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"
26 #include "xfs_mount.h"
27 #include "xfs_da_format.h"
28 #include "xfs_da_btree.h"
29 #include "xfs_inode.h"
31 #include "xfs_ialloc.h"
32 #include "xfs_alloc.h"
33 #include "xfs_rtalloc.h"
35 #include "xfs_trans.h"
36 #include "xfs_trans_priv.h"
38 #include "xfs_error.h"
39 #include "xfs_quota.h"
40 #include "xfs_fsops.h"
41 #include "xfs_trace.h"
42 #include "xfs_icache.h"
43 #include "xfs_sysfs.h"
47 STATIC
void xfs_icsb_balance_counter(xfs_mount_t
*, xfs_sb_field_t
,
49 STATIC
void xfs_icsb_balance_counter_locked(xfs_mount_t
*, xfs_sb_field_t
,
51 STATIC
void xfs_icsb_disable_counter(xfs_mount_t
*, xfs_sb_field_t
);
54 #define xfs_icsb_balance_counter(mp, a, b) do { } while (0)
55 #define xfs_icsb_balance_counter_locked(mp, a, b) do { } while (0)
58 static DEFINE_MUTEX(xfs_uuid_table_mutex
);
59 static int xfs_uuid_table_size
;
60 static uuid_t
*xfs_uuid_table
;
63 * See if the UUID is unique among mounted XFS filesystems.
64 * Mount fails if UUID is nil or a FS with the same UUID is already mounted.
70 uuid_t
*uuid
= &mp
->m_sb
.sb_uuid
;
73 if (mp
->m_flags
& XFS_MOUNT_NOUUID
)
76 if (uuid_is_nil(uuid
)) {
77 xfs_warn(mp
, "Filesystem has nil UUID - can't mount");
81 mutex_lock(&xfs_uuid_table_mutex
);
82 for (i
= 0, hole
= -1; i
< xfs_uuid_table_size
; i
++) {
83 if (uuid_is_nil(&xfs_uuid_table
[i
])) {
87 if (uuid_equal(uuid
, &xfs_uuid_table
[i
]))
92 xfs_uuid_table
= kmem_realloc(xfs_uuid_table
,
93 (xfs_uuid_table_size
+ 1) * sizeof(*xfs_uuid_table
),
94 xfs_uuid_table_size
* sizeof(*xfs_uuid_table
),
96 hole
= xfs_uuid_table_size
++;
98 xfs_uuid_table
[hole
] = *uuid
;
99 mutex_unlock(&xfs_uuid_table_mutex
);
104 mutex_unlock(&xfs_uuid_table_mutex
);
105 xfs_warn(mp
, "Filesystem has duplicate UUID %pU - can't mount", uuid
);
111 struct xfs_mount
*mp
)
113 uuid_t
*uuid
= &mp
->m_sb
.sb_uuid
;
116 if (mp
->m_flags
& XFS_MOUNT_NOUUID
)
119 mutex_lock(&xfs_uuid_table_mutex
);
120 for (i
= 0; i
< xfs_uuid_table_size
; i
++) {
121 if (uuid_is_nil(&xfs_uuid_table
[i
]))
123 if (!uuid_equal(uuid
, &xfs_uuid_table
[i
]))
125 memset(&xfs_uuid_table
[i
], 0, sizeof(uuid_t
));
128 ASSERT(i
< xfs_uuid_table_size
);
129 mutex_unlock(&xfs_uuid_table_mutex
);
135 struct rcu_head
*head
)
137 struct xfs_perag
*pag
= container_of(head
, struct xfs_perag
, rcu_head
);
139 ASSERT(atomic_read(&pag
->pag_ref
) == 0);
144 * Free up the per-ag resources associated with the mount structure.
151 struct xfs_perag
*pag
;
153 for (agno
= 0; agno
< mp
->m_sb
.sb_agcount
; agno
++) {
154 spin_lock(&mp
->m_perag_lock
);
155 pag
= radix_tree_delete(&mp
->m_perag_tree
, agno
);
156 spin_unlock(&mp
->m_perag_lock
);
158 ASSERT(atomic_read(&pag
->pag_ref
) == 0);
159 call_rcu(&pag
->rcu_head
, __xfs_free_perag
);
164 * Check size of device based on the (data/realtime) block count.
165 * Note: this check is used by the growfs code as well as mount.
168 xfs_sb_validate_fsb_count(
172 ASSERT(PAGE_SHIFT
>= sbp
->sb_blocklog
);
173 ASSERT(sbp
->sb_blocklog
>= BBSHIFT
);
175 /* Limited by ULONG_MAX of page cache index */
176 if (nblocks
>> (PAGE_CACHE_SHIFT
- sbp
->sb_blocklog
) > ULONG_MAX
)
182 xfs_initialize_perag(
184 xfs_agnumber_t agcount
,
185 xfs_agnumber_t
*maxagi
)
187 xfs_agnumber_t index
;
188 xfs_agnumber_t first_initialised
= 0;
192 xfs_sb_t
*sbp
= &mp
->m_sb
;
196 * Walk the current per-ag tree so we don't try to initialise AGs
197 * that already exist (growfs case). Allocate and insert all the
198 * AGs we don't find ready for initialisation.
200 for (index
= 0; index
< agcount
; index
++) {
201 pag
= xfs_perag_get(mp
, index
);
206 if (!first_initialised
)
207 first_initialised
= index
;
209 pag
= kmem_zalloc(sizeof(*pag
), KM_MAYFAIL
);
212 pag
->pag_agno
= index
;
214 spin_lock_init(&pag
->pag_ici_lock
);
215 mutex_init(&pag
->pag_ici_reclaim_lock
);
216 INIT_RADIX_TREE(&pag
->pag_ici_root
, GFP_ATOMIC
);
217 spin_lock_init(&pag
->pag_buf_lock
);
218 pag
->pag_buf_tree
= RB_ROOT
;
220 if (radix_tree_preload(GFP_NOFS
))
223 spin_lock(&mp
->m_perag_lock
);
224 if (radix_tree_insert(&mp
->m_perag_tree
, index
, pag
)) {
226 spin_unlock(&mp
->m_perag_lock
);
227 radix_tree_preload_end();
231 spin_unlock(&mp
->m_perag_lock
);
232 radix_tree_preload_end();
236 * If we mount with the inode64 option, or no inode overflows
237 * the legacy 32-bit address space clear the inode32 option.
239 agino
= XFS_OFFBNO_TO_AGINO(mp
, sbp
->sb_agblocks
- 1, 0);
240 ino
= XFS_AGINO_TO_INO(mp
, agcount
- 1, agino
);
242 if ((mp
->m_flags
& XFS_MOUNT_SMALL_INUMS
) && ino
> XFS_MAXINUMBER_32
)
243 mp
->m_flags
|= XFS_MOUNT_32BITINODES
;
245 mp
->m_flags
&= ~XFS_MOUNT_32BITINODES
;
247 if (mp
->m_flags
& XFS_MOUNT_32BITINODES
)
248 index
= xfs_set_inode32(mp
, agcount
);
250 index
= xfs_set_inode64(mp
, agcount
);
258 for (; index
> first_initialised
; index
--) {
259 pag
= radix_tree_delete(&mp
->m_perag_tree
, index
);
268 * Does the initial read of the superblock.
