Activate the metadata checksumming feature by adding it to ext4 and
jbd2's lists of supported features.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Calculate and verify a checksum covering the journal superblock.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Obtain a reference to the crc32c driver if needed for the v2 checksum.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Define flags and allocate space in on-disk journal structures to support
checksumming of journal metadata.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Normally, we have to issue a cache flush before we can update journal tail in
journal superblock, effectively wiping out old transactions from the journal.
So use the fact that during transaction commit we issue cache flush anyway and
opportunistically push journal tail as far as we can. Since update of journal
superblock is still costly (we have to use WRITE_FUA), we update log tail only
if we can free significant amount of space.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When we reach jbd2_cleanup_journal_tail(), there is no guarantee that
checkpointed buffers are on a stable storage - especially if buffers were
written out by jbd2_log_do_checkpoint(), they are likely to be only in disk's
caches. Thus when we update journal superblock effectively removing old
transaction from journal, this write of superblock can get to stable storage
before those checkpointed buffers which can result in filesystem corruption
after a crash. Thus we must unconditionally issue a cache flush before we
update journal superblock in these cases.
A similar problem can also occur if journal superblock is written only in
disk's caches, other transaction starts reusing space of the transaction
cleaned from the log and power failure happens. Subsequent journal replay would
still try to replay the old transaction but some of it's blocks may be already
overwritten by the new transaction. For this reason we must use WRITE_FUA when
updating log tail and we must first write new log tail to disk and update
in-memory information only after that.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
There are three case of updating journal superblock. In the first case, we want
to mark journal as empty (setting s_sequence to 0), in the second case we want
to update log tail, in the third case we want to update s_errno. Split these
cases into separate functions. It makes the code slightly more straightforward
and later patches will make the distinction even more important.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
There is normally only a handful of these active at any one time, but
putting them in a separate slab cache makes debugging memory
corruption problems easier. Manish Katiyar also wanted this make it
easier to test memory failure scenarios in the jbd2 layer.
Cc: Manish Katiyar <mkatiyar@gmail.com>
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Currently, we clear revoked flag only when a block is reused. However,
this can tigger a false journal error. Consider a situation when a block
is used as a meta block and is deleted(revoked) in ordered mode, then the
block is allocated as a data block to a file. At this moment, user changes
the file's journal mode from ordered to journaled and truncates the file.
The block will be considered re-revoked by journal because it has revoked
flag still pending from the last transaction and an assertion triggers.
We fix the problem by keeping the revoked status more uptodate - we clear
revoked flag when switching revoke tables to reflect there is no revoked
buffers in current transaction any more.
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The state bits and the lock functions of jbd and jbd2 are
identical. Share them.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This silences some Sparse warnings:
fs/jbd2/transaction.c:135:69: warning: incorrect type in argument 2 (different base types)
fs/jbd2/transaction.c:135:69: expected restricted gfp_t [usertype] flags
fs/jbd2/transaction.c:135:69: got int [signed] gfp_mask
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Using function calls in TP_printk causes perf heartburn, so print the
MAJOR/MINOR device numbers instead.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
jbd2_journal_remove_journal_head() can oops when trying to access
journal_head returned by bh2jh(). This is caused for example by the
following race:
TASK1 TASK2
jbd2_journal_commit_transaction()
...
processing t_forget list
__jbd2_journal_refile_buffer(jh);
if (!jh->b_transaction) {
jbd_unlock_bh_state(bh);
jbd2_journal_try_to_free_buffers()
jbd2_journal_grab_journal_head(bh)
jbd_lock_bh_state(bh)
__journal_try_to_free_buffer()
jbd2_journal_put_journal_head(jh)
jbd2_journal_remove_journal_head(bh);
jbd2_journal_put_journal_head() in TASK2 sees that b_jcount == 0 and
buffer is not part of any transaction and thus frees journal_head
before TASK1 gets to doing so. Note that even buffer_head can be
released by try_to_free_buffers() after
jbd2_journal_put_journal_head() which adds even larger opportunity for
oops (but I didn't see this happen in reality).
