Rename the "gfs_recovery" workqueue to "gfs2_recovery", and
gfs_recovery_wq to gfs2_recovery_wq.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Replace sd_freeze_state with a new SDF_FROZEN flag.
There no longer is a need for indicating that a freeze is in progress
(SDF_STARTING_FREEZE); we are now protecting the critical sections with
the sd_freeze_mutex.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
So far, at mount time, gfs2 would take the freeze glock in shared mode
and then immediately drop it again, turning it into a cached glock that
can be reclaimed at any time. To freeze the filesystem cluster-wide,
the node initiating the freeze would take the freeze glock in exclusive
mode, which would cause the freeze glock's freeze_go_sync() callback to
run on each node. There, gfs2 would freeze the filesystem and schedule
gfs2_freeze_func() to run. gfs2_freeze_func() would re-acquire the
freeze glock in shared mode, thaw the filesystem, and drop the freeze
glock again. The initiating node would keep the freeze glock held in
exclusive mode. To thaw the filesystem, the initiating node would drop
the freeze glock again, which would allow gfs2_freeze_func() to resume
on all nodes, leaving the filesystem in the thawed state.
It turns out that in freeze_go_sync(), we cannot reliably and safely
freeze the filesystem. This is primarily because the final unmount of a
filesystem takes a write lock on the s_umount rw semaphore before
calling into gfs2_put_super(), and freeze_go_sync() needs to call
freeze_super() which also takes a write lock on the same semaphore,
causing a deadlock. We could work around this by trying to take an
active reference on the super block first, which would prevent unmount
from running at the same time. But that can fail, and freeze_go_sync()
isn't actually allowed to fail.
To get around this, this patch changes the freeze glock locking scheme
as follows:
At mount time, each node takes the freeze glock in shared mode. To
freeze a filesystem, the initiating node first freezes the filesystem
locally and then drops and re-acquires the freeze glock in exclusive
mode. All other nodes notice that there is contention on the freeze
glock in their go_callback callbacks, and they schedule
gfs2_freeze_func() to run. There, they freeze the filesystem locally
and drop and re-acquire the freeze glock before re-thawing the
filesystem. This is happening outside of the glock state engine, so
there, we are allowed to fail.
From a cluster point of view, taking and immediately dropping a glock is
indistinguishable from taking the glock and only dropping it upon
contention, so this new scheme is compatible with the old one.
Thanks to Li Dong <lidong@vivo.com> for reporting a locking bug in
gfs2_freeze_func() in a previous version of this commit.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Rename gfs2_freeze_lock to gfs2_freeze_lock_shared to make it a bit more
obvious that this function establishes the "thawed" state of the freeze
glock.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
The transaction glock was repurposed to serve as the new freeze glock
years ago. Don't refer to it as the transaction glock anymore.
Also, to be more precise, call it the "freeze glock" instead of the
"freeze lock". Ditto for the journal glock.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.
To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean [1].
This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.
Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
In preparation to enable -Wimplicit-fallthrough for Clang, fix multiple
warnings by explicitly adding multiple goto statements instead of just
letting the code fall through to the next case.
Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Building the kernel with W=1 results in a number of kernel-doc warnings
like incorrect function names and parameter descriptions. Fix those,
mostly by adding missing parameter descriptions, removing left-over
descriptions, and demoting some less important kernel-doc comments into
regular comments.
Originally proposed by Lee Jones; improved and combined into a single
patch by Andreas.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Convert gfs2_extent_map to iomap and split it into gfs2_get_extent and
gfs2_alloc_extent. Instead of hardcoding the extent size, pass it in
via the extlen parameter.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
In gfs2_recover_one, fix a sd_log_flush_lock imbalance when a recovery
pass fails.
Fixes: c9ebc4b737 ("gfs2: allow journal replay to hold sd_log_flush_lock")
Cc: stable@vger.kernel.org # v5.7+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
The recovery func can recover multiple journals, but they were all using
the same bio. This resulted in use-after-free related to sdp->sd_log_bio.
This patch moves the variable to the journal descriptor, jd, so that
every recovery can operate on its own bio. And hopefully we never run out.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Many places in the gfs2 code queued and dequeued the freeze glock.
Almost all of them acquire it in SHARED mode, and need to specify the
same LM_FLAG_NOEXP and GL_EXACT flags.
This patch adds common helper functions gfs2_freeze_lock and gfs2_freeze_unlock
to make the code more readable, and to prepare for the next patch.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, function gfs2_meta_sync called filemap_fdatawrite to write
the address space for the metadata being synced. That's great for inodes, but
resource groups all point to the same superblock-address space, sdp->sd_aspace.
