* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: Add new ext4 inode tracepoints
ext4: Don't call sb_issue_discard() in ext4_free_blocks()
ext4: do not try to grab the s_umount semaphore in ext4_quota_off
ext4: fix potential race when freeing ext4_io_page structures
ext4: handle writeback of inodes which are being freed
ext4: initialize the percpu counters before replaying the journal
ext4: "ret" may be used uninitialized in ext4_lazyinit_thread()
ext4: fix lazyinit hang after removing request
Commit 5c521830cf (ext4: Support discard requests when running in
no-journal mode) attempts to add sb_issue_discard() for data blocks
(in data=writeback mode) and in no-journal mode. Unfortunately, this
no longer works, because in commit dd3932eddf (block: remove
BLKDEV_IFL_WAIT), sb_issue_discard() only presents a synchronous
interface, and there are times when we call ext4_free_blocks() when we
are are holding a spinlock, or are otherwise in an atomic context.
For now, I've removed the call to sb_issue_discard() to prevent a
deadlock or (if spinlock debugging is enabled) failures like this:
BUG: scheduling while atomic: rc.sysinit/1376/0x00000002
Pid: 1376, comm: rc.sysinit Not tainted 2.6.36-ARCH #1
Call Trace:
[<ffffffff810397ce>] __schedule_bug+0x5e/0x70
[<ffffffff81403110>] schedule+0x950/0xa70
[<ffffffff81060bad>] ? insert_work+0x7d/0x90
[<ffffffff81060fbd>] ? queue_work_on+0x1d/0x30
[<ffffffff81061127>] ? queue_work+0x37/0x60
[<ffffffff8140377d>] schedule_timeout+0x21d/0x360
[<ffffffff812031c3>] ? generic_make_request+0x2c3/0x540
[<ffffffff81402680>] wait_for_common+0xc0/0x150
[<ffffffff81041490>] ? default_wake_function+0x0/0x10
[<ffffffff812034bc>] ? submit_bio+0x7c/0x100
[<ffffffff810680a0>] ? wake_bit_function+0x0/0x40
[<ffffffff814027b8>] wait_for_completion+0x18/0x20
[<ffffffff8120a969>] blkdev_issue_discard+0x1b9/0x210
[<ffffffff811ba03e>] ext4_free_blocks+0x68e/0xb60
[<ffffffff811b1650>] ? __ext4_handle_dirty_metadata+0x110/0x120
[<ffffffff811b098c>] ext4_ext_truncate+0x8cc/0xa70
[<ffffffff810d713e>] ? pagevec_lookup+0x1e/0x30
[<ffffffff81191618>] ext4_truncate+0x178/0x5d0
[<ffffffff810eacbb>] ? unmap_mapping_range+0xab/0x280
[<ffffffff810d8976>] vmtruncate+0x56/0x70
[<ffffffff811925cb>] ext4_setattr+0x14b/0x460
[<ffffffff811319e4>] notify_change+0x194/0x380
[<ffffffff81117f80>] do_truncate+0x60/0x90
[<ffffffff811e08fa>] ? security_inode_permission+0x1a/0x20
[<ffffffff811eaec1>] ? tomoyo_path_truncate+0x11/0x20
[<ffffffff81127539>] do_last+0x5d9/0x770
[<ffffffff811278bd>] do_filp_open+0x1ed/0x680
[<ffffffff8140644f>] ? page_fault+0x1f/0x30
[<ffffffff81132bfc>] ? alloc_fd+0xec/0x140
[<ffffffff81118db1>] do_sys_open+0x61/0x120
[<ffffffff81118e8b>] sys_open+0x1b/0x20
[<ffffffff81002e6b>] system_call_fastpath+0x16/0x1b
https://bugzilla.kernel.org/show_bug.cgi?id=22302
Reported-by: Mathias Burén <mathias.buren@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: jiayingz@google.com
It's not needed to sync the filesystem, and it fixes a lock_dep complaint.
Signed-off-by: Dmitry Monakhov <dmonakhov@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Use an atomic_t and make sure we don't free the structure while we
might still be submitting I/O for that page.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The following BUG can occur when an inode which is getting freed when
it still has dirty pages outstanding, and it gets deleted (in this
because it was the target of a rename). In ordered mode, we need to
make sure the data pages are written just in case we crash before the
rename (or unlink) is committed. If the inode is being freed then
when we try to igrab the inode, we end up tripping the BUG_ON at
fs/ext4/page-io.c:146.
