#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
-#include "xfs_dir.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
-#include "xfs_dir_sf.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
STATIC void xfs_uuid_unmount(xfs_mount_t *mp);
STATIC void xfs_unmountfs_wait(xfs_mount_t *);
+
+#ifdef HAVE_PERCPU_SB
+STATIC void xfs_icsb_destroy_counters(xfs_mount_t *);
+STATIC void xfs_icsb_balance_counter(xfs_mount_t *, xfs_sb_field_t, int);
+STATIC void xfs_icsb_sync_counters(xfs_mount_t *);
+STATIC int xfs_icsb_modify_counters(xfs_mount_t *, xfs_sb_field_t,
+ int, int);
+STATIC int xfs_icsb_modify_counters_locked(xfs_mount_t *, xfs_sb_field_t,
+ int, int);
+STATIC int xfs_icsb_disable_counter(xfs_mount_t *, xfs_sb_field_t);
+
+#else
+
+#define xfs_icsb_destroy_counters(mp) do { } while (0)
+#define xfs_icsb_balance_counter(mp, a, b) do { } while (0)
+#define xfs_icsb_sync_counters(mp) do { } while (0)
+#define xfs_icsb_modify_counters(mp, a, b, c) do { } while (0)
+#define xfs_icsb_modify_counters_locked(mp, a, b, c) do { } while (0)
+
+#endif
+
static const struct {
- short offset;
- short type; /* 0 = integer
- * 1 = binary / string (no translation)
- */
+ short offset;
+ short type; /* 0 = integer
+ * 1 = binary / string (no translation)
+ */
} xfs_sb_info[] = {
{ offsetof(xfs_sb_t, sb_magicnum), 0 },
{ offsetof(xfs_sb_t, sb_blocksize), 0 },
{
xfs_mount_t *mp;
- mp = kmem_zalloc(sizeof(*mp), KM_SLEEP);
+ mp = kmem_zalloc(sizeof(xfs_mount_t), KM_SLEEP);
+
+ if (xfs_icsb_init_counters(mp)) {
+ mp->m_flags |= XFS_MOUNT_NO_PERCPU_SB;
+ }
AIL_LOCKINIT(&mp->m_ail_lock, "xfs_ail");
spinlock_init(&mp->m_sb_lock, "xfs_sb");
*/
void
xfs_mount_free(
- xfs_mount_t *mp,
- int remove_bhv)
+ xfs_mount_t *mp,
+ int remove_bhv)
{
if (mp->m_ihash)
xfs_ihash_free(mp);
kmem_free(mp->m_logname, strlen(mp->m_logname) + 1);
if (remove_bhv) {
- struct vfs *vfsp = XFS_MTOVFS(mp);
+ struct bhv_vfs *vfsp = XFS_MTOVFS(mp);
bhv_remove_all_vfsops(vfsp, 0);
VFS_REMOVEBHV(vfsp, &mp->m_bhv);
}
+ xfs_icsb_destroy_counters(mp);
kmem_free(mp, sizeof(xfs_mount_t));
}
STATIC int
xfs_mount_validate_sb(
xfs_mount_t *mp,
- xfs_sb_t *sbp)
+ xfs_sb_t *sbp,
+ int flags)
{
/*
* If the log device and data device have the
* a volume filesystem in a non-volume manner.
