| Message ID | 20190717031408.114104-3-drosen@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Casefolding in F2FS | expand |
Hi Daniel, On 2019/7/17 11:14, Daniel Rosenberg wrote: > 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> > --- > fs/f2fs/dir.c | 133 ++++++++++++++++++++++++++++++++++++++++++----- > fs/f2fs/f2fs.h | 18 +++++-- > fs/f2fs/file.c | 10 +++- > fs/f2fs/hash.c | 34 +++++++++++- > fs/f2fs/inline.c | 6 +-- > fs/f2fs/inode.c | 4 +- > fs/f2fs/namei.c | 21 ++++++++ > fs/f2fs/super.c | 5 ++ > 8 files changed, 208 insertions(+), 23 deletions(-) > > diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c > index 85a1528f319f2..4d5eea2db1657 100644 > --- a/fs/f2fs/dir.c > +++ b/fs/f2fs/dir.c > @@ -8,6 +8,7 @@ > #include <linux/fs.h> > #include <linux/f2fs_fs.h> > #include <linux/sched/signal.h> > +#include <linux/unicode.h> > #include "f2fs.h" > #include "node.h" > #include "acl.h" > @@ -81,7 +82,8 @@ static unsigned long dir_block_index(unsigned int level, > return bidx; > } > > -static struct f2fs_dir_entry *find_in_block(struct page *dentry_page, > +static struct f2fs_dir_entry *find_in_block(struct inode *dir, > + struct page *dentry_page, > struct fscrypt_name *fname, > f2fs_hash_t namehash, > int *max_slots, > @@ -94,20 +96,56 @@ static struct f2fs_dir_entry *find_in_block(struct page *dentry_page, > dentry_blk = (struct f2fs_dentry_block *)page_address(dentry_page); > > make_dentry_ptr_block(NULL, &d, dentry_blk); We can pass dir to make_dentry_ptr_block(dir, ...), then in f2fs_find_target_dentry() we use d->inode, so that it can avoid one redundant parameter. > - de = f2fs_find_target_dentry(fname, namehash, max_slots, &d); > + de = f2fs_find_target_dentry(dir, fname, namehash, max_slots, &d); > if (de) > *res_page = dentry_page; > > return de; > } > > -struct f2fs_dir_entry *f2fs_find_target_dentry(struct fscrypt_name *fname, > - f2fs_hash_t namehash, int *max_slots, > - struct f2fs_dentry_ptr *d) > +#ifdef CONFIG_UNICODE > +/* > + * Test whether a case-insensitive directory entry matches the filename > + * being searched for. > + * > + * Returns: 0 if the directory entry matches, more than 0 if it > + * doesn't match or less than zero on error. > + */ > +int f2fs_ci_compare(const struct inode *parent, const struct qstr *name, > + const struct qstr *entry) > +{ > + const struct f2fs_sb_info *sbi = F2FS_SB(parent->i_sb); > + const struct unicode_map *um = sbi->s_encoding; > + int ret; > + > + ret = utf8_strncasecmp(um, name, entry); > + if (ret < 0) { > + /* Handle invalid character sequence as either an error > + * or as an opaque byte sequence. > + */ > + if (f2fs_has_strict_mode(sbi)) > + return -EINVAL; > + > + if (name->len != entry->len) > + return 1; > + > + return !!memcmp(name->name, entry->name, name->len); > + } > + > + return ret; > +} > +#endif > + > +struct f2fs_dir_entry *f2fs_find_target_dentry(const struct inode *parent, > + struct fscrypt_name *fname, f2fs_hash_t namehash, > + int *max_slots, struct f2fs_dentry_ptr *d) > { > struct f2fs_dir_entry *de; > unsigned long bit_pos = 0; > int max_len = 0; > +#ifdef CONFIG_UNICODE > + struct qstr entry; > +#endif > > if (max_slots) > *max_slots = 0; > @@ -119,16 +157,29 @@ struct f2fs_dir_entry *f2fs_find_target_dentry(struct fscrypt_name *fname, > } > > de = &d->dentry[bit_pos]; > +#ifdef CONFIG_UNICODE > + entry.name = d->filename[bit_pos]; > + entry.len = de->name_len; > +#endif > > if (unlikely(!de->name_len)) { > bit_pos++; > continue; > } > + if (de->hash_code == namehash) { > +#ifdef CONFIG_UNICODE > + if (F2FS_SB(parent->i_sb)->s_encoding && > + IS_CASEFOLDED(parent) && > + !f2fs_ci_compare(parent, > + fname->usr_fname, &entry)) > + goto found; > > - if (de->hash_code == namehash && > - fscrypt_match_name(fname, d->filename[bit_pos], > - le16_to_cpu(de->name_len))) > - goto