Update to v4.1-rc2 and update to latest crypto changes
[ext4-patch-queue.git] / reorganize-fname-crypto
blob999e33df030189ddb31dc28a524dfaa9be00773c
1 ext4 crypto: reorganize how we store keys in the inode
3 This is a pretty massive patch which does a number of different things:
5 1) The per-inode encryption information is now stored in an allocated
6    data structure, ext4_crypt_info, instead of directly in the node.
7    This reduces the size usage of an in-memory inode when it is not
8    using encryption.
10 2) We drop the ext4_fname_crypto_ctx entirely, and use the per-inode
11    encryption structure instead.  This remove an unnecessary memory
12    allocation and free for the fname_crypto_ctx as well as allowing us
13    to reuse the ctfm in a directory for multiple lookups and file
14    creations.
16 3) We also cache the inode's policy information in the ext4_crypt_info
17    structure so we don't have to continually read it out of the
18    extended attributes.
20 4) We now keep the keyring key in the inode's encryption structure
21    instead of releasing it after we are done using it to derive the
22    per-inode key.  This allows us to test to see if the key has been
23    revoked; if it has, we prevent the use of the derived key and free
24    it.
26 5) When an inode is released (or when the derived key is freed), we
27    will use memset_explicit() to zero out the derived key, so it's not
28    left hanging around in memory.  This implies that when a user logs
29    out, it is important to first revoke the key, and then unlink it,
30    and then finally, to use "echo 3 > /proc/sys/vm/drop_caches" to
31    release any decrypted pages and dcache entries from the system
32    caches.
34 6) All this, and we also shrink the number of lines of code by around
35    100.  :-)
37 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
38 ---
39  fs/ext4/crypto.c        |   9 ++-
40  fs/ext4/crypto_fname.c  | 284 +++++++++++++++++++----------------------------------------------------
41  fs/ext4/crypto_key.c    |  74 ++++++++++++++-----
42  fs/ext4/crypto_policy.c |  76 ++++++++++---------
43  fs/ext4/dir.c           |  21 ++----
44  fs/ext4/ext4.h          |  40 ++++++----
45  fs/ext4/ext4_crypto.h   |  16 ++--
46  fs/ext4/file.c          |   4 +-
47  fs/ext4/namei.c         |  42 ++++-------
48  fs/ext4/super.c         |   5 +-
49  fs/ext4/symlink.c       |  15 ++--
50  11 files changed, 240 insertions(+), 346 deletions(-)
52 diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
53 index 918200e..3a25aa4 100644
54 --- a/fs/ext4/crypto.c
55 +++ b/fs/ext4/crypto.c
56 @@ -118,8 +118,9 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode)
57         struct ext4_crypto_ctx *ctx = NULL;
58         int res = 0;
59         unsigned long flags;
60 -       struct ext4_crypt_info *ci = &EXT4_I(inode)->i_crypt_info;
61 +       struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
63 +       BUG_ON(ci == NULL);
64         if (!ext4_read_workqueue)
65                 ext4_init_crypto();
67 @@ -322,7 +323,7 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx,
68         int res = 0;
70         BUG_ON(!ctx->tfm);
71 -       BUG_ON(ctx->mode != ei->i_crypt_info.ci_mode);
72 +       BUG_ON(ctx->mode != ei->i_crypt_info->ci_mode);
74         if (ctx->mode != EXT4_ENCRYPTION_MODE_AES_256_XTS) {
75                 printk_ratelimited(KERN_ERR
76 @@ -334,8 +335,8 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx,
77         crypto_ablkcipher_clear_flags(atfm, ~0);
78         crypto_tfm_set_flags(ctx->tfm, CRYPTO_TFM_REQ_WEAK_KEY);
80 -       res = crypto_ablkcipher_setkey(atfm, ei->i_crypt_info.ci_raw,
81 -                                      ei->i_crypt_info.ci_size);
82 +       res = crypto_ablkcipher_setkey(atfm, ei->i_crypt_info->ci_raw,
83 +                                      ei->i_crypt_info->ci_size);
84         if (res) {
85                 printk_ratelimited(KERN_ERR
86                                    "%s: crypto_ablkcipher_setkey() failed\n",
87 diff --git a/fs/ext4/crypto_fname.c b/fs/ext4/crypto_fname.c
88 index d9f08dd..374d0e7 100644
89 --- a/fs/ext4/crypto_fname.c
90 +++ b/fs/ext4/crypto_fname.c
91 @@ -48,6 +48,12 @@ bool ext4_valid_filenames_enc_mode(uint32_t mode)
92         return (mode == EXT4_ENCRYPTION_MODE_AES_256_CTS);
93  }
95 +static unsigned max_name_len(struct inode *inode)
97 +       return S_ISLNK(inode->i_mode) ? inode->i_sb->s_blocksize :
98 +               EXT4_NAME_LEN;
101  /**
102   * ext4_fname_encrypt() -
103   *
104 @@ -55,28 +61,30 @@ bool ext4_valid_filenames_enc_mode(uint32_t mode)
105   * ciphertext. Errors are returned as negative numbers.  We trust the caller to
106   * allocate sufficient memory to oname string.
107   */
108 -static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
109 +static int ext4_fname_encrypt(struct inode *inode,
110                               const struct qstr *iname,
111                               struct ext4_str *oname)
113         u32 ciphertext_len;
114         struct ablkcipher_request *req = NULL;
115         DECLARE_EXT4_COMPLETION_RESULT(ecr);
116 -       struct crypto_ablkcipher *tfm = ctx->ctfm;
117 +       struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
118 +       struct crypto_ablkcipher *tfm = ci->ci_ctfm;
119         int res = 0;
120         char iv[EXT4_CRYPTO_BLOCK_SIZE];
121         struct scatterlist src_sg, dst_sg;
122 -       int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK);
123 +       int padding = 4 << (ci->ci_flags & EXT4_POLICY_FLAGS_PAD_MASK);
124         char *workbuf, buf[32], *alloc_buf = NULL;
125 +       unsigned lim = max_name_len(inode);
127 -       if (iname->len <= 0 || iname->len > ctx->lim)
128 +       if (iname->len <= 0 || iname->len > lim)
129                 return -EIO;
131         ciphertext_len = (iname->len < EXT4_CRYPTO_BLOCK_SIZE) ?
