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2020-06-15Merge tag 'ext4-for-linus-5.8-rc1-2' of ↵Linus Torvalds13-64/+262
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull more ext4 updates from Ted Ts'o: "This is the second round of ext4 commits for 5.8 merge window [1]. It includes the per-inode DAX support, which was dependant on the DAX infrastructure which came in via the XFS tree, and a number of regression and bug fixes; most notably the "BUG: using smp_processor_id() in preemptible code in ext4_mb_new_blocks" reported by syzkaller" [1] The pull request actually came in 15 minutes after I had tagged the rc1 release. Tssk, tssk, late.. - Linus * tag 'ext4-for-linus-5.8-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4, jbd2: ensure panic by fix a race between jbd2 abort and ext4 error handlers ext4: support xattr gnu.* namespace for the Hurd ext4: mballoc: Use this_cpu_read instead of this_cpu_ptr ext4: avoid utf8_strncasecmp() with unstable name ext4: stop overwrite the errcode in ext4_setup_super ext4: fix partial cluster initialization when splitting extent ext4: avoid race conditions when remounting with options that change dax Documentation/dax: Update DAX enablement for ext4 fs/ext4: Introduce DAX inode flag fs/ext4: Remove jflag variable fs/ext4: Make DAX mount option a tri-state fs/ext4: Only change S_DAX on inode load fs/ext4: Update ext4_should_use_dax() fs/ext4: Change EXT4_MOUNT_DAX to EXT4_MOUNT_DAX_ALWAYS fs/ext4: Disallow verity if inode is DAX fs/ext4: Narrow scope of DAX check in setflags
2020-06-12ext4, jbd2: ensure panic by fix a race between jbd2 abort and ext4 error ↵zhangyi (F)1-11/+5
handlers In the ext4 filesystem with errors=panic, if one process is recording errno in the superblock when invoking jbd2_journal_abort() due to some error cases, it could be raced by another __ext4_abort() which is setting the SB_RDONLY flag but missing panic because errno has not been recorded. jbd2_journal_commit_transaction() jbd2_journal_abort() journal->j_flags |= JBD2_ABORT; jbd2_journal_update_sb_errno() | ext4_journal_check_start() | __ext4_abort() | sb->s_flags |= SB_RDONLY; | if (!JBD2_REC_ERR) | return; journal->j_flags |= JBD2_REC_ERR; Finally, it will no longer trigger panic because the filesystem has already been set read-only. Fix this by introduce j_abort_mutex to make sure journal abort is completed before panic, and remove JBD2_REC_ERR flag. Fixes: 4327ba52afd03 ("ext4, jbd2: ensure entering into panic after recording an error in superblock") Signed-off-by: zhangyi (F) <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200609073540.3810702-1-yi.zhang@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-12ext4: support xattr gnu.* namespace for the HurdJan (janneke) Nieuwenhuizen4-1/+56
The Hurd gained[0] support for moving the translator and author fields out of the inode and into the "gnu.*" xattr namespace. In anticipation of that, an xattr INDEX was reserved[1]. The Hurd has now been brought into compliance[2] with that. This patch adds support for reading and writing such attributes from Linux; you can now do something like mkdir -p hurd-root/servers/socket touch hurd-root/servers/socket/1 setfattr --name=gnu.translator --value='"/hurd/pflocal\0"' \ hurd-root/servers/socket/1 getfattr --name=gnu.translator hurd-root/servers/socket/1 # file: 1 gnu.translator="/hurd/pflocal" to setup a pipe translator, which is being used to create[3] a vm-image for the Hurd from GNU Guix. [0] https://summerofcode.withgoogle.com/projects/#5869799859027968 [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3980bd3b406addb327d858aebd19e229ea340b9a [2] https://git.savannah.gnu.org/cgit/hurd/hurd.git/commit/?id=a04c7bf83172faa7cb080fbe3b6c04a8415ca645 [3] https://git.savannah.gnu.org/cgit/guix.git/log/?h=wip-hurd-vm Signed-off-by: Jan Nieuwenhuizen <janneke@gnu.org> Link: https://lore.kernel.org/r/20200525193940.878-1-janneke@gnu.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-11ext4: mballoc: Use this_cpu_read instead of this_cpu_ptrRitesh Harjani1-1/+1
Simplify reading a seq variable by directly using this_cpu_read API instead of doing this_cpu_ptr and then dereferencing it. This also avoid the below kernel BUG: which happens when CONFIG_DEBUG_PREEMPT is enabled BUG: using smp_processor_id() in preemptible [00000000] code: syz-fuzzer/6927 caller is ext4_mb_new_blocks+0xa4d/0x3b70 fs/ext4/mballoc.c:4711 CPU: 1 PID: 6927 Comm: syz-fuzzer Not tainted 5.7.0-next-20200602-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 check_preemption_disabled+0x20d/0x220 lib/smp_processor_id.c:48 ext4_mb_new_blocks+0xa4d/0x3b70 fs/ext4/mballoc.c:4711 ext4_ext_map_blocks+0x201b/0x33e0 fs/ext4/extents.c:4244 ext4_map_blocks+0x4cb/0x1640 fs/ext4/inode.c:626 ext4_getblk+0xad/0x520 fs/ext4/inode.c:833 ext4_bread+0x7c/0x380 fs/ext4/inode.c:883 ext4_append+0x153/0x360 fs/ext4/namei.c:67 ext4_init_new_dir fs/ext4/namei.c:2757 [inline] ext4_mkdir+0x5e0/0xdf0 fs/ext4/namei.c:2802 vfs_mkdir+0x419/0x690 fs/namei.c:3632 do_mkdirat+0x21e/0x280 fs/namei.c:3655 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 42f56b7a4a7d ("ext4: mballoc: introduce pcpu seqcnt for freeing PA to improve ENOSPC handling") Suggested-by: Borislav Petkov <bp@alien8.de> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reported-by: syzbot+82f324bb69744c5f6969@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/534f275016296996f54ecf65168bb3392b6f653d.1591699601.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-11ext4: avoid utf8_strncasecmp() with unstable nameEric Biggers1-0/+16