found; > +#endif > + if (de->hash_code == namehash && It's redundant here. > + fscrypt_match_name(fname, d->filename[bit_pos], > + le16_to_cpu(de->name_len))) > + goto found; > + } > > if (max_slots && max_len > *max_slots) > *max_slots = max_len; > @@ -157,7 +208,7 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, > struct f2fs_dir_entry *de = NULL; > bool room = false; > int max_slots; > - f2fs_hash_t namehash = f2fs_dentry_hash(&name, fname); > + f2fs_hash_t namehash = f2fs_dentry_hash(dir, &name, fname); > > nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level); > nblock = bucket_blocks(level); > @@ -179,8 +230,8 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, > } > } > > - de = find_in_block(dentry_page, fname, namehash, &max_slots, > - res_page); > + de = find_in_block(dir, dentry_page, fname, namehash, > + &max_slots, res_page); > if (de) > break; > > @@ -246,10 +297,18 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, > struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir, > const struct qstr *child, struct page **res_page) > { > + struct f2fs_sb_info *sbi = F2FS_I_SB(dir); > struct f2fs_dir_entry *de = NULL; > struct fscrypt_name fname; > int err; > > +#ifdef CONFIG_UNICODE > + if (f2fs_has_strict_mode(sbi) && IS_CASEFOLDED(dir) && > + utf8_validate(sbi->s_encoding, child)) { > + *res_page = ERR_PTR(-EINVAL); > + return NULL; > + } > +#endif > err = fscrypt_setup_filename(dir, child, 1, &fname); > if (err) { > if (err == -ENOENT) > @@ -504,7 +563,7 @@ int f2fs_add_regular_entry(struct inode *dir, const struct qstr *new_name, > > level = 0; > slots = GET_DENTRY_SLOTS(new_name->len); > - dentry_hash = f2fs_dentry_hash(new_name, NULL); > + dentry_hash = f2fs_dentry_hash(dir, new_name, NULL); > > current_depth = F2FS_I(dir)->i_current_depth; > if (F2FS_I(dir)->chash == dentry_hash) { > @@ -943,3 +1002,51 @@ const struct file_operations f2fs_dir_operations = { > .compat_ioctl = f2fs_compat_ioctl, > #endif > }; > + > +#ifdef CONFIG_UNICODE > +static int f2fs_d_compare(const struct dentry *dentry, unsigned int len, > + const char *str, const struct qstr *name) > +{ > + struct qstr qstr = {.name = str, .len = len }; > + > + if (!IS_CASEFOLDED(dentry->d_parent->d_inode)) { > + if (len != name->len) > + return -1; > + return memcmp(str, name, len); > + } > + > + return f2fs_ci_compare(dentry->d_parent->d_inode, name, &qstr); > +} > + > +static int f2fs_d_hash(const struct dentry *dentry, struct qstr *str) > +{ > + const struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb); > + const struct unicode_map *um = sbi->s_encoding; > + unsigned char *norm; > + int len, ret = 0; > + > + if (!IS_CASEFOLDED(dentry->d_inode)) > + return 0; > + > + norm = kmalloc(PATH_MAX, GFP_ATOMIC); f2fs_kmalloc() > + if (!norm) > + return -ENOMEM; > + > + len = utf8_casefold(um, str, norm, PATH_MAX); > + if (len < 0) { > + if (f2fs_has_strict_mode(sbi)) > + ret = -EINVAL; > + goto out; > + } > + str->hash = full_name_hash(dentry, norm, len); > +out: > + kfree(norm); kvfree() > + return ret; > +} > + > +const struct dentry_operations f2fs_dentry_ops = { > + .d_hash = f2fs_d_hash, > + .d_compare = f2fs_d_compare, > +}; > +#endif > + > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index c6c7904572d0d..500906108937c 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -2364,10 +2364,12 @@ static inline void f2fs_change_bit(unsigned int nr, char *addr) > #define F2FS_INDEX_FL 0x00001000 /* hash-indexed directory */ > #define F2FS_DIRSYNC_FL 0x00010000 /* dirsync behaviour (directories only) */ > #define F2FS_PROJINHERIT_FL 0x20000000 /* Create with parents projid */ > +#define F2FS_CASEFOLD_FL 0x40000000 /* Casefolded file */ > > /* Flags that should be inherited by new inodes from