This patch takes advantage of the new glock holder sharing feature for
resource groups. We have already introduced local resource group
locking in a previous patch, so competing accesses of local processes
are already under control.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Prepare for treating resource group glocks as exclusive among nodes but
shared among all tasks running on a node: introduce another layer of
node-specific locking that the local tasks can use to coordinate their
accesses.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Add a rs_reserved field to struct gfs2_blkreserv to keep track of the number of
blocks reserved by this particular reservation, and a rd_reserved field to
struct gfs2_rgrpd to keep track of the total number of reserved blocks in the
resource group. Those blocks are exclusively reserved, as opposed to the
rs_requested / rd_requested blocks which are tracked in the reservation tree
(rd_rstree) and which can be stolen if necessary.
When making a reservation with gfs2_inplace_reserve, rs_reserved is set to
somewhere between ap->min_target and ap->target depending on the number of free
blocks in the resource group. When allocating blocks with gfs2_alloc_blocks,
rs_reserved is decremented accordingly. Eventually, any reserved but not
consumed blocks are returned to the resource group by gfs2_inplace_release.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
We keep track of what we've so far been referring to as reservations in
rd_rstree: the nodes in that tree indicate where in a resource group we'd
like to allocate the next couple of blocks for a particular inode. Local
processes take those as hints, but they may still "steal" blocks from those
extents, so when actually allocating a block, we must double check in the
bitmap whether that block is actually still free. Likewise, other cluster
nodes may "steal" such blocks as well.
One of the following patches introduces resource group glock sharing, i.e.,
sharing of an exclusively locked resource group glock among local processes to
speed up allocations. To make that work, we'll need to keep track of how many
blocks we've actually reserved for each inode, so we end up with two different
kinds of reservations.
Distinguish these two kinds by referring to blocks which are reserved but may
still be "stolen" as "requested". This rename also makes it more obvious that
rs_requested and rd_requested are strongly related.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
If gfs2_inplace_reserve has chosen a resource group but it couldn't make a
reservation there, there are too many other reservations in that resource
group. In that case, don't even try to respect existing reservations in
gfs2_alloc_blocks.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Only pass the current reservation down to gfs2_rbm_find rather than the entire
inode; we don't need any of the other information.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Pass a non-NULL minext to gfs2_rbm_find even for single-block allocations. In
gfs2_rbm_find, also set rgd->rd_extfail_pt when a single-block allocation
fails in a resource group: there is no reason for treating that case
differently. In gfs2_reservation_check_and_update, only check how many free
blocks we have if more than one block is requested; we already know there's at
least one free block.
In addition, when allocating N blocks fails in gfs2_rbm_find, we need to set
rd_extfail_pt to N - 1 rather than N: rd_extfail_pt defines the biggest
allocation that might still succeed.
Finally, reset rd_extfail_pt when updating the resource group statistics in
update_rgrp_lvb, as we already do in gfs2_rgrp_bh_get.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
When reading a resource group from disk or when receiving the resource group
statistics from a Lock Value Block (LVB), set/clear the GBF_FULL flags of all
bitmaps in that resource group according to whether or not the resource group
is full.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Removing a reservation doesn't make any actual space available, so don't clear
the GBF_FULL flags in that case. Otherwise, we'll only spend more time
scanning the bitmaps unnecessarily.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This reverts commit e79e0e1428.
It turns out that we're only setting the GBF_FULL flag of a bitmap if we've
been scanning from the beginning of the bitmap until the end and we haven't
found a single free block, and we're not skipping reservations in that process,
either. This means that in gfs2_rbm_find, we can always skip bitmaps with the
GBF_FULL flag set.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Variable ndata is only used inside "if (!dinode)", so it can be replaced
entirely with *nblocks.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
GFS2 uses struct gfs2_rbm to represent a filesystem block number as a
bit position within a resource group. This representation is used in
the bitmap manipulation code to prevent excessive conversions between
block numbers and bit positions, but also in struct gfs2_blkreserv which
is part of struct gfs2_inode, to mark the start of a reservation. In
the inode, the bit position representation makes less sense: first, the
start position is used as a block number about as often as a bit
position; second, the bit position representation makes the code
unnecessarily complicated and difficult to read.
