UBIFS: Implement read-only UBIFS support in U-Boot
The U-Boot UBIFS implementation is largely a direct copy from the current
Linux version (2.6.29-rc6). As already done in the UBI version we have an
"abstraction layer" to redefine or remove some OS calls (e.g. mutex_lock()
...). This makes it possible to use the original Linux code with very
little changes. And by this we can better update to later Linux versions.
I removed some of the Linux features that are not used in the U-Boot
version (e.g. garbage-collection, write support).
Signed-off-by: Stefan Roese <sr@denx.de>
CC: Artem Bityutskiy <dedekind@infradead.org>
CC: Adrian Hunter <ext-Adrian.Hunter@nokia.com>
diff --git a/fs/ubifs/key.h b/fs/ubifs/key.h
new file mode 100644
index 0000000..efb3430
--- /dev/null
+++ b/fs/ubifs/key.h
@@ -0,0 +1,557 @@
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Authors: Artem Bityutskiy (Битюцкий Артём)
+ * Adrian Hunter
+ */
+
+/*
+ * This header contains various key-related definitions and helper function.
+ * UBIFS allows several key schemes, so we access key fields only via these
+ * helpers. At the moment only one key scheme is supported.
+ *
+ * Simple key scheme
+ * ~~~~~~~~~~~~~~~~~
+ *
+ * Keys are 64-bits long. First 32-bits are inode number (parent inode number
+ * in case of direntry key). Next 3 bits are node type. The last 29 bits are
+ * 4KiB offset in case of inode node, and direntry hash in case of a direntry
+ * node. We use "r5" hash borrowed from reiserfs.
+ */
+
+#ifndef __UBIFS_KEY_H__
+#define __UBIFS_KEY_H__
+
+/**
+ * key_mask_hash - mask a valid hash value.
+ * @val: value to be masked
+ *
+ * We use hash values as offset in directories, so values %0 and %1 are
+ * reserved for "." and "..". %2 is reserved for "end of readdir" marker. This
+ * function makes sure the reserved values are not used.
+ */
+static inline uint32_t key_mask_hash(uint32_t hash)
+{
+ hash &= UBIFS_S_KEY_HASH_MASK;
+ if (unlikely(hash <= 2))
+ hash += 3;
+ return hash;
+}
+
+/**
+ * key_r5_hash - R5 hash function (borrowed from reiserfs).
+ * @s: direntry name
+ * @len: name length
+ */
+static inline uint32_t key_r5_hash(const char *s, int len)
+{
+ uint32_t a = 0;
+ const signed char *str = (const signed char *)s;
+
+ while (*str) {
+ a += *str << 4;
+ a += *str >> 4;
+ a *= 11;
+ str++;
+ }
+
+ return key_mask_hash(a);
+}
+
+/**
+ * key_test_hash - testing hash function.
+ * @str: direntry name
+ * @len: name length
+ */
+static inline uint32_t key_test_hash(const char *str, int len)
+{
+ uint32_t a = 0;
+
+ len = min_t(uint32_t, len, 4);
+ memcpy(&a, str, len);
+ return key_mask_hash(a);
+}
+
+/**
+ * ino_key_init - initialize inode key.
+ * @c: UBIFS file-system description object
+ * @key: key to initialize
+ * @inum: inode number
+ */
+static inline void ino_key_init(const struct ubifs_info *c,
+ union ubifs_key *key, ino_t inum)
+{
+ key->u32[0] = inum;
+ key->u32[1] = UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS;
+}
+
+/**
+ * ino_key_init_flash - initialize on-flash inode key.
+ * @c: UBIFS file-system description object
+ * @k: key to initialize
+ * @inum: inode number
+ */
+static inline void ino_key_init_flash(const struct ubifs_info *c, void *k,
+ ino_t inum)
+{
+ union ubifs_key *key = k;
+
+ key->j32[0] = cpu_to_le32(inum);
+ key->j32[1] = cpu_to_le32(UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS);
+ memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
+}
+
+/**
+ * lowest_ino_key - get the lowest possible inode key.
+ * @c: UBIFS file-system description object
+ * @key: key to initialize
+ * @inum: inode number
+ */
+static inline void lowest_ino_key(const struct ubifs_info *c,
+ union ubifs_key *key, ino_t inum)
+{
+ key->u32[0] = inum;
+ key->u32[1] = 0;
+}
+
+/**
+ * highest_ino_key - get the highest possible inode key.
