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authorLinus Torvalds <torvalds@linux-foundation.org>2022-04-01 19:30:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2022-04-01 19:30:44 -0700
commitb32e3819a8230332d7848a6fb067aee52d08557e (patch)
tree32f4b0f37f28cbad0a66f87f3c857bd362e06d19 /fs/xfs/xfs_log.c
parent1fdff407028c6064be96343f4bac31a0e679cbd0 (diff)
parent919edbadebe17a67193533f531c2920c03e40fa4 (diff)
Merge tag 'xfs-5.18-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs fixes from Darrick Wong: "This fixes multiple problems in the reserve pool sizing functions: an incorrect free space calculation, a pointless infinite loop, and even more braindamage that could result in the pool being overfilled. The pile of patches from Dave fix myriad races and UAF bugs in the log recovery code that much to our mutual surprise nobody's tripped over. Dave also fixed a performance optimization that had turned into a regression. Dave Chinner is taking over as XFS maintainer starting Sunday and lasting until 5.19-rc1 is tagged so that I can focus on starting a massive design review for the (feature complete after five years) online repair feature. From then on, he and I will be moving XFS to a co-maintainership model by trading duties every other release. NOTE: I hope very strongly that the other pieces of the (X)FS ecosystem (fstests and xfsprogs) will make similar changes to spread their maintenance load. Summary: - Fix an incorrect free space calculation in xfs_reserve_blocks that could lead to a request for free blocks that will never succeed. - Fix a hang in xfs_reserve_blocks caused by an infinite loop and the incorrect free space calculation. - Fix yet a third problem in xfs_reserve_blocks where multiple racing threads can overfill the reserve pool. - Fix an accounting error that lead to us reporting reserved space as "available". - Fix a race condition during abnormal fs shutdown that could cause UAF problems when memory reclaim and log shutdown try to clean up inodes. - Fix a bug where log shutdown can race with unmount to tear down the log, thereby causing UAF errors. - Disentangle log and filesystem shutdown to reduce confusion. - Fix some confusion in xfs_trans_commit such that a race between transaction commit and filesystem shutdown can cause unlogged dirty inode metadata to be committed, thereby corrupting the filesystem. - Remove a performance optimization in the log as it was discovered that certain storage hardware handle async log flushes so poorly as to cause serious performance regressions. Recent restructuring of other parts of the logging code mean that no performance benefit is seen on hardware that handle it well" * tag 'xfs-5.18-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: drop async cache flushes from CIL commits. xfs: shutdown during log recovery needs to mark the log shutdown xfs: xfs_trans_commit() path must check for log shutdown xfs: xfs_do_force_shutdown needs to block racing shutdowns xfs: log shutdown triggers should only shut down the log xfs: run callbacks before waking waiters in xlog_state_shutdown_callbacks xfs: shutdown in intent recovery has non-intent items in the AIL xfs: aborting inodes on shutdown may need buffer lock xfs: don't report reserved bnobt space as available xfs: fix overfilling of reserve pool xfs: always succeed at setting the reserve pool size xfs: remove infinite loop when reserving free block pool xfs: don't include bnobt blocks when reserving free block pool xfs: document the XFS_ALLOC_AGFL_RESERVE constant
Diffstat (limited to 'fs/xfs/xfs_log.c')
-rw-r--r--fs/xfs/xfs_log.c109
1 files changed, 58 insertions, 51 deletions
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index a8034c0afdf2..499e15b24215 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -487,7 +487,10 @@ out_error:
* Run all the pending iclog callbacks and wake log force waiters and iclog
* space waiters so they can process the newly set shutdown state. We really
* don't care what order we process callbacks here because the log is shut down
- * and so state cannot change on disk anymore.
+ * and so state cannot change on disk anymore. However, we cannot wake waiters
+ * until the callbacks have been processed because we may be in unmount and
+ * we must ensure that all AIL operations the callbacks perform have completed
+ * before we tear down the AIL.
*
* We avoid processing actively referenced iclogs so that we don't run callbacks
* while the iclog owner might still be preparing the iclog for IO submssion.
@@ -501,7 +504,6 @@ xlog_state_shutdown_callbacks(
struct xlog_in_core *iclog;
LIST_HEAD(cb_list);
- spin_lock(&log->l_icloglock);
iclog = log->l_iclog;
do {
if (atomic_read(&iclog->ic_refcnt)) {
@@ -509,26 +511,22 @@ xlog_state_shutdown_callbacks(
continue;
}
list_splice_init(&iclog->ic_callbacks, &cb_list);
+ spin_unlock(&log->l_icloglock);
+
+ xlog_cil_process_committed(&cb_list);
+
+ spin_lock(&log->l_icloglock);
wake_up_all(&iclog->ic_write_wait);
wake_up_all(&iclog->ic_force_wait);
} while ((iclog = iclog->ic_next) != log->l_iclog);
wake_up_all(&log->l_flush_wait);
- spin_unlock(&log->l_icloglock);
-
- xlog_cil_process_committed(&cb_list);
}
/*
* Flush iclog to disk if this is the last reference to the given iclog and the
* it is in the WANT_SYNC state.