132                 EXT4_CRYPTO_BLOCK_SIZE : iname->len;
133         ciphertext_len = ext4_fname_crypto_round_up(ciphertext_len, padding);
134 -       ciphertext_len = (ciphertext_len > ctx->lim)
135 -                       ? ctx->lim : ciphertext_len;
136 +       ciphertext_len = (ciphertext_len > lim)
137 +                       ? lim : ciphertext_len;
139         if (ciphertext_len <= sizeof(buf)) {
140                 workbuf = buf;
141 @@ -134,7 +142,7 @@ static int ext4_fname_encrypt(struct ext4_fname_crypto_ctx *ctx,
142   *     Errors are returned as negative numbers.
143   *     We trust the caller to allocate sufficient memory to oname string.
144   */
145 -static int ext4_fname_decrypt(struct ext4_fname_crypto_ctx *ctx,
146 +static int ext4_fname_decrypt(struct inode *inode,
147                               const struct ext4_str *iname,
148                               struct ext4_str *oname)
150 @@ -142,11 +150,13 @@ static int ext4_fname_decrypt(struct ext4_fname_crypto_ctx *ctx,
151         struct ablkcipher_request *req = NULL;
152         DECLARE_EXT4_COMPLETION_RESULT(ecr);
153         struct scatterlist src_sg, dst_sg;
154 -       struct crypto_ablkcipher *tfm = ctx->ctfm;
155 +       struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
156 +       struct crypto_ablkcipher *tfm = ci->ci_ctfm;
157         int res = 0;
158         char iv[EXT4_CRYPTO_BLOCK_SIZE];
159 +       unsigned lim = max_name_len(inode);
161 -       if (iname->len <= 0 || iname->len > ctx->lim)
162 +       if (iname->len <= 0 || iname->len > lim)
163                 return -EIO;
165         tmp_in[0].name = iname->name;
166 @@ -242,171 +252,50 @@ static int digest_decode(const char *src, int len, char *dst)
167         return cp - dst;
170 -/**
171 - * ext4_free_fname_crypto_ctx() -
172 - *
173 - * Frees up a crypto context.
174 - */
175 -void ext4_free_fname_crypto_ctx(struct ext4_fname_crypto_ctx *ctx)
177 -       if (ctx == NULL || IS_ERR(ctx))
178 -               return;
180 -       if (ctx->ctfm && !IS_ERR(ctx->ctfm))
181 -               crypto_free_ablkcipher(ctx->ctfm);
182 -       if (ctx->htfm && !IS_ERR(ctx->htfm))
183 -               crypto_free_hash(ctx->htfm);
184 -       kfree(ctx);
187 -/**
188 - * ext4_put_fname_crypto_ctx() -
189 - *
190 - * Return: The crypto context onto free list. If the free list is above a
191 - * threshold, completely frees up the context, and returns the memory.
192 - *
193 - * TODO: Currently we directly free the crypto context. Eventually we should
194 - * add code it to return to free list. Such an approach will increase
195 - * efficiency of directory lookup.
196 - */
197 -void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx)
198 +int ext4_setup_fname_crypto(struct inode *inode)
200 -       if (*ctx == NULL || IS_ERR(*ctx))
201 -               return;
202 -       ext4_free_fname_crypto_ctx(*ctx);
203 -       *ctx = NULL;
206 -/**
207 - * ext4_alloc_fname_crypto_ctx() -
208 - */
209 -struct ext4_fname_crypto_ctx *ext4_alloc_fname_crypto_ctx(
210 -       const struct ext4_crypt_info *ci)
212 -       struct ext4_fname_crypto_ctx *ctx;
214 -       ctx = kmalloc(sizeof(struct ext4_fname_crypto_ctx), GFP_NOFS);
215 -       if (ctx == NULL)
216 -               return ERR_PTR(-ENOMEM);
217 -       if (ci->ci_mode == EXT4_ENCRYPTION_MODE_INVALID) {
218 -               /* This will automatically set key mode to invalid
219 -                * As enum for ENCRYPTION_MODE_INVALID is zero */
220 -               memset(&ctx->ci, 0, sizeof(ctx->ci));
221 -       } else {
222 -               memcpy(&ctx->ci, ci, sizeof(struct ext4_crypt_info));
223 -       }
224 -       ctx->has_valid_key = (EXT4_ENCRYPTION_MODE_INVALID == ci->ci_mode)
225 -               ? 0 : 1;
226 -       ctx->ctfm_key_is_ready = 0;
227 -       ctx->ctfm = NULL;
228 -       ctx->htfm = NULL;
229 -       return ctx;
232 -/**
233 - * ext4_get_fname_crypto_ctx() -
234 - *
235 - * Allocates a free crypto context and initializes it to hold
236 - * the crypto material for the inode.
237 - *
238 - * Return: NULL if not encrypted. Error value on error. Valid pointer otherwise.