*/
if (sbp->sb_magicnum != XFS_SB_MAGIC) {
- cmn_err(CE_WARN, "XFS: bad magic number");
+ xfs_fs_mount_cmn_err(flags, "bad magic number");
return XFS_ERROR(EWRONGFS);
}
if (!XFS_SB_GOOD_VERSION(sbp)) {
- cmn_err(CE_WARN, "XFS: bad version");
+ xfs_fs_mount_cmn_err(flags, "bad version");
return XFS_ERROR(EWRONGFS);
}
if (unlikely(
sbp->sb_logstart == 0 && mp->m_logdev_targp == mp->m_ddev_targp)) {
- cmn_err(CE_WARN,
- "XFS: filesystem is marked as having an external log; "
- "specify logdev on the\nmount command line.");
- XFS_CORRUPTION_ERROR("xfs_mount_validate_sb(1)",
- XFS_ERRLEVEL_HIGH, mp, sbp);
- return XFS_ERROR(EFSCORRUPTED);
+ xfs_fs_mount_cmn_err(flags,
+ "filesystem is marked as having an external log; "
+ "specify logdev on the\nmount command line.");
+ return XFS_ERROR(EINVAL);
}
if (unlikely(
sbp->sb_logstart != 0 && mp->m_logdev_targp != mp->m_ddev_targp)) {
- cmn_err(CE_WARN,
- "XFS: filesystem is marked as having an internal log; "
- "don't specify logdev on\nthe mount command line.");
- XFS_CORRUPTION_ERROR("xfs_mount_validate_sb(2)",
- XFS_ERRLEVEL_HIGH, mp, sbp);
- return XFS_ERROR(EFSCORRUPTED);
+ xfs_fs_mount_cmn_err(flags,
+ "filesystem is marked as having an internal log; "
+ "do not specify logdev on\nthe mount command line.");
+ return XFS_ERROR(EINVAL);
}
/*
sbp->sb_blocklog > XFS_MAX_BLOCKSIZE_LOG ||
sbp->sb_inodesize < XFS_DINODE_MIN_SIZE ||
sbp->sb_inodesize > XFS_DINODE_MAX_SIZE ||
+ sbp->sb_inodelog < XFS_DINODE_MIN_LOG ||
+ sbp->sb_inodelog > XFS_DINODE_MAX_LOG ||
+ (sbp->sb_blocklog - sbp->sb_inodelog != sbp->sb_inopblog) ||
(sbp->sb_rextsize * sbp->sb_blocksize > XFS_MAX_RTEXTSIZE) ||
(sbp->sb_rextsize * sbp->sb_blocksize < XFS_MIN_RTEXTSIZE) ||
- sbp->sb_imax_pct > 100)) {
- cmn_err(CE_WARN, "XFS: SB sanity check 1 failed");
- XFS_CORRUPTION_ERROR("xfs_mount_validate_sb(3)",
- XFS_ERRLEVEL_LOW, mp, sbp);
+ (sbp->sb_imax_pct > 100 /* zero sb_imax_pct is valid */))) {
+ xfs_fs_mount_cmn_err(flags, "SB sanity check 1 failed");
return XFS_ERROR(EFSCORRUPTED);
}
(xfs_drfsbno_t)sbp->sb_agcount * sbp->sb_agblocks ||
sbp->sb_dblocks < (xfs_drfsbno_t)(sbp->sb_agcount - 1) *
sbp->sb_agblocks + XFS_MIN_AG_BLOCKS)) {
- cmn_err(CE_WARN, "XFS: SB sanity check 2 failed");
- XFS_ERROR_REPORT("xfs_mount_validate_sb(4)",
- XFS_ERRLEVEL_LOW, mp);
+ xfs_fs_mount_cmn_err(flags, "SB sanity check 2 failed");
return XFS_ERROR(EFSCORRUPTED);
}
(sbp->sb_dblocks << (sbp->sb_blocklog - BBSHIFT)) > UINT_MAX ||
(sbp->sb_rblocks << (sbp->sb_blocklog - BBSHIFT)) > UINT_MAX)) {
#endif
- cmn_err(CE_WARN,
- "XFS: File system is too large to be mounted on this system.");
+ xfs_fs_mount_cmn_err(flags,
+ "file system too large to be mounted on this system.");
return XFS_ERROR(E2BIG);
}
if (unlikely(sbp->sb_inprogress)) {
- cmn_err(CE_WARN, "XFS: file system busy");
- XFS_ERROR_REPORT("xfs_mount_validate_sb(5)",
- XFS_ERRLEVEL_LOW, mp);
+ xfs_fs_mount_cmn_err(flags, "file system busy");
return XFS_ERROR(EFSCORRUPTED);
}
* Version 1 directory format has never worked on Linux.
*/
if (unlikely(!XFS_SB_VERSION_HASDIRV2(sbp))) {
- cmn_err(CE_WARN,
- "XFS: Attempted to mount file system using version 1 directory format");
+ xfs_fs_mount_cmn_err(flags,
+ "file system using version 1 directory format");
return XFS_ERROR(ENOSYS);
}
* Until this is fixed only page-sized or smaller data blocks work.
*/
if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
- cmn_err(CE_WARN,
- "XFS: Attempted to mount file system with blocksize %d bytes",
+ xfs_fs_mount_cmn_err(flags,
+ "file system with blocksize %d bytes",
sbp->sb_blocksize);
- cmn_err(CE_WARN,
- "XFS: Only page-sized (%ld) or less blocksizes currently work.",
+ xfs_fs_mount_cmn_err(flags,
+ "only pagesize (%ld) or less will currently work.",
PAGE_SIZE);
return XFS_ERROR(ENOSYS);
}
xfs_agnumber_t
xfs_initialize_perag(
- struct vfs *vfs,
+ bhv_vfs_t *vfs,
xfs_mount_t *mp,
xfs_agnumber_t agcount)
{
break;
}
- /* This ag is prefered for inodes */
+ /* This ag is preferred for inodes */
pag = &mp->m_perag[index];
pag->pagi_inodeok = 1;
if (index < max_metadata)
* Does the initial read of the superblock.
