linux.git/fs/ext4/inode.c, branch v5.6 Linux kernel source tree ext4: rename s_journal_flag_rwsem to s_writepages_rwsem 2020-02-22T00:32:07+00:00 Eric Biggers ebiggers@google.com 2020-02-19T18:30:46+00:00 bbd55937de8f2754adc5792b0f8e5ff7d9c0420e In preparation for making s_journal_flag_rwsem synchronize ext4_writepages() with changes to both the EXTENTS and JOURNAL_DATA flags (rather than just JOURNAL_DATA as it does currently), rename it to s_writepages_rwsem. Link: https://lore.kernel.org/r/20200219183047.47417-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Cc: stable@kernel.org 
In preparation for making s_journal_flag_rwsem synchronize
ext4_writepages() with changes to both the EXTENTS and JOURNAL_DATA
flags (rather than just JOURNAL_DATA as it does currently), rename it to
s_writepages_rwsem.

Link: https://lore.kernel.org/r/20200219183047.47417-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
ext4: fix a data race in EXT4_I(inode)->i_disksize 2020-02-20T04:17:02+00:00 Qian Cai cai@lca.pw 2020-02-07T14:29:11+00:00 35df4299a6487f323b0aca120ea3f485dfee2ae3 EXT4_I(inode)->i_disksize could be accessed concurrently as noticed by KCSAN, BUG: KCSAN: data-race in ext4_write_end [ext4] / ext4_writepages [ext4] write to 0xffff91c6713b00f8 of 8 bytes by task 49268 on cpu 127: ext4_write_end+0x4e3/0x750 [ext4] ext4_update_i_disksize at fs/ext4/ext4.h:3032 (inlined by) ext4_update_inode_size at fs/ext4/ext4.h:3046 (inlined by) ext4_write_end at fs/ext4/inode.c:1287 generic_perform_write+0x208/0x2a0 ext4_buffered_write_iter+0x11f/0x210 [ext4] ext4_file_write_iter+0xce/0x9e0 [ext4] new_sync_write+0x29c/0x3b0 __vfs_write+0x92/0xa0 vfs_write+0x103/0x260 ksys_write+0x9d/0x130 __x64_sys_write+0x4c/0x60 do_syscall_64+0x91/0xb47 entry_SYSCALL_64_after_hwframe+0x49/0xbe read to 0xffff91c6713b00f8 of 8 bytes by task 24872 on cpu 37: ext4_writepages+0x10ac/0x1d00 [ext4] mpage_map_and_submit_extent at fs/ext4/inode.c:2468 (inlined by) ext4_writepages at fs/ext4/inode.c:2772 do_writepages+0x5e/0x130 __writeback_single_inode+0xeb/0xb20 writeback_sb_inodes+0x429/0x900 __writeback_inodes_wb+0xc4/0x150 wb_writeback+0x4bd/0x870 wb_workfn+0x6b4/0x960 process_one_work+0x54c/0xbe0 worker_thread+0x80/0x650 kthread+0x1e0/0x200 ret_from_fork+0x27/0x50 Reported by Kernel Concurrency Sanitizer on: CPU: 37 PID: 24872 Comm: kworker/u261:2 Tainted: G W O L 5.5.0-next-20200204+ #5 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 Workqueue: writeback wb_workfn (flush-7:0) Since only the read is operating as lockless (outside of the "i_data_sem"), load tearing could introduce a logic bug. Fix it by adding READ_ONCE() for the read and WRITE_ONCE() for the write. Signed-off-by: Qian Cai <cai@lca.pw> Link: https://lore.kernel.org/r/1581085751-31793-1-git-send-email-cai@lca.pw Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org 
EXT4_I(inode)->i_disksize could be accessed concurrently as noticed by
KCSAN,