Fix the problem by making transactions hold their own journal_head
reference (in b_jcount). That way we don't have to remove journal_head
explicitely via jbd2_journal_remove_journal_head() and instead just
remove journal_head when b_jcount drops to zero. The result of this is
that [__]jbd2_journal_refile_buffer(),
[__]jbd2_journal_unfile_buffer(), and
__jdb2_journal_remove_checkpoint() can free journal_head which needs
modification of a few callers. Also we have to be careful because once
journal_head is removed, buffer_head might be freed as well. So we
have to get our own buffer_head reference where it matters.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Provide a function which returns whether a transaction with given tid
will send a flush to the filesystem device. The function will be used
by ext4 to detect whether fsync needs to send a separate flush or not.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
In data=ordered mode, it's theoretically possible (however rare) that
an inode is filed to transaction's t_inode_list and a flusher thread
writes all the data and inode is reclaimed before the transaction
starts to commit. In such a case, we could erroneously omit sending a
flush to file system device when it is different from the journal
device (because data can still be in disk cache only).
Fix the problem by setting a flag in a transaction when some inode is added
to it and then send disk flush in the commit code when the flag is set.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Add fields needed for the copy-on-write ext4 development work.
The h_cowing flag is used by ext4 snapshots code to mark the task in
COWING state.
The h_XXX_credits fields are used to track buffer credits usage
(accounted by COW and non-COW operations).
The h_cow_XXX fields are used as per task debugging counters.
Merging this commit into mainline will allow users to test ext4
snapshots as a standalone module, without the need to patch and
install a development kernel.
Signed-off-by: Amir Goldstein <amir73il@users.sf.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Replace the jbd2_inode structure (which is 48 bytes) with a pointer
and only allocate the jbd2_inode when it is needed --- that is, when
the file system has a journal present and the inode has been opened
for writing. This allows us to further slim down the ext4_inode_info
structure.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This fixes a hang seen in jbd2_journal_release_jbd_inode
on a lot of Power 6 systems running with ext4. When we get
in the hung state, all I/O to the disk in question gets blocked
where we stay indefinitely. Looking at the task list, I can see
we are stuck in jbd2_journal_release_jbd_inode waiting on a
wake up. I added some debug code to detect this scenario and
dump additional data if we were stuck in jbd2_journal_release_jbd_inode
for longer than 30 minutes. When it hit, I was able to see that
i_flags was 0, suggesting we missed the wake up.
This patch changes i_flags to be an unsigned long, uses bit operators
to access it, and adds barriers around the accesses. Prior to applying
this patch, we were regularly hitting this hang on numerous systems
in our test environment. After applying the patch, the hangs no longer
occur.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (40 commits)
ext4: Adding error check after calling ext4_mb_regular_allocator()
ext4: Fix dirtying of journalled buffers in data=journal mode
ext4: re-inline ext4_rec_len_(to|from)_disk functions
jbd2: Remove t_handle_lock from start_this_handle()
jbd2: Change j_state_lock to be a rwlock_t
jbd2: Use atomic variables to avoid taking t_handle_lock in jbd2_journal_stop
ext4: Add mount options in superblock
ext4: force block allocation on quota_off
ext4: fix freeze deadlock under IO
ext4: drop inode from orphan list if ext4_delete_inode() fails
ext4: check to make make sure bd_dev is set before dereferencing it
jbd2: Make barrier messages less scary
ext4: don't print scary messages for allocation failures post-abort
ext4: fix EFBIG edge case when writing to large non-extent file
ext4: fix ext4_get_blocks references
ext4: Always journal quota file modifications
ext4: Fix potential memory leak in ext4_fill_super
ext4: Don't error out the fs if the user tries to make a file too big
ext4: allocate stripe-multiple IOs on stripe boundaries
ext4: move aio completion after unwritten extent conversion
...
Fix up conflicts in fs/ext4/inode.c as per Ted.
Fix up xfs conflicts as per earlier xfs merge.
This should remove the last exclusive lock from start_this_handle(),
so that we should now be able to start multiple transactions at the
same time on large SMP systems.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Lockstat reports have shown that j_state_lock is a major source of
lock contention, especially on systems with more than 4 CPU cores. So
change it to be a read/write spinlock.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
By using an atomic_t for t_updates and t_outstanding credits, this
should allow us to not need to take transaction t_handle_lock in
jbd2_journal_stop().