*/
int
-xfs_readsb(xfs_mount_t *mp)
+xfs_readsb(xfs_mount_t *mp, int flags)
{
unsigned int sector_size;
unsigned int extra_flags;
bp = xfs_buf_read_flags(mp->m_ddev_targp, XFS_SB_DADDR,
BTOBB(sector_size), extra_flags);
if (!bp || XFS_BUF_ISERROR(bp)) {
- cmn_err(CE_WARN, "XFS: SB read failed");
+ xfs_fs_mount_cmn_err(flags, "SB read failed");
error = bp ? XFS_BUF_GETERROR(bp) : ENOMEM;
goto fail;
}
sbp = XFS_BUF_TO_SBP(bp);
xfs_xlatesb(XFS_BUF_PTR(bp), &(mp->m_sb), 1, XFS_SB_ALL_BITS);
- error = xfs_mount_validate_sb(mp, &(mp->m_sb));
+ error = xfs_mount_validate_sb(mp, &(mp->m_sb), flags);
if (error) {
- cmn_err(CE_WARN, "XFS: SB validate failed");
+ xfs_fs_mount_cmn_err(flags, "SB validate failed");
goto fail;
}
* We must be able to do sector-sized and sector-aligned IO.
*/
if (sector_size > mp->m_sb.sb_sectsize) {
- cmn_err(CE_WARN,
- "XFS: device supports only %u byte sectors (not %u)",
+ xfs_fs_mount_cmn_err(flags,
+ "device supports only %u byte sectors (not %u)",
sector_size, mp->m_sb.sb_sectsize);
error = ENOSYS;
goto fail;
bp = xfs_buf_read_flags(mp->m_ddev_targp, XFS_SB_DADDR,
BTOBB(sector_size), extra_flags);
if (!bp || XFS_BUF_ISERROR(bp)) {
- cmn_err(CE_WARN, "XFS: SB re-read failed");
+ xfs_fs_mount_cmn_err(flags, "SB re-read failed");
error = bp ? XFS_BUF_GETERROR(bp) : ENOMEM;
goto fail;
}
ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
}
+ xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
+ xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
+ xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
+
mp->m_sb_bp = bp;
xfs_buf_relse(bp);
ASSERT(XFS_BUF_VALUSEMA(bp) > 0);
*/
int
xfs_mountfs(
- vfs_t *vfsp,
+ bhv_vfs_t *vfsp,
xfs_mount_t *mp,
int mfsi_flags)
{
xfs_buf_t *bp;
xfs_sb_t *sbp = &(mp->m_sb);
xfs_inode_t *rip;
- vnode_t *rvp = NULL;
+ bhv_vnode_t *rvp = NULL;
int readio_log, writeio_log;
xfs_daddr_t d;
__uint64_t ret64;
int error = 0;
if (mp->m_sb_bp == NULL) {
- if ((error = xfs_readsb(mp))) {
+ if ((error = xfs_readsb(mp, mfsi_flags))) {
return error;
}
}
vfsp->vfs_altfsid = (xfs_fsid_t *)mp->m_fixedfsid;
mp->m_dmevmask = 0; /* not persistent; set after each mount */
- /*
- * Select the right directory manager.
- */
- mp->m_dirops =
- XFS_SB_VERSION_HASDIRV2(&mp->m_sb) ?
- xfsv2_dirops :
- xfsv1_dirops;
-
- /*
- * Initialize directory manager's entries.
- */
- XFS_DIR_MOUNT(mp);
+ xfs_dir_mount(mp);
/*
* Initialize the attribute manager's entries.
