summaryrefslogtreecommitdiff
path: root/fs/ext4/balloc.c
AgeCommit message (Collapse)AuthorFilesLines
2020-06-04ext4: balloc: use task_pid_nr() helperRitesh Harjani1-2/+3
Use task_pid_nr() function instead of current->pid. There should be no functionality change in this patch. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/4b58403e15e9c8deb34a1b93deb3fc9cd153ab84.1589086800.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-04-16ext4: fix return-value types in several function commentsJosh Triplett1-2/+2
The documentation comments for ext4_read_block_bitmap_nowait and ext4_read_inode_bitmap describe them as returning NULL on error, but they return an ERR_PTR on error; update the documentation to match. The documentation comment for ext4_wait_block_bitmap describes it as returning 1 on error, but it returns -errno on error; update the documentation to match. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Ritesh Harani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/60a3f4996f4932c45515aaa6b75ca42f2a78ec9b.1585512514.git.josh@joshtriplett.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-04-02ext4: save all error info in save_error_info() and drop ext4_set_errno()Theodore Ts'o1-4/+3
Using a separate function, ext4_set_errno() to set the errno is problematic because it doesn't do the right thing once s_last_error_errorcode is non-zero. It's also less racy to set all of the error information all at once. (Also, as a bonus, it shrinks code size slightly.) Link: https://lore.kernel.org/r/20200329020404.686965-1-tytso@mit.edu Fixes: 878520ac45f9 ("ext4: save the error code which triggered...") Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-02-21ext4: fix potential race between online resizing and write operationsTheodore Ts'o1-3/+11
During an online resize an array of pointers to buffer heads gets replaced so it can get enlarged. If there is a racing block allocation or deallocation which uses the old array, and the old array has gotten reused this can lead to a GPF or some other random kernel memory getting modified. Link: https://bugzilla.kernel.org/show_bug.cgi?id=206443 Link: https://lore.kernel.org/r/20200221053458.730016-2-tytso@mit.edu Reported-by: Suraj Jitindar Singh <surajjs@amazon.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
2019-12-26ext4: simulate various I/O and checksum errors when reading metadataTheodore Ts'o1-1/+3
This allows us to test various error handling code paths Link: https://lore.kernel.org/r/20191209012317.59398-1-tytso@mit.edu Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-12-26ext4: save the error code which triggered an ext4_error() in the superblockTheodore Ts'o1-0/+1
This allows the cause of an ext4_error() report to be categorized based on whether it was triggered due to an I/O error, or an memory allocation error, or other possible causes. Most errors are caused by a detected file system inconsistency, so the default code stored in the superblock will be EXT4_ERR_EFSCORRUPTED. Link: https://lore.kernel.org/r/20191204032335.7683-1-tytso@mit.edu Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-06-19ext4: clean up kerneldoc warnigns when building with W=1Theodore Ts'o1-2/+2
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-08-01ext4: use ext4_warning() for sb_getblk failureWang Shilong1-3/+3
Out of memory should not be considered as critical errors; so replace ext4_error() with ext4_warnig(). Signed-off-by: Wang Shilong <wshilong@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
2018-07-13ext4: check for allocation block validity with block group lockedTheodore Ts'o1-0/+3
With commit 044e6e3d74a3: "ext4: don't update checksum of new initialized bitmaps" the buffer valid bit will get set without actually setting up the checksum for the allocation bitmap, since the checksum will get calculated once we actually allocate an inode or block. If we are doing this, then we need to (re-)check the verified bit after we take the block group lock. Otherwise, we could race with another process reading and verifying the bitmap, which would then complain about the checksum being invalid. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1780137 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
2018-06-14ext4: only look at the bg_flags field if it is validTheodore Ts'o1-1/+10
The bg_flags field in the block group descripts is only valid if the uninit_bg or metadata_csum feature is enabled. We were not consistently looking at this field; fix this. Also block group #0 must never have uninitialized allocation bitmaps, or need to be zeroed, since that's where the root inode, and other special inodes are set up. Check for these conditions and mark the file system as corrupted if they are detected. This addresses CVE-2018-10876. https://bugzilla.kernel.org/show_bug.cgi?id=199403 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
2018-06-14ext4: always check block group bounds in ext4_init_block_bitmap()Theodore Ts'o1-7/+3
Regardless of whether the flex_bg feature is set, we should always check to make sure the bits we are setting in the block bitmap are within the block group bounds. https://bugzilla.kernel.org/show_bug.cgi?id=199865 Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
2018-05-12ext4: mark block bitmap corrupted when foundWang Shilong1-0/+4
There are still some cases that we missed to set block bitmaps corrupted bit properly: 1) block bitmap number is wrong. 2) failed to read block bitmap due to disk errors. 3) double free block bitmaps.. 4) some mismatch check with bitmaps vs buddy information. Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Signed-off-by: Wang Shilong <wshilong@ddn.com> Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca>
2018-05-12ext4: add new ext4_mark_group_bitmap_corrupted() helperWang Shilong1-22/+7
Since there are many places to set inode/block bitmap corrupt bit, add a new helper for it, which will make codes more clear. Signed-off-by: Wang Shilong <wshilong@ddn.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Andreas Dilger <adilger@dilger.ca>