272 struct xfs_mount
*mp
,
275 unsigned int sector_size
;
277 struct xfs_sb
*sbp
= &mp
->m_sb
;
279 int loud
= !(flags
& XFS_MFSI_QUIET
);
280 const struct xfs_buf_ops
*buf_ops
;
282 ASSERT(mp
->m_sb_bp
== NULL
);
283 ASSERT(mp
->m_ddev_targp
!= NULL
);
286 * For the initial read, we must guess at the sector
287 * size based on the block device. It's enough to
288 * get the sb_sectsize out of the superblock and
289 * then reread with the proper length.
290 * We don't verify it yet, because it may not be complete.
292 sector_size
= xfs_getsize_buftarg(mp
->m_ddev_targp
);
296 * Allocate a (locked) buffer to hold the superblock.
297 * This will be kept around at all times to optimize
298 * access to the superblock.
301 error
= xfs_buf_read_uncached(mp
->m_ddev_targp
, XFS_SB_DADDR
,
302 BTOBB(sector_size
), 0, &bp
, buf_ops
);
305 xfs_warn(mp
, "SB validate failed with error %d.", error
);
306 /* bad CRC means corrupted metadata */
307 if (error
== -EFSBADCRC
)
308 error
= -EFSCORRUPTED
;
313 * Initialize the mount structure from the superblock.
315 xfs_sb_from_disk(sbp
, XFS_BUF_TO_SBP(bp
));
318 * If we haven't validated the superblock, do so now before we try
319 * to check the sector size and reread the superblock appropriately.
321 if (sbp
->sb_magicnum
!= XFS_SB_MAGIC
) {
323 xfs_warn(mp
, "Invalid superblock magic number");
329 * We must be able to do sector-sized and sector-aligned IO.
331 if (sector_size
> sbp
->sb_sectsize
) {
333 xfs_warn(mp
, "device supports %u byte sectors (not %u)",
334 sector_size
, sbp
->sb_sectsize
);
339 if (buf_ops
== NULL
) {
341 * Re-read the superblock so the buffer is correctly sized,
342 * and properly verified.
345 sector_size
= sbp
->sb_sectsize
;
346 buf_ops
= loud
? &xfs_sb_buf_ops
: &xfs_sb_quiet_buf_ops
;
350 /* Initialize per-cpu counters */
351 xfs_icsb_reinit_counters(mp
);
353 /* no need to be quiet anymore, so reset the buf ops */
354 bp
->b_ops
= &xfs_sb_buf_ops
;
366 * Update alignment values based on mount options and sb values
369 xfs_update_alignment(xfs_mount_t
*mp
)
371 xfs_sb_t
*sbp
= &(mp
->m_sb
);
375 * If stripe unit and stripe width are not multiples
376 * of the fs blocksize turn off alignment.
378 if ((BBTOB(mp
->m_dalign
) & mp
->m_blockmask
) ||
379 (BBTOB(mp
->m_swidth
) & mp
->m_blockmask
)) {
381 "alignment check failed: sunit/swidth vs. blocksize(%d)",
386 * Convert the stripe unit and width to FSBs.
388 mp
->m_dalign
= XFS_BB_TO_FSBT(mp
, mp
->m_dalign
);
389 if (mp
->m_dalign
&& (sbp
->sb_agblocks
% mp
->m_dalign
)) {
391 "alignment check failed: sunit/swidth vs. agsize(%d)",
394 } else if (mp
->m_dalign
) {
395 mp
->m_swidth
= XFS_BB_TO_FSBT(mp
, mp
->m_swidth
);
398 "alignment check failed: sunit(%d) less than bsize(%d)",
399 mp
->m_dalign
, sbp
->sb_blocksize
);
405 * Update superblock with new values
408 if (xfs_sb_version_hasdalign(sbp
)) {
409 if (sbp
->sb_unit
!= mp
->m_dalign
) {
410 sbp
->sb_unit
= mp
->m_dalign
;
411 mp
->m_update_sb
= true;
413 if (sbp
->sb_width
!= mp
->m_swidth
) {
414 sbp
->sb_width
= mp
->m_swidth
;
415 mp
->m_update_sb
= true;
419 "cannot change alignment: superblock does not support data alignment");
422 } else if ((mp
->m_flags
& XFS_MOUNT_NOALIGN
) != XFS_MOUNT_NOALIGN
&&
423 xfs_sb_version_hasdalign(&mp
->m_sb
)) {
424 mp
->m_dalign
= sbp
->sb_unit
;
425 mp
->m_swidth
= sbp
->sb_width
;
432 * Set the maximum inode count for this filesystem
435 xfs_set_maxicount(xfs_mount_t
*mp
)
437 xfs_sb_t
*sbp
= &(mp
->m_sb
);
440 if (sbp
->sb_imax_pct
) {
442 * Make sure the maximum inode count is a multiple
443 * of the units we allocate inodes in.
445 icount
= sbp
->sb_dblocks
* sbp
->sb_imax_pct
;
447 do_div(icount
, mp
->m_ialloc_blks
);
448 mp
->m_maxicount
= (icount
* mp
->m_ialloc_blks
) <<
456 * Set the default minimum read and write sizes unless
457 * already specified in a mount option.
458 * We use smaller I/O sizes when the file system
459 * is being used for NFS service (wsync mount option).
462 xfs_set_rw_sizes(xfs_mount_t
*mp
)
464 xfs_sb_t
*sbp
= &(mp
->m_sb
);
465 int readio_log
, writeio_log
;
467 if (!(mp
->m_flags
& XFS_MOUNT_DFLT_IOSIZE
)) {
468 if (mp
->m_flags
& XFS_MOUNT_WSYNC
) {
469 readio_log
= XFS_WSYNC_READIO_LOG
;
470 writeio_log
= XFS_WSYNC_WRITEIO_LOG
;
472 readio_log
= XFS_READIO_LOG_LARGE
;
473 writeio_log
= XFS_WRITEIO_LOG_LARGE
;
476 readio_log
= mp
->m_readio_log
;
477 writeio_log
= mp
->m_writeio_log
;
480 if (sbp
->sb_blocklog
> readio_log
) {
481 mp
->m_readio_log
= sbp
->sb_blocklog
;
483 mp
->m_readio_log
= readio_log
;
485 mp
->m_readio_blocks
= 1 << (mp
->m_readio_log
- sbp
->sb_blocklog
);
486 if (sbp
->sb_blocklog
> writeio_log
) {
487 mp
->m_writeio_log
= sbp
->sb_blocklog
;
489 mp
->m_writeio_log
= writeio_log
;
491 mp
->m_writeio_blocks
= 1 << (mp
->m_writeio_log
- sbp
->sb_blocklog
);
495 * precalculate the low space thresholds for dynamic speculative preallocation.
