Adds OMFS to the fs Kconfig and Makefile
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While fixing CONFIG_ leakages to the userspace kernel headers I ran into
CODA_FS_OLD_API.
After five years, are there still people using the old API left?
Especially considering that you have to choose at compile time which API
to support in the kernel (and distributions tend to offer the new API for
some time).
Jan: "The old API can definitely go. Around the time the new
interface went in there were some non-Coda userspace file system
implementations that took a while longer to convert to the new API,
but by now they all switched to the new interface or in some cases
to a FUSE-based solution."
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Jan Harkes <jaharkes@cs.cmu.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2:
[PATCH] ocfs2: fix oops in mmap_truncate testing
configfs: call drop_link() to cleanup after create_link() failure
configfs: Allow ->make_item() and ->make_group() to return detailed errors.
configfs: Fix failing mkdir() making racing rmdir() fail
configfs: Fix deadlock with racing rmdir() and rename()
configfs: Make configfs_new_dirent() return error code instead of NULL
configfs: Protect configfs_dirent s_links list mutations
configfs: Introduce configfs_dirent_lock
ocfs2: Don't snprintf() without a format.
ocfs2: Fix CONFIG_OCFS2_DEBUG_FS #ifdefs
ocfs2/net: Silence build warnings on sparc64
ocfs2: Handle error during journal load
ocfs2: Silence an error message in ocfs2_file_aio_read()
ocfs2: use simple_read_from_buffer()
ocfs2: fix printk format warnings with OCFS2_FS_STATS=n
[PATCH 2/2] ocfs2: Instrument fs cluster locks
[PATCH 1/2] ocfs2: Add CONFIG_OCFS2_FS_STATS config option
* 'for_linus' of git://git.infradead.org/~dedekind/ubifs-2.6:
UBIFS: include to compilation
UBIFS: add new flash file system
UBIFS: add brief documentation
MAINTAINERS: add UBIFS section
do_mounts: allow UBI root device name
VFS: export sync_sb_inodes
VFS: move inode_lock into sync_sb_inodes
Add UBIFS to Makefile and Kbuild.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
This patch adds config option CONFIG_OCFS2_FS_STATS to allow building
the fs with instrumentation enabled. An upcoming patch will provide
support to instrument cluster locking, which is a crucial overhead in
a cluster file system. This config option allows users to avoid the cpu
and memory overhead that is involved in gathering such statistics.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Some server vendors support the higher versions of rpcbind only for
AF_INET6. The kernel doesn't need to use v3 or v4 for AF_INET anyway,
so change the kernel's rpcbind client to query AF_INET servers over
rpcbind v2 only.
This has a few interesting benefits:
1. If the rpcbind request is going over TCP, and the server doesn't
support rpcbind versions 3 or 4, the client reduces by two the number
of ephemeral ports left in TIME_WAIT for each rpcbind request. This
will help during NFS mount storms.
2. The rpcbind interaction with servers that don't support rpcbind
versions 3 or 4 will use less network traffic. Also helpful
during mount storms.
3. We can eliminate the kernel build option that controls whether the
kernel's rpcbind client uses rpcbind version 3 and 4 for AF_INET
servers. Less complicated kernel configuration...
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up: refresh the help text for Kconfig items related to the NFS
client. Remove obsolete URLs, and make the language consistent among
the options.
Also move the ROOT_NFS config option next to the options related to the
NFS client.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
I would suggest to remove the "experimental" status from Kdump.
Kdump is now in the kernel since a long time and used by Enterprise
distributions. I don't think that "experimental" is true any more.
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: vgoyal@redhat.com
Cc: kexec@lists.infradead.org
Cc: Bernhard Walle <bwalle@suse.de>
Cc: akpm@linux-foundation.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The url in the help text for ntfs should be updated.
Acked-by: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds hugetlbfs support on System z, using both hardware large page
support if available and software large page emulation on older hardware.
Shared (large) page tables are implemented in software emulation mode,
by using page->index of the first tail page from a compound large page
to store page table information.
Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (80 commits)
SUNRPC: Invalidate the RPCSEC_GSS session if the server dropped the request
make nfs_automount_list static
NFS: remove duplicate flags assignment from nfs_validate_mount_data
NFS - fix potential NULL pointer dereference v2
SUNRPC: Don't change the RPCSEC_GSS context on a credential that is in use
SUNRPC: Fix a race in gss_refresh_upcall()
SUNRPC: Don't disconnect more than once if retransmitting NFSv4 requests
SUNRPC: Remove the unused export of xprt_force_disconnect
SUNRPC: remove XS_SENDMSG_RETRY
SUNRPC: Protect creds against early garbage collection
NFSv4: Attempt to use machine credentials in SETCLIENTID calls
NFSv4: Reintroduce machine creds
NFSv4: Don't use cred->cr_ops->cr_name in nfs4_proc_setclientid()
nfs: fix printout of multiword bitfields
nfs: return negative error value from nfs{,4}_stat_to_errno
NLM/lockd: Ensure client locking calls use correct credentials
NFS: Remove the buggy lock-if-signalled case from do_setlk()
NLM/lockd: Fix a race when cancelling a blocking lock
NLM/lockd: Ensure that nlmclnt_cancel() returns results of the CANCEL call
NLM: Remove the signal masking in nlmclnt_proc/nlmclnt_cancel
...
Clean up: Because NFSD_V4 "depends on" NFSD_V3, it appears as a child of
the NFSD_V3 menu entry, and is not visible if NFSD_V3 is unselected.
Replace the dependency on NFSD_V3 with a "select NFSD_V3". This makes
NFSD_V4 look and work just like NFS_V3, while ensuring that NFSD_V3 is
enabled if NFSD_V4 is.
Sam Ravnborg adds:
"This use of select is questionable. In general it is bad to select
a symbol with dependencies.
In this case the dependencies of NFSD_V3 are duplicated for NFSD_V4
so we will not se erratic configurations but do you remember to
update NFSD_V4 when you add a depends on NFSD_V3?
But I see no other clean way to do it right now."
Later he said:
"My comment was more to say we have things to address in kconfig.
This is abuse in the acceptable range."
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Recently, commit 440bcc59 added a reverse dependency to fs/Kconfig to
ensure that PROC_FS was enabled if SUNRPC_GSS was enabled.
Apparently this isn't necessary because the auth_gss components under
net/sunrpc will build correctly even if PROC_FS is disabled, though
RPCSEC_GSS will not work without /proc.
It also violates the guideline in Documentation/kbuild/kconfig-language.txt
that states "In general use select only for non-visible symbols (no prompts
anywhere) and for symbols with no dependencies."
To address these issues, remove the dependency.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Recently, commit 440bcc59 added a reverse dependency to fs/Kconfig to
ensure that PROC_FS was enabled if NFSD_V4 was enabled.
There is a guideline in Documentation/kbuild/kconfig-language.txt that
states "In general use select only for non-visible symbols (no prompts
anywhere) and for symbols with no dependencies."
A quick grep around other Kconfig files reveals that no entry currently
uses "select PROC_FS" -- every one uses "depends on". Thus CONFIG_NFSD_V4
should use "depends on PROC_FS" as well.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
As far as I can tell, selecting the CRYPTO and CRYPTO_MD5 entries under
CONFIG_NFSD is redundant, since CONFIG_NFSD_V4 already selects
RPCSEC_GSS_KRB5, which selects these entries.
Testing with "make menuconfig" shows that the entries under CRYPTO still
properly reflect "Y" or "M" based on the setting of CONFIG_NFSD after this
change is applied.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Clean up: since NFSD_V2_ACL is a boolean, it can be selected safely
under the NFSD_V3_ACL entry (also a boolean).
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Clean up: since FS_POSIX_ACL is a non-visible boolean entry, it can be
selected safely under the NFSD_V4 entry (also a boolean).
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Clean up: refresh the help text for Kconfig items related to the NFS
server. Remove obsolete URLs, and make the language consistent among
the options.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Likewise, distros usually leave CONFIG_NFSD_TCP enabled.