*
- * If the caller passes in a non-zero @old_tail_lsn and the current log tail
- * does not match, there may be metadata on disk that must be persisted before
- * this iclog is written. To satisfy that requirement, set the
- * XLOG_ICL_NEED_FLUSH flag as a condition for writing this iclog with the new
- * log tail value.
- *
* If XLOG_ICL_NEED_FUA is already set on the iclog, we need to ensure that the
* log tail is updated correctly. NEED_FUA indicates that the iclog will be
* written to stable storage, and implies that a commit record is contained
@@ -545,12 +543,10 @@ xlog_state_shutdown_callbacks(
* always capture the tail lsn on the iclog on the first NEED_FUA release
* regardless of the number of active reference counts on this iclog.
*/
-
int
xlog_state_release_iclog(
struct xlog *log,
- struct xlog_in_core *iclog,
- xfs_lsn_t old_tail_lsn)
+ struct xlog_in_core *iclog)
{
xfs_lsn_t tail_lsn;
bool last_ref;
@@ -561,18 +557,14 @@ xlog_state_release_iclog(
/*
* Grabbing the current log tail needs to be atomic w.r.t. the writing
* of the tail LSN into the iclog so we guarantee that the log tail does
- * not move between deciding if a cache flush is required and writing
- * the LSN into the iclog below.
+ * not move between the first time we know that the iclog needs to be
+ * made stable and when we eventually submit it.
*/
- if (old_tail_lsn || iclog->ic_state == XLOG_STATE_WANT_SYNC) {
+ if ((iclog->ic_state == XLOG_STATE_WANT_SYNC ||
+ (iclog->ic_flags & XLOG_ICL_NEED_FUA)) &&
+ !iclog->ic_header.h_tail_lsn) {
tail_lsn = xlog_assign_tail_lsn(log->l_mp);
-
- if (old_tail_lsn && tail_lsn != old_tail_lsn)
- iclog->ic_flags |= XLOG_ICL_NEED_FLUSH;
-
- if ((iclog->ic_flags & XLOG_ICL_NEED_FUA) &&
- !iclog->ic_header.h_tail_lsn)
- iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn);
+ iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn);
}
last_ref = atomic_dec_and_test(&iclog->ic_refcnt);
@@ -583,11 +575,8 @@ xlog_state_release_iclog(
* pending iclog callbacks that were waiting on the release of
* this iclog.
*/
- if (last_ref) {
- spin_unlock(&log->l_icloglock);
+ if (last_ref)
xlog_state_shutdown_callbacks(log);
- spin_lock(&log->l_icloglock);
- }
return -EIO;
}
@@ -600,8 +589,6 @@ xlog_state_release_iclog(
}
iclog->ic_state = XLOG_STATE_SYNCING;
- if (!iclog->ic_header.h_tail_lsn)
- iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn);
xlog_verify_tail_lsn(log, iclog);
trace_xlog_iclog_syncing(iclog, _RET_IP_);
@@ -873,7 +860,7 @@ xlog_force_iclog(
iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA;
if (iclog->ic_state == XLOG_STATE_ACTIVE)
xlog_state_switch_iclogs(iclog->ic_log, iclog, 0);
- return xlog_state_release_iclog(iclog->ic_log, iclog, 0);
+ return xlog_state_release_iclog(iclog->ic_log, iclog);
}
/*
@@ -1373,7 +1360,7 @@ xlog_ioend_work(
*/
if (XFS_TEST_ERROR(error, log->l_mp, XFS_ERRTAG_IODONE_IOERR)) {
xfs_alert(log->l_mp, "log I/O error %d", error);
- xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
+ xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
}
xlog_state_done_syncing(iclog);
@@ -1912,7 +1899,7 @@ xlog_write_iclog(
iclog->ic_flags &= ~(XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA);
if (xlog_map_iclog_data(&iclog->ic_bio, iclog->ic_data, count)) {
- xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
+ xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
return;
}
if (is_vmalloc_addr(iclog->ic_data))
@@ -2411,7 +2398,7 @@ xlog_write_copy_finish(
ASSERT(iclog->ic_state == XLOG_STATE_WANT_SYNC ||
xlog_is_shutdown(log));
release_iclog:
- error = xlog_state_release_iclog(log, iclog, 0);
+ error = xlog_state_release_iclog(log, iclog);
spin_unlock(&log->l_icloglock);
return error;
}
@@ -2487,7 +2474,7 @@ xlog_write(
xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
"ctx ticket reservation ran out. Need to up reservation");
xlog_print_tic_res(log->l_mp, ticket);
- xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
+ xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
}
len = xlog_write_calc_vec_length(ticket, log_vector, optype);
@@ -2628,7 +2615,7 @@ next_lv:
spin_lock(&log->l_icloglock);
xlog_state_finish_copy(log, iclog, record_cnt, data_cnt);
- error = xlog_state_release_iclog(log, iclog, 0);
+ error = xlog_state_release_iclog(log, iclog);
spin_unlock(&log->l_icloglock);
return error;
@@ -3052,7 +3039,7 @@ restart:
* reference to the iclog.