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
__GFP_NOFAIL is going away, so add our own retry loop. Also add
jbd2__journal_start() and jbd2__journal_restart() which take a gfp
mask, so that file systems can optionally (re)start transaction
handles using GFP_KERNEL. If they do this, then they need to be
prepared to handle receiving an PTR_ERR(-ENOMEM) error, and be ready
to reflect that error up to userspace.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
OCFS2 uses t_commit trigger to compute and store checksum of the just
committed blocks. When a buffer has b_frozen_data, checksum is computed
for it instead of b_data but this can result in an old checksum being
written to the filesystem in the following scenario:
1) transaction1 is opened
2) handle1 is opened
3) journal_access(handle1, bh)
- This sets jh->b_transaction to transaction1
4) modify(bh)
5) journal_dirty(handle1, bh)
6) handle1 is closed
7) start committing transaction1, opening transaction2
8) handle2 is opened
9) journal_access(handle2, bh)
- This copies off b_frozen_data to make it safe for transaction1 to commit.
jh->b_next_transaction is set to transaction2.
10) jbd2_journal_write_metadata() checksums b_frozen_data
11) the journal correctly writes b_frozen_data to the disk journal
12) handle2 is closed
- There was no dirty call for the bh on handle2, so it is never queued for
any more journal operation
13) Checkpointing finally happens, and it just spools the bh via normal buffer
writeback. This will write b_data, which was never triggered on and thus
contains a wrong (old) checksum.
This patch fixes the problem by calling the trigger at the moment data is
frozen for journal commit - i.e., either when b_frozen_data is created by
do_get_write_access or just before we write a buffer to the log if
b_frozen_data does not exist. We also rename the trigger to t_frozen as
that better describes when it is called.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6: (33 commits)
quota: stop using QUOTA_OK / NO_QUOTA
dquot: cleanup dquot initialize routine
dquot: move dquot initialization responsibility into the filesystem
dquot: cleanup dquot drop routine
dquot: move dquot drop responsibility into the filesystem
dquot: cleanup dquot transfer routine
dquot: move dquot transfer responsibility into the filesystem
dquot: cleanup inode allocation / freeing routines
dquot: cleanup space allocation / freeing routines
ext3: add writepage sanity checks
ext3: Truncate allocated blocks if direct IO write fails to update i_size
quota: Properly invalidate caches even for filesystems with blocksize < pagesize
quota: generalize quota transfer interface
quota: sb_quota state flags cleanup
jbd: Delay discarding buffers in journal_unmap_buffer
ext3: quota_write cross block boundary behaviour
quota: drop permission checks from xfs_fs_set_xstate/xfs_fs_set_xquota
quota: split out compat_sys_quotactl support from quota.c
quota: split out netlink notification support from quota.c
quota: remove invalid optimization from quota_sync_all
...
Fixed trivial conflicts in fs/namei.c and fs/ufs/inode.c
CONFIG_BUFFER_DEBUG seems to have been removed from the documentation
somewhere around 2.4.15 and seemingly hasn't been available even
longer. It is, however, still referenced at one place from the jbd
code (one is a copy of the other header). Time to clean it up
Signed-off-by: Christoph Egger <siccegge@stud.informatik.uni-erlangen.de>
Signed-off-by: Jan Kara <jack@suse.cz>
This is a bit complicated because we are trying to optimize when we
send barriers to the fs data disk. We could just throw in an extra
barrier to the data disk whenever we send a barrier to the journal
disk, but that's not always strictly necessary.
We only need to send a barrier during a commit when there are data
blocks which are must be written out due to an inode written in
ordered mode, or if fsync() depends on the commit to force data blocks
to disk. Finally, before we drop transactions from the beginning of
the journal during a checkpoint operation, we need to guarantee that
any blocks that were flushed out to the data disk are firmly on the
rust platter before we drop the transaction from the journal.
Thanks to Oleg Drokin for pointing out this flaw in ext3/ext4.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Now that the SLUB seems to be fixed so that it respects the requested
alignment, use kmem_cache_alloc() to allocator if the block size of
the buffer heads to be allocated is less than the page size.