2018-04-24ext4: fix bitmap position validationLukas Czerner1-4/+5
Currently in ext4_valid_block_bitmap() we expect the bitmap to be positioned anywhere between 0 and s_blocksize clusters, but that's wrong because the bitmap can be placed anywhere in the block group. This causes false positives when validating bitmaps on perfectly valid file system layouts. Fix it by checking whether the bitmap is within the group boundary. The problem can be reproduced using the following mkfs -t ext3 -E stride=256 /dev/vdb1 mount /dev/vdb1 /mnt/test cd /mnt/test wget https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.16.3.tar.xz tar xf linux-4.16.3.tar.xz This will result in the warnings in the logs EXT4-fs error (device vdb1): ext4_validate_block_bitmap:399: comm tar: bg 84: block 2774529: invalid block bitmap [ Changed slightly for clarity and to not drop a overflow test -- TYT ] Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reported-by: Ilya Dryomov <idryomov@gmail.com> Fixes: 7dac4a1726a9 ("ext4: add validity checks for bitmap block numbers") Cc: stable@vger.kernel.org
2018-03-27ext4: add validity checks for bitmap block numbersTheodore Ts'o1-2/+14
An privileged attacker can cause a crash by mounting a crafted ext4 image which triggers a out-of-bounds read in the function ext4_valid_block_bitmap() in fs/ext4/balloc.c. This issue has been assigned CVE-2018-1093. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=199181 BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1560782 Reported-by: Wen Xu <wen.xu@gatech.edu> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
2018-02-19ext4: don't update checksum of new initialized bitmapsTheodore Ts'o1-2/+1
When reading the inode or block allocation bitmap, if the bitmap needs to be initialized, do not update the checksum in the block group descriptor. That's because we're not set up to journal those changes. Instead, just set the verified bit on the bitmap block, so that it's not necessary to validate the checksum. When a block or inode allocation actually happens, at that point the checksum will be calculated, and update of the bg descriptor block will be properly journalled. Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
2018-01-11ext4: use 'sbi' instead of 'EXT4_SB(sb)'Jun Piao1-2/+2
We could use 'sbi' instead of 'EXT4_SB(sb)' to make code more elegant. Signed-off-by: Jun Piao <piaojun@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-11-14Merge tag 'ext4_for_linus' of ↵Linus Torvalds1-8/+7
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 updates from Ted Ts'o: - Add support for online resizing of file systems with bigalloc - Fix a two data corruption bugs involving DAX, as well as a corruption bug after a crash during a racing fallocate and delayed allocation. - Finally, a number of cleanups and optimizations. * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: improve smp scalability for inode generation ext4: add support for online resizing with bigalloc ext4: mention noload when recovering on read-only device Documentation: fix little inconsistencies ext4: convert timers to use timer_setup() jbd2: convert timers to use timer_setup() ext4: remove duplicate extended attributes defs ext4: add ext4_should_use_dax() ext4: add sanity check for encryption + DAX ext4: prevent data corruption with journaling + DAX ext4: prevent data corruption with inline data + DAX ext4: fix interaction between i_size, fallocate, and delalloc after a crash ext4: retry allocations conservatively ext4: Switch to iomap for SEEK_HOLE / SEEK_DATA ext4: Add iomap support for inline data iomap: Add IOMAP_F_DATA_INLINE flag iomap: Switch from blkno to disk offset
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-02ext4: retry allocations conservativelyTheodore Ts'o1-8/+7
Now that we no longer try to reserve metadata blocks for delayed allocations (which tended to overestimate the required number of blocks significantly), we really don't need retry allocations when the disk is very full as aggressively any more. The only time when it makes sense to retry an allocation is if we have freshly deleted blocks that will only become available after a transaction commit. And if we lose that race, it's not worth it to try more than once. Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-07-27Merge tag 'ext4_for_linus' of ↵Linus Torvalds1-1/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 updates from Ted Ts'o: "The major change this cycle is deleting ext4's copy of the file system encryption code and switching things over to using the copies in fs/crypto. I've updated the MAINTAINERS file to add an entry for fs/crypto listing Jaeguk Kim and myself as the maintainers. There are also a number of bug fixes, most notably for some problems found by American Fuzzy Lop (AFL) courtesy of Vegard Nossum. Also fixed is a writeback deadlock detected by generic/130, and some potential races in the metadata checksum code" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (21 commits) ext4: verify extent header depth ext4: short-cut orphan cleanup on error ext4: fix reference counting bug on block allocation error MAINTAINRES: fs-crypto maintainers update ext4 crypto: migrate into vfs's crypto engine ext2: fix filesystem deadlock while reading corrupted xattr block ext4: fix project quota accounting without quota limits enabled ext4: validate s_reserved_gdt_blocks on mount ext4: remove unused page_idx ext4: don't call ext4_should_journal_data() on the journal inode ext4: Fix WARN_ON_ONCE in ext4_commit_super() ext4: fix deadlock during page writeback ext4: correct error value of function verifying dx checksum ext4: avoid modifying checksum fields directly during checksum verification ext4: check for extents that wrap around jbd2: make journal y2038 safe jbd2: track more dependencies on transaction commit jbd2: move lockdep tracking to journal_s jbd2: move lockdep instrumentation for jbd2 handles ext4: respect the nobarrier mount option in nojournal mode ...