+ * @c: UBIFS file-system description object
+ * @key: key to initialize
+ * @inum: inode number
+ */
+static inline void highest_ino_key(const struct ubifs_info *c,
+ union ubifs_key *key, ino_t inum)
+{
+ key->u32[0] = inum;
+ key->u32[1] = 0xffffffff;
+}
+
+/**
+ * dent_key_init - initialize directory entry key.
+ * @c: UBIFS file-system description object
+ * @key: key to initialize
+ * @inum: parent inode number
+ * @nm: direntry name and length
+ */
+static inline void dent_key_init(const struct ubifs_info *c,
+ union ubifs_key *key, ino_t inum,
+ const struct qstr *nm)
+{
+ uint32_t hash = c->key_hash(nm->name, nm->len);
+
+ ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
+ key->u32[0] = inum;
+ key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS);
+}
+
+/**
+ * dent_key_init_hash - initialize directory entry key without re-calculating
+ * hash function.
+ * @c: UBIFS file-system description object
+ * @key: key to initialize
+ * @inum: parent inode number
+ * @hash: direntry name hash
+ */
+static inline void dent_key_init_hash(const struct ubifs_info *c,
+ union ubifs_key *key, ino_t inum,
+ uint32_t hash)
+{
+ ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
+ key->u32[0] = inum;
+ key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS);
+}
+
+/**
+ * dent_key_init_flash - initialize on-flash directory entry key.
+ * @c: UBIFS file-system description object
+ * @k: key to initialize
+ * @inum: parent inode number
+ * @nm: direntry name and length
+ */
+static inline void dent_key_init_flash(const struct ubifs_info *c, void *k,
+ ino_t inum, const struct qstr *nm)
+{
+ union ubifs_key *key = k;
+ uint32_t hash = c->key_hash(nm->name, nm->len);
+
+ ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
+ key->j32[0] = cpu_to_le32(inum);
+ key->j32[1] = cpu_to_le32(hash |
+ (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS));
+ memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
+}
+
+/**
+ * lowest_dent_key - get the lowest possible directory entry key.
+ * @c: UBIFS file-system description object
+ * @key: where to store the lowest key
+ * @inum: parent inode number
+ */
+static inline void lowest_dent_key(const struct ubifs_info *c,
+ union ubifs_key *key, ino_t inum)
+{
+ key->u32[0] = inum;
+ key->u32[1] = UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS;
+}
+
+/**
+ * xent_key_init - initialize extended attribute entry key.
+ * @c: UBIFS file-system description object
+ * @key: key to initialize
+ * @inum: host inode number
+ * @nm: extended attribute entry name and length
+ */
+static inline void xent_key_init(const struct ubifs_info *c,
+ union ubifs_key *key, ino_t inum,
+ const struct qstr *nm)
+{
+ uint32_t hash = c->key_hash(nm->name, nm->len);
+
+ ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
+ key->u32[0] = inum;
+ key->u32[1] = hash | (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS);
+}
+
+/**
+ * xent_key_init_hash - initialize extended attribute entry key without
+ * re-calculating hash function.
+ * @c: UBIFS file-system description object
+ * @key: key to initialize
+ * @inum: host inode number
+ * @hash: extended attribute entry name hash
+ */
+static inline void xent_key_init_hash(const struct ubifs_info *c,
+ union ubifs_key *key, ino_t inum,
+ uint32_t hash)
+{
+ ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
+ key->u32[0] = inum;
+ key->u32[1] = hash | (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS);
+}
+
+/**
+ * xent_key_init_flash - initialize on-flash extended attribute entry key.
+ * @c: UBIFS file-system description object
+ * @k: key to initialize
+ * @inum: host inode number
+ * @nm: extended attribute entry name and length
+ */
+static inline void xent_key_init_flash(const struct ubifs_info *c, void *k,
+ ino_t inum, const struct qstr *nm)
+{
+ union ubifs_key *key = k;
+ uint32_t hash = c->key_hash(nm->name, nm->len);
+
+ ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
+ key->j32[0] = cpu_to_le32(inum);
+ key->j32[1] = cpu_to_le32(hash |
+ (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS));
+ memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
+}
+
+/**
+ * lowest_xent_key - get the lowest possible extended attribute entry key.
+ * @c: UBIFS file-system description object
+ * @key: where to store the lowest key
+ * @inum: host inode number
+ */
+static inline void lowest_xent_key(const struct ubifs_info *c,
+ union ubifs_key *key, ino_t inum)
+{
+ key->u32[0] = inum;
+ key->u32[1] = UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS;
+}
+
+/**
+ * data_key_init - initialize data key.