If the dentry name passed to ->d_compare() fits in dentry::d_iname, then it may be concurrently modified by a rename. This can cause undefined behavior (possibly out-of-bounds memory accesses or crashes) in utf8_strncasecmp(), since fs/unicode/ isn't written to handle strings that may be concurrently modified. Fix this by first copying the filename to a stack buffer if needed. This way we get a stable snapshot of the filename. Fixes: b886ee3e778e ("ext4: Support case-insensitive file name lookups") Cc: <stable@vger.kernel.org> # v5.2+ Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Daniel Rosenberg <drosen@google.com> Cc: Gabriel Krisman Bertazi <krisman@collabora.co.uk> Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Link: https://lore.kernel.org/r/20200601200543.59417-1-ebiggers@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-11ext4: stop overwrite the errcode in ext4_setup_superyangerkun1-0/+1
Now the errcode from ext4_commit_super will overwrite EROFS exists in ext4_setup_super. Actually, no need to call ext4_commit_super since we will return EROFS. Fix it by goto done directly. Fixes: c89128a00838 ("ext4: handle errors on ext4_commit_super") Signed-off-by: yangerkun <yangerkun@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200601073404.3712492-1-yangerkun@huawei.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-11ext4: fix partial cluster initialization when splitting extentJeffle Xu1-1/+1
Fix the bug when calculating the physical block number of the first block in the split extent. This bug will cause xfstests shared/298 failure on ext4 with bigalloc enabled occasionally. Ext4 error messages indicate that previously freed blocks are being freed again, and the following fsck will fail due to the inconsistency of block bitmap and bg descriptor. The following is an example case: 1. First, Initialize a ext4 filesystem with cluster size '16K', block size '4K', in which case, one cluster contains four blocks. 2. Create one file (e.g., xxx.img) on this ext4 filesystem. Now the extent tree of this file is like: ... 36864:[0]4:220160 36868:[0]14332:145408 51200:[0]2:231424 ... 3. Then execute PUNCH_HOLE fallocate on this file. The hole range is like: .. ext4_ext_remove_space: dev 254,16 ino 12 since 49506 end 49506 depth 1 ext4_ext_remove_space: dev 254,16 ino 12 since 49544 end 49546 depth 1 ext4_ext_remove_space: dev 254,16 ino 12 since 49605 end 49607 depth 1 ... 4. Then the extent tree of this file after punching is like ... 49507:[0]37:158047 49547:[0]58:158087 ... 5. Detailed procedure of punching hole [49544, 49546] 5.1. The block address space: ``` lblk ~49505 49506 49507~49543 49544~49546 49547~ ---------+------+-------------+----------------+-------- extent | hole | extent | hole | extent ---------+------+-------------+----------------+-------- pblk ~158045 158046 158047~158083 158084~158086 158087~ ``` 5.2. The detailed layout of cluster 39521: ``` cluster 39521 <-------------------------------> hole extent <----------------------><-------- lblk 49544 49545 49546 49547 +-------+-------+-------+-------+ | | | | | +-------+-------+-------+-------+ pblk 158084 1580845 158086 158087 ``` 5.3. The ftrace output when punching hole [49544, 49546]: - ext4_ext_remove_space (start 49544, end 49546) - ext4_ext_rm_leaf (start 49544, end 49546, last_extent [49507(158047), 40], partial [pclu 39522 lblk 0 state 2]) - ext4_remove_blocks (extent [49507(158047), 40], from 49544 to 49546, partial [pclu 39522 lblk 0 state 2] - ext4_free_blocks: (block 158084 count 4) - ext4_mballoc_free (extent 1/6753/1) 5.4. Ext4 error message in dmesg: EXT4-fs error (device vdb): mb_free_blocks:1457: group 1, block 158084:freeing already freed block (bit 6753); block bitmap corrupt. EXT4-fs error (device vdb): ext4_mb_generate_buddy:747: group 1, block bitmap and bg descriptor inconsistent: 19550 vs 19551 free clusters In this case, the whole cluster 39521 is freed mistakenly when freeing pblock 158084~158086 (i.e., the first three blocks of this cluster), although pblock 158087 (the last remaining block of this cluster) has not been freed yet. The root cause of this isuue is that, the pclu of the partial cluster is calculated mistakenly in ext4_ext_remove_space(). The correct partial_cluster.pclu (i.e., the cluster number of the first block in the next extent, that is, lblock 49597 (pblock 158086)) should be 39521 rather than 39522. Fixes: f4226d9ea400 ("ext4: fix partial cluster initialization") Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Reviewed-by: Eric Whitney <enwlinux@gmail.com> Cc: stable@kernel.org # v3.19+ Link: https://lore.kernel.org/r/1590121124-37096-1-git-send-email-jefflexu@linux.alibaba.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-11ext4: avoid race conditions when remounting with options that change daxTheodore Ts'o1-18/+24