498 xfs_set_low_space_thresholds(
499 struct xfs_mount
*mp
)
503 for (i
= 0; i
< XFS_LOWSP_MAX
; i
++) {
504 __uint64_t space
= mp
->m_sb
.sb_dblocks
;
507 mp
->m_low_space
[i
] = space
* (i
+ 1);
513 * Set whether we're using inode alignment.
516 xfs_set_inoalignment(xfs_mount_t
*mp
)
518 if (xfs_sb_version_hasalign(&mp
->m_sb
) &&
519 mp
->m_sb
.sb_inoalignmt
>=
520 XFS_B_TO_FSBT(mp
, mp
->m_inode_cluster_size
))
521 mp
->m_inoalign_mask
= mp
->m_sb
.sb_inoalignmt
- 1;
523 mp
->m_inoalign_mask
= 0;
525 * If we are using stripe alignment, check whether
526 * the stripe unit is a multiple of the inode alignment
528 if (mp
->m_dalign
&& mp
->m_inoalign_mask
&&
529 !(mp
->m_dalign
& mp
->m_inoalign_mask
))
530 mp
->m_sinoalign
= mp
->m_dalign
;
536 * Check that the data (and log if separate) is an ok size.
540 struct xfs_mount
*mp
)
546 d
= (xfs_daddr_t
)XFS_FSB_TO_BB(mp
, mp
->m_sb
.sb_dblocks
);
547 if (XFS_BB_TO_FSB(mp
, d
) != mp
->m_sb
.sb_dblocks
) {
548 xfs_warn(mp
, "filesystem size mismatch detected");
551 error
= xfs_buf_read_uncached(mp
->m_ddev_targp
,
552 d
- XFS_FSS_TO_BB(mp
, 1),
553 XFS_FSS_TO_BB(mp
, 1), 0, &bp
, NULL
);
555 xfs_warn(mp
, "last sector read failed");
560 if (mp
->m_logdev_targp
== mp
->m_ddev_targp
)
563 d
= (xfs_daddr_t
)XFS_FSB_TO_BB(mp
, mp
->m_sb
.sb_logblocks
);
564 if (XFS_BB_TO_FSB(mp
, d
) != mp
->m_sb
.sb_logblocks
) {
565 xfs_warn(mp
, "log size mismatch detected");
568 error
= xfs_buf_read_uncached(mp
->m_logdev_targp
,
569 d
- XFS_FSB_TO_BB(mp
, 1),
570 XFS_FSB_TO_BB(mp
, 1), 0, &bp
, NULL
);
572 xfs_warn(mp
, "log device read failed");
580 * Clear the quotaflags in memory and in the superblock.
583 xfs_mount_reset_sbqflags(
584 struct xfs_mount
*mp
)
588 /* It is OK to look at sb_qflags in the mount path without m_sb_lock. */
589 if (mp
->m_sb
.sb_qflags
== 0)
591 spin_lock(&mp
->m_sb_lock
);
592 mp
->m_sb
.sb_qflags
= 0;
593 spin_unlock(&mp
->m_sb_lock
);
595 if (!xfs_fs_writable(mp
, SB_FREEZE_WRITE
))
598 return xfs_sync_sb(mp
, false);
602 xfs_default_resblks(xfs_mount_t
*mp
)
607 * We default to 5% or 8192 fsbs of space reserved, whichever is
608 * smaller. This is intended to cover concurrent allocation
609 * transactions when we initially hit enospc. These each require a 4
610 * block reservation. Hence by default we cover roughly 2000 concurrent
611 * allocation reservations.
613 resblks
= mp
->m_sb
.sb_dblocks
;
615 resblks
= min_t(__uint64_t
, resblks
, 8192);
620 * This function does the following on an initial mount of a file system:
621 * - reads the superblock from disk and init the mount struct
622 * - if we're a 32-bit kernel, do a size check on the superblock
623 * so we don't mount terabyte filesystems
624 * - init mount struct realtime fields
625 * - allocate inode hash table for fs
626 * - init directory manager
627 * - perform recovery and init the log manager
633 xfs_sb_t
*sbp
= &(mp
->m_sb
);
640 xfs_sb_mount_common(mp
, sbp
);
643 * Check for a mismatched features2 values. Older kernels read & wrote
644 * into the wrong sb offset for sb_features2 on some platforms due to
645 * xfs_sb_t not being 64bit size aligned when sb_features2 was added,
646 * which made older superblock reading/writing routines swap it as a
649 * For backwards compatibility, we make both slots equal.
651 * If we detect a mismatched field, we OR the set bits into the existing
652 * features2 field in case it has already been modified; we don't want
653 * to lose any features. We then update the bad location with the ORed
654 * value so that older kernels will see any features2 flags. The
655 * superblock writeback code ensures the new sb_features2 is copied to
656 * sb_bad_features2 before it is logged or written to disk.
658 if (xfs_sb_has_mismatched_features2(sbp
)) {
659 xfs_warn(mp
, "correcting sb_features alignment problem");
660 sbp
->sb_features2
|= sbp
->sb_bad_features2
;
661 mp
->m_update_sb
= true;
664 * Re-check for ATTR2 in case it was found in bad_features2
667 if (xfs_sb_version_hasattr2(&mp
->m_sb
) &&
668 !(mp
->m_flags
& XFS_MOUNT_NOATTR2
))
669 mp
->m_flags
|= XFS_MOUNT_ATTR2
;
672 if (xfs_sb_version_hasattr2(&mp
->m_sb
) &&
673 (mp
->m_flags
& XFS_MOUNT_NOATTR2
)) {
674 xfs_sb_version_removeattr2(&mp
->m_sb
);
675 mp
->m_update_sb
= true;
677 /* update sb_versionnum for the clearing of the morebits */
678 if (!sbp
->sb_features2
)
679 mp
->m_update_sb
= true;
682 /* always use v2 inodes by default now */
683 if (!(mp
->m_sb
.sb_versionnum
& XFS_SB_VERSION_NLINKBIT
)) {
684 mp
->m_sb
.sb_versionnum
|= XFS_SB_VERSION_NLINKBIT
;
685 mp
->m_update_sb
= true;
689 * Check if sb_agblocks is aligned at stripe boundary
690 * If sb_agblocks is NOT aligned turn off m_dalign since
691 * allocator alignment is within an ag, therefore ag has
692 * to be aligned at stripe boundary.
694 error
= xfs_update_alignment(mp
);
698 xfs_alloc_compute_maxlevels(mp
);
699 xfs_bmap_compute_maxlevels(mp
, XFS_DATA_FORK
);
700 xfs_bmap_compute_maxlevels(mp
, XFS_ATTR_FORK
);
701 xfs_ialloc_compute_maxlevels(mp
);
703 xfs_set_maxicount(mp
);
705 error
= xfs_sysfs_init(&mp
->m_kobj
, &xfs_mp_ktype
, NULL
, mp
->m_fsname
);
709 error
= xfs_uuid_mount(mp
);
711 goto out_remove_sysfs
;
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
;
741 * Set inode alignment fields
743 xfs_set_inoalignment(mp
);
746 * Check that the data (and log if separate) is an ok size.
