It is frequently useful to sync a single file system, instead of all
mounted file systems via sync(2):
- On machines with many mounts, it is not at all uncommon for some of
them to hang (e.g. unresponsive NFS server). sync(2) will get stuck on
those and may never get to the one you do care about (e.g., /).
- Some applications write lots of data to the file system and then
want to make sure it is flushed to disk. Calling fsync(2) on each
file introduces unnecessary ordering constraints that result in a large
amount of sub-optimal writeback/flush/commit behavior by the file
system.
There are currently two ways (that I know of) to sync a single super_block:
- BLKFLSBUF ioctl on the block device: That also invalidates the bdev
mapping, which isn't usually desirable, and doesn't work for non-block
file systems.
- 'mount -o remount,rw' will call sync_filesystem as an artifact of the
current implemention. Relying on this little-known side effect for
something like data safety sounds foolish.
Both of these approaches require root privileges, which some applications
do not have (nor should they need?) given that sync(2) is an unprivileged
operation.
This patch introduces a new system call syncfs(2) that takes an fd and
syncs only the file system it references. Maybe someday we can
$ sync /some/path
and not get
sync: ignoring all arguments
The syscall is motivated by comments by Al and Christoph at the last LSF.
syncfs(2) seems like an appropriate name given statfs(2).
A similar ioctl was also proposed a while back, see
http://marc.info/?l=linux-fsdevel&m=127970513829285&w=2
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Hi,
I was backporting the coredump over pipe feature and noticed this small typo,
I wish I would have something bigger to contribute...
>From 15d6080e0ed4267da103c706917a33b1015e8804 Mon Sep 17 00:00:00 2001
From: Holger Hans Peter Freyther <holger@moiji-mobile.com>
Date: Thu, 24 Feb 2011 17:42:50 +0100
Subject: [PATCH] fs: Fix a small typo in the comment
The function is called umh_pipe_setup not uhm_pipe_setup.
Signed-off-by: Holger Hans Peter Freyther <holger@moiji-mobile.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Remove the leftover from the commit 8ff3e8e85f ("select:
switch select() and poll() over to hrtimers").
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Move declaration of 'inode' to beginning of the function. Since it
is referenced directly or indirectly (in case of FIFREEZE/FITHAW/
FS_IOC_FIEMAP) it's not harmful IMHO. And remove unnecessary casts
using 'argp' instead.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6: (25 commits)
video: change to new flag variable
scsi: change to new flag variable
rtc: change to new flag variable
rapidio: change to new flag variable
pps: change to new flag variable
net: change to new flag variable
misc: change to new flag variable
message: change to new flag variable
memstick: change to new flag variable
isdn: change to new flag variable
ieee802154: change to new flag variable
ide: change to new flag variable
hwmon: change to new flag variable
dma: change to new flag variable
char: change to new flag variable
fs: change to new flag variable
xtensa: change to new flag variable
um: change to new flag variables
s390: change to new flag variable
mips: change to new flag variable
...
Fix up trivial conflict in drivers/hwmon/Makefile
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
nilfs2: move NILFS_SUPER_MAGIC to linux/magic.h
nilfs2: get rid of nilfs_sb_info structure
nilfs2: use sb instance instead of nilfs_sb_info struct
nilfs2: get rid of sc_sbi back pointer
nilfs2: move log writer onto nilfs object
nilfs2: move next generation counter into nilfs object
nilfs2: move s_inode_lock and s_dirty_files into nilfs object
nilfs2: move parameters on nilfs_sb_info into nilfs object
nilfs2: move mount options to nilfs object
nilfs2: record used amount of each checkpoint in checkpoint list
nilfs2: optimize rec_len functions
nilfs2: append blocksize info to warnings during loading super blocks
nilfs2: add compat ioctl
nilfs2: implement FS_IOC_GETFLAGS/SETFLAGS/GETVERSION
nilfs2: tighten restrictions on inode flags
nilfs2: mark S_NOATIME on inodes only if NOATIME attribute is set
nilfs2: use common file attribute macros
nilfs2: add free entries count only if clear bit operation succeeded
nilfs2: decrement inodes count only if raw inode was successfully deleted
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm:
dlm: use alloc_workqueue function
dlm: increase default hash table sizes
dlm: record full callback state
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
fs: call security_d_instantiate in d_obtain_alias V2
lose 'mounting_here' argument in ->d_manage()
don't pass 'mounting_here' flag to follow_down()
change the locking order for namespace_sem
fix deadlock in pivot_root()
vfs: split off vfsmount-related parts of vfs_kern_mount()
Some fixes for pstore
kill simple_set_mnt()
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bcopeland/omfs:
omfs: make readdir stop when filldir says so
omfs: merge unlink() and rmdir(), close leak in rename()
omfs: stop playing silly buggers with omfs_unlink() in ->rename()
omfs: rename() needs to mark old_inode dirty after ctime update
* 'linux-next' of git://git.infradead.org/ubifs-2.6: (25 commits)
UBIFS: clean-up commentaries
UBIFS: save 128KiB or more RAM
UBIFS: allocate orphans scan buffer on demand
UBIFS: allocate lpt dump buffer on demand
UBIFS: allocate ltab checking buffer on demand
UBIFS: allocate scanning buffer on demand
UBIFS: allocate dump buffer on demand
UBIFS: do not check data crc by default
UBIFS: simplify UBIFS Kconfig menu
UBIFS: print max. index node size
UBIFS: handle allocation failures in UBIFS write path
UBIFS: use max_write_size during recovery
UBIFS: use max_write_size for write-buffers
UBIFS: introduce write-buffer size field
UBI: incorporate LEB offset information
UBIFS: incorporate maximum write size
UBI: provide LEB offset information
UBI: incorporate maximum write size
UBIFS: fix LEB number in printk
UBIFS: restrict world-writable debugfs files
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (47 commits)
doc: CONFIG_UNEVICTABLE_LRU doesn't exist anymore
Update cpuset info & webiste for cgroups
dcdbas: force SMI to happen when expected
arch/arm/Kconfig: remove one to many l's in the word.