Each rgrp has its own range of blocks on which it should operate. That meant
every time an rgrp's metadata was synced, it would write all of them instead
of just the range.
This patch eliminates function gfs2_meta_sync and tailors specific metasync
functions for inodes and rgrps.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Apply the outstanding statfs changes in the journal head to the
master statfs file. Zero out the local statfs file for good measure.
Previously, statfs updates would be read in from the local statfs inode and
synced to the master statfs inode during recovery.
We now use the statfs updates in the journal head to update the master statfs
inode instead of reading in from the local statfs inode. To preserve backward
compatibility with kernels that can't do this, we still need to keep the
local statfs inode up to date by writing changes to it. At some point in the
future, we can do away with the local statfs inodes altogether and keep the
statfs changes solely in the journal.
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
And read these in __get_log_header() from the log header.
Also make gfs2_statfs_change_out() non-static so it can be used
outside of super.c
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, the freeze code in gfs2 specified GL_NOCACHE in
several places. That's wrong because we always want to know the state
of whether the file system is frozen.
There was also a problem with freeze/thaw transitioning the glock from
frozen (EX) to thawed (SH) because gfs2 will normally grant glocks in EX
to processes that request it in SH mode, unless GL_EXACT is specified.
Therefore, the freeze/thaw code, which tried to reacquire the glock in
SH mode would get the glock in EX mode, and miss the transition from EX
to SH. That made it think the thaw had completed normally, but since the
glock was still cached in EX, other nodes could not freeze again.
This patch removes the GL_NOCACHE flag to allow the freeze glock to be
cached. It also adds the GL_EXACT flag so the glock is fully transitioned
from EX to SH, thereby allowing future freeze operations.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Function gfs2_recover_func grabs the sd_log_flush_lock rw_semaphore in
write mode. This is unnecessary because we only need to prevent log flush
from using sd_log_bio bio while it does. Therefore, a read lock will be
enough. This is a small step in cleaning up log flush.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Replace open-coded versions of list_first_entry and list_last_entry with those
functions.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Before this patch, journal replays could stomp on log flushes
and each other because both log flushes and journal replays used
the same sd_log_bio. Function gfs2_log_flush prevents other log
flushes from interfering by taking the sd_log_flush_lock rwsem
during the flush. However, it does not protect against journal
replays. This patch allows the journal replay to take the same
sd_log_flush_lock rwsem so use of the sd_log_bio is not stomped.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
When a node fails, user space informs dlm of the node failure,
and dlm instructs gfs2 on the surviving nodes to perform journal
recovery. It does this by calling various callback functions in
lock_dlm.c. To mark its progress, it keeps generation numbers
and recover bits in a dlm "control" lock lvb, which is seen by
all nodes to determine which journals need to be replayed.
The gfs2 on all nodes get the same recovery requests from dlm,
so they all try to do the recovery, but only one will be
granted the exclusive lock on the journal. The others fail
with a "Busy" message on their "try lock."
However, when a node is withdrawn, it cannot safely do any
recovery or replay any journals. To make matters worse,
gfs2 might withdraw as a result of attempting recovery. For
example, this might happen if the device goes offline, or if
an hba fails. But in today's gfs2 code, it doesn't check for
being withdrawn at any step in the recovery process. What's
worse is that these callbacks from dlm have no return code,
so there is no way to indicate failure back to dlm. We can
send a "Recovery failed" uevent eventually, but that tells
user space what happened, not dlm's kernel code.
Before this patch, lock_dlm would perform its recovery steps but
ignore the result, and eventually it would still update its
generation number in the lvb, despite the fact that it may have
withdrawn or encountered an error. The other nodes would then
see the newer generation number in the lvb and conclude that
they don't need to do recovery because the generation number
is newer than the last one they saw. They think a different
node has already recovered the journal.
This patch adds checks to several of the callbacks used by dlm
in its recovery state machine so that the functions are ignored
and skipped if an io error has occurred or if the file system
is withdrawn. That prevents the lvb bits from being updated, and
therefore dlm and user space still see the need for recovery to
take place.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
Function gfs2_write_log_header can be used to write a log header into any of
the journals of a filesystem. When used on the node's own journal,
gfs2_write_log_header advances the current position in the log
(sdp->sd_log_flush_head) as a side effect, through function gfs2_log_bmap.
