linux-stable.git/fs/ext4/ioctl.c, branch linux-5.2.y Linux kernel stable tree ext4: don't allow any modifications to an immutable file 2019-07-28T06:27:22+00:00 Darrick J. Wong darrick.wong@oracle.com 2019-06-10T01:41:41+00:00 d3a01f07b76e0cdcdef9d6f56c93e4ed2e83a090 commit 2e53840362771c73eb0a5ff71611507e64e8eecd upstream. Don't allow any modifications to a file that's marked immutable, which means that we have to flush all the writable pages to make the readonly and we have to check the setattr/setflags parameters more closely. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2e53840362771c73eb0a5ff71611507e64e8eecd upstream.

Don't allow any modifications to a file that's marked immutable, which
means that we have to flush all the writable pages to make the readonly
and we have to check the setattr/setflags parameters more closely.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ext4: fix miscellaneous sparse warnings 2019-05-12T08:49:47+00:00 Theodore Ts'o tytso@mit.edu 2019-05-12T08:49:47+00:00 0ba33facfc9bb556d1938caa67dfe452695a9be9 Signed-off-by: Theodore Ts'o <tytso@mit.edu> 
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4: Support case-insensitive file name lookups 2019-04-25T18:12:08+00:00 Gabriel Krisman Bertazi krisman@collabora.co.uk 2019-04-25T18:12:08+00:00 b886ee3e778ec2ad43e276fd378ab492cf6819b7 This patch implements the actual support for case-insensitive file name lookups in ext4, based on the feature bit and the encoding stored in the superblock. A filesystem that has the casefold feature set is able to configure directories with the +F (EXT4_CASEFOLD_FL) attribute, enabling lookups to succeed in that directory in a case-insensitive fashion, i.e: match a directory entry even if the name used by userspace is not a byte per byte match with the disk name, but is an equivalent case-insensitive version of the Unicode string. This operation is called a case-insensitive file name lookup. The feature is configured as an inode attribute applied to directories and inherited by its children. This attribute can only be enabled on empty directories for filesystems that support the encoding feature, thus preventing collision of file names that only differ by case. * dcache handling: For a +F directory, Ext4 only stores the first equivalent name dentry used in the dcache. This is done to prevent unintentional duplication of dentries in the dcache, while also allowing the VFS code to quickly find the right entry in the cache despite which equivalent string was used in a previous lookup, without having to resort to ->lookup(). d_hash() of casefolded directories is implemented as the hash of the casefolded string, such that we always have a well-known bucket for all the equivalencies of the same string. d_compare() uses the utf8_strncasecmp() infrastructure, which handles the comparison of equivalent, same case, names as well. For now, negative lookups are not inserted in the dcache, since they would need to be invalidated anyway, because we can't trust missing file dentries. This is bad for performance but requires some leveraging of the vfs layer to fix. We can live without that for now, and so does everyone else. * on-disk data: Despite using a specific version of the name as the internal representation within the dcache, the name stored and fetched from the disk is a byte-per-byte match with what the user requested, making this implementation 'name-preserving'. i.e. no actual information is lost when writing to storage. DX is supported by modifying the hashes used in +F directories to make them case/encoding-aware. The new disk hashes are calculated as the hash of the full casefolded string, instead of the string directly. This allows us to efficiently search for file names in the htree without requiring the user to provide an exact name. * Dealing with invalid sequences: By default, when a invalid UTF-8 sequence is identified, ext4 will treat it as an opaque byte sequence, ignoring the encoding and reverting to the old behavior for that unique file. This means that case-insensitive file name lookup will not work only for that file. An optional bit can be set in the superblock telling the filesystem code and userspace tools to enforce the encoding. When that optional bit is set, any attempt to create a file name using an invalid UTF-8 sequence will fail and return an error to userspace. * Normalization algorithm: The UTF-8 algorithms used to compare strings in ext4 is implemented lives in fs/unicode, and is based on a previous version developed by SGI. It implements the Canonical decomposition (NFD) algorithm described by the Unicode specification 12.1, or higher, combined with the elimination of ignorable code points (NFDi) and full case-folding (CF) as documented in fs/unicode/utf8_norm.c. NFD seems to be the best normalization method for EXT4 because: - It has a lower cost than NFC/NFKC (which requires decomposing to NFD as an intermediary step) - It doesn't eliminate important semantic meaning like compatibility decompositions. Although: - This implementation is not completely linguistic accurate, because different languages have conflicting rules, which would require the specialization of the filesystem to a given locale, which brings all sorts of problems for removable media and for users who use more than one language. Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk> Signed-off-by: Theodore Ts'o <tytso@mit.edu> 
This patch implements the actual support for case-insensitive file name
lookups in ext4, based on the feature bit and the encoding stored in the
superblock.