239 - */
240 -struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(
241 -       struct inode *inode, u32 max_ciphertext_len)
243 -       struct ext4_fname_crypto_ctx *ctx;
244         struct ext4_inode_info *ei = EXT4_I(inode);
245 +       struct ext4_crypt_info *ci = ei->i_crypt_info;
246 +       struct crypto_ablkcipher *ctfm;
247         int res;
249         /* Check if the crypto policy is set on the inode */
250         res = ext4_encrypted_inode(inode);
251         if (res == 0)
252 -               return NULL;
254 -       if (!ext4_has_encryption_key(inode))
255 -               ext4_generate_encryption_key(inode);
257 -       /* Get a crypto context based on the key. */
258 -       ctx = ext4_alloc_fname_crypto_ctx(&(ei->i_crypt_info));
259 -       if (IS_ERR(ctx))
260 -               return ctx;
262 -       ctx->flags = ei->i_crypt_policy_flags;
263 -       if (ctx->has_valid_key) {
264 -               if (ctx->ci.ci_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) {
265 -                       printk_once(KERN_WARNING
266 -                                   "ext4: unsupported key mode %d\n",
267 -                                   ctx->ci.ci_mode);
268 -                       return ERR_PTR(-ENOKEY);
269 -               }
270 +               return 0;
272 -               /* As a first cut, we will allocate new tfm in every call.
273 -                * later, we will keep the tfm around, in case the key gets
274 -                * re-used */
275 -               if (ctx->ctfm == NULL) {
276 -                       ctx->ctfm = crypto_alloc_ablkcipher("cts(cbc(aes))",
277 -                                       0, 0);
278 -               }
279 -               if (IS_ERR(ctx->ctfm)) {
280 -                       res = PTR_ERR(ctx->ctfm);
281 -                       printk(
282 -                           KERN_DEBUG "%s: error (%d) allocating crypto tfm\n",
283 -                           __func__, res);
284 -                       ctx->ctfm = NULL;
285 -                       ext4_put_fname_crypto_ctx(&ctx);
286 -                       return ERR_PTR(res);
287 -               }
288 -               if (ctx->ctfm == NULL) {
289 -                       printk(
290 -                           KERN_DEBUG "%s: could not allocate crypto tfm\n",
291 -                           __func__);
292 -                       ext4_put_fname_crypto_ctx(&ctx);
293 -                       return ERR_PTR(-ENOMEM);
294 -               }
295 -               ctx->lim = max_ciphertext_len;
296 -               crypto_ablkcipher_clear_flags(ctx->ctfm, ~0);
297 -               crypto_tfm_set_flags(crypto_ablkcipher_tfm(ctx->ctfm),
298 -                       CRYPTO_TFM_REQ_WEAK_KEY);
300 -               /* If we are lucky, we will get a context that is already
301 -                * set up with the right key. Else, we will have to
302 -                * set the key */
303 -               if (!ctx->ctfm_key_is_ready) {
304 -                       /* Since our crypto objectives for filename encryption
305 -                        * are pretty weak,
306 -                        * we directly use the inode master key */
307 -                       res = crypto_ablkcipher_setkey(ctx->ctfm,
308 -                                       ctx->ci.ci_raw, ctx->ci.ci_size);
309 -                       if (res) {
310 -                               ext4_put_fname_crypto_ctx(&ctx);
311 -                               return ERR_PTR(-EIO);
312 -                       }
313 -                       ctx->ctfm_key_is_ready = 1;
314 -               } else {
315 -                       /* In the current implementation, key should never be
316 -                        * marked "ready" for a context that has just been
317 -                        * allocated. So we should never reach here */
318 -                        BUG();
319 -               }
320 -       }
321 -       if (ctx->htfm == NULL)
322 -               ctx->htfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
323 -       if (IS_ERR(ctx->htfm)) {
324 -               res = PTR_ERR(ctx->htfm);
325 -               printk(KERN_DEBUG "%s: error (%d) allocating hash tfm\n",
326 -                       __func__, res);
327 -               ctx->htfm = NULL;
328 -               ext4_put_fname_crypto_ctx(&ctx);
329 -               return ERR_PTR(res);
330 +       res = ext4_get_encryption_info(inode);
331 +       if (res < 0)
332 +               return res;
333 +       ci = ei->i_crypt_info;
335 +       if (!ci || ci->ci_ctfm)
336 +               return 0;
338 +       if (ci->ci_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) {
339 +               printk_once(KERN_WARNING "ext4: unsupported key mode %d\n",
340 +                           ci->ci_mode);
341 +               return -ENOKEY;
342         }
343 -       if (ctx->htfm == NULL) {
344 -               printk(KERN_DEBUG "%s: could not allocate hash tfm\n",
345 -                               __func__);
346 -               ext4_put_fname_crypto_ctx(&ctx);
347 -               return ERR_PTR(-ENOMEM);
349 +       ctfm = crypto_alloc_ablkcipher("cts(cbc(aes))", 0, 0);
350 +       if (!ctfm || IS_ERR(ctfm)) {
351 +               res = ctfm ? PTR_ERR(ctfm) : -ENOMEM;
352 +               printk(KERN_DEBUG "%s: error (%d) allocating crypto tfm\n",
353 +                      __func__, res);
354 +               return res;
355         }
356 +       crypto_ablkcipher_clear_flags(ctfm, ~0);
357 +       crypto_tfm_set_flags(crypto_ablkcipher_tfm(ctfm),
358 +                            CRYPTO_TFM_REQ_WEAK_KEY);
360 -       return ctx;
361 +       res = crypto_ablkcipher_setkey(ctfm, ci->ci_raw, ci->ci_size);
362 +       if (res) {
363 +               crypto_free_ablkcipher(ctfm);
364 +               return -EIO;
365 +       }
366 +       ci->ci_ctfm = ctfm;
367 +       return 0;
370  /**
371 @@ -420,40 +309,20 @@ u32 ext4_fname_crypto_round_up(u32 size, u32 blksize)
374  /**
375 - * ext4_fname_crypto_namelen_on_disk() -
376 - */
377 -int ext4_fname_crypto_namelen_on_disk(struct ext4_fname_crypto_ctx *ctx,
378 -                                     u32 namelen)
380 -       u32 ciphertext_len;
381 -       int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK);
383 -       if (ctx == NULL)
384 -               return -EIO;
385 -       if (!(ctx->has_valid_key))
386 -               return -EACCES;
387 -       ciphertext_len = (namelen < EXT4_CRYPTO_BLOCK_SIZE) ?