This is confusing, and it also means that we can't use gfs2_log_bmap for other
journals even if they have an extent map. So clean this mess up by not
advancing sdp->sd_log_flush_head in gfs2_write_log_header or gfs2_log_bmap
anymore and making that a responsibility of the callers instead.
This is related to commit 7c70b89695 ("gfs2: clean_journal improperly set
sd_log_flush_head").
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
There is use of unnecessary semicolon after switch case.
Removed the semicolon.
Signed-off-by: Aliasgar Surti <aliasgar.surti500@gmail.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
When a journal is replayed, gfs2 logs a message similar to:
jid=X: Replaying journal...
This patch adds the tail and block number so that the range of the
replayed block is also printed. These values will match the values
shown if the journal is dumped with gfs2_edit -p journalX. The
resulting output looks something like this:
jid=1: Replaying journal...0x28b7 to 0x2beb
This will allow us to better debug file system corruption problems.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Based on 1 normalized pattern(s):
this copyrighted material is made available to anyone wishing to use
modify copy or redistribute it subject to the terms and conditions
of the gnu general public license version 2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 44 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081038.653000175@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use bios to read in the journal into the address space of the journal inode
(jd_inode), sequentially and in large chunks. This is faster for locating the
journal head that the previous binary search approach. When performing
recovery, we keep the journal in the address space until recovery is done,
which further speeds up things.
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch fixes regressions in 588bff95c9.
Due to that patch, function clean_journal was setting the value of
sd_log_flush_head, but that's only valid if it is replaying the node's
own journal. If it's replaying another node's journal, that's completely
wrong and will lead to multiple problems. This patch tries to clean up
the mess by passing the value of the logical journal block number into
gfs2_write_log_header so the function can treat non-owned journals
generically. For the local journal, the journal extent map is used for
best performance. For other nodes from other journals, new function
gfs2_lblk_to_dblk is called to figure it out using gfs2_iomap_get.
This patch also tries to establish more consistency when passing journal
block parameters by changing several unsigned int types to a consistent
u32.
Fixes: 588bff95c9 ("GFS2: Reduce code redundancy writing log headers")
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This reverts commit 2a5f14f279.
This patch causes xfstests generic/311 to fail. Reverting this for
now until we have a proper fix.
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use bio(s) to read in the journal sequentially in large chunks and
locate the head of the journal.
This version addresses the issues Christoph pointed out w.r.t error handling
and using deprecated API.
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Move and re-order the error checks and hash/crc computations into another
function __get_log_header() so it can be used in scenarios where buffer_heads
are not being used for the log header.
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Tells you how many milliseconds map_journal_extents and find_jhead
take.
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch fixes a couple problems dealing with spectators who
remain with gfs2 mounts after the last non-spectator node fails.
Before this patch, spectator mounts would try to acquire the dlm's
mounted lock EX as part of its normal recovery sequence.
The mounted lock is only used to determine whether the node is
the first mounter, the first node to mount the file system, for
the purposes of file system recovery and journal replay.
It's not necessary for spectators: they should never do journal
recovery. If they acquire the lock it will prevent another "real"
first-mounter from acquiring the lock in EX mode, which means it
also cannot do journal recovery because it doesn't think it's the
first node to mount the file system.
This patch checks if the mounter is a spectator, and if so, avoids
grabbing the mounted lock. This allows a secondary mounter who is
really the first non-spectator mounter, to do journal recovery:
since the spectator doesn't acquire the lock, it can grab it in
EX mode, and therefore consider itself to be the first mounter
both as a "real" first mount, and as a first-real-after-spectator.
Note that the control lock still needs to be taken in PR mode
in order to fetch the lvb value so it has the current status of
all journal's recovery. This is used as it is today by a first
mounter to replay the journals. For spectators, it's merely
used to fetch the status bits. All recovery is bypassed and the
node waits until recovery is completed by a non-spectator node.
I also improved the cryptic message given by control_mount when
a spectator is waiting for a non-spectator to perform recovery.
It also fixes a problem in gfs2_recover_set whereby spectators
were never queueing recovery work for their own journal.
They cannot do recovery themselves, but they still need to queue
the work so they can check the recovery bits and clear the
DFL_BLOCK_LOCKS bit once the recovery happens on another node.