if (unlikely((rip->i_d.di_mode & S_IFMT) != S_IFDIR)) {
cmn_err(CE_WARN, "XFS: corrupted root inode");
- prdev("Root inode %llu is not a directory",
- mp->m_ddev_targp, (unsigned long long)rip->i_ino);
+ cmn_err(CE_WARN, "Device %s - root %llu is not a directory",
+ XFS_BUFTARG_NAME(mp->m_ddev_targp),
+ (unsigned long long)rip->i_ino);
xfs_iunlock(rip, XFS_ILOCK_EXCL);
XFS_ERROR_REPORT("xfs_mountfs_int(2)", XFS_ERRLEVEL_LOW,
mp);
int
xfs_unmountfs(xfs_mount_t *mp, struct cred *cr)
{
- struct vfs *vfsp = XFS_MTOVFS(mp);
+ struct bhv_vfs *vfsp = XFS_MTOVFS(mp);
#if defined(DEBUG) || defined(INDUCE_IO_ERROR)
int64_t fsid;
#endif
sbp = xfs_getsb(mp, 0);
if (!(XFS_MTOVFS(mp)->vfs_flag & VFS_RDONLY ||
XFS_FORCED_SHUTDOWN(mp))) {
+
+ xfs_icsb_sync_counters(mp);
+
/*
* mark shared-readonly if desired
*/
xfs_trans_log_buf(tp, bp, first, last);
}
+/*
+ * In order to avoid ENOSPC-related deadlock caused by
+ * out-of-order locking of AGF buffer (PV 947395), we place
+ * constraints on the relationship among actual allocations for
+ * data blocks, freelist blocks, and potential file data bmap
+ * btree blocks. However, these restrictions may result in no
+ * actual space allocated for a delayed extent, for example, a data
+ * block in a certain AG is allocated but there is no additional
+ * block for the additional bmap btree block due to a split of the
+ * bmap btree of the file. The result of this may lead to an
+ * infinite loop in xfssyncd when the file gets flushed to disk and
+ * all delayed extents need to be actually allocated. To get around
+ * this, we explicitly set aside a few blocks which will not be
+ * reserved in delayed allocation. Considering the minimum number of
+ * needed freelist blocks is 4 fsbs, a potential split of file's bmap
+ * btree requires 1 fsb, so we set the number of set-aside blocks to 8.
+*/
+#define SET_ASIDE_BLOCKS 8
+
/*
* xfs_mod_incore_sb_unlocked() is a utility routine common used to apply
* a delta to a specified field in the in-core superblock. Simply
*
* The SB_LOCK must be held when this routine is called.
*/
-STATIC int
+int
xfs_mod_incore_sb_unlocked(xfs_mount_t *mp, xfs_sb_field_t field,
int delta, int rsvd)
{
return 0;
case XFS_SBS_FDBLOCKS:
- lcounter = (long long)mp->m_sb.sb_fdblocks;
+ lcounter = (long long)mp->m_sb.sb_fdblocks - SET_ASIDE_BLOCKS;
res_used = (long long)(mp->m_resblks - mp->m_resblks_avail);
if (delta > 0) { /* Putting blocks back */
}
}
- mp->m_sb.sb_fdblocks = lcounter;
+ mp->m_sb.sb_fdblocks = lcounter + SET_ASIDE_BLOCKS;
return 0;
case XFS_SBS_FREXTENTS:
lcounter = (long long)mp->m_sb.sb_frextents;
unsigned long s;
int status;
- s = XFS_SB_LOCK(mp);
- status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
- XFS_SB_UNLOCK(mp, s);
+ /* check for per-cpu counters */
+ switch (field) {
+#ifdef HAVE_PERCPU_SB
+ case XFS_SBS_ICOUNT:
+ case XFS_SBS_IFREE:
+ case XFS_SBS_FDBLOCKS:
+ if (!(mp->m_flags & XFS_MOUNT_NO_PERCPU_SB)) {
+ status = xfs_icsb_modify_counters(mp, field,
+ delta, rsvd);
+ break;
+ }
+ /* FALLTHROUGH */
+#endif
+ default:
+ s = XFS_SB_LOCK(mp);
+ status = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
+ XFS_SB_UNLOCK(mp, s);
+ break;
+ }
+
return status;
}
* from the loop so we'll fall into the undo loop
* below.
*/
- status = xfs_mod_incore_sb_unlocked(mp, msbp->msb_field,
- msbp->msb_delta, rsvd);
+ switch (msbp->msb_field) {
+#ifdef HAVE_PERCPU_SB
+ case XFS_SBS_ICOUNT:
+ case XFS_SBS_IFREE:
+ case XFS_SBS_FDBLOCKS:
+ if (!(mp->m_flags & XFS_MOUNT_NO_PERCPU_SB)) {
+ status = xfs_icsb_modify_counters_locked(mp,
+ msbp->msb_field,
+ msbp->msb_delta, rsvd);
+ break;
+ }
+ /* FALLTHROUGH */
+#endif
+ default:
+ status = xfs_mod_incore_sb_unlocked(mp,
+ msbp->msb_field,
+ msbp->msb_delta, rsvd);
+ break;
+ }
+
if (status != 0) {
break;
}
if (status != 0) {
msbp--;
while (msbp >= msb) {
- status = xfs_mod_incore_sb_unlocked(mp,
- msbp->msb_field, -(msbp->msb_delta), rsvd);
+ switch (msbp->msb_field) {
+#ifdef HAVE_PERCPU_SB
+ case XFS_SBS_ICOUNT:
+ case XFS_SBS_IFREE:
+ case XFS_SBS_FDBLOCKS:
+ if (!(mp->m_flags & XFS_MOUNT_NO_PERCPU_SB)) {
+ status =
+ xfs_icsb_modify_counters_locked(mp,
+ msbp->msb_field,
+ -(msbp->msb_delta),
+ rsvd);
+ break;
+ }
+ /* FALLTHROUGH */
+#endif
+ default:
+ status = xfs_mod_incore_sb_unlocked(mp,
+ msbp->msb_field,
+ -(msbp->msb_delta),
+ rsvd);
+ break;
+ }
ASSERT(status == 0);
msbp--;
}
xfs_mod_sb(tp, fields);
xfs_trans_commit(tp, 0, NULL);
}
+
+
+#ifdef HAVE_PERCPU_SB
+/*
+ * Per-cpu incore superblock counters
+ *
+ * Simple concept, difficult implementation
+ *
+ * Basically, replace the incore superblock counters with a distributed per cpu
+ * counter for contended fields (e.g. free block count).