388 -               EXT4_CRYPTO_BLOCK_SIZE : namelen;
389 -       ciphertext_len = ext4_fname_crypto_round_up(ciphertext_len, padding);
390 -       ciphertext_len = (ciphertext_len > ctx->lim)
391 -                       ? ctx->lim : ciphertext_len;
392 -       return (int) ciphertext_len;
395 -/**
396   * ext4_fname_crypto_alloc_obuff() -
397   *
398   * Allocates an output buffer that is sufficient for the crypto operation
399   * specified by the context and the direction.
400   */
401 -int ext4_fname_crypto_alloc_buffer(struct ext4_fname_crypto_ctx *ctx,
402 +int ext4_fname_crypto_alloc_buffer(struct inode *inode,
403                                    u32 ilen, struct ext4_str *crypto_str)
405         unsigned int olen;
406 -       int padding = 4 << (ctx->flags & EXT4_POLICY_FLAGS_PAD_MASK);
407 +       int padding = 16;
408 +       struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
410 -       if (!ctx)
411 -               return -EIO;
412 +       if (ci)
413 +               padding = 4 << (ci->ci_flags & EXT4_POLICY_FLAGS_PAD_MASK);
414         if (padding < EXT4_CRYPTO_BLOCK_SIZE)
415                 padding = EXT4_CRYPTO_BLOCK_SIZE;
416         olen = ext4_fname_crypto_round_up(ilen, padding);
417 @@ -484,7 +353,7 @@ void ext4_fname_crypto_free_buffer(struct ext4_str *crypto_str)
418  /**
419   * ext4_fname_disk_to_usr() - converts a filename from disk space to user space
420   */
421 -int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
422 +int _ext4_fname_disk_to_usr(struct inode *inode,
423                             struct dx_hash_info *hinfo,
424                             const struct ext4_str *iname,
425                             struct ext4_str *oname)
426 @@ -492,8 +361,6 @@ int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
427         char buf[24];
428         int ret;
430 -       if (ctx == NULL)
431 -               return -EIO;
432         if (iname->len < 3) {
433                 /*Check for . and .. */
434                 if (iname->name[0] == '.' && iname->name[iname->len-1] == '.') {
435 @@ -503,8 +370,8 @@ int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
436                         return oname->len;
437                 }
438         }
439 -       if (ctx->has_valid_key)
440 -               return ext4_fname_decrypt(ctx, iname, oname);
441 +       if (EXT4_I(inode)->i_crypt_info)
442 +               return ext4_fname_decrypt(inode, iname, oname);
444         if (iname->len <= EXT4_FNAME_CRYPTO_DIGEST_SIZE) {
445                 ret = digest_encode(iname->name, iname->len, oname->name);
446 @@ -523,7 +390,7 @@ int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
447         return ret + 1;
450 -int ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
451 +int ext4_fname_disk_to_usr(struct inode *inode,
452                            struct dx_hash_info *hinfo,
453                            const struct ext4_dir_entry_2 *de,
454                            struct ext4_str *oname)
455 @@ -531,21 +398,20 @@ int ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
456         struct ext4_str iname = {.name = (unsigned char *) de->name,
457                                  .len = de->name_len };
459 -       return _ext4_fname_disk_to_usr(ctx, hinfo, &iname, oname);
460 +       return _ext4_fname_disk_to_usr(inode, hinfo, &iname, oname);
464  /**
465   * ext4_fname_usr_to_disk() - converts a filename from user space to disk space
466   */
467 -int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
468 +int ext4_fname_usr_to_disk(struct inode *inode,
469                            const struct qstr *iname,
470                            struct ext4_str *oname)
472         int res;
473 +       struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
475 -       if (ctx == NULL)
476 -               return -EIO;
477         if (iname->len < 3) {
478                 /*Check for . and .. */
479                 if (iname->name[0] == '.' &&
480 @@ -556,8 +422,8 @@ int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
481                         return oname->len;
482                 }
483         }
484 -       if (ctx->has_valid_key) {
485 -               res = ext4_fname_encrypt(ctx, iname, oname);
486 +       if (ci) {
487 +               res = ext4_fname_encrypt(inode, iname, oname);
488                 return res;
489         }
490         /* Without a proper key, a user is not allowed to modify the filenames
491 @@ -569,16 +435,13 @@ int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
492  int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
493                               int lookup, struct ext4_filename *fname)
495 -       struct ext4_fname_crypto_ctx *ctx;
496 +       struct ext4_crypt_info *ci;
497         int ret = 0, bigname = 0;
499         memset(fname, 0, sizeof(struct ext4_filename));
500         fname->usr_fname = iname;
502 -       ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
503 -       if (IS_ERR(ctx))
504 -               return PTR_ERR(ctx);
505 -       if ((ctx == NULL) ||
506 +       if (!ext4_encrypted_inode(dir) ||
507             ((iname->name[0] == '.') &&
508              ((iname->len == 1) ||
509               ((iname->name[1] == '.') && (iname->len == 2))))) {
510 @@ -586,12 +449,16 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
511                 fname->disk_name.len = iname->len;
512                 goto out;
513         }
514 -       if (ctx->has_valid_key) {
515 -               ret = ext4_fname_crypto_alloc_buffer(ctx, iname->len,
516 +       ret = ext4_setup_fname_crypto(dir);
517 +       if (ret)
518 +               return ret;
519 +       ci = EXT4_I(dir)->i_crypt_info;
520 +       if (ci) {
521 +               ret = ext4_fname_crypto_alloc_buffer(dir, iname->len,
522                                                      &fname->crypto_buf);
523                 if (ret < 0)
524                         goto out;
525 -               ret = ext4_fname_encrypt(ctx, iname, &fname->crypto_buf);
526 +               ret = ext4_fname_encrypt(dir, iname, &fname->crypto_buf);
527                 if (ret < 0)
528                         goto out;
529                 fname->disk_name.name = fname->crypto_buf.name;
530 @@ -634,7 +501,6 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
531         }
532         ret = 0;
533  out:
534 -       ext4_put_fname_crypto_ctx(&ctx);
535         return ret;
538 diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c
539 index ec6635d..0075e43 100644
540 --- a/fs/ext4/crypto_key.c
541 +++ b/fs/ext4/crypto_key.c
542 @@ -84,14 +84,26 @@ out:
543         return res;
546 -/**
547 - * ext4_generate_encryption_key() - generates an encryption key
548 - * @inode: The inode to generate the encryption key for.