748 error
= xfs_check_sizes(mp
);
750 goto out_remove_uuid
;
753 * Initialize realtime fields in the mount structure
755 error
= xfs_rtmount_init(mp
);
757 xfs_warn(mp
, "RT mount failed");
758 goto out_remove_uuid
;
762 * Copies the low order bits of the timestamp and the randomly
763 * set "sequence" number out of a UUID.
765 uuid_getnodeuniq(&sbp
->sb_uuid
, mp
->m_fixedfsid
);
767 mp
->m_dmevmask
= 0; /* not persistent; set after each mount */
769 error
= xfs_da_mount(mp
);
771 xfs_warn(mp
, "Failed dir/attr init: %d", error
);
772 goto out_remove_uuid
;
776 * Initialize the precomputed transaction reservations values.
781 * Allocate and initialize the per-ag data.
783 spin_lock_init(&mp
->m_perag_lock
);
784 INIT_RADIX_TREE(&mp
->m_perag_tree
, GFP_ATOMIC
);
785 error
= xfs_initialize_perag(mp
, sbp
->sb_agcount
, &mp
->m_maxagi
);
787 xfs_warn(mp
, "Failed per-ag init: %d", error
);
791 if (!sbp
->sb_logblocks
) {
792 xfs_warn(mp
, "no log defined");
793 XFS_ERROR_REPORT("xfs_mountfs", XFS_ERRLEVEL_LOW
, mp
);
794 error
= -EFSCORRUPTED
;
799 * log's mount-time initialization. Perform 1st part recovery if needed
801 error
= xfs_log_mount(mp
, mp
->m_logdev_targp
,
802 XFS_FSB_TO_DADDR(mp
, sbp
->sb_logstart
),
803 XFS_FSB_TO_BB(mp
, sbp
->sb_logblocks
));
805 xfs_warn(mp
, "log mount failed");
810 * Now the log is mounted, we know if it was an unclean shutdown or
811 * not. If it was, with the first phase of recovery has completed, we
812 * have consistent AG blocks on disk. We have not recovered EFIs yet,
813 * but they are recovered transactionally in the second recovery phase
816 * Hence we can safely re-initialise incore superblock counters from
817 * the per-ag data. These may not be correct if the filesystem was not
818 * cleanly unmounted, so we need to wait for recovery to finish before
821 * If the filesystem was cleanly unmounted, then we can trust the
822 * values in the superblock to be correct and we don't need to do
825 * If we are currently making the filesystem, the initialisation will
826 * fail as the perag data is in an undefined state.
828 if (xfs_sb_version_haslazysbcount(&mp
->m_sb
) &&
829 !XFS_LAST_UNMOUNT_WAS_CLEAN(mp
) &&
830 !mp
->m_sb
.sb_inprogress
) {
831 error
= xfs_initialize_perag_data(mp
, sbp
->sb_agcount
);
833 goto out_log_dealloc
;
837 * Get and sanity-check the root inode.
838 * Save the pointer to it in the mount structure.
840 error
= xfs_iget(mp
, NULL
, sbp
->sb_rootino
, 0, XFS_ILOCK_EXCL
, &rip
);
842 xfs_warn(mp
, "failed to read root inode");
843 goto out_log_dealloc
;
848 if (unlikely(!S_ISDIR(rip
->i_d
.di_mode
))) {
849 xfs_warn(mp
, "corrupted root inode %llu: not a directory",
850 (unsigned long long)rip
->i_ino
);
851 xfs_iunlock(rip
, XFS_ILOCK_EXCL
);
852 XFS_ERROR_REPORT("xfs_mountfs_int(2)", XFS_ERRLEVEL_LOW
,
854 error
= -EFSCORRUPTED
;
857 mp
->m_rootip
= rip
; /* save it */
859 xfs_iunlock(rip
, XFS_ILOCK_EXCL
);
862 * Initialize realtime inode pointers in the mount structure
864 error
= xfs_rtmount_inodes(mp
);
867 * Free up the root inode.
869 xfs_warn(mp
, "failed to read RT inodes");
874 * If this is a read-only mount defer the superblock updates until
875 * the next remount into writeable mode. Otherwise we would never
876 * perform the update e.g. for the root filesystem.
878 if (mp
->m_update_sb
&& !(mp
->m_flags
& XFS_MOUNT_RDONLY
)) {
879 error
= xfs_sync_sb(mp
, false);
881 xfs_warn(mp
, "failed to write sb changes");
887 * Initialise the XFS quota management subsystem for this mount
889 if (XFS_IS_QUOTA_RUNNING(mp
)) {
890 error
= xfs_qm_newmount(mp
, "amount
, "aflags
);
894 ASSERT(!XFS_IS_QUOTA_ON(mp
));
897 * If a file system had quotas running earlier, but decided to
898 * mount without -o uquota/pquota/gquota options, revoke the
899 * quotachecked license.
901 if (mp
->m_sb
.sb_qflags
& XFS_ALL_QUOTA_ACCT
) {
902 xfs_notice(mp
, "resetting quota flags");
903 error
= xfs_mount_reset_sbqflags(mp
);
910 * Finish recovering the file system. This part needed to be
911 * delayed until after the root and real-time bitmap inodes
912 * were consistently read in.
914 error
= xfs_log_mount_finish(mp
);
916 xfs_warn(mp
, "log mount finish failed");
921 * Complete the quota initialisation, post-log-replay component.
924 ASSERT(mp
->m_qflags
== 0);
925 mp
->m_qflags
= quotaflags
;
927 xfs_qm_mount_quotas(mp
);
931 * Now we are mounted, reserve a small amount of unused space for
932 * privileged transactions. This is needed so that transaction
933 * space required for critical operations can dip into this pool
934 * when at ENOSPC. This is needed for operations like create with
935 * attr, unwritten extent conversion at ENOSPC, etc. Data allocations
936 * are not allowed to use this reserved space.
938 * This may drive us straight to ENOSPC on mount, but that implies
939 * we were already there on the last unmount. Warn if this occurs.
941 if (!(mp
->m_flags
& XFS_MOUNT_RDONLY
)) {
942 resblks
= xfs_default_resblks(mp
);
943 error
= xfs_reserve_blocks(mp
, &resblks
, NULL
);
946 "Unable to allocate reserve blocks. Continuing without reserve pool.");
952 xfs_rtunmount_inodes(mp
);
958 if (mp
->m_logdev_targp
&& mp
->m_logdev_targp
!= mp
->m_ddev_targp
)
959 xfs_wait_buftarg(mp
->m_logdev_targp
);
960 xfs_wait_buftarg(mp
->m_ddev_targp
);
966 xfs_uuid_unmount(mp
);
968 xfs_sysfs_del(&mp
->m_kobj
);
974 * This flushes out the inodes,dquots and the superblock, unmounts the
975 * log and makes sure that incore structures are freed.