*/
if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1))
- error = xlog_state_release_iclog(log, iclog, 0);
+ error = xlog_state_release_iclog(log, iclog);
spin_unlock(&log->l_icloglock);
if (error)
return error;
@@ -3821,9 +3808,10 @@ xlog_verify_iclog(
#endif
/*
- * Perform a forced shutdown on the log. This should be called once and once
- * only by the high level filesystem shutdown code to shut the log subsystem
- * down cleanly.
+ * Perform a forced shutdown on the log.
+ *
+ * This can be called from low level log code to trigger a shutdown, or from the
+ * high level mount shutdown code when the mount shuts down.
*
* Our main objectives here are to make sure that:
* a. if the shutdown was not due to a log IO error, flush the logs to
@@ -3832,6 +3820,8 @@ xlog_verify_iclog(
* parties to find out. Nothing new gets queued after this is done.
* c. Tasks sleeping on log reservations, pinned objects and
* other resources get woken up.
+ * d. The mount is also marked as shut down so that log triggered shutdowns
+ * still behave the same as if they called xfs_forced_shutdown().
*
* Return true if the shutdown cause was a log IO error and we actually shut the
* log down.
@@ -3843,25 +3833,25 @@ xlog_force_shutdown(
{
bool log_error = (shutdown_flags & SHUTDOWN_LOG_IO_ERROR);
- /*
- * If this happens during log recovery then we aren't using the runtime
- * log mechanisms yet so there's nothing to shut down.
- */
- if (!log || xlog_in_recovery(log))
+ if (!log)
return false;
- ASSERT(!xlog_is_shutdown(log));
-
/*
* Flush all the completed transactions to disk before marking the log
* being shut down. We need to do this first as shutting down the log
* before the force will prevent the log force from flushing the iclogs
* to disk.
*
- * Re-entry due to a log IO error shutdown during the log force is
- * prevented by the atomicity of higher level shutdown code.
+ * When we are in recovery, there are no transactions to flush, and
+ * we don't want to touch the log because we don't want to perturb the
+ * current head/tail for future recovery attempts. Hence we need to
+ * avoid a log force in this case.
+ *
+ * If we are shutting down due to a log IO error, then we must avoid
+ * trying to write the log as that may just result in more IO errors and
+ * an endless shutdown/force loop.
*/
- if (!log_error)
+ if (!log_error && !xlog_in_recovery(log))
xfs_log_force(log->l_mp, XFS_LOG_SYNC);
/*
@@ -3878,12 +3868,25 @@ xlog_force_shutdown(
spin_lock(&log->l_icloglock);
if (test_and_set_bit(XLOG_IO_ERROR, &log->l_opstate)) {
spin_unlock(&log->l_icloglock);
- ASSERT(0);
return false;
}
spin_unlock(&log->l_icloglock);
/*
+ * If this log shutdown also sets the mount shutdown state, issue a
+ * shutdown warning message.
+ */
+ if (!test_and_set_bit(XFS_OPSTATE_SHUTDOWN, &log->l_mp->m_opstate)) {
+ xfs_alert_tag(log->l_mp, XFS_PTAG_SHUTDOWN_LOGERROR,
+"Filesystem has been shut down due to log error (0x%x).",
+ shutdown_flags);
+ xfs_alert(log->l_mp,
+"Please unmount the filesystem and rectify the problem(s).");
+ if (xfs_error_level >= XFS_ERRLEVEL_HIGH)
+ xfs_stack_trace();
+ }
+
+ /*
* We don't want anybody waiting for log reservations after this. That
* means we have to wake up everybody queued up on reserveq as well as
* writeq. In addition, we make sure in xlog_{re}grant_log_space that
@@ -3903,8 +3906,12 @@ xlog_force_shutdown(
wake_up_all(&log->l_cilp->xc_start_wait);
wake_up_all(&log->l_cilp->xc_commit_wait);
spin_unlock(&log->l_cilp->xc_push_lock);
+
+ spin_lock(&log->l_icloglock);
xlog_state_shutdown_callbacks(log);
+ spin_unlock(&log->l_icloglock);
+ wake_up_var(&log->l_opstate);
return log_error;
}