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2020-12-02f2fs: Handle casefolding with EncryptionDaniel Rosenberg
Expand f2fs's casefolding support to include encrypted directories. To index casefolded+encrypted directories, we use the SipHash of the casefolded name, keyed by a key derived from the directory's fscrypt master key. This ensures that the dirhash doesn't leak information about the plaintext filenames. Encryption keys are unavailable during roll-forward recovery, so we can't compute the dirhash when recovering a new dentry in an encrypted + casefolded directory. To avoid having to force a checkpoint when a new file is fsync'ed, store the dirhash on-disk appended to i_name. This patch incorporates work by Eric Biggers <ebiggers@google.com> and Jaegeuk Kim <jaegeuk@kernel.org>. Co-developed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Daniel Rosenberg <drosen@google.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2020-06-09Merge tag 'f2fs-for-5.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs Pull f2fs updates from Jaegeuk Kim: "In this round, we've added some knobs to enhance compression feature and harden testing environment. In addition, we've fixed several bugs reported from Android devices such as long discarding latency, device hanging during quota_sync, etc. Enhancements: - support lzo-rle algorithm - add two ioctls to release and reserve blocks for compression - support partial truncation/fiemap on compressed file - introduce sysfs entries to attach IO flags explicitly - add iostat trace point along with read io stat Bug fixes: - fix long discard latency - flush quota data by f2fs_quota_sync correctly - fix to recover parent inode number for power-cut recovery - fix lz4/zstd output buffer budget - parse checkpoint mount option correctly - avoid inifinite loop to wait for flushing node/meta pages - manage discard space correctly And some refactoring and clean up patches were added" * tag 'f2fs-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (51 commits) f2fs: attach IO flags to the missing cases f2fs: add node_io_flag for bio flags likewise data_io_flag f2fs: remove unused parameter of f2fs_put_rpages_mapping() f2fs: handle readonly filesystem in f2fs_ioc_shutdown() f2fs: avoid utf8_strncasecmp() with unstable name f2fs: don't return vmalloc() memory from f2fs_kmalloc() f2fs: fix retry logic in f2fs_write_cache_pages() f2fs: fix wrong discard space f2fs: compress: don't compress any datas after cp stop f2fs: remove unneeded return value of __insert_discard_tree() f2fs: fix wrong value of tracepoint parameter f2fs: protect new segment allocation in expand_inode_data f2fs: code cleanup by removing ifdef macro surrounding f2fs: avoid inifinite loop to wait for flushing node pages at cp_error f2fs: flush dirty meta pages when flushing them f2fs: fix checkpoint=disable:%u%% f2fs: compress: fix zstd data corruption f2fs: add compressed/gc data read IO stat f2fs: fix potential use-after-free issue f2fs: compress: don't handle non-compressed data in workqueue ...
2020-05-11f2fs: rework filename handlingEric Biggers
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>
2020-05-08crypto: lib/sha1 - remove unnecessary includes of linux/cryptohash.hEric Biggers
<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>
2019-08-23f2fs: Support case-insensitive file name lookupsDaniel Rosenberg
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>
2018-09-12f2fs: add SPDX license identifiersChao Yu
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>
2017-05-04f2fs: check entire encrypted bigname when finding a dentryJaegeuk Kim
If user has no key under an encrypted dir, fscrypt gives digested dentries. Previously, when looking up a dentry, f2fs only checks its hash value with first 4 bytes of the digested dentry, which didn't handle hash collisions fully. This patch enhances to check entire dentry bytes likewise ext4. Eric reported how to reproduce this issue by: # seq -f "edir/abcdefghijklmnopqrstuvwxyz012345%.0f" 100000 | xargs touch # find edir -type f | xargs stat -c %i | sort | uniq | wc -l 100000 # sync # echo 3 > /proc/sys/vm/drop_caches # keyctl new_session # find edir -type f | xargs stat -c %i | sort | uniq | wc -l 99999 Cc: <stable@vger.kernel.org> Reported-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> (fixed f2fs_dentry_hash() to work even when the hash is 0) Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2015-05-28f2fs: introduce dot and dotdot name checkJaegeuk Kim
This patch adds an inline function to check dot and dotdot names. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-08-29f2fs: fix wrong casting for dentry nameJaegeuk Kim
The dentry name type is unsigned char *. If we don't match this type, some character codes can be changed by signed bit. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2014-07-09f2fs: arguments cleanup of finding file flow functionsGu Zheng
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2012-12-28f2fs: unify string length declarations and usageLeon Romanovsky
This patch is intended to unify string length declarations and usage. There are number of calls to strlen which return size_t object. The size of this object depends on compiler if it will be bigger, equal or even smaller than an unsigned int Signed-off-by: Leon Romanovsky <leon@leon.nu> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-28f2fs: clean up unused variables and return valuesJaegeuk Kim
This patch cleans up a couple of unnecessary codes related to unused variables and return values. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-26f2fs: fix up f2fs_get_parent issue to retrieve correct parent inode numberNamjae Jeon
Test Case: [NFS Client] ls -lR . [NFS Server] while [ 1 ] do echo 3 > /proc/sys/vm/drop_caches done Error on NFS Client: "No such file or directory" When cache is dropped at the server, it results in lookup failure at the NFS client due to non-connection with the parent. The default path is it initiates a lookup by calculating the hash value for the name, even though the hash values stored on the disk for "." and ".." is maintained as zero, which results in failure from find_in_block due to not matching HASH values. Fix up, by using the correct hashing values for these entries. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-11f2fs: adjust kernel coding styleJaegeuk Kim
As pointed out by Randy Dunlap, this patch removes all usage of "/**" for comment blocks. Instead, just use "/*". Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-11f2fs: fix endian conversion bugs reported by sparseJaegeuk Kim
This patch should resolve the bugs reported by the sparse tool. Initial reports were written by "kbuild test robot" managed by fengguang.wu. In my local machines, I've tested also by running: > make C=2 CF="-D__CHECK_ENDIAN__" Accordingly, I've found lots of warnings and bugs related to the endian conversion. And I've fixed all at this moment. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
2012-12-11f2fs: add core directory operationsJaegeuk Kim
this adds core functions to find, add, delete, and link dentries. Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>