To solve this problem, we need to keep track of the number of io
callbacks which are pending, and avoid destroying the inode until they
have all been completed. That way we don't have to bump the inode
count to keep the inode from being destroyed; an approach which
doesn't work because the count could have already been dropped down to
zero before the inode writeback has started (at which point we're not
allowed to bump the count back up to 1, since it's already started
getting freed).
Thanks to Dave Chinner for suggesting this approach, which is also
used by XFS.
kernel BUG at /scratch_space/linux-2.6/fs/ext4/page-io.c:146!
Call Trace:
[<ffffffff811075b1>] ext4_bio_write_page+0x172/0x307
[<ffffffff811033a7>] mpage_da_submit_io+0x2f9/0x37b
[<ffffffff811068d7>] mpage_da_map_and_submit+0x2cc/0x2e2
[<ffffffff811069b3>] mpage_add_bh_to_extent+0xc6/0xd5
[<ffffffff81106c66>] write_cache_pages_da+0x2a4/0x3ac
[<ffffffff81107044>] ext4_da_writepages+0x2d6/0x44d
[<ffffffff81087910>] do_writepages+0x1c/0x25
[<ffffffff810810a4>] __filemap_fdatawrite_range+0x4b/0x4d
[<ffffffff810815f5>] filemap_fdatawrite_range+0xe/0x10
[<ffffffff81122a2e>] jbd2_journal_begin_ordered_truncate+0x7b/0xa2
[<ffffffff8110615d>] ext4_evict_inode+0x57/0x24c
[<ffffffff810c14a3>] evict+0x22/0x92
[<ffffffff810c1a3d>] iput+0x212/0x249
[<ffffffff810bdf16>] dentry_iput+0xa1/0xb9
[<ffffffff810bdf6b>] d_kill+0x3d/0x5d
[<ffffffff810be613>] dput+0x13a/0x147
[<ffffffff810b990d>] sys_renameat+0x1b5/0x258
[<ffffffff81145f71>] ? _atomic_dec_and_lock+0x2d/0x4c
[<ffffffff810b2950>] ? cp_new_stat+0xde/0xea
[<ffffffff810b29c1>] ? sys_newlstat+0x2d/0x38
[<ffffffff810b99c6>] sys_rename+0x16/0x18
[<ffffffff81002a2b>] system_call_fastpath+0x16/0x1b
Reported-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Tested-by: Nick Bowler <nbowler@elliptictech.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
cifs: make cifs_set_oplock_level() take a cifsInodeInfo pointer
cifs: dereferencing first then checking
cifs: trivial comment fix: tlink_tree is now a rbtree
[CIFS] Cleanup unused variable build warning
cifs: convert tlink_tree to a rbtree
cifs: store pointer to master tlink in superblock (try #2)
cifs: trivial doc fix: note setlease implemented
CIFS: Add cifs_set_oplock_level
FS: cifs, remove unneeded NULL tests
All the callers already have a pointer to struct cifsInodeInfo. Use it.
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This patch is based on Dan's original patch. His original description is
below:
Smatch complained about a couple checking for NULL after dereferencing
bugs. I'm not super familiar with the code so I did the conservative
thing and move the dereferences after the checks.
The dereferences in cifs_lock() and cifs_fsync() were added in
ba00ba64cf "cifs: make various routines use the cifsFileInfo->tcon
pointer". The dereference in find_writable_file() was added in
6508d904e6 "cifs: have find_readable/writable_file filter by fsuid".
The comments there say it's possible to trigger the NULL dereference
under stress.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Noticed while reviewing (late) the rbtree conversion patchset (which has been merged
already).
Cc: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
We now initialize the percpu counters before replaying the journal,
but after the journal, we recalculate the global counters, to deal
with the possibility of the per-blockgroup counts getting updated by
the journal replay.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Radix trees are ideal when you want to track a bunch of pointers and
can't embed a tracking structure within the target of those pointers.
The tradeoff is an increase in memory, particularly if the tree is
sparse.
In CIFS, we use the tlink_tree to track tcon_link structs. A tcon_link
can never be in more than one tlink_tree, so there's no impediment to
using a rb_tree here instead of a radix tree.
Convert the new multiuser mount code to use a rb_tree instead. This
should reduce the memory required to manage the tlink_tree.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This is the second version of this patch, the only difference between
it and the first one is that this explicitly makes cifs_sb_master_tlink
a static inline.