2016-07-06ext4: validate s_reserved_gdt_blocks on mountTheodore Ts'o1-0/+3
If s_reserved_gdt_blocks is extremely large, it's possible for ext4_init_block_bitmap(), which is called when ext4 sets up an uninitialized block bitmap, to corrupt random kernel memory. Add the same checks which e2fsck has --- it must never be larger than blocksize / sizeof(__u32) --- and then add a backup check in ext4_init_block_bitmap() in case the superblock gets modified after the file system is mounted. Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
2016-06-27ext4: optimize ext4_should_retry_alloc() to improve ENOSPC performanceTheodore Ts'o1-1/+3
If there are no pending blocks to be released after a commit, forcing a journal commit has no hope of helping. It's possible that a commit had just completed, so if there are now free blocks available for allocation, it's worth retrying the commit. Reported-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-06-07fs: have submit_bh users pass in op and flags separatelyMike Christie1-1/+1
This has submit_bh users pass in the operation and flags separately, so submit_bh_wbc can setup the bio op and bi_rw flags on the bio that is submitted. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-05-13ext4: fix race in transient ENOSPC detectionJan Kara1-1/+2
When there are blocks to free in the running transaction, block allocator can return ENOSPC although the filesystem has some blocks to free. We use ext4_should_retry_alloc() to force commit of the current transaction and return whether anything was committed so that it makes sense to retry the allocation. However the transaction may get committed after block allocation fails but before we call ext4_should_retry_alloc(). So ext4_should_retry_alloc() returns false because there is nothing to commit and we wrongly return ENOSPC. Fix the race by unconditionally returning 1 from ext4_should_retry_alloc() when we tried to commit a transaction. This should not add any unnecessary retries since we had a transaction running a while ago when trying to allocate blocks and we want to retry the allocation once that transaction has committed anyway. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-12ext4: fix scheduling in atomic on group checksum failureJan Kara1-3/+4
When block group checksum is wrong, we call ext4_error() while holding group spinlock from ext4_init_block_bitmap() or ext4_init_inode_bitmap() which results in scheduling while in atomic. Fix the issue by calling ext4_error() later after dropping the spinlock. CC: stable@vger.kernel.org Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
2015-10-18ext4: make the bitmap read routines return real error codesDarrick J. Wong1-33/+41
Make the bitmap reaading routines return real error codes (EIO, EFSCORRUPTED, EFSBADCRC) which can then be reflected back to userspace for more precise diagnosis work. In particular, this means that mballoc no longer claims that we're out of memory if the block bitmaps become corrupt. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-10-17ext4: clean up feature test macros with predicate functionsDarrick J. Wong1-9/+7
Create separate predicate functions to test/set/clear feature flags, thereby replacing the wordy old macros. Furthermore, clean out the places where we open-coded feature tests. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2015-10-17ext4: call out CRC and corruption errors with specific error codesDarrick J. Wong1-1/+1
Instead of overloading EIO for CRC errors and corrupt structures, return the same error codes that XFS returns for the same issues. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-06-08ext4: verify block bitmap even after fresh initializationLukas Czerner1-2/+2
If we want to rely on the buffer_verified() flag of the block bitmap buffer, we have to set it consistently. However currently if we're initializing uninitialized block bitmap in ext4_read_block_bitmap_nowait() we're not going to set buffer verified at all. We can do this by simply setting the flag on the buffer, but I think it's actually better to run ext4_validate_block_bitmap() to make sure that what we did in the ext4_init_block_bitmap() is right. So run ext4_validate_block_bitmap() even after the block bitmap initialization. Also bail out early from ext4_validate_block_bitmap() if we see corrupt bitmap, since we already know it's corrupt and we do not need to verify that. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-04-03ext4: remove unnecessary lock/unlock of i_block_reservation_lockMaurizio Lombardi1-2/+0
