f2fs: rework filename handling

Rework f2fs's handling of filenames to use a new 'struct f2fs_filename'.
Similar to 'struct ext4_filename', this stores the usr_fname, disk_name,
dirhash, crypto_buf,

f2fs: rework filename handling

Rework f2fs's handling of filenames to use a new 'struct f2fs_filename'.
Similar to 'struct ext4_filename', this stores the usr_fname, disk_name,
dirhash, crypto_buf, and casefolded name. Some of these names can be
NULL in some cases. 'struct f2fs_filename' differs from
'struct fscrypt_name' mainly in that the casefolded name is included.

For user-initiated directory operations like lookup() and create(),
initialize the f2fs_filename by translating the corresponding
fscrypt_name, then computing the dirhash and casefolded name if needed.

This makes the dirhash and casefolded name be cached for each syscall,
so we don't have to recompute them repeatedly. (Previously, f2fs
computed the dirhash once per directory level, and the casefolded name
once per directory block.) This improves performance.

This rework also makes it much easier to correctly handle all
combinations of normal, encrypted, casefolded, and encrypted+casefolded
directories. (The fourth isn't supported yet but is being worked on.)

The only other cases where an f2fs_filename gets initialized are for two
filesystem-internal operations: (1) when converting an inline directory
to a regular one, we grab the needed disk_name and hash from an existing
f2fs_dir_entry; and (2) when roll-forward recovering a new dentry, we
grab the needed disk_name from f2fs_inode::i_name and compute the hash.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

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crypto: lib/sha1 - remove unnecessary includes of linux/cryptohash.h

<linux/cryptohash.h> sounds very generic and important, like it's the
header to include if you're doing cryptographic hashing in

crypto: lib/sha1 - remove unnecessary includes of linux/cryptohash.h

<linux/cryptohash.h> sounds very generic and important, like it's the
header to include if you're doing cryptographic hashing in the kernel.
But actually it only includes the library implementation of the SHA-1
compression function (not even the full SHA-1). This should basically
never be used anymore; SHA-1 is no longer considered secure, and there
are much better ways to do cryptographic hashing in the kernel.

Most files that include this header don't actually need it. So in
preparation for removing it, remove all these unneeded includes of it.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

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Merge branch 'next' into for-linus

Prepare input updates for 5.5 merge window.

Merge tag 'v5.4-rc8' into WIP.x86/mm, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge branch 'linus' into x86/hyperv

Pick up upstream fixes to avoid conflicts.

Merge tag 'v5.4-rc5' into next

Sync up with mainline.

Merge tag 'v5.4-rc3' into spi-5.4

Linux 5.4-rc3

Merge drm/drm-next into drm-intel-next-queued

Backmerging to pull in HDR DP code:

https://lists.freedesktop.org/archives/dri-devel/2019-September/236453.html

Signed-off-by: Joonas Lahtinen <joonas

Merge drm/drm-next into drm-intel-next-queued

Backmerging to pull in HDR DP code:

https://lists.freedesktop.org/archives/dri-devel/2019-September/236453.html

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

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Merge tag 'fix-missing-panels' into fixes

Merge drm/drm-next into drm-misc-next

We haven't done any backmerge for a while due to the merge window, and it
starts to become an issue for komeda. Let's bring 5.4-rc1 in.

Signed-off-by: Maxime R

Merge drm/drm-next into drm-misc-next

We haven't done any backmerge for a while due to the merge window, and it
starts to become an issue for komeda. Let's bring 5.4-rc1 in.

Signed-off-by: Maxime Ripard <mripard@kernel.org>

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Merge drm/drm-fixes into drm-misc-fixes

We haven't backmerged for a while, let's start the -rc period by pulling
rc1.

Signed-off-by: Maxime Ripard <mripard@kernel.org>

Merge tag 'f2fs-for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

Pull f2fs updates from Jaegeuk Kim:
"In this round, we introduced casefolding support in f2fs, and fixed
var

Merge tag 'f2fs-for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

Pull f2fs updates from Jaegeuk Kim:
"In this round, we introduced casefolding support in f2fs, and fixed
various bugs in individual features such as IO alignment,
checkpoint=disable, quota, and swapfile.

Enhancement:
- support casefolding w/ enhancement in ext4
- support fiemap for directory
- support FS_IO_GET|SET_FSLABEL

Bug fix:
- fix IO stuck during checkpoint=disable
- avoid infinite GC loop
- fix panic/overflow related to IO alignment feature
- fix livelock in swap file
- fix discard command leak
- disallow dio for atomic_write"

* tag 'f2fs-for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (51 commits)
f2fs: add a condition to detect overflow in f2fs_ioc_gc_range()
f2fs: fix to add missing F2FS_IO_ALIGNED() condition
f2fs: fix to fallback to buffered IO in IO aligned mode
f2fs: fix to handle error path correctly in f2fs_map_blocks
f2fs: fix extent corrupotion during directIO in LFS mode
f2fs: check all the data segments against all node ones
f2fs: Add a small clarification to CONFIG_FS_F2FS_FS_SECURITY
f2fs: fix inode rwsem regression
f2fs: fix to avoid accessing uninitialized field of inode page in is_alive()
f2fs: avoid infinite GC loop due to stale atomic files
f2fs: Fix indefinite loop in f2fs_gc()
f2fs: convert inline_data in prior to i_size_write
f2fs: fix error path of f2fs_convert_inline_page()
f2fs: add missing documents of reserve_root/resuid/resgid
f2fs: fix flushing node pages when checkpoint is disabled
f2fs: enhance f2fs_is_checkpoint_ready()'s readability
f2fs: clean up __bio_alloc()'s parameter
f2fs: fix wrong error injection path in inc_valid_block_count()
f2fs: fix to writeout dirty inode during node flush
f2fs: optimize case-insensitive lookups
...