Instead of keeping a tag on the master tlink in the tree, just keep a
pointer to the master in the superblock. That eliminates the need for
using the radix tree to look up a tagged entry.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Simplify many places when we need to set oplock level on an inode.
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Newer GCC's reported the following build warning:
fs/ext4/super.c: In function 'ext4_lazyinit_thread':
fs/ext4/super.c:2702: warning: 'ret' may be used uninitialized in this function
Fix it by removing the need for the ret variable in the first place.
Signed-off-by: "Lukas Czerner" <lczerner@redhat.com>
Reported-by: "Stefan Richter" <stefanr@s5r6.in-berlin.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When the request has been removed from the list and no other request
has been issued, we will end up with next wakeup scheduled to
MAX_JIFFY_OFFSET which is bad. So check for that.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Linus noted, and complained to me, that doing while lots of "git diff"'s
of kernel sources, these spinlocks were responsible for 27% of the
spinlock cost on his two-processor system as reported by perf.
Git was doing lots of parallel stats, and this was putting a lot of
pressure on ext4_getattr(). A spinlock to protect a single
memory-to-memory copy is pointless, so remove it.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stanse found that pSMBFile in cifs_ioctl and file->f_path.dentry in
cifs_user_write are dereferenced prior their test to NULL.
The alternative is not to dereference them before the tests. The patch is
to point out the problem, you have to decide.
While at it we cache the inode in cifs_user_write to a local variable
and use all over the function.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Steve French <sfrench@samba.org>
Cc: linux-cifs@vger.kernel.org
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Commit 7d945a3aa7 ("logfs get_sb, part 3") broke the logfs build when
CONFIG_MTD is set due to a mangled logfs_get_sb_mtd() definition.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
genirq: Fix up irq_node() for irq_data changes.
genirq: Add single IRQ reservation helper
genirq: Warn if enable_irq is called before irq is set up
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
semaphore: Remove mutex emulation
staging: Final semaphore cleanup
jbd2: Convert jbd2_slab_create_sem to mutex
hpfs: Convert sbi->hpfs_creation_de to mutex
Fix up trivial change/delete conflicts with deleted 'dream' drivers
(drivers/staging/dream/camera/{mt9d112.c,mt9p012_fox.c,mt9t013.c,s5k3e2fx.c})
This one was only used for a nasty hack in nfsd, which has recently
been removed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The caller allocated it, the caller should free it.
The only issue so far is that we could change the flp pointer even on an
error return if the fl_change callback failed. But we can simply move
the flp assignment after the fl_change invocation, as the callers don't
care about the flp return value if the setlease call failed.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The NFSv4 server was initializing the dp->dl_flock pointer by the
somewhat ridiculous method of a locks_copy_lock callback.
Now that setlease uses the passed-in lock instead of doing a copy,
dl_flock no longer gets set, resulting in the lock leaking on delegation
release, and later possible hangs (among other problems).
So, initialize dl_flock and get rid of the callback.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We modified setlease to require the caller to allocate the new lease in
the case of creating a new lease, but forgot to fix up the filesystem
methods.
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Steve French <sfrench@samba.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We're depending on setlease to free the passed-in lease on failure.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Removing a lock shouldn't require any allocations; a failure due to
ENOMEM leaves the caller with a choice between retrying or giving up and
leaking an unused lease.
Next we should split the other lease calls into add and delete cases.
I wanted to start with just the bugfix.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.infradead.org/users/eparis/notify: (22 commits)
Ensure FMODE_NONOTIFY is not set by userspace
make fanotify_read() restartable across signals
fsnotify: remove alignment padding from fsnotify_mark on 64 bit builds
fs/notify/fanotify/fanotify_user.c: fix warnings
fanotify: Fix FAN_CLOSE comments
fanotify: do not recalculate the mask if the ignored mask changed
fanotify: ignore events on directories unless specifically requested
fsnotify: rename FS_IN_ISDIR to FS_ISDIR
fanotify: do not send events for irregular files
fanotify: limit number of listeners per user
fanotify: allow userspace to override max marks
fanotify: limit the number of marks in a single fanotify group
fanotify: allow userspace to override max queue depth
fsnotify: implement a default maximum queue depth
fanotify: ignore fanotify ignore marks if open writers
fanotify: allow userspace to flush all marks
fsnotify: call fsnotify_parent in perm events
fsnotify: correctly handle return codes from listeners
fanotify: use __aligned_u64 in fanotify userspace metadata
fanotify: implement fanotify listener ordering
...