549 - */
550 -int ext4_generate_encryption_key(struct inode *inode)
551 +void ext4_free_encryption_info(struct inode *inode)
553 +       struct ext4_inode_info *ei = EXT4_I(inode);
554 +       struct ext4_crypt_info *ci = ei->i_crypt_info;
556 +       if (!ci)
557 +               return;
559 +       if (ci->ci_keyring_key)
560 +               key_put(ci->ci_keyring_key);
561 +       crypto_free_ablkcipher(ci->ci_ctfm);
562 +       memzero_explicit(&ci->ci_raw, sizeof(ci->ci_raw));
563 +       kfree(ci);
564 +       ei->i_crypt_info = NULL;
567 +int _ext4_get_encryption_info(struct inode *inode)
569         struct ext4_inode_info *ei = EXT4_I(inode);
570 -       struct ext4_crypt_info *crypt_info = &ei->i_crypt_info;
571 +       struct ext4_crypt_info *crypt_info;
572         char full_key_descriptor[EXT4_KEY_DESC_PREFIX_SIZE +
573                                  (EXT4_KEY_DESCRIPTOR_SIZE * 2) + 1];
574         struct key *keyring_key = NULL;
575 @@ -99,18 +111,40 @@ int ext4_generate_encryption_key(struct inode *inode)
576         struct ext4_encryption_context ctx;
577         struct user_key_payload *ukp;
578         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
579 -       int res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
580 -                                EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
581 -                                &ctx, sizeof(ctx));
582 +       int res;
584 -       if (res != sizeof(ctx)) {
585 -               if (res > 0)
586 -                       res = -EINVAL;
587 -               goto out;
588 +       if (ei->i_crypt_info) {
589 +               if (!ei->i_crypt_info->ci_keyring_key ||
590 +                   key_validate(ei->i_crypt_info->ci_keyring_key) == 0)
591 +                       return 0;
592 +               ext4_free_encryption_info(inode);
593         }
595 +       res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
596 +                                EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
597 +                                &ctx, sizeof(ctx));
598 +       if (res < 0) {
599 +               if (!DUMMY_ENCRYPTION_ENABLED(sbi))
600 +                       return res;
601 +               ctx.contents_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_XTS;
602 +               ctx.filenames_encryption_mode =
603 +                       EXT4_ENCRYPTION_MODE_AES_256_CTS;
604 +               ctx.flags = 0;
605 +       } else if (res != sizeof(ctx))
606 +               return -EINVAL;
607         res = 0;
609 +       crypt_info = kmalloc(sizeof(struct ext4_crypt_info), GFP_KERNEL);
610 +       if (!crypt_info)
611 +               return -ENOMEM;
613         ei->i_crypt_policy_flags = ctx.flags;
614 +       crypt_info->ci_flags = ctx.flags;
615 +       crypt_info->ci_data_mode = ctx.contents_encryption_mode;
616 +       crypt_info->ci_filename_mode = ctx.filenames_encryption_mode;
617 +       crypt_info->ci_ctfm = NULL;
618 +       memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
619 +              sizeof(crypt_info->ci_master_key));
620         if (S_ISREG(inode->i_mode))
621                 crypt_info->ci_mode = ctx.contents_encryption_mode;
622         else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
623 @@ -151,17 +185,23 @@ int ext4_generate_encryption_key(struct inode *inode)
624         res = ext4_derive_key_aes(ctx.nonce, master_key->raw,
625                                   crypt_info->ci_raw);
626  out:
627 +       if (res < 0) {
628 +               if (res == -ENOKEY)
629 +                       res = 0;
630 +               kfree(crypt_info);
631 +       } else {
632 +               ei->i_crypt_info = crypt_info;
633 +               crypt_info->ci_keyring_key = keyring_key;
634 +               keyring_key = NULL;
635 +       }
636         if (keyring_key)
637                 key_put(keyring_key);
638 -       if (res < 0)
639 -               crypt_info->ci_mode = EXT4_ENCRYPTION_MODE_INVALID;
640         return res;
643  int ext4_has_encryption_key(struct inode *inode)
645         struct ext4_inode_info *ei = EXT4_I(inode);
646 -       struct ext4_crypt_info *crypt_info = &ei->i_crypt_info;
648 -       return (crypt_info->ci_mode != EXT4_ENCRYPTION_MODE_INVALID);
649 +       return (ei->i_crypt_info != NULL);
651 diff --git a/fs/ext4/crypto_policy.c b/fs/ext4/crypto_policy.c
652 index a6d6291..370d3aa 100644
653 --- a/fs/ext4/crypto_policy.c
654 +++ b/fs/ext4/crypto_policy.c
655 @@ -126,7 +126,7 @@ int ext4_get_policy(struct inode *inode, struct ext4_encryption_policy *policy)
656  int ext4_is_child_context_consistent_with_parent(struct inode *parent,
657                                                  struct inode *child)
659 -       struct ext4_encryption_context parent_ctx, child_ctx;
660 +       struct ext4_crypt_info *parent_ci, *child_ci;
661         int res;
663         if ((parent == NULL) || (child == NULL)) {
664 @@ -136,26 +136,28 @@ int ext4_is_child_context_consistent_with_parent(struct inode *parent,
665         /* no restrictions if the parent directory is not encrypted */
666         if (!ext4_encrypted_inode(parent))
667                 return 1;
668 -       res = ext4_xattr_get(parent, EXT4_XATTR_INDEX_ENCRYPTION,
669 -                            EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
670 -                            &parent_ctx, sizeof(parent_ctx));
671 -       if (res != sizeof(parent_ctx))
672 -               return 0;
673         /* if the child directory is not encrypted, this is always a problem */
674         if (!ext4_encrypted_inode(child))
675                 return 0;
676 -       res = ext4_xattr_get(child, EXT4_XATTR_INDEX_ENCRYPTION,
677 -                            EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
678 -                            &child_ctx, sizeof(child_ctx));
679 -       if (res != sizeof(child_ctx))
680 +       res = ext4_get_encryption_info(parent);
681 +       if (res)