This is a leftover of commit 71d4f7d032149b935a26eb3ff85c6c837f3714e1 Signed-off-by: Maurizio Lombardi <mlombard@redhat.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Lukas Czerner <lczerner@redhat.com>
2015-04-03ext4: remove unused header filesSheng Yong1-1/+0
Remove unused header files and header files which are included in ext4.h. Signed-off-by: Sheng Yong <shengyong1@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-10-13ext4: move error report out of atomic context in ext4_init_block_bitmap()Dmitry Monakhov1-4/+8
Error report likely result in IO so it is bad idea to do it from atomic context. This patch should fix following issue: BUG: sleeping function called from invalid context at include/linux/buffer_head.h:349 in_atomic(): 1, irqs_disabled(): 0, pid: 137, name: kworker/u128:1 5 locks held by kworker/u128:1/137: #0: ("writeback"){......}, at: [<ffffffff81085618>] process_one_work+0x228/0x4d0 #1: ((&(&wb->dwork)->work)){......}, at: [<ffffffff81085618>] process_one_work+0x228/0x4d0 #2: (jbd2_handle){......}, at: [<ffffffff81242622>] start_this_handle+0x712/0x7b0 #3: (&ei->i_data_sem){......}, at: [<ffffffff811fa387>] ext4_map_blocks+0x297/0x430 #4: (&(&bgl->locks[i].lock)->rlock){......}, at: [<ffffffff811f3180>] ext4_read_block_bitmap_nowait+0x5d0/0x630 CPU: 3 PID: 137 Comm: kworker/u128:1 Not tainted 3.17.0-rc2-00184-g82752e4 #165 Hardware name: Intel Corporation W2600CR/W2600CR, BIOS SE5C600.86B.99.99.x028.061320111235 06/13/2011 Workqueue: writeback bdi_writeback_workfn (flush-1:0) 0000000000000411 ffff880813777288 ffffffff815c7fdc ffff880813777288 ffff880813a8bba0 ffff8808137772a8 ffffffff8108fb30 ffff880803e01e38 ffff880803e01e38 ffff8808137772c8 ffffffff811a8d53 ffff88080ecc6000 Call Trace: [<ffffffff815c7fdc>] dump_stack+0x51/0x6d [<ffffffff8108fb30>] __might_sleep+0xf0/0x100 [<ffffffff811a8d53>] __sync_dirty_buffer+0x43/0xe0 [<ffffffff811a8e03>] sync_dirty_buffer+0x13/0x20 [<ffffffff8120f581>] ext4_commit_super+0x1d1/0x230 [<ffffffff8120fa03>] save_error_info+0x23/0x30 [<ffffffff8120fd06>] __ext4_error+0xb6/0xd0 [<ffffffff8120f260>] ? ext4_group_desc_csum+0x140/0x190 [<ffffffff811f2d8c>] ext4_read_block_bitmap_nowait+0x1dc/0x630 [<ffffffff8122e23a>] ext4_mb_init_cache+0x21a/0x8f0 [<ffffffff8113ae95>] ? lru_cache_add+0x55/0x60 [<ffffffff8112e16c>] ? add_to_page_cache_lru+0x6c/0x80 [<ffffffff8122eaa0>] ext4_mb_init_group+0x190/0x280 [<ffffffff8122ec51>] ext4_mb_good_group+0xc1/0x190 [<ffffffff8123309a>] ext4_mb_regular_allocator+0x17a/0x410 [<ffffffff8122c821>] ? ext4_mb_use_preallocated+0x31/0x380 [<ffffffff81233535>] ? ext4_mb_new_blocks+0x205/0x8e0 [<ffffffff8116ed5c>] ? kmem_cache_alloc+0xfc/0x180 [<ffffffff812335b0>] ext4_mb_new_blocks+0x280/0x8e0 [<ffffffff8116f2c4>] ? __kmalloc+0x144/0x1c0 [<ffffffff81221797>] ? ext4_find_extent+0x97/0x320 [<ffffffff812257f4>] ext4_ext_map_blocks+0xbc4/0x1050 [<ffffffff811fa387>] ? ext4_map_blocks+0x297/0x430 [<ffffffff811fa3ab>] ext4_map_blocks+0x2bb/0x430 [<ffffffff81200e43>] ? ext4_init_io_end+0x23/0x50 [<ffffffff811feb44>] ext4_writepages+0x564/0xaf0 [<ffffffff815cde3b>] ? _raw_spin_unlock+0x2b/0x40 [<ffffffff810ac7bd>] ? lock_release_non_nested+0x2fd/0x3c0 [<ffffffff811a009e>] ? writeback_sb_inodes+0x10e/0x490 [<ffffffff811a009e>] ? writeback_sb_inodes+0x10e/0x490 [<ffffffff811377e3>] do_writepages+0x23/0x40 [<ffffffff8119c8ce>] __writeback_single_inode+0x9e/0x280 [<ffffffff811a026b>] writeback_sb_inodes+0x2db/0x490 [<ffffffff811a0664>] wb_writeback+0x174/0x2d0 [<ffffffff810ac359>] ? lock_release_holdtime+0x29/0x190 [<ffffffff811a0863>] wb_do_writeback+0xa3/0x200 [<ffffffff811a0a40>] bdi_writeback_workfn+0x80/0x230 [<ffffffff81085618>] ? process_one_work+0x228/0x4d0 [<ffffffff810856cd>] process_one_work+0x2dd/0x4d0 [<ffffffff81085618>] ? process_one_work+0x228/0x4d0 [<ffffffff81085c1d>] worker_thread+0x35d/0x460 [<ffffffff810858c0>] ? process_one_work+0x4d0/0x4d0 [<ffffffff810858c0>] ? process_one_work+0x4d0/0x4d0 [<ffffffff8108a885>] kthread+0xf5/0x100 [<ffffffff810990e5>] ? local_clock+0x25/0x30 [<ffffffff8108a790>] ? __init_kthread_worker+0x70/0x70 [<ffffffff815ce2ac>] ret_from_fork+0x7c/0xb0 [<ffffffff8108a790>] ? __init_kthread_work Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org