+ *
+ * Difficulties arise in that the incore sb is used for ENOSPC checking, and
+ * hence needs to be accurately read when we are running low on space. Hence
+ * there is a method to enable and disable the per-cpu counters based on how
+ * much "stuff" is available in them.
+ *
+ * Basically, a counter is enabled if there is enough free resource to justify
+ * running a per-cpu fast-path. If the per-cpu counter runs out (i.e. a local
+ * ENOSPC), then we disable the counters to synchronise all callers and
+ * re-distribute the available resources.
+ *
+ * If, once we redistributed the available resources, we still get a failure,
+ * we disable the per-cpu counter and go through the slow path.
+ *
+ * The slow path is the current xfs_mod_incore_sb() function. This means that
+ * when we disable a per-cpu counter, we need to drain it's resources back to
+ * the global superblock. We do this after disabling the counter to prevent
+ * more threads from queueing up on the counter.
+ *
+ * Essentially, this means that we still need a lock in the fast path to enable
+ * synchronisation between the global counters and the per-cpu counters. This
+ * is not a problem because the lock will be local to a CPU almost all the time
+ * and have little contention except when we get to ENOSPC conditions.
+ *
+ * Basically, this lock becomes a barrier that enables us to lock out the fast
+ * path while we do things like enabling and disabling counters and
+ * synchronising the counters.
+ *
+ * Locking rules:
+ *
+ * 1. XFS_SB_LOCK() before picking up per-cpu locks
+ * 2. per-cpu locks always picked up via for_each_online_cpu() order
+ * 3. accurate counter sync requires XFS_SB_LOCK + per cpu locks
+ * 4. modifying per-cpu counters requires holding per-cpu lock
+ * 5. modifying global counters requires holding XFS_SB_LOCK
+ * 6. enabling or disabling a counter requires holding the XFS_SB_LOCK
+ * and _none_ of the per-cpu locks.
+ *
+ * Disabled counters are only ever re-enabled by a balance operation
+ * that results in more free resources per CPU than a given threshold.
+ * To ensure counters don't remain disabled, they are rebalanced when
+ * the global resource goes above a higher threshold (i.e. some hysteresis
+ * is present to prevent thrashing).
+ */
+
+/*
+ * hot-plug CPU notifier support.
+ *
+ * We cannot use the hotcpu_register() function because it does
+ * not allow notifier instances. We need a notifier per filesystem
+ * as we need to be able to identify the filesystem to balance
+ * the counters out. This is achieved by having a notifier block
+ * embedded in the xfs_mount_t and doing pointer magic to get the
+ * mount pointer from the notifier block address.