682 +               return 0;
683 +       res = ext4_get_encryption_info(child);
684 +       if (res)
685 +               return 0;
686 +       parent_ci = EXT4_I(parent)->i_crypt_info;
687 +       child_ci = EXT4_I(child)->i_crypt_info;
688 +       if (!parent_ci && !child_ci)
689 +               return 1;
690 +       if (!parent_ci || !child_ci)
691                 return 0;
692 -       return (memcmp(parent_ctx.master_key_descriptor,
693 -                      child_ctx.master_key_descriptor,
695 +       return (memcmp(parent_ci->ci_master_key,
696 +                      child_ci->ci_master_key,
697                        EXT4_KEY_DESCRIPTOR_SIZE) == 0 &&
698 -               (parent_ctx.contents_encryption_mode ==
699 -                child_ctx.contents_encryption_mode) &&
700 -               (parent_ctx.filenames_encryption_mode ==
701 -                child_ctx.filenames_encryption_mode));
702 +               (parent_ci->ci_data_mode == child_ci->ci_data_mode) &&
703 +               (parent_ci->ci_filename_mode == child_ci->ci_filename_mode) &&
704 +               (parent_ci->ci_flags == child_ci->ci_flags));
707  /**
708 @@ -168,31 +170,37 @@ int ext4_is_child_context_consistent_with_parent(struct inode *parent,
709  int ext4_inherit_context(struct inode *parent, struct inode *child)
711         struct ext4_encryption_context ctx;
712 -       int res = ext4_xattr_get(parent, EXT4_XATTR_INDEX_ENCRYPTION,
713 -                                EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
714 -                                &ctx, sizeof(ctx));
715 +       struct ext4_crypt_info *ci;
716 +       int res;
718 +       res = ext4_get_encryption_info(parent);
719 +       if (res < 0)
720 +               return res;
721 +       ci = EXT4_I(parent)->i_crypt_info;
722 +       BUG_ON(ci == NULL);
724 -       if (res != sizeof(ctx)) {
725 -               if (DUMMY_ENCRYPTION_ENABLED(EXT4_SB(parent->i_sb))) {
726 -                       ctx.format = EXT4_ENCRYPTION_CONTEXT_FORMAT_V1;
727 -                       ctx.contents_encryption_mode =
728 -                               EXT4_ENCRYPTION_MODE_AES_256_XTS;
729 -                       ctx.filenames_encryption_mode =
730 -                               EXT4_ENCRYPTION_MODE_AES_256_CTS;
731 -                       ctx.flags = 0;
732 -                       memset(ctx.master_key_descriptor, 0x42,
733 -                              EXT4_KEY_DESCRIPTOR_SIZE);
734 -                       res = 0;
735 -               } else {
736 -                       goto out;
737 -               }
738 +       ctx.format = EXT4_ENCRYPTION_CONTEXT_FORMAT_V1;
739 +       if (DUMMY_ENCRYPTION_ENABLED(EXT4_SB(parent->i_sb))) {
740 +               ctx.contents_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_XTS;
741 +               ctx.filenames_encryption_mode =
742 +                       EXT4_ENCRYPTION_MODE_AES_256_CTS;
743 +               ctx.flags = 0;
744 +               memset(ctx.master_key_descriptor, 0x42,
745 +                      EXT4_KEY_DESCRIPTOR_SIZE);
746 +               res = 0;
747 +       } else {
748 +               ctx.contents_encryption_mode = ci->ci_data_mode;
749 +               ctx.filenames_encryption_mode = ci->ci_filename_mode;
750 +               ctx.flags = ci->ci_flags;
751 +               memcpy(ctx.master_key_descriptor, ci->ci_master_key,
752 +                      EXT4_KEY_DESCRIPTOR_SIZE);
753         }
754         get_random_bytes(ctx.nonce, EXT4_KEY_DERIVATION_NONCE_SIZE);
755         res = ext4_xattr_set(child, EXT4_XATTR_INDEX_ENCRYPTION,
756                              EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, &ctx,
757                              sizeof(ctx), 0);
758 -out:
759         if (!res)
760                 ext4_set_inode_flag(child, EXT4_INODE_ENCRYPT);
761         return res;
764 diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
765 index d799d5d..28cb94f 100644
766 --- a/fs/ext4/dir.c
767 +++ b/fs/ext4/dir.c
768 @@ -110,7 +110,6 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
769         struct super_block *sb = inode->i_sb;
770         struct buffer_head *bh = NULL;
771         int dir_has_error = 0;
772 -       struct ext4_fname_crypto_ctx *enc_ctx = NULL;
773         struct ext4_str fname_crypto_str = {.name = NULL, .len = 0};
775         if (is_dx_dir(inode)) {
776 @@ -134,16 +133,14 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
777                         return err;
778         }
780 -       enc_ctx = ext4_get_fname_crypto_ctx(inode, EXT4_NAME_LEN);
781 -       if (IS_ERR(enc_ctx))
782 -               return PTR_ERR(enc_ctx);
783 -       if (enc_ctx) {
784 -               err = ext4_fname_crypto_alloc_buffer(enc_ctx, EXT4_NAME_LEN,
785 +       err = ext4_setup_fname_crypto(inode);
786 +       if (err)
787 +               return err;
788 +       if (ext4_encrypted_inode(inode)) {
789 +               err = ext4_fname_crypto_alloc_buffer(inode, EXT4_NAME_LEN,
790                                                      &fname_crypto_str);
791 -               if (err < 0) {
792 -                       ext4_put_fname_crypto_ctx(&enc_ctx);
793 +               if (err < 0)
794                         return err;
795 -               }
796         }
798         offset = ctx->pos & (sb->s_blocksize - 1);
799 @@ -239,8 +236,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
800                         offset += ext4_rec_len_from_disk(de->rec_len,
801                                         sb->s_blocksize);
802                         if (le32_to_cpu(de->inode)) {
803 -                               if (enc_ctx == NULL) {
804 -                                       /* Directory is not encrypted */
805 +                               if (!ext4_encrypted_inode(inode)) {
806                                         if (!dir_emit(ctx, de->name,
807                                             de->name_len,
808                                             le32_to_cpu(de->inode),