Trying to change dax mount options when remounting could allow mount options to be enabled for a small amount of time, and then the mount option change would be reverted. In the case of "mount -o remount,dax", this can cause a race where files would temporarily treated as DAX --- and then not. Cc: stable@kernel.org Reported-by: syzbot+bca9799bf129256190da@syzkaller.appspotmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-11Enable ext4 support for per-file/directory dax operationsTheodore Ts'o6-42/+168
This adds the same per-file/per-directory DAX support for ext4 as was done for xfs, now that we finally have consensus over what the interface should be.
2020-06-09Merge tag 'linux-kselftest-kunit-5.8-rc1' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest Pull Kunit updates from Shuah Khan: "This consists of: - Several config fragment fixes from Anders Roxell to improve test coverage. - Improvements to kunit run script to use defconfig as default and restructure the code for config/build/exec/parse from Vitor Massaru Iha and David Gow. - Miscellaneous documentation warn fix" * tag 'linux-kselftest-kunit-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: security: apparmor: default KUNIT_* fragments to KUNIT_ALL_TESTS fs: ext4: default KUNIT_* fragments to KUNIT_ALL_TESTS drivers: base: default KUNIT_* fragments to KUNIT_ALL_TESTS lib: Kconfig.debug: default KUNIT_* fragments to KUNIT_ALL_TESTS kunit: default KUNIT_* fragments to KUNIT_ALL_TESTS kunit: Kconfig: enable a KUNIT_ALL_TESTS fragment kunit: Fix TabError, remove defconfig code and handle when there is no kunitconfig kunit: use KUnit defconfig by default kunit: use --build_dir=.kunit as default Documentation: test.h - fix warnings kunit: kunit_tool: Separate out config/build/exec/parse
2020-06-09mmap locking API: convert mmap_sem commentsMichel Lespinasse1-3/+3
Convert comments that reference mmap_sem to reference mmap_lock instead. [akpm@linux-foundation.org: fix up linux-next leftovers] [akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil] [akpm@linux-foundation.org: more linux-next fixups, per Michel] Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-05Merge tag 'afs-next-20200604' of ↵Linus Torvalds1-22/+22
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull AFS updates from David Howells: "There's some core VFS changes which affect a couple of filesystems: - Make the inode hash table RCU safe and providing some RCU-safe accessor functions. The search can then be done without taking the inode_hash_lock. Care must be taken because the object may be being deleted and no wait is made. - Allow iunique() to avoid taking the inode_hash_lock. - Allow AFS's callback processing to avoid taking the inode_hash_lock when using the inode table to find an inode to notify. - Improve Ext4's time updating. Konstantin Khlebnikov said "For now, I've plugged this issue with try-lock in ext4 lazy time update. This solution is much better." Then there's a set of changes to make a number of improvements to the AFS driver: - Improve callback (ie. third party change notification) processing by: (a) Relying more on the fact we're doing this under RCU and by using fewer locks. This makes use of the RCU-based inode searching outlined above. (b) Moving to keeping volumes in a tree indexed by volume ID rather than a flat list. (c) Making the server and volume records logically part of the cell. This means that a server record now points directly at the cell and the tree of volumes is there. This removes an N:M mapping table, simplifying things. - Improve keeping NAT or firewall channels open for the server callbacks to reach the client by actively polling the fileserver on a timed basis, instead of only doing it when we have an operation to process. - Improving detection of delayed or lost callbacks by including the parent directory in the list of file IDs to be queried when doing a bulk status fetch from lookup. We can then check to see if our copy of the directory has changed under us without us getting notified. - Determine aliasing of cells (such as a cell that is pointed to be a DNS alias). This allows us to avoid having ambiguity due to apparently different cells using the same volume and file servers. - Improve the fileserver rotation to do more probing when it detects that all of the addresses to a server are listed as non-responsive. It's possible that an address that previously stopped responding has become responsive again. Beyond that, lay some foundations for making some calls asynchronous: - Turn the fileserver cursor struct into a general operation struct and hang the parameters off of that rather than keeping them in local variables and hang results off of that rather than the call