2014-09-05ext4: prepare to drop EXT4_STATE_DELALLOC_RESERVEDTheodore Ts'o1-2/+1
The EXT4_STATE_DELALLOC_RESERVED flag was originally implemented because it was too hard to make sure the mballoc and get_block flags could be reliably passed down through all of the codepaths that end up calling ext4_mb_new_blocks(). Since then, we have mb_flags passed down through most of the code paths, so getting rid of EXT4_STATE_DELALLOC_RESERVED isn't as tricky as it used to. This commit plumbs in the last of what is required, and then adds a WARN_ON check to make sure we haven't missed anything. If this passes a full regression test run, we can then drop EXT4_STATE_DELALLOC_RESERVED. Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2014-07-15ext4: remove metadata reservation checksTheodore Ts'o1-1/+0
Commit 27dd43854227b ("ext4: introduce reserved space") reserves 2% of the file system space to make sure metadata allocations will always succeed. Given that, tracking the reservation of metadata blocks is no longer necessary. Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2014-06-26ext4: decrement free clusters/inodes counters when block group declared badNamjae Jeon1-0/+16
We should decrement free clusters counter when block bitmap is marked as corrupt and free inodes counter when the allocation bitmap is marked as corrupt to avoid misunderstanding due to incorrect available size in statfs result. User can get immediately ENOSPC error from write begin without reaching for the writepages. Cc: Darrick J. Wong<darrick.wong@oracle.com> Reported-by: Amit Sahrawat <amit.sahrawat83@gmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
2014-05-12ext4: make local functions staticStephen Hemminger1-10/+11
I have been running make namespacecheck to look for unneeded globals, and found these in ext4. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-05-12ext4: fix block bitmap validation when bigalloc, ^flex_bgDarrick J. Wong1-5/+7
On a bigalloc,^flex_bg filesystem, the ext4_valid_block_bitmap function fails to convert from blocks to clusters when spot-checking the validity of the bitmap block that we've just read from disk. This causes ext4 to think that the bitmap is garbage, which results in the block group being taken offline when it's not necessary. Add in the necessary EXT4_B2C() calls to perform the conversions. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-05-12ext4: fix block bitmap initialization under sparse_super2Darrick J. Wong1-14/+19
The ext4_bg_has_super() function doesn't know about the new rules for where backup superblocks go on a sparse_super2 filesystem. Therefore, block bitmap initialization doesn't know that it shouldn't reserve space for backups in groups that are never going to contain backups. The result of this is e2fsck complaining about the block bitmap being incorrect (fortunately not in a way that results in cross-linked files), so fix the whole thing. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2014-04-15ext4: fix ext4_count_free_clusters() with EXT4FS_DEBUG and bigalloc enabledAzat Khuzhin1-1/+1
With bigalloc enabled we must use EXT4_CLUSTERS_PER_GROUP() instead of EXT4_BLOCKS_PER_GROUP() otherwise we will go beyond the allocated buffer. $ mount -t ext4 /dev/vde /vde [ 70.573993] EXT4-fs DEBUG (fs/ext4/mballoc.c, 2346): ext4_mb_alloc_groupinfo: [ 70.575174] allocated s_groupinfo array for 1 meta_bg's [ 70.576172] EXT4-fs DEBUG (fs/ext4/super.c, 2092): ext4_check_descriptors: [ 70.576972] Checking group descriptorsBUG: unable to handle kernel paging request at ffff88006ab56000 [ 72.463686] IP: [<ffffffff81394eb9>] __bitmap_weight+0x2a/0x7f [ 72.464168] PGD 295e067 PUD 2961067 PMD 7fa8e067 PTE 800000006ab56060 [ 72.464738] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC [ 72.465139] Modules linked in: [ 72.465402] CPU: 1 PID: 3560 Comm: mount Tainted: G W 3.14.0-rc2-00069-ge57bce1 #60 [ 72.466079] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 72.466505] task: ffff88007ce6c8a0 ti: ffff88006b7f0000 task.ti: ffff88006b7f0000 [ 72.466505] RIP: 0010:[<ffffffff81394eb9>] [<ffffffff81394eb9>] __bitmap_weight+0x2a/0x7f [ 72.466505] RSP: 0018:ffff88006b7f1c00 EFLAGS: 00010206 [ 72.466505] RAX: 0000000000000000 RBX: 000000000000050a RCX: 0000000000000040 [ 72.466505] RDX: 0000000000000000 RSI: 0000000000080000 RDI: 0000000000000000 [ 72.466505] RBP: ffff88006b7f1c28 R08: 0000000000000002 R09: 0000000000000000 [ 72.466505] R10: 000000000000babe