In data=writeback mode, start an asynchronous flush when renaming a
file on top of an already-existing file. This lowers the probability
of data loss in the case of applications that attempt to replace a
file via using rename().
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
In data=writeback mode, start an asynchronous flush when closing a
file which had been previously truncated down to zero. This lowers
the probability of data loss in the case of applications that attempt
to replace a file using truncate.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
Remove two unneeded exports and make two symbols static in fs/mpage.c
Cleanup after commit 585d3bc06f
Trim includes of fdtable.h
Don't crap into descriptor table in binfmt_som
Trim includes in binfmt_elf
Don't mess with descriptor table in load_elf_binary()
Get rid of indirect include of fs_struct.h
New helper - current_umask()
check_unsafe_exec() doesn't care about signal handlers sharing
New locking/refcounting for fs_struct
Take fs_struct handling to new file (fs/fs_struct.c)
Get rid of bumping fs_struct refcount in pivot_root(2)
Kill unsharing fs_struct in __set_personality()
Make reiserfs3 return f_fsid info for statfs(2). By Andreas' suggestion,
this patch populates a persistent f_fsid between boots/mounts with help of
on-disk uuid record.
Randy Dunlap reported a compiling error from v2 patch like:
fs/built-in.o: In function `reiserfs_statfs':
super.c:(.text+0x7332b): undefined reference to `crc32_le'
super.c:(.text+0x7333f): undefined reference to `crc32_le'
Also he provided helpful solution to fix this error. The modification of v3
patch is based on Randy's suggestion, add 'select CRC32' in fs/reiserfs/Kconfig.
Signed-off-by: Coly Li <coly.li@suse.de>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds preadv and pwritev system calls. These syscalls are a
pretty straightforward combination of pread and readv (same for write).
They are quite useful for doing vectored I/O in threaded applications.
Using lseek+readv instead opens race windows you'll have to plug with
locking.
Other systems have such system calls too, for example NetBSD, check
here: http://www.daemon-systems.org/man/preadv.2.html
The application-visible interface provided by glibc should look like
this to be compatible to the existing implementations in the *BSD family:
ssize_t preadv(int d, const struct iovec *iov, int iovcnt, off_t offset);
ssize_t pwritev(int d, const struct iovec *iov, int iovcnt, off_t offset);
This prototype has one problem though: On 32bit archs is the (64bit)
offset argument unaligned, which the syscall ABI of several archs doesn't
allow to do. At least s390 needs a wrapper in glibc to handle this. As
we'll need a wrappers in glibc anyway I've decided to push problem to
glibc entriely and use a syscall prototype which works without
arch-specific wrappers inside the kernel: The offset argument is
explicitly splitted into two 32bit values.
The patch sports the actual system call implementation and the windup in
the x86 system call tables. Other archs follow as separate patches.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <linux-api@vger.kernel.org>
Cc: <linux-arch@vger.kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Decompression errors can arise due to corruption of compressed blocks on
flash or in memory. This patch propagates errors detected during
decompression back to the block layer.
Signed-off-by: David VomLehn <dvomlehn@cisco.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hppfs_read_file() may return (ssize_t) -ENOMEM, or -EFAULT. When stored
in size_t 'count', these errors will not be noticed, a large value will be
added to *ppos.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sometimes block_write_begin() can map buffers in a page but later we
fail to copy data into those buffers (because the source page has been
paged out in the mean time). We then end up with !uptodate mapped
buffers. To add a bit more to the confusion, block_write_end() does
not commit any data (and thus does not any mark buffers as uptodate) if
we didn't succeed with copying all the data.
Commit f4fc66a894 (ext3: convert to new
aops) missed these cases and thus we were inserting non-uptodate
buffers to transaction's list which confuses JBD code and it reports IO
errors, aborts a transaction and generally makes users afraid about
their data ;-P.
This patch fixes the problem by reorganizing ext3_..._write_end() code
to first call block_write_end() to mark buffers with valid data
uptodate and after that we file only uptodate buffers to transaction's
lists.
We also fix a problem where we could leave blocks allocated beyond i_size
(i_disksize in fact) because of failed write. We now add inode to orphan
list when write fails (to be safe in case we crash) and then truncate blocks
beyond i_size in a separate transaction.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ext3_iget() returns -ESTALE if invoked on a deleted inode, in order to
report errors to NFS properly. However, in ext[234]_lookup(), this
-ESTALE can be propagated to userspace if the filesystem is corrupted such
that a directory entry references a deleted inode. This leads to a
misleading error message - "Stale NFS file handle" - and confusion on the
part of the admin.
The bug can be easily reproduced by creating a new filesystem, making a
link to an unused inode using debugfs, then mounting and attempting to ls
-l said link.
This patch thus changes ext3_lookup to return -EIO if it receives -ESTALE
from ext3_iget(), as ext3 does for other filesystem metadata corruption;
and also invokes the appropriate ext*_error functions when this case is
detected.
Signed-off-by: Bryan Donlan <bdonlan@gmail.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use unsigned instead of int for the parameter which carries a blocksize.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Check bh->b_blocknr only if BH_Mapped is set.
akpm: I doubt if b_blocknr is ever uninitialised here, but it could
conceivably cause a problem if we're doing a lookup for block zero.
Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The dirtied_when value on an inode is supposed to represent the first time
that an inode has one of its pages dirtied. This value is in units of
jiffies. It's used in several places in the writeback code to determine
when to write out an inode.
The problem is that these checks assume that dirtied_when is updated
periodically. If an inode is continuously being used for I/O it can be
persistently marked as dirty and will continue to age. Once the time
compared to is greater than or equal to half the maximum of the jiffies
type, the logic of the time_*() macros inverts and the opposite of what is
needed is returned. On 32-bit architectures that's just under 25 days
(assuming HZ == 1000).