struct. - Implement some general operation handling code and simplify the callers of operations that affect a volume or a volume component (such as a file). Most of the operation is now done by core code. - Operations are supplied with a table of operations to issue different variants of RPCs and to manage the completion, where all the required data is held in the operation object, thereby allowing these to be called from a workqueue. - Put the standard "if (begin), while(select), call op, end" sequence into a canned function that just emulates the current behaviour for now. There are also some fixes interspersed: - Don't let the EACCES from ICMP6 mapping reach the user as such, since it's confusing as to whether it's a filesystem error. Convert it to EHOSTUNREACH. - Don't use the epoch value acquired through probing a server. If we have two servers with the same UUID but in different cells, it's hard to draw conclusions from them having different epoch values. - Don't interpret the argument to the CB.ProbeUuid RPC as a fileserver UUID and look up a fileserver from it. - Deal with servers in different cells having the same UUIDs. In the event that a CB.InitCallBackState3 RPC is received, we have to break the callback promises for every server record matching that UUID. - Don't let afs_statfs return values that go below 0. - Don't use running fileserver probe state to make server selection and address selection decisions on. Only make decisions on final state as the running state is cleared at the start of probing" Acked-by: Al Viro <viro@zeniv.linux.org.uk> (fs/inode.c part) * tag 'afs-next-20200604' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (27 commits) afs: Adjust the fileserver rotation algorithm to reprobe/retry more quickly afs: Show more a bit more server state in /proc/net/afs/servers afs: Don't use probe running state to make decisions outside probe code afs: Fix afs_statfs() to not let the values go below zero afs: Fix the by-UUID server tree to allow servers with the same UUID afs: Reorganise volume and server trees to be rooted on the cell afs: Add a tracepoint to track the lifetime of the afs_volume struct afs: Detect cell aliases 3 - YFS Cells with a canonical cell name op afs: Detect cell aliases 2 - Cells with no root volumes afs: Detect cell aliases 1 - Cells with root volumes afs: Implement client support for the YFSVL.GetCellName RPC op afs: Retain more of the VLDB record for alias detection afs: Fix handling of CB.ProbeUuid cache manager op afs: Don't get epoch from a server because it may be ambiguous afs: Build an abstraction around an "operation" concept afs: Rename struct afs_fs_cursor to afs_operation afs: Remove the error argument from afs_protocol_error() afs: Set error flag rather than return error from file status decode afs: Make callback processing more efficient. afs: Show more information in /proc/net/afs/servers ...
2020-06-05Merge tag 'ext4_for_linus' of ↵Linus Torvalds21-552/+795
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 updates from Ted Ts'o: "A lot of bug fixes and cleanups for ext4, including: - Fix performance problems found in dioread_nolock now that it is the default, caused by transaction leaks. - Clean up fiemap handling in ext4 - Clean up and refactor multiple block allocator (mballoc) code - Fix a problem with mballoc with a smaller file systems running out of blocks because they couldn't properly use blocks that had been reserved by inode preallocation. - Fixed a race in ext4_sync_parent() versus rename() - Simplify the error handling in the extent manipulation code - Make sure all metadata I/O errors are felected to ext4_ext_dirty()'s and ext4_make_inode_dirty()'s callers. - Avoid passing an error pointer to brelse in ext4_xattr_set() - Fix race which could result to freeing an inode on the dirty last in data=journal mode. - Fix refcount handling if ext4_iget() fails - Fix a crash in generic/019 caused by a corrupted extent node" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (58 commits) ext4: avoid unnecessary transaction starts during writeback ext4: don't block for O_DIRECT if IOCB_NOWAIT is set ext4: remove the access_ok() check in ext4_ioctl_get_es_cache fs: remove the access_ok() check in ioctl_fiemap fs: handle FIEMAP_FLAG_SYNC in fiemap_prep fs: move fiemap range validation into the file systems instances iomap: fix the iomap_fiemap prototype fs: move the fiemap definitions out of fs.h fs: mark __generic_block_fiemap static ext4: remove the call to fiemap_check_flags in ext4_fiemap ext4: split _ext4_fiemap ext4: fix fiemap size checks for bitmap files ext4: fix EXT4_MAX_LOGICAL_BLOCK macro add comment for ext4_dir_entry_2 file_type member jbd2: avoid leaking transaction credits when unreserving handle ext4: drop ext4_journal_free_reserved() ext4: mballoc: use lock for checking free blocks while retrying ext4: mballoc: refactor ext4_mb_good_group() ext4: mballoc: introduce pcpu seqcnt for freeing PA to improve ENOSPC handling ext4: mballoc: refactor ext4_mb_discard_preallocations() ...