R11: 0000000000000400 R12: 0000000000080000 [ 72.466505] R13: 0000000000000200 R14: 0000000000002000 R15: ffff88006ab55000 [ 72.466505] FS: 00007f43ba1fa840(0000) GS:ffff88007f800000(0000) knlGS:0000000000000000 [ 72.466505] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 72.466505] CR2: ffff88006ab56000 CR3: 000000006b7e6000 CR4: 00000000000006e0 [ 72.466505] Stack: [ 72.466505] ffff88006ab65000 0000000000000000 0000000000000000 0000000000010000 [ 72.466505] ffff88006ab6f400 ffff88006b7f1c58 ffffffff81396bb8 0000000000010000 [ 72.466505] 0000000000000000 ffff88007b869a90 ffff88006a48a000 ffff88006b7f1c70 [ 72.466505] Call Trace: [ 72.466505] [<ffffffff81396bb8>] memweight+0x5f/0x8a [ 72.466505] [<ffffffff811c3b19>] ext4_count_free+0x13/0x21 [ 72.466505] [<ffffffff811c396c>] ext4_count_free_clusters+0xdb/0x171 [ 72.466505] [<ffffffff811e3bdd>] ext4_fill_super+0x117c/0x28ef [ 72.466505] [<ffffffff81391569>] ? vsnprintf+0x1c7/0x3f7 [ 72.466505] [<ffffffff8114d8dc>] mount_bdev+0x145/0x19c [ 72.466505] [<ffffffff811e2a61>] ? ext4_calculate_overhead+0x2a1/0x2a1 [ 72.466505] [<ffffffff811dab1d>] ext4_mount+0x15/0x17 [ 72.466505] [<ffffffff8114e3aa>] mount_fs+0x67/0x150 [ 72.466505] [<ffffffff811637ea>] vfs_kern_mount+0x64/0xde [ 72.466505] [<ffffffff81165d19>] do_mount+0x6fe/0x7f5 [ 72.466505] [<ffffffff81126cc8>] ? strndup_user+0x3a/0xd9 [ 72.466505] [<ffffffff8116604b>] SyS_mount+0x85/0xbe [ 72.466505] [<ffffffff81619e90>] tracesys+0xdd/0xe2 [ 72.466505] Code: c3 89 f0 b9 40 00 00 00 55 99 48 89 e5 41 57 f7 f9 41 56 49 89 ff 41 55 45 31 ed 41 54 41 89 f4 53 31 db 41 89 c6 45 39 ee 7e 10 <4b> 8b 3c ef 49 ff c5 e8 bf ff ff ff 01 c3 eb eb 31 c0 45 85 f6 [ 72.466505] RIP [<ffffffff81394eb9>] __bitmap_weight+0x2a/0x7f [ 72.466505] RSP <ffff88006b7f1c00> [ 72.466505] CR2: ffff88006ab56000 [ 72.466505] ---[ end trace 7d051a08ae138573 ]--- Killed Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-10-31ext4: don't count free clusters from a corrupt block groupDarrick J. Wong1-2/+11
A bg that's been flagged "corrupt" by definition has no free blocks, so that the allocator won't be tempted to use the damaged bg. Therefore, we shouldn't count the clusters in the damaged group when calculating free counts. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
2013-08-29ext4: mark group corrupt on group descriptor checksumDarrick J. Wong1-5/+4
If the group descriptor fails validation, mark the whole blockgroup corrupt so that the inode/block allocators skip this group. The previous approach takes the risk of writing to a damaged group descriptor; hopefully it was never the case that the [ib]bitmap fields pointed to another valid block and got dirtied, since the memset would fill the page with 1s. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-08-29ext4: mark block group as corrupt on block bitmap errorDarrick J. Wong1-0/+3
When we notice a block-bitmap corruption (because of device failure or something else), we should mark this group as corrupt and prevent further block allocations/deallocations from it. Currently, we end up generating one error message for every block in the bitmap. This potentially could make the system unstable as noticed in some bugs. With this patch, the error will be printed only the first time and mark the entire block group as corrupted. This prevents future access allocations/deallocations from it. Also tested by corrupting the block bitmap and forcefully introducing the mb_free_blocks error: (1) create a largefile (2Gb) $ dd if=/dev/zero of=largefile oflag=direct bs=10485760 count=200 (2) umount filesystem. use dumpe2fs to see which block-bitmaps are in use by largefile and note their block numbers (3) use dd to zero-out the used block bitmaps $ dd if=/dev/zero of=/dev/hdc4 bs=4096 seek=14 count=8 oflag=direct (4) mount the FS and delete the largefile. (5) recreate the largefile. verify that the new largefile does not get any blocks from the groups marked as bad. Without the patch, we will see mb_free_blocks error for each bit in each zero'ed out bitmap at (4). With the patch, we only see the error once per blockgroup: [ 309.706803] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 15: 32768 clusters in bitmap, 0 in gd. blk grp corrupted. [ 309.720824] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 14: 32768 clusters in bitmap, 0 in gd. blk grp corrupted. [ 309.732858] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure [ 309.748321] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 13: 32768 clusters in bitmap, 0 in gd. blk grp corrupted. [ 309.760331] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure [ 309.769695] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 12: 32768 clusters in bitmap, 0 in gd. blk grp corrupted. [ 309.781721] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure [ 309.798166] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 11: 32768 clusters in bitmap, 0 in gd. blk grp corrupted. [ 309.810184] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure [ 309.819532] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 10: 32768 clusters in bitmap, 0 in gd. blk grp corrupted. Google-Bug-Id: 7258357 [darrick.wong@oracle.com] Further modifications (by Darrick) to make more obvious that this corruption bit applies to blocks only. Set the corruption flag if the block group bitmap verification fails. Original-author: Aditya Kali <adityakali@google.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-08-28ext4: fix type declaration of ext4_validate_block_bitmapDarrick J. Wong1-2/+2
The block_group parameter to ext4_validate_block_bitmap is both used as a ext4_group_t inside the function and the same type is passed in by all callers. We might as well use the typedef consistently instead of open-coding the 'unsigned int'. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-08-28ext4: error out if verifying the block bitmap failsDarrick J. Wong1-2/+6
The block bitmap verification code assumes that calling ext4_error() either panics the system or makes the fs readonly. However, this is not always true: when 'errors=continue' is specified, an error is printed but we don't return any indication of error to the caller, which is (probably) the block allocator, which pretends that the crud we read in off the disk is a usable bitmap. Yuck. A block bitmap that fails the check should at least return no bitmap to the caller. The block allocator should be told to go look in a different group, but that's a separate issue. The easiest way to reproduce this is to modify bg_block_bitmap (on a ^flex_bg fs) to point to a block outside the block group; or you can create a metadata_csum filesystem and zero out the block bitmaps. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-07-06ext4: fix ext4_get_group_number()Theodore Ts'o1-2/+2
The function ext4_get_group_number() was introduced as an optimization in commit bd86298e60b8. Unfortunately, this commit incorrectly calculate the group number for file systems with a 1k block size (when s_first_data_block is 1 instead of zero). This could cause the following kernel BUG: [ 568.877799] ------------[ cut here ]------------ [ 568.877833] kernel BUG at fs/ext4/mballoc.c:3728! [ 568.877840] Oops: Exception in kernel mode, sig: 5 [#1] [ 568.877845] SMP NR_CPUS=32 NUMA pSeries [ 568.877852] Modules linked in: binfmt_misc [ 568.877861] CPU: 1 PID: 3516 Comm: fs_mark Not tainted 3.10.0-03216-g7c6809f-dirty #1 [ 568.877867] task: c0000001fb0b8000 ti: c0000001fa954000 task.ti: c0000001fa954000 [ 568.877873] NIP: c0000000002f42a4 LR: c0000000002f4274 CTR: c000000000317ef8 [ 568.877879] REGS: c0000001fa956ed0 TRAP: 0700 Not tainted (3.10.0-03216-g7c6809f-dirty) [ 568.877884] MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI> CR: 24000428 XER: 00000000 [ 568.877902] SOFTE: 1 [ 568.877905] CFAR: c0000000002b5464 [ 568.877908] GPR00: 0000000000000001 c0000001fa957150 c000000000c6a408 c0000001fb588000 GPR04: 0000000000003fff c0000001fa9571c0 c0000001fa9571c4 000138098c50625f GPR08: 1301200000000000 0000000000000002 0000000000000001 0000000000000000 GPR12: 0000000024000422 c00000000f33a300 0000000000008000 c0000001fa9577f0 GPR16: c0000001fb7d0100 c000000000c29190 c0000000007f46e8 c000000000a14672 GPR20: 0000000000000001 0000000000000008 ffffffffffffffff 0000000000000000 GPR24: 0000000000000100 c0000001fa957278 c0000001fdb2bc78 c0000001fa957288 GPR28: 0000000000100100 c0000001fa957288 c0000001fb588000 c0000001fdb2bd10 [ 568.877993] NIP [c0000000002f42a4] .ext4_mb_release_group_pa+0xec/0x1c0 [ 568.877999] LR [c0000000002f4274] .ext4_mb_release_group_pa+0xbc/0x1c0 [ 568.878004] Call Trace: [ 568.878008] [c0000001fa957150] [c0000000002f4274] .ext4_mb_release_group_pa+0xbc/0x1c0 (unreliable) [ 568.878017] [c0000001fa957200] [c0000000002fb070] .ext4_mb_discard_lg_preallocations+0x394/0x444 [ 568.878025] [c0000001fa957340] [c0000000002fb45c] .ext4_mb_release_context+0x33c/0x734 [ 568.878032] [c0000001fa957440] [c0000000002fbcf8] .ext4_mb_new_blocks+0x4a4/0x5f4 [ 568.878039] [c0000001fa957510] [c0000000002ef56c] .ext4_ext_map_blocks+0xc28/0x1178 [ 568.878047] [c0000001fa957640] [c0000000002c1a94] .ext4_map_blocks+0x2c8/0x490 [ 568.878054] [c0000001fa957730] [c0000000002c536c] .ext4_writepages+0x738/0xc60 [ 568.878062] [c0000001fa957950] [c000000000168a78] .do_writepages+0x5c/0x80 [ 568.878069] [c0000001fa9579d0] [c00000000015d1c4] .