Therefore, change struct gfs2_blkreserv to represent the start of a
reservation as a block number instead of a bit position. (This requires
keeping track of the resource group in gfs2_blkreserv separately.) With
that change, various things can be slightly simplified, and struct
gfs2_rbm can be moved to rgrp.c.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Change gfs2_rbm_incr to advance an rbm by a given number of blocks. Use that
in gfs2_reservation_check_and_update to save a gfs2_rbm_to_block ->
gfs2_rbm_from_block round trip.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
If gfs2 tries to mount a (corrupt) file system that has no resource
groups it still tries to set preferences on the first one, which causes
a kernel null pointer dereference. This patch adds a check to function
gfs2_ri_update so this condition is detected and reported back as an
error.
Reported-by: syzbot+e3f23ce40269a4c9053a@syzkaller.appspotmail.com
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
In the fail path of gfs2_check_blk_type, forgetting to call
gfs2_glock_dq_uninit will result in rgd_gh reference leak.
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, gfs2_fitrim was not properly checking for a "live" file
system. If the file system had something to trim and the file system
was read-only (or spectator) it would start the trim, but when it starts
the transaction, gfs2_trans_begin returns -EROFS (read-only file system)
and it errors out. However, if the file system was already trimmed so
there's no work to do, it never called gfs2_trans_begin. That code is
bypassed so it never returns the error. Instead, it returns a good
return code with 0 work. All this makes for inconsistent behavior:
The same fstrim command can return -EROFS in one case and 0 in another.
This tripped up xfstests generic/537 which reports the error as:
+fstrim with unrecovered metadata just ate your filesystem
This patch adds a check for a "live" (iow, active journal, iow, RW)
file system, and if not, returns the error properly.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Function gfs2_clear_rgrpd calls kfree(rgd->rd_bits) before calling
return_all_reservations, but return_all_reservations still dereferences
rgd->rd_bits in __rs_deltree. Fix that by moving the call to kfree below the
call to return_all_reservations.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
The gfs2_glock structure has a gl_vm member, introduced in commit 7005c3e4ae
("GFS2: Use range based functions for rgrp sync/invalidation"), which stores
the location of resource groups within their address space. This structure is
in a union with iopen glock specific fields. It was introduced because at
unmount time, the resource group objects were destroyed before flushing out any
pending resource group glock work, and flushing out such work could require
flushing / truncating the address space.
Since commit b3422cacdd ("gfs2: Rework how rgrp buffer_heads are managed"),
any pending resource group glock work is flushed out before destroying the
resource group objects. So the resource group objects will now always exist in
rgrp_go_sync and rgrp_go_inval, and we now simply compute the gl_vm values
where needed instead of caching them. This also eliminates the union.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, when blocks were freed, it called gfs2_meta_wipe to
take the metadata out of the pending journal blocks. It did this mostly
by calling another function called gfs2_remove_from_journal. This is
shortsighted because it does not do anything with jdata blocks which
may also be in the journal.
This patch expands the function so that it wipes out jdata blocks from
the journal as well, and it wipes it from the ail1 list if it hasn't
been written back yet. Since it now processes jdata blocks as well,
the function has been renamed from gfs2_meta_wipe to gfs2_journal_wipe.
New function gfs2_ail1_wipe wants a static view of the ail list, so it
locks the sd_ail_lock when removing items. To accomplish this, function
gfs2_remove_from_journal no longer locks the sd_ail_lock, and it's now
the caller's responsibility to do so.
I was going to make sd_ail_lock locking conditional, but the practice is
generally frowned upon. For details, see: https://lwn.net/Articles/109066/
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
When an rindex entry is found to be corrupt, compute_bitstructs() calls
gfs2_consist_rgrpd() which calls gfs2_rgrp_dump() like this:
gfs2_rgrp_dump(NULL, rgd->rd_gl, fs_id_buf);
gfs2_rgrp_dump then dereferences the gl without checking it and we get
BUG: KASAN: null-ptr-deref in gfs2_rgrp_dump+0x28/0x280
because there's no rgrp glock involved while reading the rindex on mount.