979 struct xfs_mount
*mp
)
984 cancel_delayed_work_sync(&mp
->m_eofblocks_work
);
986 xfs_qm_unmount_quotas(mp
);
987 xfs_rtunmount_inodes(mp
);
991 * We can potentially deadlock here if we have an inode cluster
992 * that has been freed has its buffer still pinned in memory because
993 * the transaction is still sitting in a iclog. The stale inodes
994 * on that buffer will have their flush locks held until the
995 * transaction hits the disk and the callbacks run. the inode
996 * flush takes the flush lock unconditionally and with nothing to
997 * push out the iclog we will never get that unlocked. hence we
998 * need to force the log first.
1000 xfs_log_force(mp
, XFS_LOG_SYNC
);
1003 * Flush all pending changes from the AIL.
1005 xfs_ail_push_all_sync(mp
->m_ail
);
1008 * And reclaim all inodes. At this point there should be no dirty
1009 * inodes and none should be pinned or locked, but use synchronous
1010 * reclaim just to be sure. We can stop background inode reclaim
1011 * here as well if it is still running.
1013 cancel_delayed_work_sync(&mp
->m_reclaim_work
);
1014 xfs_reclaim_inodes(mp
, SYNC_WAIT
);
1019 * Unreserve any blocks we have so that when we unmount we don't account
1020 * the reserved free space as used. This is really only necessary for
1021 * lazy superblock counting because it trusts the incore superblock
1022 * counters to be absolutely correct on clean unmount.
1024 * We don't bother correcting this elsewhere for lazy superblock
1025 * counting because on mount of an unclean filesystem we reconstruct the
1026 * correct counter value and this is irrelevant.
1028 * For non-lazy counter filesystems, this doesn't matter at all because
1029 * we only every apply deltas to the superblock and hence the incore
1030 * value does not matter....
1033 error
= xfs_reserve_blocks(mp
, &resblks
, NULL
);
1035 xfs_warn(mp
, "Unable to free reserved block pool. "
1036 "Freespace may not be correct on next mount.");
1038 error
= xfs_log_sbcount(mp
);
1040 xfs_warn(mp
, "Unable to update superblock counters. "
1041 "Freespace may not be correct on next mount.");
1043 xfs_log_unmount(mp
);
1045 xfs_uuid_unmount(mp
);
1048 xfs_errortag_clearall(mp
, 0);
1052 xfs_sysfs_del(&mp
->m_kobj
);
1056 * Determine whether modifications can proceed. The caller specifies the minimum
1057 * freeze level for which modifications should not be allowed. This allows
1058 * certain operations to proceed while the freeze sequence is in progress, if
1063 struct xfs_mount
*mp
,
1066 ASSERT(level
> SB_UNFROZEN
);
1067 if ((mp
->m_super
->s_writers
.frozen
>= level
) ||
1068 XFS_FORCED_SHUTDOWN(mp
) || (mp
->m_flags
& XFS_MOUNT_RDONLY
))
1077 * Sync the superblock counters to disk.
1079 * Note this code can be called during the process of freezing, so we use the
1080 * transaction allocator that does not block when the transaction subsystem is
1081 * in its frozen state.
1084 xfs_log_sbcount(xfs_mount_t
*mp
)
1086 /* allow this to proceed during the freeze sequence... */
1087 if (!xfs_fs_writable(mp
, SB_FREEZE_COMPLETE
))
1090 xfs_icsb_sync_counters(mp
, 0);
1093 * we don't need to do this if we are updating the superblock
1094 * counters on every modification.
1096 if (!xfs_sb_version_haslazysbcount(&mp
->m_sb
))
1099 return xfs_sync_sb(mp
, true);
1104 struct xfs_mount
*mp
,
1107 /* deltas are +/-64, hence the large batch size of 128. */
1108 __percpu_counter_add(&mp
->m_icount
, delta
, 128);
1109 if (percpu_counter_compare(&mp
->m_icount
, 0) < 0) {
1111 percpu_counter_add(&mp
->m_icount
, -delta
);
1119 struct xfs_mount
*mp
,
1122 percpu_counter_add(&mp
->m_ifree
, delta
);
1123 if (percpu_counter_compare(&mp
->m_ifree
, 0) < 0) {
1125 percpu_counter_add(&mp
->m_ifree
, -delta
);
1133 struct xfs_mount
*mp
,
1143 * If the reserve pool is depleted, put blocks back into it
1144 * first. Most of the time the pool is full.
1146 if (likely(mp
->m_resblks
== mp
->m_resblks_avail
)) {
1147 percpu_counter_add(&mp
->m_fdblocks
, delta
);
1151 spin_lock(&mp
->m_sb_lock
);
1152 res_used
= (long long)(mp
->m_resblks
- mp
->m_resblks_avail
);
1154 if (res_used
> delta
) {
1155 mp
->m_resblks_avail
+= delta
;
1158 mp
->m_resblks_avail
= mp
->m_resblks
;
1159 percpu_counter_add(&mp
->m_fdblocks
, delta
);
1161 spin_unlock(&mp
->m_sb_lock
);
1166 * Taking blocks away, need to be more accurate the closer we
1169 * batch size is set to a maximum of 1024 blocks - if we are
1170 * allocating of freeing extents larger than this then we aren't
1171 * going to be hammering the counter lock so a lock per update
1174 * If the counter has a value of less than 2 * max batch size,
1175 * then make everything serialise as we are real close to
1178 #define __BATCH 1024
1179 if (percpu_counter_compare(&mp
->m_fdblocks
, 2 * __BATCH
) < 0)
1185 __percpu_counter_add(&mp
->m_fdblocks
, delta
, batch
);
1186 if (percpu_counter_compare(&mp
->m_fdblocks
,
1187 XFS_ALLOC_SET_ASIDE(mp
)) >= 0) {
1193 * lock up the sb for dipping into reserves before releasing the space
1194 * that took us to ENOSPC.
1196 spin_lock(&mp
->m_sb_lock
);
1197 percpu_counter_add(&mp
->m_fdblocks
, -delta
);
1199 goto fdblocks_enospc
;
1201 lcounter
= (long long)mp
->m_resblks_avail
+ delta
;
1202 if (lcounter
>= 0) {
1203 mp
->m_resblks_avail
= lcounter
;
1204 spin_unlock(&mp
->m_sb_lock
);
1207 printk_once(KERN_WARNING
1208 "Filesystem \"%s\": reserve blocks depleted! "
1209 "Consider increasing reserve pool size.",
1212 spin_unlock(&mp
->m_sb_lock
);
1217 * xfs_mod_incore_sb_unlocked() is a utility routine commonly used to apply
1218 * a delta to a specified field in the in-core superblock. Simply
1219 * switch on the field indicated and apply the delta to that field.