TCP support in the Linux NFS server is stable enough that we can leave it
on always. CONFIG_NFSD_TCP adds about 10 lines of code, and defaults to
"Y" anyway.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-udf-2.6: (41 commits)
udf: use crc_itu_t from lib instead of udf_crc
udf: Fix compilation warnings when UDF debug is on
udf: Fix bug in VAT mapping code
udf: Add read-only support for 2.50 UDF media
udf: Fix handling of multisession media
udf: Mount filesystem read-only if it has pseudooverwrite partition
udf: Handle VAT packed inside inode properly
udf: Allow loading of VAT inode
udf: Fix detection of VAT version
udf: Silence warning about accesses beyond end of device
udf: Improve anchor block detection
udf: Cleanup anchor block detection.
udf: Move processing of virtual partitions
udf: Move filling of partition descriptor info into a separate function
udf: Improve error recovery on mount
udf: Cleanup volume descriptor sequence processing
udf: fix anchor point detection
udf: Remove declarations of arrays of size UDF_NAME_LEN (256 bytes)
udf: Remove checking of existence of filename in udf_add_entry()
udf: Mark udf_process_sequence() as noinline
...
ocfs2 now supports plug-ins for the classic O2CB stack as well as
userspace cluster stacks in conjunction with fs/dlm. This allows zero,
one, or both of the plug-ins to be selected in Kconfig. For local mounts
(non-clustered), neither plug-in is needed. Both plugins can be loaded
at one time, the runtime will select the one needed for the cluster
systme in use.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
As pointed out by Sergey Vlasov, UDF implements its own version of
the CRC ITU-T V.41. Convert it to use the one in the library.
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Cc: Sergey Vlasov <vsu@altlinux.ru>
Signed-off-by: Jan Kara <jack@suse.cz>
Documentation/ is a little large, and filesystems/ seems an obvious
place for this file.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Most distros will want support for rpcbind protocols 3 and 4 to default off
until they have integrated user-space support for the new rpcbind daemon
which supports IPv6 RPC services.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up: refresh the help text for Kconfig items related to the sunrpc
module. Remove obsolete URLs, and make the language consistent among
the options.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Since O_DIRECT is a standard feature that is enabled in most distros,
eliminate the CONFIG_NFS_DIRECTIO build option, and change the
fs/nfs/Makefile to always build in the NFS direct I/O engine.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Trond and Bruce,
This is a patch for 2.6.25. This is the same version that was sent out
on December 12 for review (no comments to date).
To simplify the RPC/RDMA client and server build configuration, make
SUNRPC_XPRT_RDMA a hidden config option that continues to depend on
SUNRPC and INFINIBAND. The value of SUNRPC_XPRT_RDMA will be:
- N if either SUNRPC or INFINIBAND are N
- M if both SUNRPC and INFINIBAND are on (M or Y) and at least one is M
- Y if both SUNRPC and INFINIBAND are Y
In 2.6.25, all of the RPC/RDMA related files are grouped in
net/sunrpc/xprtrdma and the net/sunrpc/xprtrdma/Makefile builds both
the client and server RPC/RDMA support using this config option.
Signed-off-by: James Lentini <jlentini@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
- move minixfs and ROMfs to the Miscellaneous filesystems menu
- move DNOTIFY config symbol so that it is adjacent to INOTIFY
instead of being split by the QUOTA config options
- add some 'endif' annotations
- remove some whitespace (extra blank lines)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
smbfs is a bit buggy and has no maintainer. Change it to shout at the user on
the first five mount attempts - tell them to switch to CIFS.
Come December we'll mark it BROKEN and see what happens.
[olecom@flower.upol.cz: documentation update]
Cc: Urban Widmark <urban@teststation.com>
Acked-by: Steven French <sfrench@us.ibm.com>
Signed-off-by: Oleg Verych <olecom@flower.upol.cz>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The server depends on upcalls under /proc to support nfsv4 and gss.
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
The journal checksum feature adds two new flags i.e
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT and JBD2_FEATURE_COMPAT_CHECKSUM.
JBD2_FEATURE_CHECKSUM flag indicates that the commit block contains the
checksum for the blocks described by the descriptor blocks.
Due to checksums, writing of the commit record no longer needs to be
synchronous. Now commit record can be sent to disk without waiting for
descriptor blocks to be written to disk. This behavior is controlled
using JBD2_FEATURE_ASYNC_COMMIT flag. Older kernels/e2fsck should not be
able to recover the journal with _ASYNC_COMMIT hence it is made
incompat.
The commit header has been extended to hold the checksum along with the
type of the checksum.
For recovery in pass scan checksums are verified to ensure the sanity
and completeness(in case of _ASYNC_COMMIT) of every transaction.