Previously, we were using 16k page on a Power system for each buffer,
even when the file system was using 1k or 4k block size.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The /proc/fs/jbd2/<dev>/history was maintained manually; by using
tracepoints, we can get all of the existing functionality of the /proc
file plus extra capabilities thanks to the ftrace infrastructure. We
save memory as a bonus.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This fixes sparse noise:
error: dubious one-bit signed bitfield
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jan Kara <jack@ucw.cz>
The revoke records must be written using the same way as the rest of
the blocks during the commit process; that is, either marked as
synchronous writes or as asynchornous writes.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If a commit is triggered by fsync(), set a flag indicating the journal
blocks associated with the transaction should be flushed out using
WRITE_SYNC.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If we race with commit code setting i_transaction to NULL, we could
possibly dereference it. Proper locking requires the journal pointer
(to access journal->j_list_lock), which we don't have. So we have to
change the prototype of the function so that filesystem passes us the
journal pointer. Also add a more detailed comment about why the
function jbd2_journal_begin_ordered_truncate() does what it does and
how it should be used.
Thanks to Dan Carpenter <error27@gmail.com> for pointing to the
suspitious code.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Joel Becker <joel.becker@oracle.com>
CC: linux-ext4@vger.kernel.org
CC: ocfs2-devel@oss.oracle.com
CC: mfasheh@suse.de
CC: Dan Carpenter <error27@gmail.com>
Otherwise it can be very confusing to find a "EXT3-fs: " failure in
the middle of EXT4-fs failures, and it makes it harder to track the
source of the failure.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (57 commits)
jbd2: Fix oops in jbd2_journal_init_inode() on corrupted fs
ext4: Remove "extents" mount option
block: Add Kconfig help which notes that ext4 needs CONFIG_LBD
ext4: Make printk's consistently prefixed with "EXT4-fs: "
ext4: Add sanity checks for the superblock before mounting the filesystem
ext4: Add mount option to set kjournald's I/O priority
jbd2: Submit writes to the journal using WRITE_SYNC
jbd2: Add pid and journal device name to the "kjournald2 starting" message
ext4: Add markers for better debuggability
ext4: Remove code to create the journal inode
ext4: provide function to release metadata pages under memory pressure
ext3: provide function to release metadata pages under memory pressure
add releasepage hooks to block devices which can be used by file systems
ext4: Fix s_dirty_blocks_counter if block allocation failed with nodelalloc
ext4: Init the complete page while building buddy cache
ext4: Don't allow new groups to be added during block allocation
ext4: mark the blocks/inode bitmap beyond end of group as used
ext4: Use new buffer_head flag to check uninit group bitmaps initialization
ext4: Fix the race between read_inode_bitmap() and ext4_new_inode()
ext4: code cleanup
...
Filesystems often to do compute intensive operation on some
metadata. If this operation is repeated many times, it can be very
expensive. It would be much nicer if the operation could be performed
once before a buffer goes to disk.
This adds triggers to jbd2 buffer heads. Just before writing a metadata
buffer to the journal, jbd2 will optionally call a commit trigger associated
with the buffer. If the journal is aborted, an abort trigger will be
called on any dirty buffers as they are dropped from pending
transactions.
ocfs2 will use this feature.
Initially I tried to come up with a more generic trigger that could be
used for non-buffer-related events like transaction completion. It
doesn't tie nicely, because the information a buffer trigger needs
(specific to a journal_head) isn't the same as what a transaction
trigger needs (specific to a tranaction_t or perhaps journal_t). So I
implemented a buffer set, with the understanding that
journal/transaction wide triggers should be implemented separately.
There is only one trigger set allowed per buffer. I can't think of any
reason to attach more than one set. Contrast this with a journal or
transaction in which multiple places may want to watch the entire
transaction separately.
The trigger sets are considered static allocation from the jbd2
perspective. ocfs2 will just have one trigger set per block type,
setting the same set on every bh of the same type.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Add this so that file systems using JBD2 can safely allocate unused b_state
bits.
In this case, we add it so that Ocfs2 can define a single bit for tracking
the validation state of a buffer.
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This code has been obsolete in quite some time, since the supported
method for adding a journal inode is to use tune2fs (or to creating
new filesystem with a journal via mke2fs or mkfs.ext4).