their parent. */ > #define F2FS_FL_INHERITED (F2FS_SYNC_FL | F2FS_NODUMP_FL | F2FS_NOATIME_FL | \ > - F2FS_DIRSYNC_FL | F2FS_PROJINHERIT_FL) > + F2FS_DIRSYNC_FL | F2FS_PROJINHERIT_FL | \ > + F2FS_CASEFOLD_FL) We need to add one more entry f2fs_fsflags_map[] to map F2FS_CASEFOLD_FL to FS_CASEFOLD_FL correctly and adapt F2FS_GETTABLE_FS_FL/F2FS_SETTABLE_FS_FL as well. > > /* Flags that are appropriate for regular files (all but dir-specific ones). */ > #define F2FS_REG_FLMASK (~(F2FS_DIRSYNC_FL | F2FS_PROJINHERIT_FL)) > @@ -2930,11 +2932,16 @@ int f2fs_update_extension_list(struct f2fs_sb_info *sbi, const char *name, > bool hot, bool set); > struct dentry *f2fs_get_parent(struct dentry *child); > > +extern int f2fs_ci_compare(const struct inode *parent, > + const struct qstr *name, > + const struct qstr *entry); > + > /* > * dir.c > */ > unsigned char f2fs_get_de_type(struct f2fs_dir_entry *de); > -struct f2fs_dir_entry *f2fs_find_target_dentry(struct fscrypt_name *fname, > +struct f2fs_dir_entry *f2fs_find_target_dentry(const struct inode *parent, > + struct fscrypt_name *fname, > f2fs_hash_t namehash, int *max_slots, > struct f2fs_dentry_ptr *d); > int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, > @@ -2993,8 +3000,8 @@ int f2fs_sanity_check_ckpt(struct f2fs_sb_info *sbi); > /* > * hash.c > */ > -f2fs_hash_t f2fs_dentry_hash(const struct qstr *name_info, > - struct fscrypt_name *fname); > +f2fs_hash_t f2fs_dentry_hash(const struct inode *dir, > + const struct qstr *name_info, struct fscrypt_name *fname); > > /* > * node.c > @@ -3437,6 +3444,9 @@ static inline void f2fs_destroy_root_stats(void) { } > #endif > > extern const struct file_operations f2fs_dir_operations; > +#ifdef CONFIG_UNICODE > +extern const struct dentry_operations f2fs_dentry_ops; > +#endif > extern const struct file_operations f2fs_file_operations; > extern const struct inode_operations f2fs_file_inode_operations; > extern const struct address_space_operations f2fs_dblock_aops; > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > index f8d46df8fa9ee..9bdef3aa38eab 100644 > --- a/fs/f2fs/file.c > +++ b/fs/f2fs/file.c > @@ -1660,7 +1660,16 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask) > return -EPERM; > > oldflags = fi->i_flags; > + if ((iflags ^ oldflags) & F2FS_CASEFOLD_FL) { > + if (!f2fs_sb_has_casefold(F2FS_I_SB(inode))) > + return -EOPNOTSUPP; > + > + if (!S_ISDIR(inode->i_mode)) > + return -ENOTDIR; > > + if (!f2fs_empty_dir(inode)) > + return -ENOTEMPTY; > + } > if ((iflags ^ oldflags) & (F2FS_APPEND_FL | F2FS_IMMUTABLE_FL)) > if (!capable(CAP_LINUX_IMMUTABLE)) > return -EPERM; > @@ -1671,7 +1680,6 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask) > set_inode_flag(inode, FI_PROJ_INHERIT); > else > clear_inode_flag(inode, FI_PROJ_INHERIT); > - Unneeded removal... > inode->i_ctime = current_time(inode); > f2fs_set_inode_flags(inode); > f2fs_mark_inode_dirty_sync(inode, true); > diff --git a/fs/f2fs/hash.c b/fs/f2fs/hash.c > index cc82f142f811f..f5b8e02bde049 100644 > --- a/fs/f2fs/hash.c > +++ b/fs/f2fs/hash.c > @@ -14,6 +14,7 @@ > #include <linux/f2fs_fs.h> > #include <linux/cryptohash.h> > #include <linux/pagemap.h> > +#include <linux/unicode.h> > > #include "f2fs.h" > > @@ -67,7 +68,7 @@ static void str2hashbuf(const unsigned char *msg, size_t len, > *buf++ = pad; > } > > -f2fs_hash_t f2fs_dentry_hash(const struct qstr *name_info, > +static f2fs_hash_t __f2fs_dentry_hash(const struct qstr *name_info, > struct fscrypt_name *fname) > { > __u32 hash; > @@ -103,3 +104,34 @@ f2fs_hash_t f2fs_dentry_hash(const struct qstr *name_info, > f2fs_hash = cpu_to_le32(hash & ~F2FS_HASH_COL_BIT); > return f2fs_hash; > } > + > +f2fs_hash_t f2fs_dentry_hash(const struct inode *dir, > + const struct qstr *name_info, struct fscrypt_name *fname) > +{ > +#ifdef CONFIG_UNICODE > + const struct unicode_map *um = F2FS_SB(dir->i_sb)->s_encoding; > + int r, dlen; > + unsigned char *buff; > + struct qstr *folded; > + > + if (name_info->len && IS_CASEFOLDED(dir)) { > + buff = kzalloc(sizeof(char) * PATH_MAX, GFP_KERNEL); f2fs_kzalloc() > + if (!buff) > + return -ENOMEM; > + > + dlen = utf8_casefold(um, name_info, buff, PATH_MAX); > + if (dlen < 0) { > + kfree(buff); > + goto opaque_seq; > + } > + folded->name = buff; > + folded->len = dlen; > + r = __f2fs_dentry_hash(folded, fname); > + > + kfree(buff); kvfree() > + return r; > + } > +opaque_seq: > +#endif > + return __f2fs_dentry_hash(name_info, fname); > +} > diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c > index 3613efca8c00c..7cff67af4fadb 100644 > --- a/fs/f2fs/inline.c > +++ b/fs/f2fs/inline.c > @@ -320,12 +320,12 @@ struct f2fs_dir_entry *f2fs_find_in_inline_dir(struct inode *dir, > return NULL; > } > > - namehash = f2fs_dentry_hash(&name, fname); > + namehash = f2fs_dentry_hash(dir, &name, fname); > > inline_dentry = inline_data_addr(dir, ipage); > > make_dentry_ptr_inline(dir, &d, inline_dentry); > - de = f2fs_find_target_dentry(fname, namehash, NULL, &d); > + de = f2fs_find_target_dentry(dir, fname, namehash, NULL, &d); We don't need to pass @dir, try using d->inode in f2fs_find_target_dentry() > unlock_page(ipage); > if (de) > *res_page = ipage; > @@ -580,7 +580,7 @@ int f2fs_add_inline_entry(struct inode *dir, const struct qstr *new_name, > > f2fs_wait_on_page_writeback(ipage, NODE, true, true); > > - name_hash = f2fs_dentry_hash(new_name, NULL); > + name_hash = f2fs_dentry_hash(dir, new_name, NULL); > f2fs_update_dentry(ino, mode, &d, new_name, name_hash, bit_pos); > > set_page_dirty(ipage); > diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c > index a33d7a849b2df..9a1f0d6616577 100644 > --- a/fs/f2fs/inode.c > +++ b/fs/f2fs/inode.c > @@ -46,9 +46,11 @@ void f2fs_set_inode_flags(struct inode *inode) > new_fl |= S_DIRSYNC; > if (file_is_encrypt(inode)) > new_fl |= S_ENCRYPTED; > + if (flags & F2FS_CASEFOLD_FL) > + new_fl |= S_CASEFOLD; > inode_set_flags(inode, new_fl, > S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC| > - S_ENCRYPTED); > + S_ENCRYPTED|S_CASEFOLD); > } > > static void __get_inode_rdev(struct inode *inode, struct f2fs_inode *ri) > diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c > index c5b99042e6f2b..727de2f8620f2 100644 > --- a/fs/f2fs/namei.c > +++ b/fs/f2fs/namei.c > @@ -489,6 +489,17 @@ static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry, > goto out_iput; > } > out_splice: > +#ifdef CONFIG_UNICODE > + if (!inode && IS_CASEFOLDED(dir)) { > + /* Eventually we want to call d_add_ci(dentry, NULL) > + * for negative dentries in the encoding case as > + * well. For now, prevent the negative dentry > + * from being cached. > + */ > + trace_f2fs_lookup_end(dir, dentry, ino, err); > + return NULL; > + } > +#endif > new = d_splice_alias(inode, dentry); > err = PTR_ERR_OR_ZERO(new); > trace_f2fs_lookup_end(dir, dentry, ino, err); > @@ -537,6 +548,16 @@ static int f2fs_unlink(struct inode *dir, struct dentry *dentry) > goto fail; > } > f2fs_delete_entry(de, page, dir, inode); > +#ifdef CONFIG_UNICODE > + /* VFS negative dentries are incompatible with Encoding and > + * Case-insensitiveness. Eventually we'll want avoid > + * invalidating the dentries here, alongside with returning the > + * negative dentries at f2fs_lookup(), when it is better > + * supported by the VFS for the CI case. > + */ > + if (IS_CASEFOLDED(dir)) > + d_invalidate(dentry); > +#endif > f2fs_unlock_op(sbi); > > if (IS_DIRSYNC(dir)) > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c > index 7927071ef5e95..edc8482a43604 100644 > --- a/fs/f2fs/super.c > +++ b/fs/f2fs/super.c > @@ -3397,6 +3397,11 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) > goto free_node_inode; > } > > +#ifdef CONFIG_UNICODE > + if (sbi->s_encoding) > + sb->s_d_op = &f2fs_dentry_ops; > +#endif > + > sb->s_root = d_make_root(root); /* allocate root dentry */ > if (!sb->s_root) { > err = -ENOMEM; >