A filesystem that has the casefold feature set is able to configure
directories with the +F (EXT4_CASEFOLD_FL) attribute, enabling lookups
to succeed in that directory in a case-insensitive fashion, i.e: match
a directory entry even if the name used by userspace is not a byte per
byte match with the disk name, but is an equivalent case-insensitive
version of the Unicode string.  This operation is called a
case-insensitive file name lookup.

The feature is configured as an inode attribute applied to directories
and inherited by its children.  This attribute can only be enabled on
empty directories for filesystems that support the encoding feature,
thus preventing collision of file names that only differ by case.

* dcache handling:

For a +F directory, Ext4 only stores the first equivalent name dentry
used in the dcache. This is done to prevent unintentional duplication of
dentries in the dcache, while also allowing the VFS code to quickly find
the right entry in the cache despite which equivalent string was used in
a previous lookup, without having to resort to ->lookup().

d_hash() of casefolded directories is implemented as the hash of the
casefolded string, such that we always have a well-known bucket for all
the equivalencies of the same string. d_compare() uses the
utf8_strncasecmp() infrastructure, which handles the comparison of
equivalent, same case, names as well.

For now, negative lookups are not inserted in the dcache, since they
would need to be invalidated anyway, because we can't trust missing file
dentries.  This is bad for performance but requires some leveraging of
the vfs layer to fix.  We can live without that for now, and so does
everyone else.

* on-disk data:

Despite using a specific version of the name as the internal
representation within the dcache, the name stored and fetched from the
disk is a byte-per-byte match with what the user requested, making this
implementation 'name-preserving'. i.e. no actual information is lost
when writing to storage.

DX is supported by modifying the hashes used in +F directories to make
them case/encoding-aware.  The new disk hashes are calculated as the
hash of the full casefolded string, instead of the string directly.
This allows us to efficiently search for file names in the htree without
requiring the user to provide an exact name.

* Dealing with invalid sequences:

By default, when a invalid UTF-8 sequence is identified, ext4 will treat
it as an opaque byte sequence, ignoring the encoding and reverting to
the old behavior for that unique file.  This means that case-insensitive
file name lookup will not work only for that file.  An optional bit can
be set in the superblock telling the filesystem code and userspace tools
to enforce the encoding.  When that optional bit is set, any attempt to
create a file name using an invalid UTF-8 sequence will fail and return
an error to userspace.

* Normalization algorithm:

The UTF-8 algorithms used to compare strings in ext4 is implemented
lives in fs/unicode, and is based on a previous version developed by
SGI.  It implements the Canonical decomposition (NFD) algorithm
described by the Unicode specification 12.1, or higher, combined with
the elimination of ignorable code points (NFDi) and full
case-folding (CF) as documented in fs/unicode/utf8_norm.c.

NFD seems to be the best normalization method for EXT4 because:

  - It has a lower cost than NFC/NFKC (which requires
    decomposing to NFD as an intermediary step)
  - It doesn't eliminate important semantic meaning like
    compatibility decompositions.