Signed-off-by: Andreas Dilger <adilger@clusterfs.com>
Signed-off-by: Girish Shilamkar <girish@clusterfs.com>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
[CIFS] DFS build fixes
[CIFS] DFS support: provide shrinkable mounts
[CIFS] Do not log path names in lookup errors
[CIFS] DFS support patchset: Added mountdata
[CIFS] Forgot to add two new files from previous commit
[CIFS] DNS name resolution helper upcall for cifs
[CIFS] fix checkpatch warnings in fs/cifs/inode.c
[CIFS] hold ses sem on tcp session reconnect during mount
[CIFS] Allow setting mode via cifs acl
[CIFS] fix unicode string alignment in SPNEGO setup
[CIFS] cifs_partialpagewrite() cleanup
[CIFS] use krb5 session key from first SMB session after a NegProt
[CIFS] redo existing session setup if needed in cifs_mount
[CIFS] Only dump SPNEGO key if CONFIG_CIFS_DEBUG2 is set
[CIFS] fix SetEA failure to some Samba versions
configfs has been alive and kicking for a while now. It underpins some
non-EXPERIMENTAL subsystems, such as OCFS2's cluster stack.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Remove 'readpages' from the list in ocfs2.txt. Instead of having two
identical lists, I just removed the list in the OCFS2 section of fs/Kconfig
and added a pointer to Documentation/filesystems/ocfs2.txt.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This patch implements a new version of RCU which allows its read-side
critical sections to be preempted. It uses a set of counter pairs
to keep track of the read-side critical sections and flips them
when all tasks exit read-side critical section. The details
of this implementation can be found in this paper -
http://www.rdrop.com/users/paulmck/RCU/OLSrtRCU.2006.08.11a.pdf
and the article-
http://lwn.net/Articles/253651/
This patch was developed as a part of the -rt kernel development and
meant to provide better latencies when read-side critical sections of
RCU don't disable preemption. As a consequence of keeping track of RCU
readers, the readers have a slight overhead (optimizations in the paper).
This implementation co-exists with the "classic" RCU implementations
and can be switched to at compiler.
Also includes RCU tracing summarized in debugfs.
[ akpm@linux-foundation.org: build fixes on non-preempt architectures ]
Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com>
Reviewed-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix typo in arch/powerpc/boot/flatdevtree_env.h.
There is no Documentation/networking/ixgbe.txt.
README.cycladesZ is now in Documentation/.
wavelan.p.h is now in drivers/net/wireless/.
HFS.txt is now Documentation/filesystems/hfs.txt.
OSS-files are now in sound/oss/.
Signed-off-by: Johann Felix Soden <johfel@users.sourceforge.net>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Adds additional option CIFS_DFS_UPCALL to fs/Kconfig for enabling
DFS support. Resolved IP address is saved as a string in the
key payload.
Igor has a series of related patches that will follow which finish up
CIFS DFS support
Acked-by: Igor Mammedov <niallain@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This was introduced in 4af8e944c22d8af92a7548354a9567250cc1a782
Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enable expensive bitmap scanning only if DEBUG option is enabled.
The bitmap scanning quite loads the CPU and on my machine the write
throughput of dd if=/dev/zero of=/ocfs2/file bs=1M count=500 conv=sync
improves from 37 MB/s to 45.4 MB/s in local mode...
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6: (21 commits)
[CIFS] fix oops on second mount to same server when null auth is used
[CIFS] Fix stale mode after readdir when cifsacl specified
[CIFS] add mode to acl conversion helper function
[CIFS] Fix incorrect mode when ACL had deny access control entries
[CIFS] Add uid to key description so krb can handle user mounts
[CIFS] Fix walking out end of cifs dacl
[CIFS] Add upcall files for cifs to use spnego/kerberos
[CIFS] add OIDs for KRB5 and MSKRB5 to ASN1 parsing routines
[CIFS] Register and unregister cifs_spnego_key_type on module init/exit
[CIFS] implement upcalls for SPNEGO blob via keyctl API
[CIFS] allow cifs_calc_signature2 to deal with a zero length iovec
[CIFS] If no Access Control Entries, set mode perm bits to zero
[CIFS] when mount helper missing fix slash wrong direction in share
[CIFS] Don't request too much permission when reading an ACL
[CIFS] enable get mode from ACL when cifsacl mount option specified
[CIFS] ACL support part 8
[CIFS] acl support part 7
[CIFS] acl support part 6
[CIFS] acl support part 6
[CIFS] remove unused funtion compile warning when experimental off
...