As the least-recently dirtied inode, it'll end up being the first one that
pdflush will try to write out. sync_sb_inodes does this check:
/* Was this inode dirtied after sync_sb_inodes was called? */
if (time_after(inode->dirtied_when, start))
break;
...but now dirtied_when appears to be in the future. sync_sb_inodes bails
out without attempting to write any dirty inodes. When this occurs,
pdflush will stop writing out inodes for this superblock. Nothing can
unwedge it until jiffies moves out of the problematic window.
This patch fixes this problem by changing the checks against dirtied_when
to also check whether it appears to be in the future. If it does, then we
consider the value to be far in the past.
This should shrink the problematic window of time to such a small period
(30s) as not to matter.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Acked-by: Ian Kent <raven@themaw.net>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
clear_inode() will switch inode state from I_FREEING to I_CLEAR, and do so
_outside_ of inode_lock. So any I_FREEING testing is incomplete without a
coupled testing of I_CLEAR.
So add I_CLEAR tests to drop_pagecache_sb(), generic_sync_sb_inodes() and
add_dquot_ref().
Masayoshi MIZUMA discovered the bug in drop_pagecache_sb() and Jan Kara
reminds fixing the other two cases.
Masayoshi MIZUMA has a nice panic flow:
=====================================================================
[process A] | [process B]
| |
| prune_icache() | drop_pagecache()
| spin_lock(&inode_lock) | drop_pagecache_sb()
| inode->i_state |= I_FREEING; | |
| spin_unlock(&inode_lock) | V
| | | spin_lock(&inode_lock)
| V | |
| dispose_list() | |
| list_del() | |
| clear_inode() | |
| inode->i_state = I_CLEAR | |
| | | V
| | | if (inode->i_state & (I_FREEING|I_WILL_FREE))
| | | continue; <==== NOT MATCH
| | |
| | | (DANGER from here on! Accessing disposing inode!)
| | |
| | | __iget()
| | | list_move() <===== PANIC on poisoned list !!
V V |
(time)
=====================================================================
Reported-by: Masayoshi MIZUMA <m.mizuma@jp.fujitsu.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a number of issues with the per-MM VMA patch:
(1) Make mmap_pages_allocated an atomic_long_t, just in case this is used on
a NOMMU system with more than 2G pages. Makes no difference on a 32-bit
system.
(2) Report vma->vm_pgoff * PAGE_SIZE as a 64-bit value, not a 32-bit value,
lest it overflow.
(3) Move the allocation of the vm_area_struct slab back for fork.c.
(4) Use KMEM_CACHE() for both vm_area_struct and vm_region slabs.
(5) Use BUG_ON() rather than if () BUG().
(6) Make the default validate_nommu_regions() a static inline rather than a
#define.
(7) Make free_page_series()'s objection to pages with a refcount != 1 more
informative.
(8) Adjust the __put_nommu_region() banner comment to indicate that the
semaphore must be held for writing.
(9) Limit the number of warnings about munmaps of non-mmapped regions.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We get this on 32 builds:
fs/built-in.o: In function `extent_fiemap':
(.text+0x1019f2): undefined reference to `__ucmpdi2'
Happens because of a switch statement with a 64 bit argument.
Convert this to an if statement to fix this.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
btrfs_new_inode doesn't call iput to free the inode
when it fails.
Signed-off-by: Shen Feng <shen@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Need to check kthread_should_stop after schedule_timeout() before calling
schedule(). This causes threads to sleep with potentially no one to wake them
up causing mount(2) to hang in btrfs_stop_workers waiting for threads to stop.
Signed-off-by: Amit Gud <gud@ksu.edu>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
The 'flushoncommit' mount option forces any data dirtied by a write in a
prior transaction to commit as part of the current commit. This makes
the committed state a fully consistent view of the file system from the
application's perspective (i.e., it includes all completed file system
operations). This was previously the behavior only when a snapshot is
created.
This is used by Ceph to ensure that completed writes make it to the
platter along with the metadata operations they are bound to (by
BTRFS_IOC_TRANS_{START,END}).
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Add a 'notreelog' mount option to disable the tree log (used by fsync,
O_SYNC writes). This is much slower, but the tree logging produces
inconsistent views into the FS for ceph.
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
btrfs options can change at times other than mount, yet /proc/mounts shows the
options string used when the fs was mounted (an example would be when btrfs
determines that barriers aren't useful and turns them off.) This patch
instead outputs the actual options in use by btrfs.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Because btrfs is copy-on-write, we end up picking new locations for
blocks very often. This makes it fairly difficult to maintain perfect
read patterns over time, but we can at least do some optimizations
for writes.
This is done today by remembering the last place we allocated and
trying to find a free space hole big enough to hold more than just one
allocation. The end result is that we tend to write sequentially to
the drive.
This happens all the time for metadata and it happens for data
when mounted -o ssd. But, the way we record it is fairly racey
and it tends to fragment the free space over time because we are trying
to allocate fairly large areas at once.
This commit gets rid of the races by adding a free space cluster object
with dedicated locking to make sure that only one process at a time
is out replacing the cluster.
The free space fragmentation is somewhat solved by allowing a cluster
to be comprised of smaller free space extents. This part definitely
adds some CPU time to the cluster allocations, but it allows the allocator
to consume the small holes left behind by cow.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
btrfs_next_leaf was using blocking locks when it could have been using
faster spinning ones instead. This adds a few extra checks around
the pieces that block and switches over to spinning locks.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Theodore Ts'o