8 files changed, 204 insertions, 20 deletions

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 85a1528f319f..dac07d17cdbd 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,
@@ -93,7 +95,7 @@ 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);
+        make_dentry_ptr_block(dir, &d, dentry_blk);
         de = f2fs_find_target_dentry(fname, namehash, max_slots, &d);
         if (de)
                 *res_page = dentry_page;
@@ -101,6 +103,39 @@ static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
         return de;
 }
 
+#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(struct fscrypt_name *fname,
                         f2fs_hash_t namehash, int *max_slots,
                         struct f2fs_dentry_ptr *d)
@@ -108,6 +143,9 @@ struct f2fs_dir_entry *f2fs_find_target_dentry(struct fscrypt_name *fname,
         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 +157,28 @@ 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(d->inode->i_sb)->s_encoding &&
+                                        IS_CASEFOLDED(d->inode) &&
+                                        !f2fs_ci_compare(d->inode,
+                                                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 (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 +207,7 @@ 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 +229,8 @@ 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;
 
@@ -250,6 +300,14 @@ struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
         struct fscrypt_name fname;
         int err;
 
+#ifdef CONFIG_UNICODE
+        if (f2fs_has_strict_mode(F2FS_I_SB(dir)) && IS_CASEFOLDED(dir) &&
+                        utf8_validate(F2FS_I_SB(dir)->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 +562,7 @@ 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 +1001,50 @@ 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)
+{
+        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 = f2fs_kmalloc(sbi, 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:
+        kvfree(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 dd69e1559839..3f57ab6c9137 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2367,13 +2367,16 @@ 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))
+#define F2FS_REG_FLMASK         (~(F2FS_DIRSYNC_FL | F2FS_PROJINHERIT_FL | \
+                                F2FS_CASEFOLD_FL))
 
 /* Flags that are appropriate for non-directories/regular files. */
 #define F2FS_OTHER_FLMASK       (F2FS_NODUMP_FL | F2FS_NOATIME_FL)
@@ -2933,6 +2936,10 @@ 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
  */
@@ -2996,8 +3003,8 @@ 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
@@ -3440,6 +3447,9 @@ 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 a5080bea6b0b..103636c52206 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1664,6 +1664,13 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask)
         if (IS_NOQUOTA(inode))
                 return -EPERM;
 
+        if ((iflags ^ fi->i_flags) & F2FS_CASEFOLD_FL) {
+                if (!f2fs_sb_has_casefold(F2FS_I_SB(inode)))
+                        return -EOPNOTSUPP;
+                if (!f2fs_empty_dir(inode))
+                        return -ENOTEMPTY;
+        }
+
         fi->i_flags = iflags | (fi->i_flags & ~mask);
 
         if (fi->i_flags & F2FS_PROJINHERIT_FL)
@@ -1698,6 +1705,7 @@ static const struct {
         { F2FS_INDEX_FL,        FS_INDEX_FL },
         { F2FS_DIRSYNC_FL,      FS_DIRSYNC_FL },
         { F2FS_PROJINHERIT_FL,  FS_PROJINHERIT_FL },
+        { F2FS_CASEFOLD_FL,     FS_CASEFOLD_FL },
 };
 
 #define F2FS_GETTABLE_FS_FL (           \
@@ -1711,7 +1719,8 @@ static const struct {
                 FS_PROJINHERIT_FL |     \
                 FS_ENCRYPT_FL |         \
                 FS_INLINE_DATA_FL |     \
-                FS_NOCOW_FL)
+                FS_NOCOW_FL |           \
+                FS_CASEFOLD_FL)
 
 #define F2FS_SETTABLE_FS_FL (           \
                 FS_SYNC_FL |            \
@@ -1720,7 +1729,8 @@ static const struct {
                 FS_NODUMP_FL |          \
                 FS_NOATIME_FL |         \
                 FS_DIRSYNC_FL |         \
-                FS_PROJINHERIT_FL)
+                FS_PROJINHERIT_FL |     \
+                FS_CASEFOLD_FL)
 
 /* Convert f2fs on-disk i_flags to FS_IOC_{GET,SET}FLAGS flags */
 static inline u32 f2fs_iflags_to_fsflags(u32 iflags)
diff --git a/fs/f2fs/hash.c b/fs/f2fs/hash.c
index cc82f142f811..5bc4dcd8fc03 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 +104,37 @@ 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
+        struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
+        const struct unicode_map *um = sbi->s_encoding;
+        int r, dlen;
+        unsigned char *buff;
+        struct qstr folded;
+
+        if (!name_info->len || !IS_CASEFOLDED(dir))
+                goto opaque_seq;
+
+        buff = f2fs_kzalloc(sbi, sizeof(char) * PATH_MAX, GFP_KERNEL);
+        if (!buff)
+                return -ENOMEM;
+
+        dlen = utf8_casefold(um, name_info, buff, PATH_MAX);
+        if (dlen < 0) {
+                kvfree(buff);
+                goto opaque_seq;
+        }
+        folded.name = buff;
+        folded.len = dlen;
+        r = __f2fs_dentry_hash(&folded, fname);
+
+        kvfree(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 8c0712154fb1..78d6ebe165cd 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -320,7 +320,7 @@ 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);
 
@@ -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 d1998ddf14fd..5d78f2db7a67 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 7560c7ed38b1..9a28c5d9b3e9 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 8bebee8e0186..3435c8bccf3e 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -3152,6 +3152,7 @@ static int f2fs_setup_casefold(struct f2fs_sb_info *sbi)
 
                 sbi->s_encoding = encoding;
                 sbi->s_encoding_flags = encoding_flags;
+                sbi->sb->s_d_op = &f2fs_dentry_ops;
         }
 #else
         if (f2fs_sb_has_casefold(sbi)) {