asm-generic/user.h: Fix spelling in comment
drm: fix printk typo 'sracth'
Remove one to many n's in a word
Documentation/filesystems/romfs.txt: fixing link to genromfs
drivers:scsi Change printk typo initate -> initiate
serial, pch uart: Remove duplicate inclusion of linux/pci.h header
fs/eventpoll.c: fix spelling
mm: Fix out-of-date comments which refers non-existent functions
drm: Fix printk typo 'failled'
coh901318.c: Change initate to initiate.
mbox-db5500.c Change initate to initiate.
edac: correct i82975x error-info reported
edac: correct i82975x mci initialisation
edac: correct commented info
fs: update comments to point correct document
target: remove duplicate include of target/target_core_device.h from drivers/target/target_core_hba.c
...
Trivial conflict in fs/eventpoll.c (spelling vs addition)
While trying to track down some NFS problems with BTRFS, I kept noticing I was
getting -EACCESS for no apparent reason. Eric Paris and printk() helped me
figure out that it was SELinux that was giving me grief, with the following
denial
type=AVC msg=audit(1290013638.413:95): avc: denied { 0x800000 } for pid=1772
comm="nfsd" name="" dev=sda1 ino=256 scontext=system_u:system_r:kernel_t:s0
tcontext=system_u:object_r:unlabeled_t:s0 tclass=file
Turns out this is because in d_obtain_alias if we can't find an alias we create
one and do all the normal instantiation stuff, but we don't do the
security_d_instantiate.
Usually we are protected from getting a hashed dentry that hasn't yet run
security_d_instantiate() by the parent's i_mutex, but obviously this isn't an
option there, so in order to deal with the case that a second thread comes in
and finds our new dentry before we get to run security_d_instantiate(), we go
ahead and call it if we find a dentry already. Eric assures me that this is ok
as the code checks to see if the dentry has been initialized already so calling
security_d_instantiate() against the same dentry multiple times is ok. With
this patch I'm no longer getting errant -EACCESS values.
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Have it nested inside ->i_mutex. Instead of using follow_down()
under namespace_sem, followed by grabbing i_mutex and checking that
mountpoint to be is not dead, do the following:
grab i_mutex
check that it's not dead
grab namespace_sem
see if anything is mounted there
if not, we've won
otherwise
drop locks
put_path on what we had
replace with what's mounted
retry everything with new mountpoint to be
New helper (lock_mount()) does that. do_add_mount(), do_move_mount(),
do_loopback() and pivot_root() switched to it; in case of the last
two that eliminates a race we used to have - original code didn't
do follow_down().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Don't hold vfsmount_lock over the loop traversing ->mnt_parent;
do check_mnt(new.mnt) under namespace_sem instead; combined with
namespace_sem held over all that code it'll guarantee the stability
of ->mnt_parent chain all the way to the root.