 BUG: KCSAN: data-race in ext4_write_end [ext4] / ext4_writepages [ext4]

 write to 0xffff91c6713b00f8 of 8 bytes by task 49268 on cpu 127:
  ext4_write_end+0x4e3/0x750 [ext4]
  ext4_update_i_disksize at fs/ext4/ext4.h:3032
  (inlined by) ext4_update_inode_size at fs/ext4/ext4.h:3046
  (inlined by) ext4_write_end at fs/ext4/inode.c:1287
  generic_perform_write+0x208/0x2a0
  ext4_buffered_write_iter+0x11f/0x210 [ext4]
  ext4_file_write_iter+0xce/0x9e0 [ext4]
  new_sync_write+0x29c/0x3b0
  __vfs_write+0x92/0xa0
  vfs_write+0x103/0x260
  ksys_write+0x9d/0x130
  __x64_sys_write+0x4c/0x60
  do_syscall_64+0x91/0xb47
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 read to 0xffff91c6713b00f8 of 8 bytes by task 24872 on cpu 37:
  ext4_writepages+0x10ac/0x1d00 [ext4]
  mpage_map_and_submit_extent at fs/ext4/inode.c:2468
  (inlined by) ext4_writepages at fs/ext4/inode.c:2772
  do_writepages+0x5e/0x130
  __writeback_single_inode+0xeb/0xb20
  writeback_sb_inodes+0x429/0x900
  __writeback_inodes_wb+0xc4/0x150
  wb_writeback+0x4bd/0x870
  wb_workfn+0x6b4/0x960
  process_one_work+0x54c/0xbe0
  worker_thread+0x80/0x650
  kthread+0x1e0/0x200
  ret_from_fork+0x27/0x50

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 37 PID: 24872 Comm: kworker/u261:2 Tainted: G        W  O L 5.5.0-next-20200204+ #5
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019
 Workqueue: writeback wb_workfn (flush-7:0)

Since only the read is operating as lockless (outside of the
"i_data_sem"), load tearing could introduce a logic bug. Fix it by
adding READ_ONCE() for the read and WRITE_ONCE() for the write.

Signed-off-by: Qian Cai <cai@lca.pw>
Link: https://lore.kernel.org/r/1581085751-31793-1-git-send-email-cai@lca.pw
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 2020-02-16T19:12:06+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-02-16T19:12:06+00:00 8a8b80967b421218d89c1af61e759c54ab94fdb6 Pull ext4 fixes from Ted Ts'o: "Miscellaneous ext4 bug fixes (all stable fodder)" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: improve explanation of a mount failure caused by a misconfigured kernel jbd2: do not clear the BH_Mapped flag when forgetting a metadata buffer jbd2: move the clearing of b_modified flag to the journal_unmap_buffer() ext4: add cond_resched() to ext4_protect_reserved_inode ext4: fix checksum errors with indexed dirs ext4: fix support for inode sizes > 1024 bytes ext4: simplify checking quota limits in ext4_statfs() ext4: don't assume that mmp_nodename/bdevname have NUL 
Pull ext4 fixes from Ted Ts'o:
 "Miscellaneous ext4 bug fixes (all stable fodder)"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: improve explanation of a mount failure caused by a misconfigured kernel
  jbd2: do not clear the BH_Mapped flag when forgetting a metadata buffer
  jbd2: move the clearing of b_modified flag to the journal_unmap_buffer()
  ext4: add cond_resched() to ext4_protect_reserved_inode
  ext4: fix checksum errors with indexed dirs
  ext4: fix support for inode sizes > 1024 bytes
  ext4: simplify checking quota limits in ext4_statfs()
  ext4: don't assume that mmp_nodename/bdevname have NUL
ext4: fix checksum errors with indexed dirs 2020-02-13T16:56:19+00:00 Jan Kara jack@suse.cz 2020-02-10T14:43:16+00:00 48a34311953d921235f4d7bbd2111690d2e469cf DIR_INDEX has been introduced as a compat ext4 feature. That means that even kernels / tools that don't understand the feature may modify the filesystem. This works because for kernels not understanding indexed dir format, internal htree nodes appear just as empty directory entries. Index dir aware kernels then check the htree structure is still consistent before using the data. This all worked reasonably well until metadata checksums were introduced. The problem is that these effectively made DIR_INDEX only ro-compatible because internal htree nodes store checksums in a different place than normal directory blocks. Thus any modification ignorant to DIR_INDEX (or just clearing EXT4_INDEX_FL from the inode) will effectively cause checksum mismatch and trigger kernel errors. So we have to be more careful when dealing with indexed directories on filesystems with checksumming enabled. 1) We just disallow loading any directory inodes with EXT4_INDEX_FL when DIR_INDEX is not enabled. This is harsh but it should be very rare (it means someone disabled DIR_INDEX on existing filesystem and didn't run e2fsck), e2fsck can fix the problem, and we don't want to answer the difficult question: "Should we rather corrupt the directory more or should we ignore that DIR_INDEX feature is not set?" 2) When we find out htree structure is corrupted (but the filesystem and the directory should in support htrees), we continue just ignoring htree information for reading but we refuse to add new entries to the directory to avoid corrupting it more. Link: https://lore.kernel.org/r/20200210144316.22081-1-jack@suse.cz Fixes: dbe89444042a ("ext4: Calculate and verify checksums for htree nodes") Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org 
DIR_INDEX has been introduced as a compat ext4 feature. That means that
even kernels / tools that don't understand the feature may modify the
filesystem. This works because for kernels not understanding indexed dir
format, internal htree nodes appear just as empty directory entries.
Index dir aware kernels then check the htree structure is still
consistent before using the data. This all worked reasonably well until
metadata checksums were introduced. The problem is that these
effectively made DIR_INDEX only ro-compatible because internal htree
nodes store checksums in a different place than normal directory blocks.
Thus any modification ignorant to DIR_INDEX (or just clearing
EXT4_INDEX_FL from the inode) will effectively cause checksum mismatch
and trigger kernel errors. So we have to be more careful when dealing
with indexed directories on filesystems with checksumming enabled.