+ */
+STATIC int
+xfs_icsb_cpu_notify(
+ struct notifier_block *nfb,
+ unsigned long action,
+ void *hcpu)
+{
+ xfs_icsb_cnts_t *cntp;
+ xfs_mount_t *mp;
+ int s;
+
+ mp = (xfs_mount_t *)container_of(nfb, xfs_mount_t, m_icsb_notifier);
+ cntp = (xfs_icsb_cnts_t *)
+ per_cpu_ptr(mp->m_sb_cnts, (unsigned long)hcpu);
+ switch (action) {
+ case CPU_UP_PREPARE:
+ /* Easy Case - initialize the area and locks, and
+ * then rebalance when online does everything else for us. */
+ memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
+ break;
+ case CPU_ONLINE:
+ xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, 0);
+ xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, 0);
+ xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, 0);
+ break;
+ case CPU_DEAD:
+ /* Disable all the counters, then fold the dead cpu's
+ * count into the total on the global superblock and
+ * re-enable the counters. */
+ s = XFS_SB_LOCK(mp);
+ xfs_icsb_disable_counter(mp, XFS_SBS_ICOUNT);
+ xfs_icsb_disable_counter(mp, XFS_SBS_IFREE);
+ xfs_icsb_disable_counter(mp, XFS_SBS_FDBLOCKS);
+
+ mp->m_sb.sb_icount += cntp->icsb_icount;
+ mp->m_sb.sb_ifree += cntp->icsb_ifree;
+ mp->m_sb.sb_fdblocks += cntp->icsb_fdblocks;
+
+ memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
+
+ xfs_icsb_balance_counter(mp, XFS_SBS_ICOUNT, XFS_ICSB_SB_LOCKED);
+ xfs_icsb_balance_counter(mp, XFS_SBS_IFREE, XFS_ICSB_SB_LOCKED);
+ xfs_icsb_balance_counter(mp, XFS_SBS_FDBLOCKS, XFS_ICSB_SB_LOCKED);
+ XFS_SB_UNLOCK(mp, s);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+int
+xfs_icsb_init_counters(
+ xfs_mount_t *mp)
+{
+ xfs_icsb_cnts_t *cntp;
+ int i;
+
+ mp->m_sb_cnts = alloc_percpu(xfs_icsb_cnts_t);
+ if (mp->m_sb_cnts == NULL)
+ return -ENOMEM;
+
+ mp->m_icsb_notifier.notifier_call = xfs_icsb_cpu_notify;
+ mp->m_icsb_notifier.priority = 0;
+ register_cpu_notifier(&mp->m_icsb_notifier);
+
+ for_each_online_cpu(i) {
+ cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
+ memset(cntp, 0, sizeof(xfs_icsb_cnts_t));
+ }
+ /*
+ * start with all counters disabled so that the
+ * initial balance kicks us off correctly
+ */
+ mp->m_icsb_counters = -1;
+ return 0;
+}
+
+STATIC void
+xfs_icsb_destroy_counters(
+ xfs_mount_t *mp)
+{
+ if (mp->m_sb_cnts) {
+ unregister_cpu_notifier(&mp->m_icsb_notifier);
+ free_percpu(mp->m_sb_cnts);
+ }
+}
+
+STATIC inline void
+xfs_icsb_lock_cntr(
+ xfs_icsb_cnts_t *icsbp)
+{
+ while (test_and_set_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags)) {
+ ndelay(1000);
+ }
+}
+
+STATIC inline void
+xfs_icsb_unlock_cntr(
+ xfs_icsb_cnts_t *icsbp)
+{
+ clear_bit(XFS_ICSB_FLAG_LOCK, &icsbp->icsb_flags);
+}
+
+
+STATIC inline void
+xfs_icsb_lock_all_counters(
+ xfs_mount_t *mp)
+{
+ xfs_icsb_cnts_t *cntp;
+ int i;
+
+ for_each_online_cpu(i) {
+ cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
+ xfs_icsb_lock_cntr(cntp);
+ }
+}
+
+STATIC inline void
+xfs_icsb_unlock_all_counters(
+ xfs_mount_t *mp)
+{
+ xfs_icsb_cnts_t *cntp;
+ int i;
+
+ for_each_online_cpu(i) {
+ cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
+ xfs_icsb_unlock_cntr(cntp);
+ }
+}
+
+STATIC void
+xfs_icsb_count(
+ xfs_mount_t *mp,
+ xfs_icsb_cnts_t *cnt,
+ int flags)
+{
+ xfs_icsb_cnts_t *cntp;
+ int i;
+
+ memset(cnt, 0, sizeof(xfs_icsb_cnts_t));
+