2020-06-03ext4: avoid unnecessary transaction starts during writebackJan Kara1-18/+13
ext4_writepages() currently works in a loop like: start a transaction scan inode for pages to write map and submit these pages stop the transaction This loop results in starting transaction once more than is needed because in the last iteration we start a transaction only to scan the inode and find there are no pages to write. This can be significant increase in number of transaction starts for single-extent files or files that have all blocks already mapped. Furthermore we already know from previous iteration whether there are more pages to write or not. So propagate the information from mpage_prepare_extent_to_map() and avoid unnecessary looping in case there are no more pages to write. Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200525081215.29451-1-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: don't block for O_DIRECT if IOCB_NOWAIT is setJens Axboe1-0/+6
Running with some debug patches to detect illegal blocking triggered the extend/unaligned condition in ext4. If ext4 needs to extend the file (and hence go to buffered IO), or if the app is doing unaligned IO, then ext4 asks the iomap code to wait for IO completion. If the caller asked for no-wait semantics by setting IOCB_NOWAIT, then ext4 should return -EAGAIN instead. Signed-off-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/76152096-2bbb-7682-8fce-4cb498bcd909@kernel.dk Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: remove the access_ok() check in ext4_ioctl_get_es_cacheChristoph Hellwig1-5/+0
access_ok just checks we are fed a proper user pointer. We also do that in copy_to_user itself, so no need to do this early. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200523073016.2944131-10-hch@lst.de Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03fs: handle FIEMAP_FLAG_SYNC in fiemap_prepChristoph Hellwig2-4/+1
By moving FIEMAP_FLAG_SYNC handling to fiemap_prep we ensure it is handled once instead of duplicated, but can still be done under fs locks, like xfs/iomap intended with its duplicate handling. Also make sure the error value of filemap_write_and_wait is propagated to user space. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Link: https://lore.kernel.org/r/20200523073016.2944131-8-hch@lst.de Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03fs: move fiemap range validation into the file systems instancesChristoph Hellwig1-2/+3
Replace fiemap_check_flags with a fiemap_prep helper that also takes the inode and mapped range, and performs the sanity check and truncation previously done in fiemap_check_range. This way the validation is inside the file system itself and thus properly works for the stacked overlayfs case as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Link: https://lore.kernel.org/r/20200523073016.2944131-7-hch@lst.de Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03fs: move the fiemap definitions out of fs.hChristoph Hellwig1-0/+1
No need to pull the fiemap definitions into almost every file in the kernel build. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Link: https://lore.kernel.org/r/20200523073016.2944131-5-hch@lst.de Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: remove the call to fiemap_check_flags in ext4_fiemapChristoph Hellwig1-3/+0
iomap_fiemap already calls fiemap_check_flags first thing, so this additional check is redundant. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200523073016.2944131-3-hch@lst.de Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: split _ext4_fiemapChristoph Hellwig1-37/+35
The fiemap and EXT4_IOC_GET_ES_CACHE cases share almost no code, so split them into entirely separate functions. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200523073016.2944131-2-hch@lst.de Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: fix fiemap size checks for bitmap filesChristoph Hellwig2-31/+33
Add an extra validation of the len parameter, as for ext4 some files might have smaller file size limits than others. This also means the redundant size check in ext4_ioctl_get_es_cache can go away, as all size checking is done in the shared fiemap handler. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200505154324.3226743-3-hch@lst.de Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: fix EXT4_MAX_LOGICAL_BLOCK macroRitesh Harjani1-1/+1
ext4 supports max number of logical blocks in a file to be 0xffffffff. (This is since ext4_extent's ee_block is __le32). This means that EXT4_MAX_LOGICAL_BLOCK should be 0xfffffffe (starting from 0 logical offset). This patch fixes this. The issue was seen when ext4 moved to iomap_fiemap API and when overlayfs was mounted on top of ext4. Since overlayfs was missing filemap_check_ranges(), so it could pass a arbitrary huge length which lead to overflow of map.m_len logic. This patch fixes that. Fixes: d3b6f23f7167 ("ext4: move ext4_fiemap to use iomap framework") Reported-by: syzbot+77fa5bdb65cc39711820@syzkaller.appspotmail.com Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20200505154324.3226743-2-hch@lst.de Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03add comment for ext4_dir_entry_2 file_type memberJonathan Grant1-1/+1
Signed-off-by: Jonathan Grant <jg@jguk.org> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Link: https://lore.kernel.org/r/ad3290d5-86af-99c1-f9d5-cd1bab710429@jguk.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: drop ext4_journal_free_reserved()Jan Kara1-6/+0
Remove ext4_journal_free_reserved() function. It is never used. Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Link: https://lore.kernel.org/r/20200520133119.1383-2-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: mballoc: use lock for checking free blocks while retryingRitesh Harjani2-1/+14