Fix this by changing gfs2_rgrp_dump to take an rgrp argument.
Reported-by: syzbot+43fa87986bdd31df9de6@syzkaller.appspotmail.com
Signed-off-by: Andrew Price <anprice@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This requires flushing delayed work items in gfs2_make_fs_ro (which is called
before unmounting a filesystem).
When inodes are deleted and then recreated, pending gl_delete work items would
have no effect because the inode generations will have changed, so we can
cancel any pending gl_delete works before reusing iopen glocks.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
In function try_rgrp_unlink, we added a temporary lock of the
sd_log_flush_lock while searching the bitmaps. This protected us from
problems in which dinodes being freed were still in a state of flux
because the rgrp was in an active transaction. It was a kludge.
Now that we've straightened out the code for inode eviction, deletes,
and all the recovery mess, we no longer need this kludge.
This patch removes it, and should improve performance.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Keeping reservations and quotas separate helps reviewing the code.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Before this patch, multiple users called gfs2_qa_alloc which allocated
a qadata structure to the inode, if quotas are turned on. Later, in
file close or evict, the structure was deleted with gfs2_qa_delete.
But there can be several competing processes who need access to the
structure. There were races between file close (release) and the others.
Thus, a release could delete the structure out from under a process
that relied upon its existence. For example, chown.
This patch changes the management of the qadata structures to be
a get/put scheme. Function gfs2_qa_alloc has been changed to gfs2_qa_get
and if the structure is allocated, the count essentially starts out at
1. Function gfs2_qa_delete has been renamed to gfs2_qa_put, and the
last guy to decrement the count to 0 frees the memory.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Before this patch, multiple callers called gfs2_rsqa_alloc to force
the existence of a reservations structure and a quota data structure
if needed. However, now the reservations are handled separately, so
the quota data is only the quota data. So we eliminate the one in
favor of just calling gfs2_qa_alloc directly.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Before this patch, the rgrp code had a serious problem related to
how it managed buffer_heads for resource groups. The problem caused
file system corruption, especially in cases of journal replay.
When an rgrp glock was demoted to transfer ownership to a
different cluster node, do_xmote() first calls rgrp_go_sync and then
rgrp_go_inval, as expected. When it calls rgrp_go_sync, that called
gfs2_rgrp_brelse() that dropped the buffer_head reference count.
In most cases, the reference count went to zero, which is right.
However, there were other places where the buffers are handled
differently.
After rgrp_go_sync, do_xmote called rgrp_go_inval which called
gfs2_rgrp_brelse a second time, then rgrp_go_inval's call to
truncate_inode_pages_range would get rid of the pages in memory,
but only if the reference count drops to 0.
Unfortunately, gfs2_rgrp_brelse was setting bi->bi_bh = NULL.
So when rgrp_go_sync called gfs2_rgrp_brelse, it lost the pointer
to the buffer_heads in cases where the reference count was still 1.
Therefore, when rgrp_go_inval called gfs2_rgrp_brelse a second time,
it failed the check for "if (bi->bi_bh)" and thus failed to call
brelse a second time. Because of that, the reference count on those
buffers sometimes failed to drop from 1 to 0. And that caused
function truncate_inode_pages_range to keep the pages in page cache
rather than freeing them.
The next time the rgrp glock was acquired, the metadata read of
the rgrp buffers re-used the pages in memory, which were now
wrong because they were likely modified by the other node who
acquired the glock in EX (which is why we demoted the glock).
This re-use of the page cache caused corruption because changes
made by the other nodes were never seen, so the bitmaps were
inaccurate.
For some reason, the problem became most apparent when journal
replay forced the replay of rgrps in memory, which caused newer
rgrp data to be overwritten by the older in-core pages.
A big part of the problem was that the rgrp buffer were released
in multiple places: The go_unlock function would release them when
the glock was released rather than when the glock is demoted,
which is clearly wrong because our intent was to cache them until
the glock is demoted from SH or EX.