Doing check_mnt() outside of namespace_sem in case of pivot_root()
is wrong anyway.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
new function: mount_fs(). Does all work done by vfs_kern_mount()
except the allocation and filling of vfsmount; returns root dentry
or ERR_PTR().
vfs_kern_mount() switched to using it and taken to fs/namespace.c,
along with its wrappers.
alloc_vfsmnt()/free_vfsmnt() made static.
functions in namespace.c slightly reordered.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
1) Change from ->get_sb() to ->mount()
2) Use mount_single() instead of mount_nodev()
3) Pulled in ramfs_get_inode() & trimmed to what I need for pstore
4) Drop the ugly pstore_writefile() Just save data using kmalloc() and
provide a pstore_file_read() that uses simple_read_from_buffer().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6:
ext3: Always set dx_node's fake_dirent explicitly.
ext3: Fix an overflow in ext3_trim_fs.
jbd: Remove one to many n's in a word.
ext3: skip orphan cleanup on rocompat fs
ext2: Fix link count corruption under heavy link+rename load
ext3: speed up group trim with the right free block count.
ext3: Adjust trim start with first_data_block.
quota: return -ENOMEM when memory allocation fails
* 'nfs-for-2.6.39' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (54 commits)
RPC: killing RPC tasks races fixed
xprt: remove redundant check
SUNRPC: Convert struct rpc_xprt to use atomic_t counters
SUNRPC: Ensure we always run the tk_callback before tk_action
sunrpc: fix printk format warning
xprt: remove redundant null check
nfs: BKL is no longer needed, so remove the include
NFS: Fix a warning in fs/nfs/idmap.c
Cleanup: Factor out some cut-and-paste code.
cleanup: save 60 lines/100 bytes by combining two mostly duplicate functions.
NFS: account direct-io into task io accounting
gss:krb5 only include enctype numbers in gm_upcall_enctypes
RPCRDMA: Fix FRMR registration/invalidate handling.
RPCRDMA: Fix to XDR page base interpretation in marshalling logic.
NFSv4: Send unmapped uid/gids to the server when using auth_sys
NFSv4: Propagate the error NFS4ERR_BADOWNER to nfs4_do_setattr
NFSv4: cleanup idmapper functions to take an nfs_server argument
NFSv4: Send unmapped uid/gids to the server if the idmapper fails
NFSv4: If the server sends us a numeric uid/gid then accept it
NFSv4.1: reject zero layout with zeroed stripe unit
...
Replace EXTRA_CFLAGS with ccflags-y. And change ntfs-objs to ntfs-y
for cleaner conditional inclusion.
Signed-off-by: matt mooney <mfm@muteddisk.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
* 'mnt_devname' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
vfs: bury ->get_sb()
nfs: switch NFS from ->get_sb() to ->mount()
nfs: stop mangling ->mnt_devname on NFS
vfs: new superblock methods to override /proc/*/mount{s,info}
nfs: nfs_do_{ref,sub}mount() superblock argument is redundant
nfs: make nfs_path() work without vfsmount
nfs: store devname at disconnected NFS roots
nfs: propagate devname to nfs{,4}_get_root()
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
[IA64] tioca: Fix assignment from incompatible pointer warnings
[IA64] mca.c: Fix cast from integer to pointer warning
[IA64] setup.c Typo fix "Architechtuallly"
[IA64] Add CONFIG_MISC_DEVICES=y to configs that need it.
[IA64] disable interrupts at end of ia64_mca_cpe_int_handler()
[IA64] Add DMA_ERROR_CODE define.
pstore: fix build warning for unused return value from sysfs_create_file
pstore: X86 platform interface using ACPI/APEI/ERST
pstore: new filesystem interface to platform persistent storage
* 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
BKL: That's all, folks
fs/locks.c: Remove stale FIXME left over from BKL conversion
ipx: remove the BKL
appletalk: remove the BKL
x25: remove the BKL
ufs: remove the BKL
hpfs: remove the BKL
drivers: remove extraneous includes of smp_lock.h
tracing: don't trace the BKL
adfs: remove the big kernel lock
The last remaining instances of ->get_sb() can be converted ->mount()
now - nothing in them uses new vfsmount anymore.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
a) ->show_devname(m, mnt) - what to put into devname columns in mounts,
mountinfo and mountstats
b) ->show_path(m, mnt) - what to put into relative path column in mountinfo
Leaving those NULL gives old behaviour. NFS switched to using those.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
part 3: now we have everything to get nfs_path() just by dentry -
just follow to (disconnected) root and pick the rest of the thing
there.
Start killing propagation of struct vfsmount * on the paths that
used to bring it to nfs_path().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
part 2: make sure that disconnected roots have corresponding mnt_devname
values stashed into them.
Have nfs*_get_root() stuff a copy of devname into ->d_fsdata of the
found root, provided that it is disconnected.
Have ->d_release() free it when dentry goes away.
Have the places where NFS uses ->d_fsdata for sillyrename (and that
can *never* happen to a disconnected root - dentry will be attached
to its parent) free old devname copies if they find those.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (33 commits)
AppArmor: kill unused macros in lsm.c
AppArmor: cleanup generated files correctly
KEYS: Add an iovec version of KEYCTL_INSTANTIATE
KEYS: Add a new keyctl op to reject a key with a specified error code
KEYS: Add a key type op to permit the key description to be vetted
KEYS: Add an RCU payload dereference macro
AppArmor: Cleanup make file to remove cruft and make it easier to read
SELinux: implement the new sb_remount LSM hook
LSM: Pass -o remount options to the LSM
SELinux: Compute SID for the newly created socket
SELinux: Socket retains creator role and MLS attribute
SELinux: Auto-generate security_is_socket_class
TOMOYO: Fix memory leak upon file open.