Currently while doing block allocation grp->bb_free may be getting modified if discard is happening in parallel. For e.g. consider a case where there are lot of threads who have preallocated lot of blocks and there is a thread which is trying to discard all of this group's PA. Now it could happen that we see all of those group's bb_free is zero and fail the allocation while there is sufficient space if we free up all the PA. So this patch adds another flag "EXT4_MB_STRICT_CHECK" which will be set if we are unable to allocate any blocks in the first try (since we may not have considered blocks about to be discarded from PA lists). So during retry attempt to allocate blocks we will use ext4_lock_group() for checking if the group is good or not. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/9cb740a117c958c36596f167b12af1beae9a68b7.1589955723.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: mballoc: refactor ext4_mb_good_group()Ritesh Harjani1-28/+50
ext4_mb_good_group() definition was changed some time back and now it even initializes the buddy cache (via ext4_mb_init_group()), if in case the EXT4_MB_GRP_NEED_INIT() is true for a group. Note that ext4_mb_init_group() could sleep and so should not be called under a spinlock held. This is fine as of now because ext4_mb_good_group() is called before loading the buddy bitmap without ext4_lock_group() held and again called after loading the bitmap, only this time with ext4_lock_group() held. But still this whole thing is confusing. So this patch refactors out ext4_mb_good_group_nolock() which should be called when without holding ext4_lock_group(). Also in further patches we hold the spinlock (ext4_lock_group()) while doing any calculations which involves grp->bb_free or grp->bb_fragments. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/d9f7d031a5fbe1c943fae6bf1ff5cdf0604ae722.1589955723.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: mballoc: introduce pcpu seqcnt for freeing PA to improve ENOSPC handlingRitesh Harjani1-5/+51
There could be a race in function ext4_mb_discard_group_preallocations() where the 1st thread may iterate through group's bb_prealloc_list and remove all the PAs and add to function's local list head. Now if the 2nd thread comes in to discard the group preallocations, it will see that the group->bb_prealloc_list is empty and will return 0. Consider for a case where we have less number of groups (for e.g. just group 0), this may even return an -ENOSPC error from ext4_mb_new_blocks() (where we call for ext4_mb_discard_group_preallocations()). But that is wrong, since 2nd thread should have waited for 1st thread to release all the PAs and should have retried for allocation. Since 1st thread was anyway going to discard the PAs. The algorithm using this percpu seq counter goes below: 1. We sample the percpu discard_pa_seq counter before trying for block allocation in ext4_mb_new_blocks(). 2. We increment this percpu discard_pa_seq counter when we either allocate or free these blocks i.e. while marking those blocks as used/free in mb_mark_used()/mb_free_blocks(). 3. We also increment this percpu seq counter when we successfully identify that the bb_prealloc_list is not empty and hence proceed for discarding of those PAs inside ext4_mb_discard_group_preallocations(). Now to make sure that the regular fast path of block allocation is not affected, as a small optimization we only sample the percpu seq counter on that cpu. Only when the block allocation fails and when freed blocks found were 0, that is when we sample percpu seq counter for all cpus using below function ext4_get_discard_pa_seq_sum(). This happens after making sure that all the PAs on grp->bb_prealloc_list got freed or if it's empty. It can be well argued that why don't just check for grp->bb_free to see if there are any free blocks to be allocated. So here are the two concerns which were discussed:- 1. If for some reason the blocks available in the group are not appropriate for allocation logic (say for e.g. EXT4_MB_HINT_GOAL_ONLY, although this is not yet implemented), then the retry logic may result into infinte looping since grp->bb_free is non-zero. 2. Also before preallocation was clubbed with block allocation with the same ext4_lock_group() held, there were lot of races where grp->bb_free could not be reliably relied upon. Due to above, this patch considers discard_pa_seq logic to determine if we should retry for block allocation. Say if there are are n threads trying for block allocation and none of those could allocate or discard any of the blocks, then all of those n threads will fail the block allocation and return -ENOSPC error. (Since the seq counter for all of those will match as no block allocation/discard was done during that duration). Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/7f254686903b87c419d798742fd9a1be34f0657b.1589955723.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: mballoc: refactor ext4_mb_discard_preallocations()Ritesh Harjani1-3/+12
Implement ext4_mb_discard_preallocations_should_retry() which we will need in later patches to add more logic like check for sequence number match to see if we should retry for block allocation or not. There should be no functionality change in this patch. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/1cfae0098d2aa9afbeb59331401258182868c8f2.1589955723.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: mballoc: add blocks to PA list under same spinlock after allocating blocksRitesh Harjani1-35/+62