This patch attempts to clean up the mess and make one consistent
and centralized mechanism for managing the rgrp buffer_heads by
implementing several changes:
1. It eliminates the call to gfs2_rgrp_brelse() from rgrp_go_sync.
We don't want to release the buffers or zero the pointers when
syncing for the reasons stated above. It only makes sense to
release them when the glock is actually invalidated (go_inval).
And when we do, then we set the bh pointers to NULL.
2. The go_unlock function (which was only used for rgrps) is
eliminated, as we've talked about doing many times before.
The go_unlock function was called too early in the glock dq
process, and should not happen until the glock is invalidated.
3. It also eliminates the call to rgrp_brelse in gfs2_clear_rgrpd.
That will now happen automatically when the rgrp glocks are
demoted, and shouldn't happen any sooner or later than that.
Instead, function gfs2_clear_rgrpd has been modified to demote
the rgrp glocks, and therefore, free those pages, before the
remaining glocks are culled by gfs2_gl_hash_clear. This
prevents the gl_object from hanging around when the glocks are
culled.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
In gfs2_rgrp_verify and compute_bitstructs, make sure to report errors before
withdrawing the filesystem: otherwise, when we withdraw first and withdraw is
configured to panic, we'll never get to the error reporting.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Since commit 223b2b889f ("GFS2: Fix alignment issue and tidy
gfs2_bitfit"), these 3 macros aren't used anymore, so remove them.
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch fixes three places in which temporary character buffers
could overflow due to the addition of the file system id from patch
3792ce973f. Thanks to Dan Carpenter for pointing it out.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This patch replaces a few leftover printk errors with calls to
fs_info and similar, so that the file system having the error is
properly logged.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Before this patch, if a glock error was encountered, the glock with
the problem was dumped. But sometimes you may have lots of file systems
mounted, and that doesn't tell you which file system it was for.
This patch adds a new boolean parameter fsid to the dump_glock family
of functions. For non-error cases, such as dumping the glocks debugfs
file, the fsid is not dumped in order to keep lock dumps and glocktop
as clean as possible. For all error cases, such as GLOCK_BUG_ON, the
file system id is now printed. This will make it easier to debug.
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>
Rename gfs2_trans_add_unrevoke to gfs2_trans_remove_revoke: there is no
such thing as an "unrevoke" object; all this function does is remove
existing revoke objects plus some bookkeeping.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Fix the resource group wrap-around logic in gfs2_rbm_find that commit
e579ed4f44 broke. The bug can lead to unnecessary repeated scanning of the
same bitmaps; there is a risk that future changes will turn this into an
endless loop.
This is an updated version of commit 2d29f6b96d ("gfs2: Fix loop in
gfs2_rbm_find") which ended up being reverted because it introduced a
performance regression in iozone (see commit e74c98ca2d). Changes since v1:
- Simplify the wrap-around logic.
- Handle the case where each resource group only has a single bitmap block
(small filesystem).
- Update rd_extfail_pt whenever we scan the entire bitmap, even when we don't
start the scan at the very beginning of the bitmap.
Fixes: e579ed4f44 ("GFS2: Introduce rbm field bii")
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
This reverts commit 2d29f6b96d.
It turns out that the fix can lead to a ~20 percent performance regression
in initial writes to the page cache according to iozone. Let's revert this
for now to have more time for a proper fix.
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is based on an idea from Steve Whitehouse. The idea is
to dump the number of pages for inodes in the glock dumps.
The additional locking required me to drop const from quite a few
places.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Fix the resource group wrap-around logic in gfs2_rbm_find that commit
e579ed4f44 broke. The bug can lead to unnecessary repeated scanning of the
same bitmaps; there is a risk that future changes will turn this into an
endless loop.
Fixes: e579ed4f44 ("GFS2: Introduce rbm field bii")
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
gfs2_put_super calls gfs2_clear_rgrpd to destroy the gfs2_rgrpd objects
attached to the resource group glocks. That function should release the
buffers attached to the gfs2_bitmap objects (bi_bh), but the call to
gfs2_rgrp_brelse for doing that is missing.