809 @@ -250,7 +246,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
810                                         int save_len = fname_crypto_str.len;
812                                         /* Directory is encrypted */
813 -                                       err = ext4_fname_disk_to_usr(enc_ctx,
814 +                                       err = ext4_fname_disk_to_usr(inode,
815                                                 NULL, de, &fname_crypto_str);
816                                         fname_crypto_str.len = save_len;
817                                         if (err < 0)
818 @@ -275,7 +271,6 @@ done:
819         err = 0;
820  errout:
821  #ifdef CONFIG_EXT4_FS_ENCRYPTION
822 -       ext4_put_fname_crypto_ctx(&enc_ctx);
823         ext4_fname_crypto_free_buffer(&fname_crypto_str);
824  #endif
825         brelse(bh);
826 diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
827 index e3671c2..4ffaa02 100644
828 --- a/fs/ext4/ext4.h
829 +++ b/fs/ext4/ext4.h
830 @@ -955,7 +955,7 @@ struct ext4_inode_info {
832  #ifdef CONFIG_EXT4_FS_ENCRYPTION
833         /* Encryption params */
834 -       struct ext4_crypt_info i_crypt_info;
835 +       struct ext4_crypt_info *i_crypt_info;
836  #endif
837  };
839 @@ -2096,37 +2096,30 @@ static inline int ext4_sb_has_crypto(struct super_block *sb)
840  /* crypto_fname.c */
841  bool ext4_valid_filenames_enc_mode(uint32_t mode);
842  u32 ext4_fname_crypto_round_up(u32 size, u32 blksize);
843 -int ext4_fname_crypto_alloc_buffer(struct ext4_fname_crypto_ctx *ctx,
844 +int ext4_fname_crypto_alloc_buffer(struct inode *inode,
845                                    u32 ilen, struct ext4_str *crypto_str);
846 -int _ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
847 +int _ext4_fname_disk_to_usr(struct inode *inode,
848                             struct dx_hash_info *hinfo,
849                             const struct ext4_str *iname,
850                             struct ext4_str *oname);
851 -int ext4_fname_disk_to_usr(struct ext4_fname_crypto_ctx *ctx,
852 +int ext4_fname_disk_to_usr(struct inode *inode,
853                            struct dx_hash_info *hinfo,
854                            const struct ext4_dir_entry_2 *de,
855                            struct ext4_str *oname);
856 -int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
857 +int ext4_fname_usr_to_disk(struct inode *inode,
858                            const struct qstr *iname,
859                            struct ext4_str *oname);
860 -int ext4_fname_crypto_namelen_on_disk(struct ext4_fname_crypto_ctx *ctx,
861 -                                     u32 namelen);
862  #ifdef CONFIG_EXT4_FS_ENCRYPTION
863 -void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx);
864 -struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(struct inode *inode,
865 -                                                       u32 max_len);
866 +int ext4_setup_fname_crypto(struct inode *inode);
867  void ext4_fname_crypto_free_buffer(struct ext4_str *crypto_str);
868  int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
869                               int lookup, struct ext4_filename *fname);
870  void ext4_fname_free_filename(struct ext4_filename *fname);
871  #else
872  static inline
873 -void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx) { }
874 -static inline
875 -struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(struct inode *inode,
876 -                                                       u32 max_len)
877 +int ext4_setup_fname_crypto(struct inode *inode)
879 -       return NULL;
880 +       return 0;
882  static inline void ext4_fname_crypto_free_buffer(struct ext4_str *p) { }
883  static inline int ext4_fname_setup_filename(struct inode *dir,
884 @@ -2143,10 +2136,25 @@ static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
887  /* crypto_key.c */
888 -int ext4_generate_encryption_key(struct inode *inode);
889 +void ext4_free_encryption_info(struct inode *inode);
890 +int _ext4_get_encryption_info(struct inode *inode);
892  #ifdef CONFIG_EXT4_FS_ENCRYPTION
893  int ext4_has_encryption_key(struct inode *inode);
895 +static inline int ext4_get_encryption_info(struct inode *inode)
897 +       struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
899 +       if (!ci ||
900 +           (ci->ci_keyring_key &&
901 +            (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) |
902 +                                          (1 << KEY_FLAG_REVOKED) |
903 +                                          (1 << KEY_FLAG_DEAD)))))
904 +               return _ext4_get_encryption_info(inode);
905 +       return 0;
908  #else
909  static inline int ext4_has_encryption_key(struct inode *inode)
911 diff --git a/fs/ext4/ext4_crypto.h b/fs/ext4/ext4_crypto.h
912 index deecbe8..d29687c 100644
913 --- a/fs/ext4/ext4_crypto.h
914 +++ b/fs/ext4/ext4_crypto.h
915 @@ -76,7 +76,13 @@ struct ext4_encryption_key {
916  struct ext4_crypt_info {
917         unsigned char   ci_mode;
918         unsigned char   ci_size;
919 +       char            ci_data_mode;
920 +       char            ci_filename_mode;
921 +       char            ci_flags;
922 +       struct crypto_ablkcipher *ci_ctfm;
923 +       struct key      *ci_keyring_key;
924         char            ci_raw[EXT4_MAX_KEY_SIZE];
925 +       char            ci_master_key[EXT4_KEY_DESCRIPTOR_SIZE];
926  };
928  #define EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL             0x00000001
929 @@ -128,16 +134,6 @@ struct ext4_str {
930         u32 len;
931  };
933 -struct ext4_fname_crypto_ctx {
934 -       u32 lim;
935 -       struct crypto_ablkcipher *ctfm;
936 -       struct crypto_hash *htfm;
937 -       struct ext4_crypt_info ci;
938 -       unsigned flags : 8;
939 -       unsigned has_valid_key : 1;
940 -       unsigned ctfm_key_is_ready : 1;
943  /**
944   * For encrypted symlinks, the ciphertext length is stored at the beginning
945   * of the string in little-endian format.