When the work queue runs on a spectator, it bypasses most of the
work so it won't print a bunch of annoying messages. All it will
print is a bunch of messages that look like this until recovery
completes on the non-spectator node:
GFS2: fsid=mycluster:scratch.s: recover generation 3 jid 0
GFS2: fsid=mycluster:scratch.s: recover jid 0 result busy
These continue every 1.5 seconds until the recovery is done by
the non-spectator, at which time it says:
GFS2: fsid=mycluster:scratch.s: recover generation 4 done
Then it proceeds with its mount.
If the file system is mounted in spectator node and the last
remaining non-spectator is fenced, any IO to the file system is
blocked by dlm and the spectator waits until recovery is
performed by a non-spectator.
If a spectator tries to mount the file system before any
non-spectators, it blocks and repeatedly gives this kernel
message:
GFS2: fsid=mycluster:scratch: Recovery is required. Waiting for a non-spectator to mount.
GFS2: fsid=mycluster:scratch: Recovery is required. Waiting for a non-spectator to mount.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch spits out the time taken by the various steps in the
journal recover process. Previously, the journal recovery time
didn't account for finding the journal head in the log which takes
up a significant portion of time.
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This patch adds a new structure called gfs2_log_header_v2 which is used
to store expanded fields into previously unused areas of the log headers
(i.e., this change is backwards compatible). Some of these are used for
debug purposes so we can backtrack when problems occur. Others are
reserved for future expansion.
This patch is based on a prototype from Steve Whitehouse.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Get rid of gfs2_log_header_in by integrating it into get_log_header.
Clean up the crc32 computations and use the same functions for encoding
and decoding to make things less confusing. Eliminate lh_hash from
gfs2_log_header_host which is completely useless.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Before this patch, there was a lot of code redundancy between functions
log_write_header (which uses bio) and clean_journal (which uses
buffer_head). This patch reduces the redundancy to simplify the code
and make log header writing more consistent. We want more consistency
and reduced redundancy because we plan to add a bunch of new fields
to improve performance (by eliminating the local statfs and quota files)
improve metadata integrity (by adding new crcs and such) and for better
debugging (by adding new fields to track when and where metadata was
pushed through the journals.) We don't want to duplicate setting these
new fields, nor allow for human error in the process.
This reduction in code redundancy is accomplished by introducing a new
helper function, gfs2_write_log_header which uses bio rather than bh.
That simplifies recovery function clean_journal() to use the new helper
function and iomap rather than redundancy and block_map (and eventually
we can maybe remove block_map). It also reduces our dependency on
buffer_heads.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Firstly by applying the following with coccinelle's spatch:
@@ expression SB; @@
-SB->s_flags & MS_RDONLY
+sb_rdonly(SB)
to effect the conversion to sb_rdonly(sb), then by applying:
@@ expression A, SB; @@
(
-(!sb_rdonly(SB)) && A
+!sb_rdonly(SB) && A
|
-A != (sb_rdonly(SB))
+A != sb_rdonly(SB)
|
-A == (sb_rdonly(SB))
+A == sb_rdonly(SB)
|
-!(sb_rdonly(SB))
+!sb_rdonly(SB)
|
-A && (sb_rdonly(SB))
+A && sb_rdonly(SB)
|
-A || (sb_rdonly(SB))
+A || sb_rdonly(SB)
|
-(sb_rdonly(SB)) != A
+sb_rdonly(SB) != A
|
-(sb_rdonly(SB)) == A
+sb_rdonly(SB) == A
|
-(sb_rdonly(SB)) && A
+sb_rdonly(SB) && A
|
-(sb_rdonly(SB)) || A
+sb_rdonly(SB) || A
)
@@ expression A, B, SB; @@
(
-(sb_rdonly(SB)) ? 1 : 0
+sb_rdonly(SB)
|
-(sb_rdonly(SB)) ? A : B
+sb_rdonly(SB) ? A : B
)
to remove left over excess bracketage and finally by applying:
@@ expression A, SB; @@
(
-(A & MS_RDONLY) != sb_rdonly(SB)
+(bool)(A & MS_RDONLY) != sb_rdonly(SB)
|
-(A & MS_RDONLY) == sb_rdonly(SB)
+(bool)(A & MS_RDONLY) == sb_rdonly(SB)
)
to make comparisons against the result of sb_rdonly() (which is a bool)
work correctly.
Signed-off-by: David Howells <dhowells@redhat.com>
Before this patch, if you used gfs2_jadd to add new journals of a
size smaller than the existing journals, replaying those new journals
would withdraw. That's because function gfs2_replay_incr_blk was
using the number of journal blocks (jd_block) from the superblock's
journal pointer. In other words, "My journal's max size" rather than
"the journal we're replaying's size." This patch changes the function
to use the size of the pertinent journal rather than always using the
journal we happen to be using.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Sprintf format specifier "%d" and "%u" are mixed up in
gfs2_recovery_done() and freeze_show(). So correct them.