On 7/17/19 3:11 AM, Chao Yu wrote: > We need to add one more entry f2fs_fsflags_map[] to map F2FS_CASEFOLD_FL to > FS_CASEFOLD_FL correctly and adapt F2FS_GETTABLE_FS_FL/F2FS_SETTABLE_FS_FL as well. I don't see FS_CASEFOLD_FL. It would make sense for it to exist, but unless it's in some recent patch I don't think that's currently in the kernel. Or are you suggesting adding it in this patch?
On 2019/7/19 5:31, Daniel Rosenberg wrote: > > On 7/17/19 3:11 AM, Chao Yu wrote: >> We need to add one more entry f2fs_fsflags_map[] to map F2FS_CASEFOLD_FL to >> FS_CASEFOLD_FL correctly and adapt F2FS_GETTABLE_FS_FL/F2FS_SETTABLE_FS_FL as well. > > I don't see FS_CASEFOLD_FL. It would make sense for it to exist, but unless it's in some recent patch I don't think that's currently in the kernel. Or are you suggesting adding it in this patch? Yeah, I think we can use a separated patch to propose uplifting the flag to a common one in fs.h, and then adjust f2fs_fsflags_map/F2FS_GETTABLE_FS_FL/F2FS_SETTABLE_FS_FL mapping. Otherwise we will fail to set CASEFOLD flag to inode. Thanks, > > . >
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index 85a1528f319f2..4d5eea2db1657 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -8,6 +8,7 @@ #include <linux/fs.h> #include <linux/f2fs_fs.h> #include <linux/sched/signal.h> +#include <linux/unicode.h> #include "f2fs.h" #include "node.h" #include "acl.h" @@ -81,7 +82,8 @@ static unsigned long dir_block_index(unsigned int level, return bidx; } -static struct f2fs_dir_entry *find_in_block(struct page *dentry_page, +static struct f2fs_dir_entry *find_in_block(struct inode *dir, + struct page *dentry_page, struct fscrypt_name *fname, f2fs_hash_t namehash, int *max_slots, @@ -94,20 +96,56 @@ static struct f2fs_dir_entry *find_in_block(struct page *dentry_page, dentry_blk = (struct f2fs_dentry_block *)page_address(dentry_page); make_dentry_ptr_block(NULL, &d, dentry_blk); - de = f2fs_find_target_dentry(fname, namehash, max_slots, &d); + de = f2fs_find_target_dentry(dir, fname, namehash, max_slots, &d); if (de) *res_page = dentry_page; return de; } -struct f2fs_dir_entry *f2fs_find_target_dentry(struct fscrypt_name *fname, - f2fs_hash_t namehash, int *max_slots, - struct f2fs_dentry_ptr *d) +#ifdef CONFIG_UNICODE +/* + * Test whether a case-insensitive directory entry matches the filename + * being searched for. + * + * Returns: 0 if the directory entry matches, more than 0 if it + * doesn't match or less than zero on error. + */ +int f2fs_ci_compare(const struct inode *parent, const struct qstr *name, + const struct qstr *entry) +{ + const struct f2fs_sb_info *sbi = F2FS_SB(parent->i_sb); + const struct unicode_map *um = sbi->s_encoding; + int ret; + + ret = utf8_strncasecmp(um, name, entry); + if (ret < 0) { + /* Handle invalid character sequence as either an error + * or as an opaque byte sequence. + */ + if (f2fs_has_strict_mode(sbi)) + return -EINVAL; + + if (name->len != entry->len) + return 1; + + return !!memcmp(name->name, entry->name, name->len); + } + + return ret; +} +#endif + +struct f2fs_dir_entry *f2fs_find_target_dentry(const struct inode *parent, + struct fscrypt_name *fname, f2fs_hash_t namehash, + int *max_slots, struct f2fs_dentry_ptr *d) { struct f2fs_dir_entry *de; unsigned long bit_pos = 0; int max_len = 0; +#ifdef CONFIG_UNICODE + struct qstr entry; +#endif if (max_slots) *max_slots = 0; @@ -119,16 +157,29 @@ struct f2fs_dir_entry *f2fs_find_target_dentry(struct fscrypt_name *fname, } de = &d->dentry[bit_pos]; +#ifdef