ext4_mb_discard_preallocations() only checks for grp->bb_prealloc_list of every group to discard the group's PA to free up the space if allocation request fails. Consider below race:- Process A Process B 1. allocate blocks 1. Fails block allocation from ext4_mb_regular_allocator() ext4_lock_group() allocated blocks more than ac_o_ex.fe_len ext4_unlock_group() 2. Scans the grp->bb_prealloc_list (under ext4_lock_group()) and find nothing and thus return -ENOSPC. 2. Add the additional blocks to PA list ext4_lock_group() add blocks to grp->bb_prealloc_list ext4_unlock_group() Above race could be avoided if we add those additional blocks to grp->bb_prealloc_list at the same time with block allocation when ext4_lock_group() was still held. With this discard-PA will know if there are actually any blocks which could be freed from the PA Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/a2217dd782585b42328981832e6d396abaaccb80.1589955723.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: add casefold flag to EXT4_INODE_* flagsEric Biggers1-1/+3
No one currently needs EXT4_INODE_CASEFOLD, but add it to keep the EXT4_INODE_* definitions in sync with the EXT4_*_FL definitions. Also make it clearer that the casefold flag is only for directories. Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20200510215252.87833-1-ebiggers@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: rework map struct instantiation in ext4_ext_map_blocks()Eric Whitney1-25/+25
The path performing block allocations in ext4_ext_map_blocks() contains code trimming the length of a new extent that is repeated later in the function. This code is both redundant and unnecessary as the exact length of the new extent has already been calculated. Rewrite the instantiation of the map struct in this case to use the available values, avoiding the overhead of unnecessary conversions and improving clarity. Add another map struct instantiation tailored specifically to the separate case for an existing written extent. Remove an old comment that no longer appears applicable to the current code. Signed-off-by: Eric Whitney <enwlinux@gmail.com> Link: https://lore.kernel.org/r/20200510155805.18808-1-enwlinux@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
2020-06-03ext4: make ext_debug() implementation to use pr_debug()Ritesh Harjani4-88/+87
ext_debug() msgs could be helpful, provided those could be enabled without recompiling kernel and also if we could selectively enable only required prints for case by case debugging. So make ext_debug() implementation use pr_debug(). Also change ext_debug() to be defined with CONFIG_EXT4_DEBUG. So EXT_DEBUG macro now mostly remain for below 3 functions. ext4_ext_show_path/leaf/move() (whose print msgs use ext_debug() which again could be dynamically enabled using pr_debug()) This also changes the ext_debug() to take inode as a parameter to add inode no. in all of it's msgs. Prints additional info like process name / pid, superblock id etc. This also removes any explicit function names passed in ext_debug(). Since ext_debug() on it's own prints file, func and line no. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/d31dc189b0aeda9384fe7665e36da7cd8c61571f.1589086800.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: mballoc: make mb_debug() implementation to use pr_debug()Ritesh Harjani3-68/+55
mb_debug() msg had only 1 control level for all type of msgs. And if we enable mballoc_debug then all of those msgs would be enabled. Instead of adding multiple debug levels for mb_debug() msgs, use pr_debug() with which we could have finer control to print msgs at all of different levels (i.e. at file, func, line no.). Also add process name/pid, superblk id, and other info in mb_debug() msg. This also kills the mballoc_debug module parameter, since it is not needed any more. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/f0c660cbde9e2edbe95c67942ca9ad80dd2231eb.1589086800.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: replace EXT_DEBUG with __maybe_unused in ↵Ritesh Harjani1-3/+1
ext4_ext_handle_unwritten_extents() Replace EXT_DEBUG with __maybe_unused from inside ext4_ext_handle_unwritten_extents() function. There should be no functionality change in this patch. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/ae335b94506cd9db9d2648c1f4dd25a80f9f3ce2.1589086800.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: improve ext_debug() msg in case of block allocation failureRitesh Harjani2-2/+6
ext4_map_blocks() has ext_debug msg early at the start of function. We also get ext_debug msg if we could allocate a block from ext4_ext_map_blocks(). But there is no ext_debug() msg in case of block allocation failure. So add one along with error code. Also add more info in ext_debug() msg like how many blocks were allocated v/s how many were requested in ext4_ext_map_blocks(). Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/1610ec2aa932396be00f9d552fe29da473ead176.1589086800.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: use BIT() macro for BH_** state bitsRitesh Harjani2-6/+6
Simply use BIT() macro for all BH_** state bits instead of open coding it. There should be no functionality change in this patch. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/57667689f51a3f9dba2fcef7d3425187fa3ba69f.1589086800.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: 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>
2020-06-03ext4: mballoc: fix possible NULL ptr & remove BUG_ONs from DOUBLE_CHECKRitesh Harjani1-2/+9
