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>
CONFIG_EXT4_INDEX is not an exposed config option in the kernel, and it is
unconditionally defined in ext4_fs.h. tune2fs is already able to turn off
dir indexing, so at this point it's just cluttering up the code. Remove
it.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fragment support in ext2/3/4 was never implemented, and it probably will
never be implemented. So remove it from ext4.
Signed-off-by: Coly Li <coyli@suse.de>
Acked-by: Andreas Dilger <adilger@clusterfs.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Mostly stolen from akpm's JBD cleanup patch.
- use `#ifdef foo' instead of `#if defined(foo)'
- Make journal_enable_debug __read_mostly just for the heck of it
- Make jbd_debugfs_dir and jbd_debug static
- debugfs_remove(NULL) is legal: remove unneeded tests
- remove unnecessary empty loops
Signed-off-by: Jose R. Santos <jrs@us.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We should really call journal_abort() and not __journal_abort_hard() in
case of errors. The latter call does not record the error in the journal
superblock and thus filesystem won't be marked as with errors later (and
user could happily mount it without any warning).
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
JBD2: Replace slab allocations with page allocations
JBD2 allocate memory for committed_data and frozen_data from slab. However
JBD2 should not pass slab pages down to the block layer. Use page allocator
pages instead. This will also prepare JBD for the large blocksize patchset.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
JBD: Replace slab allocations with page allocations
JBD allocate memory for committed_data and frozen_data from slab. However
JBD should not pass slab pages down to the block layer. Use page allocator pages instead. This will also prepare JBD for the large blocksize patchset.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
arch/ia64/kernel/machine_kexec.c: In function `arch_crash_save_vmcoreinfo':
arch/ia64/kernel/machine_kexec.c:131: error: `pgdat_list' undeclared (first use in this function)
arch/ia64/kernel/machine_kexec.c:131: error: (Each undeclared identifier is reported only once
arch/ia64/kernel/machine_kexec.c:131: error: for each function it appears in.)
arch/ia64/kernel/machine_kexec.c:134: error: `node_memblk' undeclared (first use in this function)
arch/ia64/kernel/machine_kexec.c:135: error: `NR_NODE_MEMBLKS' undeclared (first use in this function)
arch/ia64/kernel/machine_kexec.c:136: error: invalid application of `sizeof' to incomplete type `node_memblk_s'
arch/ia64/kernel/machine_kexec.c:137: error: dereferencing pointer to incomplete type
arch/ia64/kernel/machine_kexec.c:138: error: dereferencing pointer to incomplete type
make[1]: *** [arch/ia64/kernel/machine_kexec.o] Error 1
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc:
net: libertas sdio driver
mmc: at91_mci: cleanup: use MCI_ERRORS
mmc: possible leak in mmc_read_ext_csd
make clean failed to delete a few files in
x86/kernel. This is because kbuild does not
see the correct/full kernel/Makefile.
As a workaround until the Makefiles are merged specify
the files to be deleted in the common Makefile.
Reported by Mike Galbraith <efault@gmx.de>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
A sysctl method was added to enable and disable debugging levels. After
further review, it was decided that there are better approaches to doing this
and the sysctl methodology isn't really desirable. This patch removes the
sysctl code from 9p.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
A small MMC driver cleanup.
Use the defined AT91_MCI_ERRORS in at91_mci_completed_command() instead
of specifying all the error bits individually.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
The exception path associated with an invalid ext_csd_struct returns
without freeing ext_csd.
Coverity CID 1909.
Signed-off-by: Florin Malita
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
This patch moves transport dynamic registration and matching to the net
module to prevent a bad Kconfig dependency between the net and fs 9p modules.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Loose mode in 9p utilizes the page cache without respecting coherency with
the server. Any writes previously invaldiated the entire mapping for a file.
This patch softens the behavior to only invalidate the region of the actual
write.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
The 9P2000 protocol requires the authentication and permission checks to be
done in the file server. For that reason every user that accesses the file
server tree has to authenticate and attach to the server separately.
Multiple users can share the same connection to the server.
Currently v9fs does a single attach and executes all I/O operations as a
single user. This makes using v9fs in multiuser environment unsafe as it
depends on the client doing the permission checking.
This patch improves the 9P2000 support by allowing every user to attach
separately. The patch defines three modes of access (new mount option
'access'):
- attach-per-user (access=user) (default mode for 9P2000.u)
If a user tries to access a file served by v9fs for the first time, v9fs
sends an attach command to the server (Tattach) specifying the user. If
the attach succeeds, the user can access the v9fs tree.
As there is no uname->uid (string->integer) mapping yet, this mode works
only with the 9P2000.u dialect.
- allow only one user to access the tree (access=<uid>)
Only the user with uid can access the v9fs tree. Other users that attempt
to access it will get EPERM error.
- do all operations as a single user (access=any) (default for 9P2000)
V9fs does a single attach and all operations are done as a single user.
If this mode is selected, the v9fs behavior is identical with the current
one.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Change the names of 'uid' and 'gid' parameters to the more appropriate
'dfltuid' and 'dfltgid'. This also sets the default uid/gid to -2
(aka nfsnobody)
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Create more general flags field in the v9fs_session_info struct and move the
'extended' flag as a bit in the flags.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
This patch abstracts out the interfaces to underlying transports so that
new transports can be added as modules. This should also allow kernel
configuration of transports without ifdef-hell.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Fix rebuild of kernel when there is no changes.
This happened for i386.
Using make V=2 hinted that the output files were
not assigned to targets - fixed by this patch.
Reported by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch:
- makes .gitignore files visible to git
- makes arch/x86/kernel/vsyscall_32.lds and arch/i386/boot invisible
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Almost identical except for the extra DR_LEN_8 and the different
DR_CONTROL_RESERVED defines.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Conflicts:
include/asm-x86/Kbuild
Same file, except for whitespace, comment formatting and the
.long/.quad delta which can be solved by a define.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Same file, except for whitespace, comment formatting and:
32-bit: if((unsigned int) addr >= (unsigned int) high_memory)
64-bit: if((unsigned long) addr >= (unsigned long) high_memory)
where the latter can be used safely for both.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Conflicts:
include/asm-x86/floppy_32.h
include/asm-x86/floppy_64.h
commit 554d284ba9 added _GPF_NORETRY
to floppy_64.h to prevent OOM killer on floppy DMA allocations.
Apply the same to the 32 bit variant.
Found during the attempt to unify the _32/_64 variants. Seperate commit
to document the resulting code change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Same file, except for whitespace, comment formatting and the two variants
of fb_is_primary_device()
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Same file, except for whitespace, comment formatting and:
32-bit: unsigned long *virt_addr = va;
64-bit: unsigned int *virt_addr = va;
Both can be safely replaced by:
u32 i, *virt_addr = va;
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Same file, except for whitespace, comment formatting and the extra
function prototype usc_tsc_delay() in _32.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Same file, except for whitespace, comment formatting and the extra
defines in _64, which are conditional on VSMP anyway.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Same file, except for whitespace, comment formatting and the extra
DEBUG_PAGE_ALLOC function in _32.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