Although:

  - This implementation is not completely linguistic accurate, because
  different languages have conflicting rules, which would require the
  specialization of the filesystem to a given locale, which brings all
  sorts of problems for removable media and for users who use more than
  one language.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4: actually request zeroing of inode table after grow 2019-04-25T17:06:18+00:00 Kirill Tkhai ktkhai@virtuozzo.com 2019-04-25T17:06:18+00:00 310a997fd74de778b9a4848a64be9cda9f18764a It is never possible, that number of block groups decreases, since only online grow is supported. But after a growing occured, we have to zero inode tables for just created new block groups. Fixes: 19c5246d2516 ("ext4: add new online resize interface") Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Cc: stable@kernel.org 
It is never possible, that number of block groups decreases,
since only online grow is supported.

But after a growing occured, we have to zero inode tables
for just created new block groups.

Fixes: 19c5246d2516 ("ext4: add new online resize interface")
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 2019-03-24T20:41:37+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-03-24T20:41:37+00:00 17403fa277eda1328a7026dfca7e40249f27dc6b Pull ext4 fixes from Ted Ts'o: "Miscellaneous ext4 bug fixes for 5.1" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: prohibit fstrim in norecovery mode ext4: cleanup bh release code in ext4_ind_remove_space() ext4: brelse all indirect buffer in ext4_ind_remove_space() ext4: report real fs size after failed resize ext4: add missing brelse() in add_new_gdb_meta_bg() ext4: remove useless ext4_pin_inode() ext4: avoid panic during forced reboot ext4: fix data corruption caused by unaligned direct AIO ext4: fix NULL pointer dereference while journal is aborted 
Pull ext4 fixes from Ted Ts'o:
 "Miscellaneous ext4 bug fixes for 5.1"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: prohibit fstrim in norecovery mode
  ext4: cleanup bh release code in ext4_ind_remove_space()
  ext4: brelse all indirect buffer in ext4_ind_remove_space()
  ext4: report real fs size after failed resize
  ext4: add missing brelse() in add_new_gdb_meta_bg()
  ext4: remove useless ext4_pin_inode()
  ext4: avoid panic during forced reboot
  ext4: fix data corruption caused by unaligned direct AIO
  ext4: fix NULL pointer dereference while journal is aborted
ext4: prohibit fstrim in norecovery mode 2019-03-23T16:10:29+00:00 Darrick J. Wong darrick.wong@oracle.com 2019-03-23T16:10:29+00:00 18915b5873f07e5030e6fb108a050fa7c71c59fb The ext4 fstrim implementation uses the block bitmaps to find free space that can be discarded. If we haven't replayed the journal, the bitmaps will be stale and we absolutely *cannot* use stale metadata to zap the underlying storage. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> 
The ext4 fstrim implementation uses the block bitmaps to find free space
that can be discarded.  If we haven't replayed the journal, the bitmaps
will be stale and we absolutely *cannot* use stale metadata to zap the
underlying storage.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 2019-03-12T22:03:21+00:00 Linus Torvalds torvalds@linux-foundation.org 2019-03-12T22:03:21+00:00 a5adcfcad55d5f034b33f79f1a873229d1e77b24 Pull ext4 updates from Ted Ts'o: "A large number of bug fixes and cleanups. One new feature to allow users to more easily find the jbd2 journal thread for a particular ext4 file system" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (25 commits) jbd2: jbd2_get_transaction does not need to return a value jbd2: fix invalid descriptor block checksum ext4: fix bigalloc cluster freeing when hole punching under load ext4: add sysfs attr /sys/fs/ext4/<disk>/journal_task ext4: Change debugging support help prefix from EXT4 to Ext4 ext4: fix compile error when using BUFFER_TRACE jbd2: fix compile warning when using JBUFFER_TRACE ext4: fix some error pointer dereferences ext4: annotate more implicit fall throughs ext4: annotate implicit fall throughs ext4: don't update s_rev_level if not required jbd2: fold jbd2_superblock_csum_{verify,set} into their callers jbd2: fix race when writing superblock ext4: fix crash during online resizing ext4: disallow files with EXT4_JOURNAL_DATA_FL from EXT4_IOC_SWAP_BOOT ext4: add mask of ext4 flags to swap ext4: update quota information while swapping boot loader inode ext4: cleanup pagecache before swap i_data ext4: fix check of inode in swap_inode_boot_loader ext4: unlock unused_pages timely when doing writeback ... 
Pull ext4 updates from Ted Ts'o:
 "A large number of bug fixes and cleanups.

