * Drop the lock and try again in the fast path....
1947 if (!(xfs_icsb_counter_disabled(mp, field))) {
1948 xfs_icsb_unlock(mp);
1953 * The counter is currently disabled. Because we are
1954 * running atomically here, we know a rebalance cannot
1955 * be in progress. Hence we can go straight to operating
1956 * on the global superblock. We do not call xfs_mod_incore_sb()
1957 * here even though we need to get the m_sb_lock. Doing so
1958 * will cause us to re-enter this function and deadlock.
1959 * Hence we get the m_sb_lock ourselves and then call
1960 * xfs_mod_incore_sb_unlocked() as the unlocked path operates
1961 * directly on the global counters.
1963 spin_lock(&mp->m_sb_lock);
1964 ret = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
1965 spin_unlock(&mp->m_sb_lock);
1968 * Now that we've modified the global superblock, we
1969 * may be able to re-enable the distributed counters
1970 * (e.g. lots of space just got freed). After that
1974 xfs_icsb_balance_counter(mp, field, 0);
1975 xfs_icsb_unlock(mp);
1979 xfs_icsb_unlock_cntr(icsbp);
1983 * We may have multiple threads here if multiple per-cpu
1984 * counters run dry at the same time. This will mean we can
1985 * do more balances than strictly necessary but it is not
1986 * the common slowpath case.
1991 * running atomically.
1993 * This will leave the counter in the correct state for future
1994 * accesses. After the rebalance, we simply try again and our retry
1995 * will either succeed through the fast path or slow path without
1996 * another balance operation being required.
1998 xfs_icsb_balance_counter(mp, field, delta);
1999 xfs_icsb_unlock(mp);