Make sure to check for e4b->bd_info->bb_bitmap == NULL, in mb_cmp_bitmaps() and return if NULL, to avoid possible NULL ptr dereference. Similar to how we do this in other ifdef DOUBLE_CHECK functions. Also remove the BUG_ON() logic if kmalloc() or ext4_read_block_bitmap() fails. We should simply mark grp->bb_bitmap as NULL if above happens. In fact ext4_read_block_bitmap() may even return an error in case of resize ioctl. Hence remove this BUG_ON logic (fstests ext4/032 may trigger this). Link: https://lore.kernel.org/r/9a54f8a696ff17c057cd571be3d15ac3ec1407f1.1589086800.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: mballoc: refactor code inside DOUBLE_CHECK into separate functionRitesh Harjani1-17/+33
This patch implemets mb_group_bb_bitmap_alloc() and mb_group_bb_bitmap_free() function to remove #ifdef DOUBLE_CHECK macro and it's related code from inside ext4_mb_add_groupinfo()/ext4_mb_release(). There should be no functionality change in this patch. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/8c2095d74b779f0254a19b24982490dc6f07c4f9.1589086800.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: mballoc: make ext4_mb_use_preallocated() return type as boolRitesh Harjani1-7/+7
Change return type of function ext4_mb_use_preallocated() to bool to better reflect what this function can return. There should be no functionality change in this patch. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/7880cb6ef911465beafefcd7e9c3ea214688744b.1589086800.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: mballoc: simplify error handling in ext4_init_mballoc()Ritesh Harjani1-10/+13
This patch simplifies error handling logic in ext4_init_mballoc(), by adding all the cleanups at one place at the end of that function. There should be no functionality change in this patch. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/8621a7bc68f7107a9ac4292afeb784515333bd25.1589086800.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: mballoc: fix few other format specifier in mb_debug()Ritesh Harjani1-6/+6
Fix few other format specifiers in mb_debug() msgs. As such no other functionality change in this patch. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/574fa7f833abf2dbf3b53a2fea3195e71f6cdbd8.1589086800.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: mballoc: correct the mb_debug() format specifier for pa_len varRitesh Harjani1-5/+5
pa->pa_len is an integer. Fix all of the format specifier used in mb_debug() for pa_len to %d instead of %u. As such no functionality change in this patch. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/af4987f643c586f62bcc9961e43f0a67151d5551.1589086800.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: mballoc: add more mb_debug() msgsRitesh Harjani1-4/+14
This patch adds some more debugging mb_debug() msgs to help improve mballoc code debugging. Other than adding more mb_debug() msgs at few more places, there should be no other functionality change in this patch. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/5fc8e7788b924e211fcfa4a4c1d2f8503511661a.1589086800.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: mballoc: refactor ext4_mb_show_ac()Ritesh Harjani1-25/+40
This factors out ext4_mb_show_pa() function to show all the group's preallocation info. This could be useful info to be added in later patches. There should be no functionality change in this patch. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/8f07d890b0038dcc935e9c10e6043ec9f3792721.1589086800.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: mballoc: print bb_free info even when it is 0Ritesh Harjani1-2/+0
Improve the debugging msg by also printing even if bb_free is 0. Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/c894f1d1d30f86ae38f4e3a861949665b6dc61cd.1589086800.git.riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: avoid ext4_error()'s caused by ENOMEM in the truncate pathTheodore Ts'o2-10/+34
We can't fail in the truncate path without requiring an fsck. Add work around for this by using a combination of retry loops and the __GFP_NOFAIL flag. From: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Anna Pendleton <pendleton@google.com> Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/20200507175028.15061-1-pendleton@google.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: fix race between ext4_sync_parent() and rename()Eric Biggers1-15/+13
'igrab(d_inode(dentry->d_parent))' without holding dentry->d_lock is broken because without d_lock, d_parent can be concurrently changed due to a rename(). Then if the old directory is immediately deleted, old d_parent->inode can be NULL. That causes a NULL dereference in igrab(). To fix this, use dget_parent() to safely grab a reference to the parent dentry, which pins the inode. This also eliminates the need to use d_find_any_alias() other than for the initial inode, as we no longer throw away the dentry at each step. This is an extremely hard race to hit, but it is possible. Adding a udelay() in between the reads of ->d_parent and its ->d_inode makes it reproducible on a no-journal filesystem using the following program: #include <fcntl.h> #include <unistd.h> int main() { if (fork()) { for (;;) { mkdir("dir1", 0700); int fd = open("dir1/file", O_RDWR|O_CREAT|O_SYNC); write(fd, "X", 1); close(fd); } } else { mkdir("dir2", 0700); for (;;) { rename("dir1/file", "dir2/file"); rmdir("dir1"); } } } Fixes: d59729f4e794 ("ext4: fix races in ext4_sync_parent()") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20200506183140.541194-1-ebiggers@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-06-03ext4: fix a typo in a commentChristophe JAILLET1-1/+1
s/extnets/extents/ Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Link: https://lore.kernel.org/r/20200503200647.154701-1-christophe.jaillet@wanadoo.fr Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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