In fanotify_read() return -ERESTARTSYS instead of -EINTR to
make read() restartable across signals (BSD semantic).
Signed-off-by: Eric Paris <eparis@redhat.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (39 commits)
Btrfs: deal with errors from updating the tree log
Btrfs: allow subvol deletion by unprivileged user with -o user_subvol_rm_allowed
Btrfs: make SNAP_DESTROY async
Btrfs: add SNAP_CREATE_ASYNC ioctl
Btrfs: add START_SYNC, WAIT_SYNC ioctls
Btrfs: async transaction commit
Btrfs: fix deadlock in btrfs_commit_transaction
Btrfs: fix lockdep warning on clone ioctl
Btrfs: fix clone ioctl where range is adjacent to extent
Btrfs: fix delalloc checks in clone ioctl
Btrfs: drop unused variable in block_alloc_rsv
Btrfs: cleanup warnings from gcc 4.6 (nonbugs)
Btrfs: Fix variables set but not read (bugs found by gcc 4.6)
Btrfs: Use ERR_CAST helpers
Btrfs: use memdup_user helpers
Btrfs: fix raid code for removing missing drives
Btrfs: Switch the extent buffer rbtree into a radix tree
Btrfs: restructure try_release_extent_buffer()
Btrfs: use the flusher threads for delalloc throttling
Btrfs: tune the chunk allocation to 5% of the FS as metadata
...
Fix up trivial conflicts in fs/btrfs/super.c and fs/fs-writeback.c, and
remove use of INIT_RCU_HEAD in fs/btrfs/extent_io.c (that init macro was
useless and removed in commit 5e8067adfdba: "rcu head remove init")
The btrfs merge looks like hell, because it changes fs-writeback.c, and
the crazy code has this repeated "estimate number of dirty pages"
counting that involves three different helper functions. And it's done
in two different places.
Just unify that whole calculation as a "get_nr_dirty_pages()" helper
function, and the merge result will look half-way decent.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.infradead.org/mtd-2.6: (82 commits)
mtd: fix build error in m25p80.c
mtd: Remove redundant mutex from mtd_blkdevs.c
MTD: Fix wrong check register_blkdev return value
Revert "mtd: cleanup Kconfig dependencies"
mtd: cfi_cmdset_0002: make sector erase command variable
mtd: cfi_cmdset_0002: add CFI detection for SST 38VF640x chips
mtd: cfi_util: add support for switching SST 39VF640xB chips into QRY mode
mtd: cfi_cmdset_0001: use defined value of P_ID_INTEL_PERFORMANCE instead of hardcoded one
block2mtd: dubious assignment
P4080/mtd: Fix the freescale lbc issue with 36bit mode
P4080/eLBC: Make Freescale elbc interrupt common to elbc devices
mtd: phram: use KBUILD_MODNAME
mtd: OneNAND: S5PC110: Fix double call suspend & resume function
mtd: nand: fix MTD_MODE_RAW writes
jffs2: use kmemdup
mtd: sm_ftl: cosmetic, use bool when possible
mtd: r852: remove useless pci powerup/down from suspend/resume routines
mtd: blktrans: fix a race vs kthread_stop
mtd: blktrans: kill BKL
mtd: allow to unload the mtdtrans module if its block devices aren't open
...
Fix up trivial whitespace-introduced conflict in drivers/mtd/mtdchar.c
The definition of PAGE_CACHE_MASK in <linux/pagemap.h> is needed to use
MAX_RW_COUNT, and on x86-64 that gets done indirectly through the
architecture header includes. But on MIPS and s390 that doesn't happen,
and we need to make sure that fs/compat.c includes pagemap.h explicitly.
Introduced in commit 435f49a518 ("readv/writev: do the same
MAX_RW_COUNT truncation that read/write does").
Reported-by: Sachin Sant <sachinp@in.ibm.com> (S390)
Reported-by: wu zhangjin <wuzhangjin@gmail.com> (MIPS)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Conflicts:
drivers/mtd/mtd_blkdevs.c
Merge Grant's device-tree bits so that we can apply the subsequent fixes.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
During unlink we remove any references to the inode from
the tree log. It can return -ENOENT and other errors,
and this changes the unlink code to deal with it.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
jbd2_slab_create_sem is used as a mutex, so make it one.