1) We just disallow loading any directory inodes with EXT4_INDEX_FL when
DIR_INDEX is not enabled. This is harsh but it should be very rare (it
means someone disabled DIR_INDEX on existing filesystem and didn't run
e2fsck), e2fsck can fix the problem, and we don't want to answer the
difficult question: "Should we rather corrupt the directory more or
should we ignore that DIR_INDEX feature is not set?"

2) When we find out htree structure is corrupted (but the filesystem and
the directory should in support htrees), we continue just ignoring htree
information for reading but we refuse to add new entries to the
directory to avoid corrupting it more.

Link: https://lore.kernel.org/r/20200210144316.22081-1-jack@suse.cz
Fixes: dbe89444042a ("ext4: Calculate and verify checksums for htree nodes")
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Merge tag 'dax-fixes-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm 2020-02-12T00:52:08+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-02-12T00:52:08+00:00 359c92c02bfae1a6f1e8e37c298e518fd256642c Pull dax fixes from Dan Williams: "A fix for an xfstest failure and some and an update that removes an fsdax dependency on block devices. Summary: - Fix RWF_NOWAIT writes to properly return -EAGAIN - Clean up an unused helper - Update dax_writeback_mapping_range to not need a block_device argument" * tag 'dax-fixes-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: dax: pass NOWAIT flag to iomap_apply dax: Get rid of fs_dax_get_by_host() helper dax: Pass dax_dev instead of bdev to dax_writeback_mapping_range() 
Pull dax fixes from Dan Williams:
 "A fix for an xfstest failure and some and an update that removes an
  fsdax dependency on block devices.

  Summary:

   - Fix RWF_NOWAIT writes to properly return -EAGAIN

   - Clean up an unused helper

   - Update dax_writeback_mapping_range to not need a block_device
     argument"

* tag 'dax-fixes-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: pass NOWAIT flag to iomap_apply
  dax: Get rid of fs_dax_get_by_host() helper
  dax: Pass dax_dev instead of bdev to dax_writeback_mapping_range()
ext4: remove unused macro MPAGE_DA_EXTENT_TAIL 2020-01-17T21:24:55+00:00 Ritesh Harjani riteshh@linux.ibm.com 2020-01-01T09:51:37+00:00 e128d516d81289db7dd977b7706c96501f48c011 Remove unused macro MPAGE_DA_EXTENT_TAIL which is no more used after below commit 4e7ea81d ("ext4: restructure writeback path") Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200101095137.25656-1-riteshh@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> 
Remove unused macro MPAGE_DA_EXTENT_TAIL which
is no more used after below commit
4e7ea81d ("ext4: restructure writeback path")

Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200101095137.25656-1-riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4: remove redundant S_ISREG() checks from ext4_fallocate() 2020-01-17T21:24:54+00:00 Eric Biggers ebiggers@google.com 2019-12-31T18:04:39+00:00 a1180994f52c0867c134e411a6a532ffa166ceac ext4_fallocate() is only used in the file_operations for regular files. Also, the VFS only allows fallocate() on regular files and block devices, but block devices always use blkdev_fallocate(). For both of these reasons, S_ISREG() is always true in ext4_fallocate(). Therefore the S_ISREG() checks in ext4_zero_range(), ext4_collapse_range(), ext4_insert_range(), and ext4_punch_hole() are redundant. Remove them. Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20191231180444.46586-4-ebiggers@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> 
ext4_fallocate() is only used in the file_operations for regular files.
Also, the VFS only allows fallocate() on regular files and block
devices, but block devices always use blkdev_fallocate().  For both of
these reasons, S_ISREG() is always true in ext4_fallocate().

Therefore the S_ISREG() checks in ext4_zero_range(),
ext4_collapse_range(), ext4_insert_range(), and ext4_punch_hole() are
redundant.  Remove them.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191231180444.46586-4-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
ext4: only use fscrypt_zeroout_range() on regular files 2020-01-17T21:24:53+00:00 Eric Biggers ebiggers@google.com 2019-12-26T16:10:22+00:00 33b4cc2501d323feef3cc3ec9a084d80bef5b5e8 fscrypt_zeroout_range() is only for encrypted regular files, not for encrypted directories or symlinks. Fortunately, currently it seems it's never called on non-regular files. But to be safe ext4 should explicitly check S_ISREG() before calling it. Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20191226161022.53490-1-ebiggers@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu> 
fscrypt_zeroout_range() is only for encrypted regular files, not for
encrypted directories or symlinks.

Fortunately, currently it seems it's never called on non-regular files.
But to be safe ext4 should explicitly check S_ISREG() before calling it.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191226161022.53490-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4: handle decryption error in __ext4_block_zero_page_range() 2020-01-17T21:24:53+00:00 Eric Biggers ebiggers@google.com 2019-12-26T15:41:05+00:00 834f1565fa3f9c8f78adbfcaa80ae510fe4971c3 fscrypt_decrypt_pagecache_blocks() can fail, because it uses skcipher_request_alloc(), which uses kmalloc(), which can fail; and also because it calls crypto_skcipher_decrypt(), which can fail depending on the driver that actually implements the crypto. Therefore it's not appropriate to WARN on decryption error in __ext4_block_zero_page_range(). Remove the WARN and just handle the error instead. Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20191226154105.4704-1-ebiggers@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu> 
fscrypt_decrypt_pagecache_blocks() can fail, because it uses
skcipher_request_alloc(), which uses kmalloc(), which can fail; and also
because it calls crypto_skcipher_decrypt(), which can fail depending on
the driver that actually implements the crypto.

Therefore it's not appropriate to WARN on decryption error in
__ext4_block_zero_page_range().

Remove the WARN and just handle the error instead.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191226154105.4704-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4: avoid fetching btime in ext4_getattr() unless requested 2020-01-17T21:24:25+00:00 Theodore Ts'o tytso@mit.edu 2019-11-29T03:26:51+00:00 d4c5e960bf202d99ec9a6922ad387eafb798b848 Linus observed that an allmodconfig build which does a lot of stat(2) calls that ext4_getattr() was a noticeable (1%) amount of CPU time, due to the cache line for i_extra_isize getting pulled in. Since the normal stat system call doesn't return btime, it's a complete waste. So only calculate btime when it is explicitly requested. [ Fixed to check against request_mask instead of query_flags. ] Link: https://lore.kernel.org/r/CAHk-=wivmk_j6KbTX+Er64mLrG8abXZo0M10PNdAnHc8fWXfsQ@mail.gmail.com Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Theodore Ts'o <tytso@mit.edu> 
Linus observed that an allmodconfig build which does a lot of stat(2)
calls that ext4_getattr() was a noticeable (1%) amount of CPU time,
due to the cache line for i_extra_isize getting pulled in.  Since the
normal stat system call doesn't return btime, it's a complete waste.
So only calculate btime when it is explicitly requested.

[ Fixed to check against request_mask instead of query_flags. ]

Link: https://lore.kernel.org/r/CAHk-=wivmk_j6KbTX+Er64mLrG8abXZo0M10PNdAnHc8fWXfsQ@mail.gmail.com
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>