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f2fs: Support case-insensitive file name lookups

Modeled after commit b886ee3e778e ("ext4: Support case-insensitive file
name lookups")

"""
This patch implements the actual support for case-insensi

f2fs: Support case-insensitive file name lookups

Modeled after commit b886ee3e778e ("ext4: Support case-insensitive file
name lookups")

"""
This patch implements the actual support for case-insensitive file name
lookups in f2fs, 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 (F2FS_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, F2Fs 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 f2fs is implemented
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 F2FS 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: Daniel Rosenberg <drosen@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

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Merge tag 'v4.20' into for-linus

Sync with mainline to get linux/overflow.h among other things.

Merge tag 'v4.20' into next

Merge with mainline to bring in the new APIs.

Merge tag 'v4.20-rc7' of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into fbdev-for-next

Linux 4.20-rc7

Sync with upstream (which now contains fbdev-v4.20 changes) to
prepare a b

Merge tag 'v4.20-rc7' of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into fbdev-for-next

Linux 4.20-rc7

Sync with upstream (which now contains fbdev-v4.20 changes) to
prepare a base for fbdev-v4.21 changes.

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Merge drm/drm-next into drm-intel-next-queued

Pull in v4.20-rc3 via drm-next.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Merge remote-tracking branch 'drm/drm-next' into drm-misc-next

drm-next is forwarded to v4.20-rc1, and we need this to make
a patch series apply.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst

Merge remote-tracking branch 'drm/drm-next' into drm-misc-next

drm-next is forwarded to v4.20-rc1, and we need this to make
a patch series apply.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

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Merge tag 'v4.20-rc2' into next-general

Sync to Linux 4.20-rc2 for downstream developers.

Merge tag 'v4.20-rc1' into omap-for-v4.21/dt-ti-sysc

Linux 4.20-rc1

Merge branch 'fixes-dts' into omap-for-v4.20/fixes

Merge branch 'linus' into perf/urgent, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge branch 'linus' into x86/urgent, to refresh the tree

Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'f2fs-for-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

Pull f2fs updates from Jaegeuk Kim:
"In this round, we've added 1) superblock checksum feature, 2)
impl

Merge tag 'f2fs-for-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

Pull f2fs updates from Jaegeuk Kim:
"In this round, we've added 1) superblock checksum feature, 2)
implemented new mount option which we can disable/enable checkpoint to
provide atomic updates of entire filesystem, 3) refactored quota
operations to enhance its consistency along with checkpoint, 4) fixed
subtle IO hang conditions and roll-forward recovery flow to resurrect
any fsync'ed inode metadata.

Enhancements:
- add checksum to keep superblock contents more safe
- add checkpoint=disable/enable to support A/B update of entire filesystem
- use plug for readahead IO in readdir
- add more IO counts to avoid block layer hacks

Bug fixes:
- prevent data corruption issue for hardware encryption
- fix IO hang issues when GC is heavily triggered
- add missing up_read in __write_node_page
- recover inode metadata during roll-forward recovery flow
- fix null pointer dereference issue in wrongly configured discard map

There are some more sanity checks and minor bug fixes as well"

* tag 'f2fs-for-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (62 commits)
f2fs: fix to keep project quota consistent
f2fs: guarantee journalled quota data by checkpoint
f2fs: cleanup dirty pages if recover failed
f2fs: fix data corruption issue with hardware encryption
f2fs: fix to recover inode->i_flags of inode block during POR
f2fs: spread f2fs_set_inode_flags()
f2fs: fix to spread clear_cold_data()
Revert "f2fs: fix to clear PG_checked flag in set_page_dirty()"
f2fs: account read IOs and use IO counts for is_idle
f2fs: fix to account IO correctly for cgroup writeback
f2fs: fix to account IO correctly
f2fs: remove request_list check in is_idle()
f2fs: allow to mount, if quota is failed
f2fs: update REQ_TIME in f2fs_cross_rename()
f2fs: do not update REQ_TIME in case of error conditions
f2fs: remove unneeded disable_nat_bits()
f2fs: remove unused sbi->trigger_ssr_threshold
f2fs: shrink sbi->sb_lock coverage in set_file_temperature()
f2fs: use rb_*_cached friends
f2fs: fix to recover cold bit of inode block during POR
...

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f2fs: add SPDX license identifiers

Remove the verbose license text from f2fs files and replace them with
SPDX tags. This does not change the license of any of the code.

Signed-off-by: Chao Yu <yuc

f2fs: add SPDX license identifiers

Remove the verbose license text from f2fs files and replace them with
SPDX tags. This does not change the license of any of the code.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

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