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* Revert "ext4: Remove journal_checksum mount option and enable it by default"Linus Torvalds2009-11-021-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit d0646f7b636d067d715fab52a2ba9c6f0f46b0d7, as requested by Eric Sandeen. It can basically cause an ext4 filesystem to miss recovery (and thus get mounted with errors) if the journal checksum does not match. Quoth Eric: "My hand-wavy hunch about what is happening is that we're finding a bad checksum on the last partially-written transaction, which is not surprising, but if we have a wrapped log and we're doing the initial scan for head/tail, and we abort scanning on that bad checksum, then we are essentially running an unrecovered filesystem. But that's hand-wavy and I need to go look at the code. We lived without journal checksums on by default until now, and at this point they're doing more harm than good, so we should revert the default-changing commit until we can fix it and do some good power-fail testing with the fixes in place." See http://bugzilla.kernel.org/show_bug.cgi?id=14354 for all the gory details. Requested-by: Eric Sandeen <sandeen@redhat.com> Cc: Theodore Tso <tytso@mit.edu> Cc: Alexey Fisher <bug-track@fisher-privat.net> Cc: Maxim Levitsky <maximlevitsky@gmail.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Mathias Burén <mathias.buren@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ext4: Update documentation about quota mount optionsJan Kara2009-09-291-3/+10
| | | | | Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Update documentation about quota mount optionsJan Kara2009-09-181-4/+12
| | | | | Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Remove journal_checksum mount option and enable it by defaultTheodore Ts'o2009-09-051-7/+1
| | | | | | | | | There's no real cost for the journal checksum feature, and we should make sure it is enabled all the time. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: document the "abort" mount optionTheodore Ts'o2009-06-131-0/+4
| | | | Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* trivial: Miscellaneous documentation typo fixesMatt LaPlante2009-06-121-3/+3
| | | | | | | Fix various typos in documentation txts. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* ext4: Regularize mount optionsTheodore Ts'o2009-03-281-2/+23
| | | | | | | | | | Add support for using the mount options "barrier" and "nobarrier", and "auto_da_alloc" and "noauto_da_alloc", which is more consistent than "barrier=<0|1>" or "auto_da_alloc=<0|1>". Most other ext3/ext4 mount options use the foo/nofoo naming convention. We allow the old forms of these mount options for backwards compatibility. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Add fine print for the 32000 subdirectory limitTheodore Ts'o2009-02-231-1/+4
| | | | | | | | | Some poeple are reading the ext4 feature list too literally and create dubious test cases involving very long filenames and 1k blocksize and then complain when they run into an htree-imposed limit. So add fine print to the "fix 32000 subdirectory limit" ext4 feature. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Remove "extents" mount optionTheodore Ts'o2009-01-061-5/+0
| | | | | | | | | | | | This mount option is largely superfluous, and in fact the way it was implemented was buggy; if a filesystem which did not have the extents feature flag was mounted -o extents, the filesystem would attempt to create and use extents-based file even though the extents feature flag was not eabled. The simplest thing to do is to nuke the mount option entirely. It's not all that useful to force the non-creation of new extent-based files if the filesystem can support it. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Add mount option to set kjournald's I/O priorityTheodore Ts'o2009-01-051-0/+7
| | | | | Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Jens Axboe <jens.axboe@oracle.com>
* ext4: Remove code to create the journal inodeTheodore Ts'o2009-01-061-4/+0
| | | | | | | | This code has been obsolete in quite some time, since the supported method for adding a journal inode is to use tune2fs (or to creating new filesystem with a journal via mke2fs or mkfs.ext4). Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: add fsync batch tuning knobsTheodore Ts'o2009-01-031-0/+29
| | | | | | | | Add new mount options, min_batch_time and max_batch_time, which controls how long the jbd2 layer should wait for additional filesystem operations to get batched with a synchronous write transaction. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* Update Documentation/filesystems/ext4.txtTheodore Ts'o2009-01-061-10/+32
| | | | | | Fix paragraph with recommendations on how to tune ext4 for benchmarks. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Update Documentation/filesystems/ext4.txtDiego Calleja2008-10-171-17/+15
| | | | | | | | | | Since Ext4 is supposed to be stable in 2.6.28-rc, ext4's documentation file should be updated. [ More updates also added by Theodore Ts'o. ] Signed-off-by: Diego Calleja <diegocg@gmail.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: add an option to control error handling on file dataHidehiro Kawai2008-10-101-0/+5
| | | | | | | | | | | | | | | | | | | | | | | If the journal doesn't abort when it gets an IO error in file data blocks, the file data corruption will spread silently. Because most of applications and commands do buffered writes without fsync(), they don't notice the IO error. It's scary for mission critical systems. On the other hand, if the journal aborts whenever it gets an IO error in file data blocks, the system will easily become inoperable. So this patch introduces a filesystem option to determine whether it aborts the journal or just call printk() when it gets an IO error in file data. If you mount an ext4 fs with data_err=abort option, it aborts on file data write error. If you mount it with data_err=ignore, it doesn't abort, just call printk(). data_err=ignore is the default. Here is the corresponding patch of the ext3 version: http://kerneltrap.org/mailarchive/linux-kernel/2008/9/9/3239374 Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
* ext4: Rename ext4dev to ext4Theodore Ts'o2008-10-101-4/+4
| | | | | | | | The ext4 filesystem is getting stable enough that it's time to drop the "dev" prefix. Also remove the requirement for the TEST_FILESYS flag. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Use readahead when reading an inode from the inode tableTheodore Ts'o2008-10-091-0/+6
| | | | | | | | | | | | With modern hard drives, reading 64k takes roughly the same time as reading a 4k block. So request readahead for adjacent inode table blocks to reduce the time it takes when iterating over directories (especially when doing this in htree sort order) in a cold cache case. With this patch, the time it takes to run "git status" on a kernel tree after flushing the caches via "echo 3 > /proc/sys/vm/drop_caches" is reduced by 21%. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Update documentation to remind users to update mke2fs.confTheodore Ts'o2008-07-271-0/+6
| | | | | Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Documention update for new ordered mode and delayed allocationMingming Cao2008-07-111-7/+14
| | | | | | | Adding some documentations for delayed allocation and new ordered mode. Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Documentation updates.Jose R. Santos2008-07-111-44/+62
| | | | | | | | Some of the information in Documentation/filesystems/ext4.txt is out of date and in need of an update. Signed-off-by: Jose R. Santos <jrs@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: enable barriers by defaultEric Sandeen2008-05-261-2/+10
| | | | | | | | | | | | | | | | | | I can't think of any valid reason for ext4 to not use barriers when they are available; I believe this is necessary for filesystem integrity in the face of a volatile write cache on storage. An administrator who trusts that the cache is sufficiently battery- backed (and power supplies are sufficiently redundant, etc...) can always turn it back off again. SuSE has carried such a patch for ext3 for quite some time now. Also document the mount option while we're at 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>
* ext4: Add multi block allocator for ext4Alex Tomas2008-01-291-1/+9
| | | | | | | | Signed-off-by: Alex Tomas <alex@clusterfs.com> Signed-off-by: Andreas Dilger <adilger@clusterfs.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* ext4: Add the journal checksum featureGirish Shilamkar2008-01-281-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] Documentation/filesystems/ext4.txtDave Kleikamp2006-10-111-0/+236
This file, ext4.txt, was put together with information from Andrew Morton, Andreas Dilger, Suparna Bhattacharya, and Ted Ts'o. I copied the mount options, with the exception of "extents", from ext3.txt, so if anyone is aware of anything out-of-date, please let me know. Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Suparna Bhattacharya <suparna@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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