CONFIG_UNICODE + entry.name = d->filename[bit_pos]; + entry.len = de->name_len; +#endif if (unlikely(!de->name_len)) { bit_pos++; continue; } + if (de->hash_code == namehash) { +#ifdef CONFIG_UNICODE + if (F2FS_SB(parent->i_sb)->s_encoding && + IS_CASEFOLDED(parent) && + !f2fs_ci_compare(parent, + fname->usr_fname, &entry)) + goto found; - if (de->hash_code == namehash && - fscrypt_match_name(fname, d->filename[bit_pos], - le16_to_cpu(de->name_len))) - goto found; +#endif + if (de->hash_code == namehash && + fscrypt_match_name(fname, d->filename[bit_pos], + le16_to_cpu(de->name_len))) + goto found; + } if (max_slots && max_len > *max_slots) *max_slots = max_len; @@ -157,7 +208,7 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, struct f2fs_dir_entry *de = NULL; bool room = false; int max_slots; - f2fs_hash_t namehash = f2fs_dentry_hash(&name, fname); + f2fs_hash_t namehash = f2fs_dentry_hash(dir, &name, fname); nbucket = dir_buckets(level, F2FS_I(dir)->i_dir_level); nblock = bucket_blocks(level); @@ -179,8 +230,8 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, } } - de = find_in_block(dentry_page, fname, namehash, &max_slots, - res_page); + de = find_in_block(dir, dentry_page, fname, namehash, + &max_slots, res_page); if (de) break; @@ -246,10 +297,18 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir, const struct qstr *child, struct page **res_page) { + struct f2fs_sb_info *sbi = F2FS_I_SB(dir); struct f2fs_dir_entry *de = NULL; struct fscrypt_name fname; int err; +#ifdef CONFIG_UNICODE + if (f2fs_has_strict_mode(sbi) && IS_CASEFOLDED(dir) && + utf8_validate(sbi->s_encoding, child)) { + *res_page = ERR_PTR(-EINVAL); + return NULL; + } +#endif err = fscrypt_setup_filename(dir, child, 1, &fname); if (err) { if (err == -ENOENT) @@ -504,7 +563,7 @@ int f2fs_add_regular_entry(struct inode *dir, const struct qstr *new_name, level = 0; slots = GET_DENTRY_SLOTS(new_name->len); - dentry_hash = f2fs_dentry_hash(new_name, NULL); + dentry_hash = f2fs_dentry_hash(dir, new_name, NULL); current_depth = F2FS_I(dir)->i_current_depth; if (F2FS_I(dir)->chash == dentry_hash) { @@ -943,3 +1002,51 @@ const struct file_operations f2fs_dir_operations = { .compat_ioctl = f2fs_compat_ioctl, #endif }; + +#ifdef CONFIG_UNICODE +static int f2fs_d_compare(const struct dentry *dentry, unsigned int len, + const char *str, const struct qstr *name) +{ + struct qstr qstr = {.name = str, .len = len }; + + if (!IS_CASEFOLDED(dentry->d_parent->d_inode)) { + if (len != name->len) + return -1; + return memcmp(str, name, len); + } + + return f2fs_ci_compare(dentry->d_parent->d_inode, name, &qstr); +} + +static int f2fs_d_hash(const struct dentry *dentry, struct qstr *str) +{ + const struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb); + const struct unicode_map *um = sbi->s_encoding; + unsigned char *norm; + int len, ret = 0; + + if (!IS_CASEFOLDED(dentry->d_inode)) + return 0; + + norm = kmalloc(PATH_MAX, GFP_ATOMIC); + if (!norm) + return -ENOMEM; + + len = utf8_casefold(um, str, norm, PATH_MAX); + if (len < 0) { + if (f2fs_has_strict_mode(sbi)) + ret = -EINVAL; + goto out; + } + str->hash = full_name_hash(dentry, norm, len); +out: + kfree(norm); + return ret; +} + +const struct dentry_operations f2fs_dentry_ops = { + .d_hash = f2fs_d_hash, + .d_compare = f2fs_d_compare, +}; +#endif + diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index c6c7904572d0d..500906108937c 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -2364,10 +2364,12 @@ static inline void f2fs_change_bit(unsigned int nr, char *addr) #define F2FS_INDEX_FL 0x00001000 /* hash-indexed directory */ #define F2FS_DIRSYNC_FL 0x00010000 /* dirsync behaviour (directories only) */ #define F2FS_PROJINHERIT_FL 0x20000000 /* Create with parents projid */ +#define F2FS_CASEFOLD_FL 