  One new feature to allow users to more easily find the jbd2 journal
  thread for a particular ext4 file system"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (25 commits)
  jbd2: jbd2_get_transaction does not need to return a value
  jbd2: fix invalid descriptor block checksum
  ext4: fix bigalloc cluster freeing when hole punching under load
  ext4: add sysfs attr /sys/fs/ext4/<disk>/journal_task
  ext4: Change debugging support help prefix from EXT4 to Ext4
  ext4: fix compile error when using BUFFER_TRACE
  jbd2: fix compile warning when using JBUFFER_TRACE
  ext4: fix some error pointer dereferences
  ext4: annotate more implicit fall throughs
  ext4: annotate implicit fall throughs
  ext4: don't update s_rev_level if not required
  jbd2: fold jbd2_superblock_csum_{verify,set} into their callers
  jbd2: fix race when writing superblock
  ext4: fix crash during online resizing
  ext4: disallow files with EXT4_JOURNAL_DATA_FL from EXT4_IOC_SWAP_BOOT
  ext4: add mask of ext4 flags to swap
  ext4: update quota information while swapping boot loader inode
  ext4: cleanup pagecache before swap i_data
  ext4: fix check of inode in swap_inode_boot_loader
  ext4: unlock unused_pages timely when doing writeback
  ...
ext4: disallow files with EXT4_JOURNAL_DATA_FL from EXT4_IOC_SWAP_BOOT 2019-02-11T06:07:10+00:00 Theodore Ts'o tytso@mit.edu 2019-02-11T06:07:10+00:00 6e589291f4b1b700ca12baec5930592a0d51e63c A malicious/clueless root user can use EXT4_IOC_SWAP_BOOT to force a corner casew which can lead to the file system getting corrupted. There's no usefulness to allowing this, so just prohibit this case. Signed-off-by: Theodore Ts'o <tytso@mit.edu> 
A malicious/clueless root user can use EXT4_IOC_SWAP_BOOT to force a
corner casew which can lead to the file system getting corrupted.
There's no usefulness to allowing this, so just prohibit this case.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4: add mask of ext4 flags to swap 2019-02-11T05:35:06+00:00 yangerkun yangerkun@huawei.com 2019-02-11T05:35:06+00:00 abdc644e8cbac2e9b19763680e5a7cf9bab2bee7 The reason is that while swapping two inode, we swap the flags too. Some flags such as EXT4_JOURNAL_DATA_FL can really confuse the things since we're not resetting the address operations structure. The simplest way to keep things sane is to restrict the flags that can be swapped. Signed-off-by: yangerkun <yangerkun@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@vger.kernel.org 
The reason is that while swapping two inode, we swap the flags too.
Some flags such as EXT4_JOURNAL_DATA_FL can really confuse the things
since we're not resetting the address operations structure.  The
simplest way to keep things sane is to restrict the flags that can be
swapped.

Signed-off-by: yangerkun <yangerkun@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org
ext4: update quota information while swapping boot loader inode 2019-02-11T05:14:02+00:00 yangerkun yangerkun@huawei.com 2019-02-11T05:14:02+00:00 aa507b5faf38784defe49f5e64605ac3c4425e26 While do swap between two inode, they swap i_data without update quota information. Also, swap_inode_boot_loader can do "revert" somtimes, so update the quota while all operations has been finished. Signed-off-by: yangerkun <yangerkun@huawei.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org 
While do swap between two inode, they swap i_data without update
quota information. Also, swap_inode_boot_loader can do "revert"
somtimes, so update the quota while all operations has been finished.

Signed-off-by: yangerkun <yangerkun@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org