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Avoid freeing the transaction in __jbd2_journal_drop_transaction() so
the journal commit callback can run without holding j_list_lock, to
avoid lock contention on this spinlock.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
jbd2_log_do_checkpoint()n is one of the kernel's largest stack users.
Move the array of buffer head's from the stack of jbd2_log_do_checkpoint()
to the in-core journal structure.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Add new mount options, min_batch_time and max_batch_time, which
controls how long the jbd2 layer should wait for additional filesystem
operations to get batched with a synchronous write transaction.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This patch removes the static sleep time in favor of a more self
optimizing approach where we measure the average amount of time it
takes to commit a transaction to disk and the ammount of time a
transaction has been running. If somebody does a sync write or an
fsync() traditionally we would sleep for 1 jiffies, which depending on
the value of HZ could be a significant amount of time compared to how
long it takes to commit a transaction to the underlying storage. With
this patch instead of sleeping for a jiffie, we check to see if the
amount of time this transaction has been running is less than the
average commit time, and if it is we sleep for the delta using
schedule_hrtimeout to give us a higher precision sleep time. This
greatly benefits high end storage where you could end up sleeping for
longer than it takes to commit the transaction and therefore sitting
idle instead of allowing the transaction to be committed by keeping
the sleep time to a minimum so you are sure to always be doing
something.
Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Add this so that file systems using JBD2 can safely allocate unused b_state
bits.
In this case, we add it so that Ocfs2 can define a single bit for tracking
the validation state of a buffer.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The multiblock allocator needs to be able to release blocks (and issue
a blkdev discard request) when the transaction which freed those
blocks is committed. Previously this was done via a polling mechanism
when blocks are allocated or freed. A much better way of doing things
is to create a jbd2 callback function and attaching the list of blocks
to be freed directly to the transaction structure.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the journal doesn't abort when it gets an IO error in file data
blocks, the file data corruption will spread silently. Because
most of applications and commands do buffered writes without fsync(),
they don't notice the IO error. It's scary for mission critical
systems. On the other hand, if the journal aborts whenever it gets
an IO error in file data blocks, the system will easily become
inoperable. So this patch introduces a filesystem option to
determine whether it aborts the journal or just call printk() when
it gets an IO error in file data.
If you mount an ext4 fs with data_err=abort option, it aborts on file
data write error. If you mount it with data_err=ignore, it doesn't
abort, just call printk(). data_err=ignore is the default.
Here is the corresponding patch of the ext3 version:
http://kerneltrap.org/mailarchive/linux-kernel/2008/9/9/3239374
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When a checkpointing IO fails, current JBD2 code doesn't check the
error and continue journaling. This means latest metadata can be
lost from both the journal and filesystem.
This patch leaves the failed metadata blocks in the journal space
and aborts journaling in the case of jbd2_log_do_checkpoint().
To achieve this, we need to do:
1. don't remove the failed buffer from the checkpoint list where in
the case of __try_to_free_cp_buf() because it may be released or
overwritten by a later transaction
2. jbd2_log_do_checkpoint() is the last chance, remove the failed
buffer from the checkpoint list and abort the journal
3. when checkpointing fails, don't update the journal super block to
prevent the journaled contents from being cleaned. For safety,
don't update j_tail and j_tail_sequence either
4. when checkpointing fails, notify this error to the ext4 layer so
that ext4 don't clear the needs_recovery flag, otherwise the
journaled contents are ignored and cleaned in the recovery phase
5. if the recovery fails, keep the needs_recovery flag
6. prevent jbd2_cleanup_journal_tail() from being called between
__jbd2_journal_drop_transaction() and jbd2_journal_abort()
(a possible race issue between jbd2_log_do_checkpoint()s called by
jbd2_journal_flush() and __jbd2_log_wait_for_space())
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Calculate the journal device name once and stash it away in the
journal_s structure. This avoids needing to call bdevname()
everywhere and reduces stack usage by not needing to allocate an
on-stack buffer. In addition, we eliminate the '/' that can appear in
device names (e.g. "cciss/c0d0p9" --- see kernel bugzilla #11321) that
can cause problems when creating proc directory names, and include the
inode number to support ocfs2 which creates multiple journals with
different inode numbers.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