Add routines to handle upcalls to userspace via keyctl for the purpose
of getting a SPNEGO blob for a particular uid and server combination.
Clean up the Makefile a bit and set it up to only compile cifs_spnego
if CONFIG_CIFS_UPCALL is set. Also change CONFIG_CIFS_UPCALL to depend
on CONFIG_KEYS rather than CONFIG_CONNECTOR.
cifs_spnego.h defines the communications between kernel and userspace
and is intended to be shared with userspace programs.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Fix links to files in Documentation/* in various Kconfig files
Signed-off-by: Dirk Hohndel <hohndel@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The jbd-debug file used to be located in /proc/sys/fs/jbd-debug, but
create_proc_entry() does not do lookups on file names that are more that
one directory deep. This causes the entry creation to fail and hence, no
proc file is created.
Instead of fixing this on procfs might as well move the jbd2-debug file to
debugfs which would be the preferred location for this kind of tunable.
The new location is now /sys/kernel/debug/jbd/jbd-debug.
[akpm@linux-foundation.org: zillions of cleanups]
Signed-off-by: Jose R. Santos <jrs@us.ibm.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In pass1 of e2fsck, every inode table in the fileystem is scanned and checked,
regardless of whether it is in use. This is this the most time consuming part
of the filesystem check. The unintialized block group feature can greatly
reduce e2fsck time by eliminating checking of uninitialized inodes.
With this feature, there is a a high water mark of used inodes for each block
group. Block and inode bitmaps can be uninitialized on disk via a flag in the
group descriptor to avoid reading or scanning them at e2fsck time. A checksum
of each group descriptor is used to ensure that corruption in the group
descriptor's bit flags does not cause incorrect operation.
The feature is enabled through a mkfs option
mke2fs /dev/ -O uninit_groups
A patch adding support for uninitialized block groups to e2fsprogs tools has
been posted to the linux-ext4 mailing list.
The patches have been stress tested with fsstress and fsx. In performance
tests testing e2fsck time, we have seen that e2fsck time on ext3 grows
linearly with the total number of inodes in the filesytem. In ext4 with the
uninitialized block groups feature, the e2fsck time is constant, based
solely on the number of used inodes rather than the total inode count.
Since typical ext4 filesystems only use 1-10% of their inodes, this feature can
greatly reduce e2fsck time for users. With performance improvement of 2-20
times, depending on how full the filesystem is.
The attached graph shows the major improvements in e2fsck times in filesystems
with a large total inode count, but few inodes in use.
In each group descriptor if we have
EXT4_BG_INODE_UNINIT set in bg_flags:
Inode table is not initialized/used in this group. So we can skip
the consistency check during fsck.
EXT4_BG_BLOCK_UNINIT set in bg_flags:
No block in the group is used. So we can skip the block bitmap
verification for this group.
We also add two new fields to group descriptor as a part of
uninitialized group patch.
__le16 bg_itable_unused; /* Unused inodes count */
__le16 bg_checksum; /* crc16(sb_uuid+group+desc) */
bg_itable_unused:
If we have EXT4_BG_INODE_UNINIT not set in bg_flags
then bg_itable_unused will give the offset within
the inode table till the inodes are used. This can be
used by fsck to skip list of inodes that are marked unused.
bg_checksum:
Now that we depend on bg_flags and bg_itable_unused to determine
the block and inode usage, we need to make sure group descriptor
is not corrupt. We add checksum to group descriptor to
detect corruption. If the descriptor is found to be corrupt, we
mark all the blocks and inodes in the group used.
Signed-off-by: Avantika Mathur <mathur@us.ibm.com>
Signed-off-by: Andreas Dilger <adilger@clusterfs.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Turn Network File Systems into a menuconfig so that it can be disabled at
once.
(Note: I added a "default y". If you do not like that, speak up.)
Signed-off-by: Jan Engelhardt <jengelh@gmx.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Steven French <sfrench@us.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Eric Van Hensbergen <ericvh@hera.kernel.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