+ * @c: UBIFS file-system description object
+ * @key: key to initialize
+ * @inum: inode number
+ * @block: block number
+ */
+static inline void data_key_init(const struct ubifs_info *c,
+ union ubifs_key *key, ino_t inum,
+ unsigned int block)
+{
+ ubifs_assert(!(block & ~UBIFS_S_KEY_BLOCK_MASK));
+ key->u32[0] = inum;
+ key->u32[1] = block | (UBIFS_DATA_KEY << UBIFS_S_KEY_BLOCK_BITS);
+}
+
+/**
+ * data_key_init_flash - initialize on-flash data key.
+ * @c: UBIFS file-system description object
+ * @k: key to initialize
+ * @inum: inode number
+ * @block: block number
+ */
+static inline void data_key_init_flash(const struct ubifs_info *c, void *k,
+ ino_t inum, unsigned int block)
+{
+ union ubifs_key *key = k;
+
+ ubifs_assert(!(block & ~UBIFS_S_KEY_BLOCK_MASK));
+ key->j32[0] = cpu_to_le32(inum);
+ key->j32[1] = cpu_to_le32(block |
+ (UBIFS_DATA_KEY << UBIFS_S_KEY_BLOCK_BITS));
+ memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
+}
+
+/**
+ * trun_key_init - initialize truncation node key.
+ * @c: UBIFS file-system description object
+ * @key: key to initialize
+ * @inum: inode number
+ *
+ * Note, UBIFS does not have truncation keys on the media and this function is
+ * only used for purposes of replay.
+ */
+static inline void trun_key_init(const struct ubifs_info *c,
+ union ubifs_key *key, ino_t inum)
+{
+ key->u32[0] = inum;
+ key->u32[1] = UBIFS_TRUN_KEY << UBIFS_S_KEY_BLOCK_BITS;
+}
+
+/**
+ * key_type - get key type.
+ * @c: UBIFS file-system description object
+ * @key: key to get type of
+ */
+static inline int key_type(const struct ubifs_info *c,
+ const union ubifs_key *key)
+{
+ return key->u32[1] >> UBIFS_S_KEY_BLOCK_BITS;
+}
+
+/**
+ * key_type_flash - get type of a on-flash formatted key.
+ * @c: UBIFS file-system description object
+ * @k: key to get type of
+ */
+static inline int key_type_flash(const struct ubifs_info *c, const void *k)
+{
+ const union ubifs_key *key = k;
+
+ return le32_to_cpu(key->j32[1]) >> UBIFS_S_KEY_BLOCK_BITS;
+}
+
+/**
+ * key_inum - fetch inode number from key.
+ * @c: UBIFS file-system description object
+ * @k: key to fetch inode number from
+ */
+static inline ino_t key_inum(const struct ubifs_info *c, const void *k)
+{
+ const union ubifs_key *key = k;
+
+ return key->u32[0];
+}
+
+/**
+ * key_inum_flash - fetch inode number from an on-flash formatted key.
+ * @c: UBIFS file-system description object
+ * @k: key to fetch inode number from
+ */
+static inline ino_t key_inum_flash(const struct ubifs_info *c, const void *k)
+{
+ const union ubifs_key *key = k;
+
+ return le32_to_cpu(key->j32[0]);
+}
+
+/**
+ * key_hash - get directory entry hash.
+ * @c: UBIFS file-system description object
+ * @key: the key to get hash from
+ */
+static inline int key_hash(const struct ubifs_info *c,
+ const union ubifs_key *key)
+{
+ return key->u32[1] & UBIFS_S_KEY_HASH_MASK;
+}
+
+/**
+ * key_hash_flash - get directory entry hash from an on-flash formatted key.
+ * @c: UBIFS file-system description object
+ * @k: the key to get hash from
+ */
+static inline int key_hash_flash(const struct ubifs_info *c, const void *k)
+{
+ const union ubifs_key *key = k;
+
+ return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_HASH_MASK;
+}
+
+/**
+ * key_block - get data block number.
+ * @c: UBIFS file-system description object
+ * @key: the key to get the block number from
+ */
+static inline unsigned int key_block(const struct ubifs_info *c,
+ const union ubifs_key *key)
+{
+ return key->u32[1] & UBIFS_S_KEY_BLOCK_MASK;
+}
+
+/**
+ * key_block_flash - get data block number from an on-flash formatted key.