Signed-off-by: Alex Chen <alex.chen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
The current "wait_on_bit" interface requires an 'action'
function to be provided which does the actual waiting.
There are over 20 such functions, many of them identical.
Most cases can be satisfied by one of just two functions, one
which uses io_schedule() and one which just uses schedule().
So:
Rename wait_on_bit and wait_on_bit_lock to
wait_on_bit_action and wait_on_bit_lock_action
to make it explicit that they need an action function.
Introduce new wait_on_bit{,_lock} and wait_on_bit{,_lock}_io
which are *not* given an action function but implicitly use
a standard one.
The decision to error-out if a signal is pending is now made
based on the 'mode' argument rather than being encoded in the action
function.
All instances of the old wait_on_bit and wait_on_bit_lock which
can use the new version have been changed accordingly and their
action functions have been discarded.
wait_on_bit{_lock} does not return any specific error code in the
event of a signal so the caller must check for non-zero and
interpolate their own error code as appropriate.
The wait_on_bit() call in __fscache_wait_on_invalidate() was
ambiguous as it specified TASK_UNINTERRUPTIBLE but used
fscache_wait_bit_interruptible as an action function.
David Howells confirms this should be uniformly
"uninterruptible"
The main remaining user of wait_on_bit{,_lock}_action is NFS
which needs to use a freezer-aware schedule() call.
A comment in fs/gfs2/glock.c notes that having multiple 'action'
functions is useful as they display differently in the 'wchan'
field of 'ps'. (and /proc/$PID/wchan).
As the new bit_wait{,_io} functions are tagged "__sched", they
will not show up at all, but something higher in the stack. So
the distinction will still be visible, only with different
function names (gds2_glock_wait versus gfs2_glock_dq_wait in the
gfs2/glock.c case).
Since first version of this patch (against 3.15) two new action
functions appeared, on in NFS and one in CIFS. CIFS also now
uses an action function that makes the same freezer aware
schedule call as NFS.
Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: David Howells <dhowells@redhat.com> (fscache, keys)
Acked-by: Steven Whitehouse <swhiteho@redhat.com> (gfs2)
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steve French <sfrench@samba.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140707051603.28027.72349.stgit@notabene.brown
Signed-off-by: Ingo Molnar <mingo@kernel.org>
It is probably also the first one without a single patch from me. That
is down to a combination of factors, and I have some things in the works
that are not quite ready yet, that I hope to put in next time around.
Returning to what is here this time... we have 3 patches which fix
various warnings. Two are bug fixes (for quotas and also a
rare recovery race condition). The final patch, from Ben Marzinski,
is an important change in the freeze code which has been in
progress for some time. This removes the need to take and drop the
transaction lock for every single transaction, when the only time it
was used, was at file system freeze time. Ben's patch integrates the
freeze operation into the journal flush code as an alternative with
lower overheads and also lands up resolving some difficult to fix races
at the same time.
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Merge tag 'gfs2-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw into next
Pull gfs2 updates from Steven Whitehouse:
"This must be about the smallest merge window patch set ever for GFS2.
It is probably also the first one without a single patch from me.
That is down to a combination of factors, and I have some things in
the works that are not quite ready yet, that I hope to put in next
time around.
Returning to what is here this time... we have 3 patches which fix
various warnings. Two are bug fixes (for quotas and also a rare
recovery race condition). The final patch, from Ben Marzinski, is an
important change in the freeze code which has been in progress for
some time. This removes the need to take and drop the transaction
lock for every single transaction, when the only time it was used, was
at file system freeze time. Ben's patch integrates the freeze
operation into the journal flush code as an alternative with lower
overheads and also lands up resolving some difficult to fix races at
the same time"
* tag 'gfs2-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw:
GFS2: Prevent recovery before the local journal is set
GFS2: fs/gfs2/file.c: kernel-doc warning fixes
GFS2: fs/gfs2/bmap.c: kernel-doc warning fixes
GFS2: remove transaction glock
GFS2: lops.c: replace 0 by NULL for pointers
GFS2: quotas not being refreshed in gfs2_adjust_quota
GFS2 has a transaction glock, which must be grabbed for every
transaction, whose purpose is to deal with freezing the filesystem.
Aside from this involving a large amount of locking, it is very easy to
make the current fsfreeze code hang on unfreezing.