+ if (!(flags & XFS_ICSB_LAZY_COUNT))
+ xfs_icsb_lock_all_counters(mp);
+
+ for_each_online_cpu(i) {
+ cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
+ cnt->icsb_icount += cntp->icsb_icount;
+ cnt->icsb_ifree += cntp->icsb_ifree;
+ cnt->icsb_fdblocks += cntp->icsb_fdblocks;
+ }
+
+ if (!(flags & XFS_ICSB_LAZY_COUNT))
+ xfs_icsb_unlock_all_counters(mp);
+}
+
+STATIC int
+xfs_icsb_counter_disabled(
+ xfs_mount_t *mp,
+ xfs_sb_field_t field)
+{
+ ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
+ return test_bit(field, &mp->m_icsb_counters);
+}
+
+STATIC int
+xfs_icsb_disable_counter(
+ xfs_mount_t *mp,
+ xfs_sb_field_t field)
+{
+ xfs_icsb_cnts_t cnt;
+
+ ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
+
+ xfs_icsb_lock_all_counters(mp);
+ if (!test_and_set_bit(field, &mp->m_icsb_counters)) {
+ /* drain back to superblock */
+
+ xfs_icsb_count(mp, &cnt, XFS_ICSB_SB_LOCKED|XFS_ICSB_LAZY_COUNT);
+ switch(field) {
+ case XFS_SBS_ICOUNT:
+ mp->m_sb.sb_icount = cnt.icsb_icount;
+ break;
+ case XFS_SBS_IFREE:
+ mp->m_sb.sb_ifree = cnt.icsb_ifree;
+ break;
+ case XFS_SBS_FDBLOCKS:
+ mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
+ break;
+ default:
+ BUG();
+ }
+ }
+
+ xfs_icsb_unlock_all_counters(mp);
+
+ return 0;
+}
+
+STATIC void
+xfs_icsb_enable_counter(
+ xfs_mount_t *mp,
+ xfs_sb_field_t field,
+ uint64_t count,
+ uint64_t resid)
+{
+ xfs_icsb_cnts_t *cntp;
+ int i;
+
+ ASSERT((field >= XFS_SBS_ICOUNT) && (field <= XFS_SBS_FDBLOCKS));
+
+ xfs_icsb_lock_all_counters(mp);
+ for_each_online_cpu(i) {
+ cntp = per_cpu_ptr(mp->m_sb_cnts, i);
+ switch (field) {
+ case XFS_SBS_ICOUNT:
+ cntp->icsb_icount = count + resid;
+ break;
+ case XFS_SBS_IFREE:
+ cntp->icsb_ifree = count + resid;
+ break;
+ case XFS_SBS_FDBLOCKS:
+ cntp->icsb_fdblocks = count + resid;
+ break;
+ default:
+ BUG();
+ break;
+ }
+ resid = 0;
+ }
+ clear_bit(field, &mp->m_icsb_counters);
+ xfs_icsb_unlock_all_counters(mp);
+}
+
+STATIC void
+xfs_icsb_sync_counters_int(
+ xfs_mount_t *mp,
+ int flags)
+{
+ xfs_icsb_cnts_t cnt;
+ int s;
+
+ /* Pass 1: lock all counters */
+ if ((flags & XFS_ICSB_SB_LOCKED) == 0)
+ s = XFS_SB_LOCK(mp);
+
+ xfs_icsb_count(mp, &cnt, flags);
+
+ /* Step 3: update mp->m_sb fields */
+ if (!xfs_icsb_counter_disabled(mp, XFS_SBS_ICOUNT))
+ mp->m_sb.sb_icount = cnt.icsb_icount;
+ if (!xfs_icsb_counter_disabled(mp, XFS_SBS_IFREE))
+ mp->m_sb.sb_ifree = cnt.icsb_ifree;
+ if (!xfs_icsb_counter_disabled(mp, XFS_SBS_FDBLOCKS))
+ mp->m_sb.sb_fdblocks = cnt.icsb_fdblocks;
+
+ if ((flags & XFS_ICSB_SB_LOCKED) == 0)
+ XFS_SB_UNLOCK(mp, s);
+}
+
+/*
+ * Accurate update of per-cpu counters to incore superblock
+ */
+STATIC void
+xfs_icsb_sync_counters(
+ xfs_mount_t *mp)
+{
+ xfs_icsb_sync_counters_int(mp, 0);
+}
+
+/*
+ * lazy addition used for things like df, background sb syncs, etc
+ */
+void
+xfs_icsb_sync_counters_lazy(
+ xfs_mount_t *mp)
+{
+ xfs_icsb_sync_counters_int(mp, XFS_ICSB_LAZY_COUNT);
+}
+
+/*
+ * Balance and enable/disable counters as necessary.
+ *
+ * Thresholds for re-enabling counters are somewhat magic.
+ * inode counts are chosen to be the same number as single
+ * on disk allocation chunk per CPU, and free blocks is
+ * something far enough zero that we aren't going thrash
+ * when we get near ENOSPC.