0x40000000 /* Casefolded file */ /* Flags that should be inherited by new inodes from their parent. */ #define F2FS_FL_INHERITED (F2FS_SYNC_FL | F2FS_NODUMP_FL | F2FS_NOATIME_FL | \ - F2FS_DIRSYNC_FL | F2FS_PROJINHERIT_FL) + F2FS_DIRSYNC_FL | F2FS_PROJINHERIT_FL | \ + F2FS_CASEFOLD_FL) /* Flags that are appropriate for regular files (all but dir-specific ones). */ #define F2FS_REG_FLMASK (~(F2FS_DIRSYNC_FL | F2FS_PROJINHERIT_FL)) @@ -2930,11 +2932,16 @@ int f2fs_update_extension_list(struct f2fs_sb_info *sbi, const char *name, bool hot, bool set); struct dentry *f2fs_get_parent(struct dentry *child); +extern int f2fs_ci_compare(const struct inode *parent, + const struct qstr *name, + const struct qstr *entry); + /* * dir.c */ unsigned char f2fs_get_de_type(struct f2fs_dir_entry *de); -struct f2fs_dir_entry *f2fs_find_target_dentry(struct fscrypt_name *fname, +struct f2fs_dir_entry *f2fs_find_target_dentry(const struct inode *parent, + struct fscrypt_name *fname, f2fs_hash_t namehash, int *max_slots, struct f2fs_dentry_ptr *d); int f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d, @@ -2993,8 +3000,8 @@ int f2fs_sanity_check_ckpt(struct f2fs_sb_info *sbi); /* * hash.c */ -f2fs_hash_t f2fs_dentry_hash(const struct qstr *name_info, - struct fscrypt_name *fname); +f2fs_hash_t f2fs_dentry_hash(const struct inode *dir, + const struct qstr *name_info, struct fscrypt_name *fname); /* * node.c @@ -3437,6 +3444,9 @@ static inline void f2fs_destroy_root_stats(void) { } #endif extern const struct file_operations f2fs_dir_operations; +#ifdef CONFIG_UNICODE +extern const struct dentry_operations f2fs_dentry_ops; +#endif extern const struct file_operations f2fs_file_operations; extern const struct inode_operations f2fs_file_inode_operations; extern const struct address_space_operations f2fs_dblock_aops; diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index f8d46df8fa9ee..9bdef3aa38eab 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1660,7 +1660,16 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask) return -EPERM; oldflags = fi->i_flags; + if ((iflags ^ oldflags) & F2FS_CASEFOLD_FL) { + if (!f2fs_sb_has_casefold(F2FS_I_SB(inode))) + return -EOPNOTSUPP; + + if (!S_ISDIR(inode->i_mode)) + return -ENOTDIR; + if (!f2fs_empty_dir(inode)) + return -ENOTEMPTY; + } if ((iflags ^ oldflags) & (F2FS_APPEND_FL | F2FS_IMMUTABLE_FL)) if (!capable(CAP_LINUX_IMMUTABLE)) return -EPERM; @@ -1671,7 +1680,6 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask) set_inode_flag(inode, FI_PROJ_INHERIT); else clear_inode_flag(inode, FI_PROJ_INHERIT); - inode->i_ctime = current_time(inode); f2fs_set_inode_flags(inode); f2fs_mark_inode_dirty_sync(inode, true); diff --git a/fs/f2fs/hash.c b/fs/f2fs/hash.c index cc82f142f811f..f5b8e02bde049 100644 --- a/fs/f2fs/hash.c +++ b/fs/f2fs/hash.c @@ -14,6 +14,7 @@ #include <linux/f2fs_fs.h> #include <linux/cryptohash.h> #include <linux/pagemap.h> +#include <linux/unicode.h> #include "f2fs.h" @@ -67,7 +68,7 @@ static void str2hashbuf(const unsigned char *msg, size_t len, *buf++ = pad; } -f2fs_hash_t f2fs_dentry_hash(const struct qstr *name_info, +static f2fs_hash_t __f2fs_dentry_hash(const struct qstr *name_info, struct fscrypt_name *fname) { __u32 hash; @@ -103,3 +104,34 @@ f2fs_hash_t f2fs_dentry_hash(const struct qstr *name_info, f2fs_hash = cpu_to_le32(hash & ~F2FS_HASH_COL_BIT); return f2fs_hash; } + +f2fs_hash_t f2fs_dentry_hash(const struct inode *dir, + const struct qstr *name_info, struct fscrypt_name *fname) +{ +#ifdef CONFIG_UNICODE + const struct unicode_map *um = F2FS_SB(dir->i_sb)->s_encoding; + int r, dlen; + unsigned char *buff; + struct qstr *folded; + + if (name_info->len && IS_CASEFOLDED(dir)) { + buff = kzalloc(sizeof(char) * PATH_MAX, GFP_KERNEL); + if (!buff) + return -ENOMEM; + + dlen = utf8_casefold(um, name_info, buff, PATH_MAX); + if (dlen < 0) { + kfree(buff); + goto opaque_seq; + } + folded->name = buff; + folded->len = dlen; + r = __f2fs_dentry_hash(folded, fname); + + kfree(buff); + return r; + } +opaque_seq: +#endif + return __f2fs_dentry_hash(name_info, fname); +} diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c index 3613efca8c00c..7cff67af4fadb 100644 --- a/fs/f2fs/inline.c +++ b/fs/f2fs/inline.c @@ -320,12 +320,12 @@ struct f2fs_dir_entry *f2fs_find_in_inline_dir(struct inode *dir, return NULL; } - namehash = f2fs_dentry_hash(&name, fname); + namehash = f2fs_dentry_hash(dir, &name, fname); inline_dentry = inline_data_addr(dir, ipage); make_dentry_ptr_inline(dir, &d, inline_dentry); - de = f2fs_find_target_dentry(fname, namehash, NULL, &d); + de = f2fs_find_target_dentry(dir, fname, namehash, NULL, &d); unlock_page(ipage); if (de) *res_page = ipage; @@ -580,7 +580,7 @@ int f2fs_add_inline_entry(struct inode *dir, const struct qstr *new_name, f2fs_wait_on_page_writeback(ipage, NODE, true, true); - name_hash = f2fs_dentry_hash(new_name, NULL); + name_hash = f2fs_dentry_hash(dir, new_name, NULL); f2fs_update_dentry(ino, mode, &d, new_name, name_hash, bit_pos); set_page_dirty(ipage); diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c index a33d7a849b2df..9a1f0d6616577 100644 --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -46,9 +46,11 @@ void f2fs_set_inode_flags(struct inode *inode) new_fl |= S_DIRSYNC; if (file_is_encrypt(inode)) new_fl |= S_ENCRYPTED; + if (flags & F2FS_CASEFOLD_FL) + new_fl |= S_CASEFOLD; inode_set_flags(inode, new_fl, S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC| - S_ENCRYPTED); + S_ENCRYPTED|S_CASEFOLD); } static void __get_inode_rdev(struct inode *inode, struct f2fs_inode *ri) diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c index c5b99042e6f2b..727de2f8620f2 100644 --- a/fs/f2fs/namei.c +++ b/fs/f2fs/namei.c @@ -489,6 +489,17 @@ static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry, goto out_iput; } out_splice: +#ifdef CONFIG_UNICODE + if (!inode && IS_CASEFOLDED(dir)) { + /* Eventually we want to call d_add_ci(dentry, NULL) + * for negative dentries in the encoding case as + * well. For now, prevent the negative dentry + * from being cached. + */ + trace_f2fs_lookup_end(dir, dentry, ino, err); + return NULL; + } +#endif new = d_splice_alias(inode, dentry); err = PTR_ERR_OR_ZERO(new); trace_f2fs_lookup_end(dir, dentry, ino, err); @@ -537,6 +548,16 @@ static int f2fs_unlink(struct inode *dir, struct dentry *dentry) goto fail; } f2fs_delete_entry(de, page, dir, inode); +#ifdef CONFIG_UNICODE + /* VFS negative dentries are incompatible with Encoding and + * Case-insensitiveness. Eventually we'll want avoid + * invalidating the dentries here, alongside with returning the + * negative dentries at f2fs_lookup(), when it is better + * supported by the VFS for the CI case. + */ + if (IS_CASEFOLDED(dir)) + d_invalidate(dentry); +#endif f2fs_unlock_op(sbi); if (IS_DIRSYNC(dir)) diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 7927071ef5e95..edc8482a43604 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -3397,6 +3397,11 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent) goto free_node_inode; } +#ifdef CONFIG_UNICODE + if (sbi->s_encoding) + sb->s_d_op = &f2fs_dentry_ops; +#endif + sb->s_root = d_make_root(root); /* allocate root dentry */ if (!sb->s_root) { err = -ENOMEM;
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> --- fs/f2fs/dir.c | 133 ++++++++++++++++++++++++++++++++++++++++++----- fs/f2fs/f2fs.h | 18 +++++-- fs/f2fs/file.c | 10 +++- fs/f2fs/hash.c | 34 +++++++++++- fs/f2fs/inline.c | 6 +-- fs/f2fs/inode.c | 4 +- fs/f2fs/namei.c | 21 ++++++++ fs/f2fs/super.c | 5 ++ 8 files changed, 208 insertions(+), 23 deletions(-)