[ akpm muttered: We may as well make it local to
jbd2_journal_create_slab() also. ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <alpine.LFD.2.00.1010162231480.2496@localhost6.localdomain6>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
sbi->hpfs_creation_de is used as mutex so make it a mutex.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
LKML-Reference: <20100907125056.228874895@linutronix.de>
Add a mount option user_subvol_rm_allowed that allows users to delete a
(potentially non-empty!) subvol when they would otherwise we allowed to do
an rmdir(2). We duplicate the may_delete() checks from the core VFS code
to implement identical security checks (minus the directory size check).
We additionally require that the user has write+exec permission on the
subvol root inode.
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
There is no reason to force an immediate commit when deleting a snapshot.
Users have some expectation that space from a deleted snapshot be freed
immediately, but even if we do commit the reclaim is a background process.
If users _do_ want the deletion to be durable, they can call 'sync'.
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Create a snap without waiting for it to commit to disk. The ioctl is
ordered such that subsequent operations will not be contained by the
created snapshot, and the commit is initiated, but the ioctl does not
wait for the snapshot to commit to disk.
We return the specific transid to userspace so that an application can wait
for this specific snapshot creation to commit via the WAIT_SYNC ioctl.
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6:
eCryptfs: Print mount_auth_tok_only param in ecryptfs_show_options
ecryptfs: added ecryptfs_mount_auth_tok_only mount parameter
ecryptfs: checking return code of ecryptfs_find_auth_tok_for_sig()
ecryptfs: release keys loaded in ecryptfs_keyring_auth_tok_for_sig()
eCryptfs: Clear LOOKUP_OPEN flag when creating lower file
ecryptfs: call vfs_setxattr() in ecryptfs_setxattr()
START_SYNC will start a sync/commit, but not wait for it to
complete. Any modification started after the ioctl returns is
guaranteed not to be included in the commit. If a non-NULL
pointer is passed, the transaction id will be returned to
userspace.
WAIT_SYNC will wait for any in-progress commit to complete. If a
transaction id is specified, the ioctl will block and then
return (success) when the specified transaction has committed.
If it has already committed when we call the ioctl, it returns
immediately. If the specified transaction doesn't exist, it
returns EINVAL.
If no transaction id is specified, WAIT_SYNC will wait for the
currently committing transaction to finish it's commit to disk.
If there is no currently committing transaction, it returns
success.
These ioctls are useful for applications which want to impose an
ordering on when fs modifications reach disk, but do not want to
wait for the full (slow) commit process to do so.
Picky callers can take the transid returned by START_SYNC and
feed it to WAIT_SYNC, and be certain to wait only as long as
necessary for the transaction _they_ started to reach disk.
Sloppy callers can START_SYNC and WAIT_SYNC without a transid,
and provided they didn't wait too long between the calls, they
will get the same result. However, if a second commit starts
before they call WAIT_SYNC, they may end up waiting longer for
it to commit as well. Even so, a START_SYNC+WAIT_SYNC still
guarantees that any operation completed before the START_SYNC
reaches disk.
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Add support for an async transaction commit that is ordered such that any
subsequent operations will join the following transaction, but does not
wait until the current commit is fully on disk. This avoids much of the
latency associated with the btrfs_commit_transaction for callers concerned
with serialization and not safety.
The wait_for_unblock flag controls whether we wait for the 'middle' portion
of commit_transaction to complete, which is necessary if the caller expects
some of the modifications contained in the commit to be available (this is
the case for subvol/snapshot creation).
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
We calculate timeout (either 1 or MAX_SCHEDULE_TIMEOUT) based on whether
num_writers > 1 or should_grow at the top of the loop. Then, much much
later, we wait for that timeout if either num_writers or should_grow is
true. However, it's possible for a racing process (calling
btrfs_end_transaction()) to decrement num_writers such that we wait
forever instead of for 1.
Fix this by deciding how long to wait when we wait. Include a smp_mb()
before checking if the waitqueue is active to ensure the num_writers
is visible.
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
I'm no lockdep expert, but this appears to make the lockdep warning go
away for the i_mutex locking in the clone ioctl.
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
We had an edge case issue where the requested range was just
following an existing extent. Instead of skipping to the next
extent, we used the previous one which lead to having zero
sized extents.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The lookup_first_ordered_extent() was done on the wrong inode, and the
->delalloc_bytes test was wrong, as the following
btrfs_wait_ordered_range() would only invoke a range write and wouldn't
write the entire file data range. Also, a bad parameter was passed to
btrfs_wait_ordered_range().
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Linus Torvalds