Revert "selinux: simplify ioctl checking"
selinux: drop unused packet flow permissions
selinux: Fix packet forwarding checks on postrouting
selinux: Fix wrong checks for selinux_policycap_netpeer
selinux: Fix check for xfrm selinux context algorithm
ima: remove unnecessary call to ima_must_measure
IMA: remove IMA imbalance checking
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs: (46 commits)
fs/9p: Make the writeback_fid owned by root
fs/9p: Writeback dirty data before setattr
fs/9p: call vmtruncate before setattr 9p opeation
fs/9p: Properly update inode attributes on link
fs/9p: Prevent multiple inclusion of same header
fs/9p: Workaround vfs rename rehash bug
fs/9p: Mark directory inode invalid for many directory inode operations
fs/9p: Add . and .. dentry revalidation flag
fs/9p: mark inode attribute invalid on rename, unlink and setattr
fs/9p: Add support for marking inode attribute invalid
fs/9p: Initialize root inode number for dotl
fs/9p: Update link count correctly on different file system operations
fs/9p: Add drop_inode 9p callback
fs/9p: Add direct IO support in cached mode
fs/9p: Fix inode i_size update in file_write
fs/9p: set default readahead pages in cached mode
fs/9p: Move writeback fid to v9fs_inode
fs/9p: Add v9fs_inode
fs/9p: Don't set stat.st_blocks based on nrpages
fs/9p: Add inode hashing
...
* 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: fix build failure introduced by s/freezeable/freezable/
workqueue: add system_freezeable_wq
rds/ib: use system_wq instead of rds_ib_fmr_wq
net/9p: replace p9_poll_task with a work
net/9p: use system_wq instead of p9_mux_wq
xfs: convert to alloc_workqueue()
reiserfs: make commit_wq use the default concurrency level
ocfs2: use system_wq instead of ocfs2_quota_wq
ext4: convert to alloc_workqueue()
scsi/scsi_tgt_lib: scsi_tgtd isn't used in memory reclaim path
scsi/be2iscsi,qla2xxx: convert to alloc_workqueue()
misc/iwmc3200top: use system_wq instead of dedicated workqueues
i2o: use alloc_workqueue() instead of create_workqueue()
acpi: kacpi*_wq don't need WQ_MEM_RECLAIM
fs/aio: aio_wq isn't used in memory reclaim path
input/tps6507x-ts: use system_wq instead of dedicated workqueue
cpufreq: use system_wq instead of dedicated workqueues
wireless/ipw2x00: use system_wq instead of dedicated workqueues
arm/omap: use system_wq in mailbox
workqueue: use WQ_MEM_RECLAIM instead of WQ_RESCUER
It turns out that while a maximum of 8 partitions may be what people
"should" have had, you can actually fit up to 18 entries(*) in a sector.
And some people clearly were taking advantage of that, like Michael
Cree, who had ten partitions on one of his OSF disks.
(*) The OSF partition data starts at byte offset 64 in the first sector,
and the array of 16-byte partition entries start at offset 148 in
the on-disk partition structure.
Reported-by: Michael Cree <mcree@orcon.net.nz>
Cc: stable@kernel.org (v2.6.38)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
iprune_sem is continously giving us lockdep warnings because we do take it in
read mode in the reclaim path, but we're also doing non-NOFS allocations under
it taken in write mode.
Taking a bit deeper look at it I think it's fixable quite trivially:
- for invalidate_inodes we do not need iprune_sem at all. We have an active
reference on the superblock, so the filesystem is not going away until it
has finished.
- for evict_inodes we do need it, to make sure prune_icache has done it's
work before we tear down the superblock. But there is no reason to
hold it over the actual reclaim operation - it's enough to cycle through
it after the actual reclaim to make sure we wait for any pending
prune_icache to complete. We just have to remove the WARN_ON for
otherwise busy inodes as they can actually happen now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
When debugging is enabled, we allocate a buffer of PEB size for
various debugging purposes. However, now all users of this buffer
are gone and we can safely remove it and save 128KiB or more RAM.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Instead of using pre-allocated 'c->dbg->buf' buffer in
'dbg_scan_orphans()', dynamically allocate it when needed. The intend
is to get rid of the pre-allocated 'c->dbg->buf' buffer and save
128KiB of RAM (or more if PEB size is larger). Indeed, currently we
allocate this memory even if the user never enables any self-check,
which is wasteful.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Sage Weil