1220 * Fields are not allowed to dip below zero, so if the delta would
1221 * do this do not apply it and return EINVAL.
1223 * The m_sb_lock must be held when this routine is called.
1226 xfs_mod_incore_sb_unlocked(
1228 xfs_sb_field_t field
,
1232 int scounter
; /* short counter for 32 bit fields */
1233 long long lcounter
; /* long counter for 64 bit fields */
1236 * With the in-core superblock spin lock held, switch
1237 * on the indicated field. Apply the delta to the
1238 * proper field. If the fields value would dip below
1239 * 0, then do not apply the delta and return EINVAL.
1242 case XFS_SBS_ICOUNT
:
1244 case XFS_SBS_FDBLOCKS
:
1247 case XFS_SBS_FREXTENTS
:
1248 lcounter
= (long long)mp
->m_sb
.sb_frextents
;
1253 mp
->m_sb
.sb_frextents
= lcounter
;
1255 case XFS_SBS_DBLOCKS
:
1256 lcounter
= (long long)mp
->m_sb
.sb_dblocks
;
1262 mp
->m_sb
.sb_dblocks
= lcounter
;
1264 case XFS_SBS_AGCOUNT
:
1265 scounter
= mp
->m_sb
.sb_agcount
;
1271 mp
->m_sb
.sb_agcount
= scounter
;
1273 case XFS_SBS_IMAX_PCT
:
1274 scounter
= mp
->m_sb
.sb_imax_pct
;
1280 mp
->m_sb
.sb_imax_pct
= scounter
;
1282 case XFS_SBS_REXTSIZE
:
1283 scounter
= mp
->m_sb
.sb_rextsize
;
1289 mp
->m_sb
.sb_rextsize
= scounter
;
1291 case XFS_SBS_RBMBLOCKS
:
1292 scounter
= mp
->m_sb
.sb_rbmblocks
;
1298 mp
->m_sb
.sb_rbmblocks
= scounter
;
1300 case XFS_SBS_RBLOCKS
:
1301 lcounter
= (long long)mp
->m_sb
.sb_rblocks
;
1307 mp
->m_sb
.sb_rblocks
= lcounter
;
1309 case XFS_SBS_REXTENTS
:
1310 lcounter
= (long long)mp
->m_sb
.sb_rextents
;
1316 mp
->m_sb
.sb_rextents
= lcounter
;
1318 case XFS_SBS_REXTSLOG
:
1319 scounter
= mp
->m_sb
.sb_rextslog
;
1325 mp
->m_sb
.sb_rextslog
= scounter
;
1334 * xfs_mod_incore_sb() is used to change a field in the in-core
1335 * superblock structure by the specified delta. This modification
1336 * is protected by the m_sb_lock. Just use the xfs_mod_incore_sb_unlocked()
1337 * routine to do the work.
1341 struct xfs_mount
*mp
,
1342 xfs_sb_field_t field
,
1348 #ifdef HAVE_PERCPU_SB
1349 ASSERT(field
< XFS_SBS_IFREE
|| field
> XFS_SBS_FDBLOCKS
);
1352 spin_lock(&mp
->m_sb_lock
);
1353 status
= xfs_mod_incore_sb_unlocked(mp
, field
, delta
, rsvd
);
1354 spin_unlock(&mp
->m_sb_lock
);
1360 * Change more than one field in the in-core superblock structure at a time.
1362 * The fields and changes to those fields are specified in the array of
1363 * xfs_mod_sb structures passed in. Either all of the specified deltas
1364 * will be applied or none of them will. If any modified field dips below 0,
1365 * then all modifications will be backed out and EINVAL will be returned.
1367 * Note that this function may not be used for the superblock values that
1368 * are tracked with the in-memory per-cpu counters - a direct call to
1369 * xfs_mod_incore_sb is required for these.
1372 xfs_mod_incore_sb_batch(
1373 struct xfs_mount
*mp
,
1382 * Loop through the array of mod structures and apply each individually.
1383 * If any fail, then back out all those which have already been applied.
1384 * Do all of this within the scope of the m_sb_lock so that all of the
1385 * changes will be atomic.
1387 spin_lock(&mp
->m_sb_lock
);
1388 for (msbp
= msb
; msbp
< (msb
+ nmsb
); msbp
++) {
1389 ASSERT(msbp
->msb_field
< XFS_SBS_ICOUNT
||
1390 msbp
->msb_field
> XFS_SBS_FDBLOCKS
);
1392 error
= xfs_mod_incore_sb_unlocked(mp
, msbp
->msb_field
,
1393 msbp
->msb_delta
, rsvd
);
1397 spin_unlock(&mp
->m_sb_lock
);
1401 while (--msbp
>= msb
) {
1402 error
= xfs_mod_incore_sb_unlocked(mp
, msbp
->msb_field
,
1403 -msbp
->msb_delta
, rsvd
);
1406 spin_unlock(&mp
->m_sb_lock
);
1411 * xfs_getsb() is called to obtain the buffer for the superblock.
1412 * The buffer is returned locked and read in from disk.
1413 * The buffer should be released with a call to xfs_brelse().
1415 * If the flags parameter is BUF_TRYLOCK, then we'll only return
1416 * the superblock buffer if it can be locked without sleeping.
1417 * If it can't then we'll return NULL.
1421 struct xfs_mount
*mp
,
1424 struct xfs_buf
*bp
= mp
->m_sb_bp
;
1426 if (!xfs_buf_trylock(bp
)) {
1427 if (flags
& XBF_TRYLOCK
)
1433 ASSERT(XFS_BUF_ISDONE(bp
));
1438 * Used to free the superblock along various error paths.
1442 struct xfs_mount
*mp
)
1444 struct xfs_buf
*bp
= mp
->m_sb_bp
;
1452 * If the underlying (data/log/rt) device is readonly, there are some
1453 * operations that cannot proceed.
1456 xfs_dev_is_read_only(
1457 struct xfs_mount
*mp
,
1460 if (xfs_readonly_buftarg(mp
->m_ddev_targp
) ||
1461 xfs_readonly_buftarg(mp
->m_logdev_targp
) ||
1462 (mp
->m_rtdev_targp
&& xfs_readonly_buftarg(mp
->m_rtdev_targp
))) {
1463 xfs_notice(mp
, "%s required on read-only device.", message
);
1464 xfs_notice(mp
, "write access unavailable, cannot proceed.");
1470 #ifdef HAVE_PERCPU_SB
1472 * Per-cpu incore superblock counters
1474 * Simple concept, difficult implementation
1476 * Basically, replace the incore superblock counters with a distributed per cpu
1477 * counter for contended fields (e.g. free block count).
1479 * Difficulties arise in that the incore sb is used for ENOSPC checking, and
1480 * hence needs to be accurately read when we are running low on space. Hence
1481 * there is a method to enable and disable the per-cpu counters based on how
1482 * much "stuff" is available in them.