This patch rewrites how gfs2 handles freezing the filesystem. The
transaction glock is removed. In it's place is a freeze glock, which is
cached (but not held) in a shared state by every node in the cluster
when the filesystem is mounted. This lock only needs to be grabbed on
freezing, and actions which need to be safe from freezing, like
recovery.
When a node wants to freeze the filesystem, it grabs this glock
exclusively. When the freeze glock state changes on the nodes (either
from shared to unlocked, or shared to exclusive), the filesystem does a
special log flush. gfs2_log_flush() does all the work for flushing out
the and shutting down the incore log, and then it tries to grab the
freeze glock in a shared state again. Since the filesystem is stuck in
gfs2_log_flush, no new transaction can start, and nothing can be written
to disk. Unfreezing the filesytem simply involes dropping the freeze
glock, allowing gfs2_log_flush() to grab and then release the shared
lock, so it is cached for next time.
However, in order for the unfreezing ioctl to occur, gfs2 needs to get a
shared lock on the filesystem root directory inode to check permissions.
If that glock has already been grabbed exclusively, fsfreeze will be
unable to get the shared lock and unfreeze the filesystem.
In order to allow the unfreeze, this patch makes gfs2 grab a shared lock
on the filesystem root directory during the freeze, and hold it until it
unfreezes the filesystem. The functions which need to grab a shared
lock in order to allow the unfreeze ioctl to be issued now use the lock
grabbed by the freeze code instead.
The freeze and unfreeze code take care to make sure that this shared
lock will not be dropped while another process is using it.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
If multiple nodes fail and their recovery work runs simultaneously, they
would use the same unprotected variables in the superblock. For example,
they would stomp on each other's revoked blocks lists, which resulted
in file system metadata corruption. This patch moves the necessary
variables so that each journal has its own separate area for tracking
its journal replay.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
If the first mounter fails to recover one of the journals
during mount, the mount should fail.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Previously, a spectator mount would not even attempt to do
journal recovery for a failed node. This meant that if all
mounted nodes were spectators, everyone would be stuck after
a node failed, all waiting for recovery to be performed.
This is unnecessary since the failed node had a clean journal.
Instead, allow a spectator mount to do a partial "read only"
recovery, which means it will check if the failed journal is
clean, and if so, report a successful recovery. If the failed
journal is not clean, it reports that journal recovery failed.
This makes it work the same as a read only mount on a read only
block device.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This new method of managing recovery is an alternative to
the previous approach of using the userland gfs_controld.
- use dlm slot numbers to assign journal id's
- use dlm recovery callbacks to initiate journal recovery
- use a dlm lock to determine the first node to mount fs
- use a dlm lock to track journals that need recovery
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
The tests further down the recovery function relating to
unlocking the journal need to be updated to match the
intial test. Also, a test in the umount code which was
surplus to requirements has been removed. Umounting
spectator mounts now works correctly, as expected.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
When checking journals for spectator mounts, we cannot rely on the
journal being locked, whatever its jid might be. This patch
ensures that we always get the journal locks when checking
journals for a spectator mount.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Workqueue can now handle high concurrency. Convert gfs to use
workqueue instead of slow-work.
* Steven pointed out that recovery path might be run from allocation
path and thus requires forward progress guarantee without memory
allocation. Create and use gfs_recovery_wq with rescuer. Please
note that forward progress wasn't guaranteed with slow-work.
* Updated to use non-reentrant workqueue.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
There are two spare field in the header common to all GFS2
metadata. One is just the right size to fit a journal id
in it, and this patch updates the journal code so that each
time a metadata block is modified, we tag it with the journal
id of the node which is performing the modification.
The reason for this is that it should make it much easier to
debug issues which arise if we can tell which node was the
last to modify a particular metadata block.
Since the field is updated before the block is written into
the journal, each journal should only contain metadata which
is tagged with its own journal id. The one exception to this
is the journal header block, which might have a different node's
id in it, if that journal was recovered by another node in the
cluster.
Thus each journal will contain a record of which nodes recovered
it, via the journal header.
The other field in the metadata header could potentially be
used to hold information about what kind of operation was
performed, but for the time being we just zero it on each
transaction so that if we use it for that in future, we'll
know that the information (where it exists) is reliable.
I did consider using the other field to hold the journal
sequence number, however since in GFS2's journaling we write
the modified data into the journal and not the original
data, this gives no information as to what action caused the
modification, so I think we can probably come up with a better
use for those 64 bits in the future.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