+ * @c: UBIFS file-system description object
+ * @k: the key to get the block number from
+ */
+static inline unsigned int key_block_flash(const struct ubifs_info *c,
+ const void *k)
+{
+ const union ubifs_key *key = k;
+
+ return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_BLOCK_MASK;
+}
+
+/**
+ * key_read - transform a key to in-memory format.
+ * @c: UBIFS file-system description object
+ * @from: the key to transform
+ * @to: the key to store the result
+ */
+static inline void key_read(const struct ubifs_info *c, const void *from,
+ union ubifs_key *to)
+{
+ const union ubifs_key *f = from;
+
+ to->u32[0] = le32_to_cpu(f->j32[0]);
+ to->u32[1] = le32_to_cpu(f->j32[1]);
+}
+
+/**
+ * key_write - transform a key from in-memory format.
+ * @c: UBIFS file-system description object
+ * @from: the key to transform
+ * @to: the key to store the result
+ */
+static inline void key_write(const struct ubifs_info *c,
+ const union ubifs_key *from, void *to)
+{
+ union ubifs_key *t = to;
+
+ t->j32[0] = cpu_to_le32(from->u32[0]);
+ t->j32[1] = cpu_to_le32(from->u32[1]);
+ memset(to + 8, 0, UBIFS_MAX_KEY_LEN - 8);
+}
+
+/**
+ * key_write_idx - transform a key from in-memory format for the index.
+ * @c: UBIFS file-system description object
+ * @from: the key to transform
+ * @to: the key to store the result
+ */
+static inline void key_write_idx(const struct ubifs_info *c,
+ const union ubifs_key *from, void *to)
+{
+ union ubifs_key *t = to;
+
+ t->j32[0] = cpu_to_le32(from->u32[0]);
+ t->j32[1] = cpu_to_le32(from->u32[1]);
+}
+
+/**
+ * key_copy - copy a key.
+ * @c: UBIFS file-system description object
+ * @from: the key to copy from
+ * @to: the key to copy to
+ */
+static inline void key_copy(const struct ubifs_info *c,
+ const union ubifs_key *from, union ubifs_key *to)
+{
+ to->u64[0] = from->u64[0];
+}
+
+/**
+ * keys_cmp - compare keys.
+ * @c: UBIFS file-system description object
+ * @key1: the first key to compare
+ * @key2: the second key to compare
+ *
+ * This function compares 2 keys and returns %-1 if @key1 is less than
+ * @key2, %0 if the keys are equivalent and %1 if @key1 is greater than @key2.
+ */
+static inline int keys_cmp(const struct ubifs_info *c,
+ const union ubifs_key *key1,
+ const union ubifs_key *key2)
+{
+ if (key1->u32[0] < key2->u32[0])
+ return -1;
+ if (key1->u32[0] > key2->u32[0])
+ return 1;
+ if (key1->u32[1] < key2->u32[1])
+ return -1;
+ if (key1->u32[1] > key2->u32[1])
+ return 1;
+
+ return 0;
+}
+
+/**
+ * keys_eq - determine if keys are equivalent.
+ * @c: UBIFS file-system description object
+ * @key1: the first key to compare
+ * @key2: the second key to compare
+ *
+ * This function compares 2 keys and returns %1 if @key1 is equal to @key2 and
+ * %0 if not.
+ */
+static inline int keys_eq(const struct ubifs_info *c,
+ const union ubifs_key *key1,
+ const union ubifs_key *key2)
+{
+ if (key1->u32[0] != key2->u32[0])
+ return 0;
+ if (key1->u32[1] != key2->u32[1])
+ return 0;
+ return 1;
+}
+
+/**
+ * is_hash_key - is a key vulnerable to hash collisions.
+ * @c: UBIFS file-system description object
+ * @key: key
+ *
+ * This function returns %1 if @key is a hashed key or %0 otherwise.
+ */
+static inline int is_hash_key(const struct ubifs_info *c,
+ const union ubifs_key *key)
+{
+ int type = key_type(c, key);
+
+ return type == UBIFS_DENT_KEY || type == UBIFS_XENT_KEY;
+}
+
+/**
+ * key_max_inode_size - get maximum file size allowed by current key format.
+ * @c: UBIFS file-system description object
+ */
+static inline unsigned long long key_max_inode_size(const struct ubifs_info *c)
+{
+ switch (c->key_fmt) {
+ case UBIFS_SIMPLE_KEY_FMT:
+ return (1ULL << UBIFS_S_KEY_BLOCK_BITS) * UBIFS_BLOCK_SIZE;
+ default:
+ return 0;
+ }
+}
+#endif /* !__UBIFS_KEY_H__ */