1484 * Basically, a counter is enabled if there is enough free resource to justify
1485 * running a per-cpu fast-path. If the per-cpu counter runs out (i.e. a local
1486 * ENOSPC), then we disable the counters to synchronise all callers and
1487 * re-distribute the available resources.
1489 * If, once we redistributed the available resources, we still get a failure,
1490 * we disable the per-cpu counter and go through the slow path.
1492 * The slow path is the current xfs_mod_incore_sb() function. This means that
1493 * when we disable a per-cpu counter, we need to drain its resources back to
1494 * the global superblock. We do this after disabling the counter to prevent
1495 * more threads from queueing up on the counter.
1497 * Essentially, this means that we still need a lock in the fast path to enable
1498 * synchronisation between the global counters and the per-cpu counters. This
1499 * is not a problem because the lock will be local to a CPU almost all the time
1500 * and have little contention except when we get to ENOSPC conditions.
1502 * Basically, this lock becomes a barrier that enables us to lock out the fast
1503 * path while we do things like enabling and disabling counters and
1504 * synchronising the counters.
1508 * 1. m_sb_lock before picking up per-cpu locks
1509 * 2. per-cpu locks always picked up via for_each_online_cpu() order
1510 * 3. accurate counter sync requires m_sb_lock + per cpu locks
1511 * 4. modifying per-cpu counters requires holding per-cpu lock
1512 * 5. modifying global counters requires holding m_sb_lock
1513 * 6. enabling or disabling a counter requires holding the m_sb_lock
1514 * and _none_ of the per-cpu locks.
1516 * Disabled counters are only ever re-enabled by a balance operation
1517 * that results in more free resources per CPU than a given threshold.
1518 * To ensure counters don't remain disabled, they are rebalanced when
1519 * the global resource goes above a higher threshold (i.e. some hysteresis
1520 * is present to prevent thrashing).
1523 #ifdef CONFIG_HOTPLUG_CPU
1525 * hot-plug CPU notifier support.
1527 * We need a notifier per filesystem as we need to be able to identify
1528 * the filesystem to balance the counters out. This is achieved by
1529 * having a notifier block embedded in the xfs_mount_t and doing pointer
1530 * magic to get the mount pointer from the notifier block address.
1533 xfs_icsb_cpu_notify(
1534 struct notifier_block
*nfb
,
1535 unsigned long action
,
1538 xfs_icsb_cnts_t
*cntp
;
1541 mp
= (xfs_mount_t
*)container_of(nfb
, xfs_mount_t
, m_icsb_notifier
);
1542 cntp
= (xfs_icsb_cnts_t
*)
1543 per_cpu_ptr(mp
->m_sb_cnts
, (unsigned long)hcpu
);
1545 case CPU_UP_PREPARE
:
1546 case CPU_UP_PREPARE_FROZEN
:
1547 /* Easy Case - initialize the area and locks, and
1548 * then rebalance when online does everything else for us. */
1549 memset(cntp
, 0, sizeof(xfs_icsb_cnts_t
));
1552 case CPU_ONLINE_FROZEN
:
1554 xfs_icsb_unlock(mp
);
1557 case CPU_DEAD_FROZEN
:
1558 /* Disable all the counters, then fold the dead cpu's
1559 * count into the total on the global superblock and
1560 * re-enable the counters. */
1562 spin_lock(&mp
->m_sb_lock
);
1564 memset(cntp
, 0, sizeof(xfs_icsb_cnts_t
));
1566 spin_unlock(&mp
->m_sb_lock
);
1567 xfs_icsb_unlock(mp
);
1573 #endif /* CONFIG_HOTPLUG_CPU */
1576 xfs_icsb_init_counters(
1579 xfs_icsb_cnts_t
*cntp
;
1583 error
= percpu_counter_init(&mp
->m_icount
, 0, GFP_KERNEL
);
1587 error
= percpu_counter_init(&mp
->m_ifree
, 0, GFP_KERNEL
);
1591 error
= percpu_counter_init(&mp
->m_fdblocks
, 0, GFP_KERNEL
);
1595 mp
->m_sb_cnts
= alloc_percpu(xfs_icsb_cnts_t
);
1596 if (!mp
->m_sb_cnts
) {
1601 for_each_online_cpu(i
) {
1602 cntp
= (xfs_icsb_cnts_t
*)per_cpu_ptr(mp
->m_sb_cnts
, i
);
1603 memset(cntp
, 0, sizeof(xfs_icsb_cnts_t
));
1606 mutex_init(&mp
->m_icsb_mutex
);
1609 * start with all counters disabled so that the
1610 * initial balance kicks us off correctly
1612 mp
->m_icsb_counters
= -1;
1614 #ifdef CONFIG_HOTPLUG_CPU
1615 mp
->m_icsb_notifier
.notifier_call
= xfs_icsb_cpu_notify
;
1616 mp
->m_icsb_notifier
.priority
= 0;
1617 register_hotcpu_notifier(&mp
->m_icsb_notifier
);
1618 #endif /* CONFIG_HOTPLUG_CPU */
1623 percpu_counter_destroy(&mp
->m_fdblocks
);
1625 percpu_counter_destroy(&mp
->m_ifree
);
1627 percpu_counter_destroy(&mp
->m_icount
);
1632 xfs_icsb_reinit_counters(
1635 percpu_counter_set(&mp
->m_icount
, mp
->m_sb
.sb_icount
);
1636 percpu_counter_set(&mp
->m_ifree
, mp
->m_sb
.sb_ifree
);
1637 percpu_counter_set(&mp
->m_fdblocks
, mp
->m_sb
.sb_fdblocks
);
1641 * start with all counters disabled so that the
1642 * initial balance kicks us off correctly
1644 mp
->m_icsb_counters
= -1;
1645 xfs_icsb_unlock(mp
);
1649 xfs_icsb_destroy_counters(
1652 if (mp
->m_sb_cnts
) {
1653 unregister_hotcpu_notifier(&mp
->m_icsb_notifier
);
1654 free_percpu(mp
->m_sb_cnts
);
1657 percpu_counter_destroy(&mp
->m_icount
);
1658 percpu_counter_destroy(&mp
->m_ifree
);
1659 percpu_counter_destroy(&mp
->m_fdblocks
);
1661 mutex_destroy(&mp
->m_icsb_mutex
);
1666 xfs_icsb_cnts_t
*icsbp
)
1668 while (test_and_set_bit(XFS_ICSB_FLAG_LOCK
, &icsbp
->icsb_flags
)) {
1674 xfs_icsb_unlock_cntr(
1675 xfs_icsb_cnts_t
*icsbp
)
1677 clear_bit(XFS_ICSB_FLAG_LOCK
, &icsbp
->icsb_flags
);
1682 xfs_icsb_lock_all_counters(
1685 xfs_icsb_cnts_t
*cntp
;
1688 for_each_online_cpu(i
) {
1689 cntp
= (xfs_icsb_cnts_t
*)per_cpu_ptr(mp
->m_sb_cnts
, i
);
1690 xfs_icsb_lock_cntr(cntp
);
1695 xfs_icsb_unlock_all_counters(
1698 xfs_icsb_cnts_t
*cntp
;