__filemap_fdatawrite_range+0x88/0xb0 [ 568.878078] [c0000001fa957aa0] [c00000000015d23c] .filemap_write_and_wait_range+0x50/0xfc [ 568.878085] [c0000001fa957b30] [c0000000002b8edc] .ext4_sync_file+0x220/0x3c4 [ 568.878092] [c0000001fa957be0] [c0000000001f849c] .vfs_fsync_range+0x64/0x80 [ 568.878098] [c0000001fa957c70] [c0000000001f84f0] .vfs_fsync+0x38/0x4c [ 568.878105] [c0000001fa957d00] [c0000000001f87f4] .do_fsync+0x54/0x90 [ 568.878111] [c0000001fa957db0] [c0000000001f8894] .SyS_fsync+0x28/0x3c [ 568.878120] [c0000001fa957e30] [c000000000009c88] syscall_exit+0x0/0x7c [ 568.878125] Instruction dump: [ 568.878130] 60000000 813d0034 81610070 38000000 7f8b4800 419e001c 813f007c 7d2bfe70 [ 568.878144] 7d604a78 7c005850 54000ffe 7c0007b4 <0b000000> e8a10076 e87f0090 7fa4eb78 [ 568.878160] ---[ end trace 594d911d9654770b ]--- In addition fix the STD_GROUP optimization so that it works for bigalloc file systems as well. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reported-by: Li Zhong <lizhongfs@gmail.com> Reviewed-by: Lukas Czerner <lczerner@redhat.com> Cc: stable@vger.kernel.org # 3.10
2013-06-06ext4: optimize test_root()Theodore Ts'o1-5/+9
The test_root() function could potentially loop forever due to overflow issues. So rewrite test_root() to avoid this issue; as a bonus, it is 38% faster when benchmarked via a test loop: int main(int argc, char **argv) { int i; for (i = 0; i < 1 << 24; i++) { if (test_root(i, 7)) printf("%d\n", i); } } Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-04-20ext4: mark all metadata I/O with REQ_METATheodore Ts'o1-1/+1
As Dave Chinner pointed out at the 2013 LSF/MM workshop, it's important that metadata I/O requests are marked as such to avoid priority inversions caused by I/O bandwidth throttling. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-04-10ext4: introduce reserved spaceLukas Czerner1-5/+13
Currently in ENOSPC condition when writing into unwritten space, or punching a hole, we might need to split the extent and grow extent tree. However since we can not allocate any new metadata blocks we'll have to zero out unwritten part of extent or punched out part of extent, or in the worst case return ENOSPC even though use actually does not allocate any space. Also in delalloc path we do reserve metadata and data blocks for the time we're going to write out, however metadata block reservation is very tricky especially since we expect that logical connectivity implies physical connectivity, however that might not be the case and hence we might end up allocating more metadata blocks than previously reserved. So in future, metadata reservation checks should be removed since we can not assure that we do not under reserve. And this is where reserved space comes into the picture. When mounting the file system we slice off a little bit of the file system space (2% or 4096 clusters, whichever is smaller) which can be then used for the cases mentioned above to prevent costly zeroout, or unexpected ENOSPC. The number of reserved clusters can be set via sysfs, however it can never be bigger than number of free clusters in the file system. Note that this patch fixes the failure of xfstest 274 as expected. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
2013-04-04ext4: introduce ext4_get_group_number()Lukas Czerner1-7/+18
Currently on many places in ext4 we're using ext4_get_group_no_and_offset() even though we're only interested in knowing the block group of the particular block, not the offset within the block group so we can use more efficient way to compute block group. This patch introduces ext4_get_group_number() which computes block group for a given block much more efficiently. Use this function instead of ext4_get_group_no_and_offset() everywhere where we're only interested in knowing the block group. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>