When gfs2_releasepage later runs across these buffers which are still
referenced, it refuses to free them. This causes the pages the buffers
are attached to to remain referenced as well. With enough mount/unmount
cycles, the system will eventually run out of memory.
Fix this by adding the missing call to gfs2_rgrp_brelse in
gfs2_clear_rgrpd.
(Also fix a gfs2_rgrp_relse -> gfs2_rgrp_brelse typo in a comment.)
Fixes: 39b0f1e929 ("GFS2: Don't brelse rgrp buffer_heads every allocation")
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Function rgblk_free can only deal with one resource group at a time, so
pass that resource group is as a parameter. Several of the callers
already have the resource group at hand, so we only need additional
lookup code in a few places.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>
The state parameter of gfs2_rlist_alloc is set to LM_ST_EXCLUSIVE in all
calls, so remove it and hardcode that state in gfs2_rlist_alloc instead.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>
Reservations in gfs can span multiple gfs2_bitmaps (but they won't span
multiple resource groups). When removing a reservation, we want to
clear the GBF_FULL flags of all involved gfs2_bitmaps, not just that of
the first bitmap.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>
This field indicates the size of the bitmap in bytes, similar to how the
bi_blocks field indicates the size of the bitmap in blocks.
In count_unlinked, replace an instance of bi_bytes * GFS2_NBBY by
bi_blocks.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>
This definition is only used to define RGRP_RSRV_MINBLKS, with no
benefit over defining RGRP_RSRV_MINBLKS directly.
In addition, instead of forcing RGRP_RSRV_MINBLKS to be of type u32,
cast it to that type where that type is required.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>
Move the rs_sizehint and rs_rgd_gh fields from struct gfs2_blkreserv
into the inode: they are more closely related to the inode than to a
particular reservation.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>
We already have a function that checks if a block is within a resource
group, so use that in gfs2_rbm_from_block as well.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>
When gfs2_rbm_from_block fails, the rbm it returns is undefined, so we
always want to make sure gfs2_rbm_from_block has succeeded before
looking at the rbm.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>
Before this patch, various errors and messages were reported using
the pr_* functions: pr_err, pr_warn, pr_info, etc., but that does
not tell you which gfs2 mount had the problem, which is often vital
to debugging. This patch changes the calls from pr_* to fs_* in
most of the messages so that the file system id is printed along
with the message.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
The GFS2_RDF_UPTODATE flag in the rgrp is used to determine when
a rgrp buffer is valid. It's cleared when the glock is invalidated,
signifying that the buffer data is now invalid. But before this
patch, function update_rgrp_lvb was setting the flag when it
determined it had a valid lvb. But that's an invalid assumption:
just because you have a valid lvb doesn't mean you have valid
buffers. After all, another node may have made the lvb valid,
and this node just fetched it from the glock via dlm.
Consider this scenario:
1. The file system is mounted with RGRPLVB option.
2. In gfs2_inplace_reserve it locks the rgrp glock EX, but thanks
to GL_SKIP, it skips the gfs2_rgrp_bh_get.
3. Since loops == 0 and the allocation target (ap->target) is
bigger than the largest known chunk of blocks in the rgrp
(rs->rs_rbm.rgd->rd_extfail_pt) it skips that rgrp and bypasses
the call to gfs2_rgrp_bh_get there as well.
4. update_rgrp_lvb sees the lvb MAGIC number is valid, so bypasses
gfs2_rgrp_bh_get, but it still sets sets GFS2_RDF_UPTODATE due
to this invalid assumption.
5. The next time update_rgrp_lvb is called, it sees the bit is set
and just returns 0, assuming both the lvb and rgrp are both
uptodate. But since this is a smaller allocation, or space has
been freed by another node, thus adjusting the lvb values,
it decides to use the rgrp for allocations, with invalid rd_free
due to the fact it was never updated.
This patch changes update_rgrp_lvb so it doesn't set the UPTODATE
flag anymore. That way, it has no choice but to fetch the latest
values.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