+ */
+#define XFS_ICSB_INO_CNTR_REENABLE 64
+#define XFS_ICSB_FDBLK_CNTR_REENABLE 512
+STATIC void
+xfs_icsb_balance_counter(
+ xfs_mount_t *mp,
+ xfs_sb_field_t field,
+ int flags)
+{
+ uint64_t count, resid = 0;
+ int weight = num_online_cpus();
+ int s;
+
+ if (!(flags & XFS_ICSB_SB_LOCKED))
+ s = XFS_SB_LOCK(mp);
+
+ /* disable counter and sync counter */
+ xfs_icsb_disable_counter(mp, field);
+
+ /* update counters - first CPU gets residual*/
+ switch (field) {
+ case XFS_SBS_ICOUNT:
+ count = mp->m_sb.sb_icount;
+ resid = do_div(count, weight);
+ if (count < XFS_ICSB_INO_CNTR_REENABLE)
+ goto out;
+ break;
+ case XFS_SBS_IFREE:
+ count = mp->m_sb.sb_ifree;
+ resid = do_div(count, weight);
+ if (count < XFS_ICSB_INO_CNTR_REENABLE)
+ goto out;
+ break;
+ case XFS_SBS_FDBLOCKS:
+ count = mp->m_sb.sb_fdblocks;
+ resid = do_div(count, weight);
+ if (count < XFS_ICSB_FDBLK_CNTR_REENABLE)
+ goto out;
+ break;
+ default:
+ BUG();
+ break;
+ }
+
+ xfs_icsb_enable_counter(mp, field, count, resid);
+out:
+ if (!(flags & XFS_ICSB_SB_LOCKED))
+ XFS_SB_UNLOCK(mp, s);
+}
+
+STATIC int
+xfs_icsb_modify_counters_int(
+ xfs_mount_t *mp,
+ xfs_sb_field_t field,
+ int delta,
+ int rsvd,
+ int flags)
+{
+ xfs_icsb_cnts_t *icsbp;
+ long long lcounter; /* long counter for 64 bit fields */
+ int cpu, s, locked = 0;
+ int ret = 0, balance_done = 0;
+
+again:
+ cpu = get_cpu();
+ icsbp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, cpu),
+ xfs_icsb_lock_cntr(icsbp);
+ if (unlikely(xfs_icsb_counter_disabled(mp, field)))
+ goto slow_path;
+
+ switch (field) {
+ case XFS_SBS_ICOUNT:
+ lcounter = icsbp->icsb_icount;
+ lcounter += delta;
+ if (unlikely(lcounter < 0))
+ goto slow_path;
+ icsbp->icsb_icount = lcounter;
+ break;
+
+ case XFS_SBS_IFREE:
+ lcounter = icsbp->icsb_ifree;
+ lcounter += delta;
+ if (unlikely(lcounter < 0))
+ goto slow_path;
+ icsbp->icsb_ifree = lcounter;
+ break;
+
+ case XFS_SBS_FDBLOCKS:
+ BUG_ON((mp->m_resblks - mp->m_resblks_avail) != 0);
+
+ lcounter = icsbp->icsb_fdblocks;
+ lcounter += delta;
+ if (unlikely(lcounter < 0))
+ goto slow_path;
+ icsbp->icsb_fdblocks = lcounter;
+ break;
+ default:
+ BUG();
+ break;
+ }
+ xfs_icsb_unlock_cntr(icsbp);
+ put_cpu();
+ if (locked)
+ XFS_SB_UNLOCK(mp, s);
+ return 0;
+
+ /*
+ * The slow path needs to be run with the SBLOCK
+ * held so that we prevent other threads from
+ * attempting to run this path at the same time.
+ * this provides exclusion for the balancing code,
+ * and exclusive fallback if the balance does not
+ * provide enough resources to continue in an unlocked
+ * manner.
+ */
+slow_path:
+ xfs_icsb_unlock_cntr(icsbp);
+ put_cpu();
+
+ /* need to hold superblock incase we need
+ * to disable a counter */
+ if (!(flags & XFS_ICSB_SB_LOCKED)) {
+ s = XFS_SB_LOCK(mp);
+ locked = 1;
+ flags |= XFS_ICSB_SB_LOCKED;
+ }
+ if (!balance_done) {
+ xfs_icsb_balance_counter(mp, field, flags);
+ balance_done = 1;
+ goto again;
+ } else {
+ /*
+ * we might not have enough on this local
+ * cpu to allocate for a bulk request.
+ * We need to drain this field from all CPUs
+ * and disable the counter fastpath
+ */
+ xfs_icsb_disable_counter(mp, field);
+ }
+
+ ret = xfs_mod_incore_sb_unlocked(mp, field, delta, rsvd);
+
+ if (locked)
+ XFS_SB_UNLOCK(mp, s);
+ return ret;
+}
+
+STATIC int
+xfs_icsb_modify_counters(
+ xfs_mount_t *mp,
+ xfs_sb_field_t field,
+ int delta,
+ int rsvd)
+{
+ return xfs_icsb_modify_counters_int(mp, field, delta, rsvd, 0);
+}
+
+/*
+ * Called when superblock is already locked
+ */
+STATIC int
+xfs_icsb_modify_counters_locked(
+ xfs_mount_t *mp,
+ xfs_sb_field_t field,
+ int delta,
+ int rsvd)
+{
+ return xfs_icsb_modify_counters_int(mp, field, delta,
+ rsvd, XFS_ICSB_SB_LOCKED);
+}
+#endif