1701 for_each_online_cpu(i
) {
1702 cntp
= (xfs_icsb_cnts_t
*)per_cpu_ptr(mp
->m_sb_cnts
, i
);
1703 xfs_icsb_unlock_cntr(cntp
);
1710 xfs_icsb_cnts_t
*cnt
,
1713 memset(cnt
, 0, sizeof(xfs_icsb_cnts_t
));
1715 if (!(flags
& XFS_ICSB_LAZY_COUNT
))
1716 xfs_icsb_lock_all_counters(mp
);
1719 if (!(flags
& XFS_ICSB_LAZY_COUNT
))
1720 xfs_icsb_unlock_all_counters(mp
);
1724 xfs_icsb_counter_disabled(
1726 xfs_sb_field_t field
)
1728 return test_bit(field
, &mp
->m_icsb_counters
);
1732 xfs_icsb_disable_counter(
1734 xfs_sb_field_t field
)
1736 xfs_icsb_cnts_t cnt
;
1739 * If we are already disabled, then there is nothing to do
1740 * here. We check before locking all the counters to avoid
1741 * the expensive lock operation when being called in the
1742 * slow path and the counter is already disabled. This is
1743 * safe because the only time we set or clear this state is under
1746 if (xfs_icsb_counter_disabled(mp
, field
))
1749 xfs_icsb_lock_all_counters(mp
);
1750 if (!test_and_set_bit(field
, &mp
->m_icsb_counters
)) {
1751 /* drain back to superblock */
1753 xfs_icsb_count(mp
, &cnt
, XFS_ICSB_LAZY_COUNT
);
1760 xfs_icsb_unlock_all_counters(mp
);
1764 xfs_icsb_enable_counter(
1766 xfs_sb_field_t field
,
1772 xfs_icsb_lock_all_counters(mp
);
1773 for_each_online_cpu(i
) {
1781 clear_bit(field
, &mp
->m_icsb_counters
);
1782 xfs_icsb_unlock_all_counters(mp
);
1786 xfs_icsb_sync_counters_locked(
1790 xfs_icsb_cnts_t cnt
;
1792 xfs_icsb_count(mp
, &cnt
, flags
);
1796 * Accurate update of per-cpu counters to incore superblock
1799 xfs_icsb_sync_counters(
1803 spin_lock(&mp
->m_sb_lock
);
1804 xfs_icsb_sync_counters_locked(mp
, flags
);
1805 spin_unlock(&mp
->m_sb_lock
);
1809 * Balance and enable/disable counters as necessary.
1811 * Thresholds for re-enabling counters are somewhat magic. inode counts are
1812 * chosen to be the same number as single on disk allocation chunk per CPU, and
1813 * free blocks is something far enough zero that we aren't going thrash when we
1814 * get near ENOSPC. We also need to supply a minimum we require per cpu to
1815 * prevent looping endlessly when xfs_alloc_space asks for more than will
1816 * be distributed to a single CPU but each CPU has enough blocks to be
1819 * Note that we can be called when counters are already disabled.
1820 * xfs_icsb_disable_counter() optimises the counter locking in this case to
1821 * prevent locking every per-cpu counter needlessly.
1824 #define XFS_ICSB_INO_CNTR_REENABLE (uint64_t)64
1825 #define XFS_ICSB_FDBLK_CNTR_REENABLE(mp) \
1826 (uint64_t)(512 + XFS_ALLOC_SET_ASIDE(mp))
1828 xfs_icsb_balance_counter_locked(
1830 xfs_sb_field_t field
,
1833 uint64_t count
, resid
;
1835 /* disable counter and sync counter */
1836 xfs_icsb_disable_counter(mp
, field
);
1838 /* update counters - first CPU gets residual*/
1842 count
= resid
= 0; /* quiet, gcc */
1846 xfs_icsb_enable_counter(mp
, field
, count
, resid
);
1850 xfs_icsb_balance_counter(
1852 xfs_sb_field_t fields
,
1855 spin_lock(&mp
->m_sb_lock
);
1856 xfs_icsb_balance_counter_locked(mp
, fields
, min_per_cpu
);
1857 spin_unlock(&mp
->m_sb_lock
);
1861 xfs_icsb_modify_counters(
1863 xfs_sb_field_t field
,
1867 xfs_icsb_cnts_t
*icsbp
;
1873 icsbp
= this_cpu_ptr(mp
->m_sb_cnts
);
1876 * if the counter is disabled, go to slow path
1878 if (unlikely(xfs_icsb_counter_disabled(mp
, field
)))
1880 xfs_icsb_lock_cntr(icsbp
);
1881 if (unlikely(xfs_icsb_counter_disabled(mp
, field
))) {
1882 xfs_icsb_unlock_cntr(icsbp
);
1889 goto balance_counter
; /* be still, gcc */
1891 xfs_icsb_unlock_cntr(icsbp
);
1899 * serialise with a mutex so we don't burn lots of cpu on
1900 * the superblock lock. We still need to hold the superblock
1901 * lock, however, when we modify the global structures.
1906 * Now running atomically.
1908 * If the counter is enabled, someone has beaten us to rebalancing.
1909 * Drop the lock and try again in the fast path....
1911 if (!(xfs_icsb_counter_disabled(mp
, field
))) {
1912 xfs_icsb_unlock(mp
);
1917 * The counter is currently disabled. Because we are
1918 * running atomically here, we know a rebalance cannot
1919 * be in progress. Hence we can go straight to operating
1920 * on the global superblock. We do not call xfs_mod_incore_sb()
1921 * here even though we need to get the m_sb_lock. Doing so
1922 * will cause us to re-enter this function and deadlock.
1923 * Hence we get the m_sb_lock ourselves and then call
1924 * xfs_mod_incore_sb_unlocked() as the unlocked path operates
1925 * directly on the global counters.
1927 spin_lock(&mp
->m_sb_lock
);
1928 ret
= xfs_mod_incore_sb_unlocked(mp
, field
, delta
, rsvd
);
1929 spin_unlock(&mp
->m_sb_lock
);
1932 * Now that we've modified the global superblock, we
1933 * may be able to re-enable the distributed counters
1934 * (e.g. lots of space just got freed). After that
1938 xfs_icsb_balance_counter(mp
, field
, 0);
1939 xfs_icsb_unlock(mp
);
1943 xfs_icsb_unlock_cntr(icsbp
);
1947 * We may have multiple threads here if multiple per-cpu
1948 * counters run dry at the same time. This will mean we can
1949 * do more balances than strictly necessary but it is not
1950 * the common slowpath case.
1955 * running atomically.
1957 * This will leave the counter in the correct state for future
1958 * accesses. After the rebalance, we simply try again and our retry
1959 * will either succeed through the fast path or slow path without
1960 * another balance operation being required.
1962 xfs_icsb_balance_counter(mp
, field
, delta
);
1963 xfs_icsb_unlock(mp
);