946 diff --git a/fs/ext4/file.c b/fs/ext4/file.c
947 index 0613c25..875ca6b 100644
948 --- a/fs/ext4/file.c
949 +++ b/fs/ext4/file.c
950 @@ -223,7 +223,7 @@ static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
951         struct inode *inode = file->f_mapping->host;
953         if (ext4_encrypted_inode(inode)) {
954 -               int err = ext4_generate_encryption_key(inode);
955 +               int err = ext4_get_encryption_info(inode);
956                 if (err)
957                         return 0;
958         }
959 @@ -289,7 +289,7 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
960         }
961         ret = dquot_file_open(inode, filp);
962         if (!ret && ext4_encrypted_inode(inode)) {
963 -               ret = ext4_generate_encryption_key(inode);
964 +               ret = ext4_get_encryption_info(inode);
965                 if (ret)
966                         ret = -EACCES;
967         }
968 diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
969 index b340643..9bed99f 100644
970 --- a/fs/ext4/namei.c
971 +++ b/fs/ext4/namei.c
972 @@ -607,17 +607,14 @@ static struct stats dx_show_leaf(struct inode *dir,
973                                 char *name;
974                                 struct ext4_str fname_crypto_str
975                                         = {.name = NULL, .len = 0};
976 -                               struct ext4_fname_crypto_ctx *ctx = NULL;
977                                 int res;
979                                 name  = de->name;
980                                 len = de->name_len;
981 -                               ctx = ext4_get_fname_crypto_ctx(dir,
982 -                                                               EXT4_NAME_LEN);
983 -                               if (IS_ERR(ctx)) {
984 -                                       printk(KERN_WARNING "Error acquiring"
985 -                                       " crypto ctxt--skipping crypto\n");
986 -                                       ctx = NULL;
987 +                               res = ext4_setup_fname_crypto(dir);
988 +                               if (res) {
989 +                                       printk(KERN_WARNING "Error setting up"
990 +                                              " fname crypto: %d\n", res);
991                                 }
992                                 if (ctx == NULL) {
993                                         /* Directory is not encrypted */
994 @@ -637,7 +634,6 @@ static struct stats dx_show_leaf(struct inode *dir,
995                                                         "allocating crypto "
996                                                         "buffer--skipping "
997                                                         "crypto\n");
998 -                                               ext4_put_fname_crypto_ctx(&ctx);
999                                                 ctx = NULL;
1000                                         }
1001                                         res = ext4_fname_disk_to_usr(ctx, NULL, de,
1002 @@ -658,7 +654,6 @@ static struct stats dx_show_leaf(struct inode *dir,
1003                                         printk("%*.s:(E)%x.%u ", len, name,
1004                                                h.hash, (unsigned) ((char *) de
1005                                                                    - base));
1006 -                                       ext4_put_fname_crypto_ctx(&ctx);
1007                                         ext4_fname_crypto_free_buffer(
1008                                                 &fname_crypto_str);
1009                                 }
1010 @@ -944,7 +939,6 @@ static int htree_dirblock_to_tree(struct file *dir_file,
1011         struct buffer_head *bh;
1012         struct ext4_dir_entry_2 *de, *top;
1013         int err = 0, count = 0;
1014 -       struct ext4_fname_crypto_ctx *ctx = NULL;
1015         struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}, tmp_str;
1017         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
1018 @@ -959,17 +953,15 @@ static int htree_dirblock_to_tree(struct file *dir_file,
1019                                            EXT4_DIR_REC_LEN(0));
1020  #ifdef CONFIG_EXT4_FS_ENCRYPTION
1021         /* Check if the directory is encrypted */
1022 -       ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
1023 -       if (IS_ERR(ctx)) {
1024 -               err = PTR_ERR(ctx);
1025 +       err = ext4_setup_fname_crypto(dir);
1026 +       if (err) {
1027                 brelse(bh);
1028                 return err;
1029         }
1030 -       if (ctx != NULL) {
1031 -               err = ext4_fname_crypto_alloc_buffer(ctx, EXT4_NAME_LEN,
1032 +       if (ext4_encrypted_inode(dir)) {
1033 +               err = ext4_fname_crypto_alloc_buffer(dir, EXT4_NAME_LEN,
1034                                                      &fname_crypto_str);
1035                 if (err < 0) {
1036 -                       ext4_put_fname_crypto_ctx(&ctx);
1037                         brelse(bh);
1038                         return err;
1039                 }
1040 @@ -990,8 +982,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
1041                         continue;
1042                 if (de->inode == 0)
1043                         continue;
1044 -               if (ctx == NULL) {
1045 -                       /* Directory is not encrypted */
1046 +               if (!ext4_encrypted_inode(dir)) {
1047                         tmp_str.name = de->name;
1048                         tmp_str.len = de->name_len;
1049                         err = ext4_htree_store_dirent(dir_file,
1050 @@ -1001,7 +992,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
1051                         int save_len = fname_crypto_str.len;
1053                         /* Directory is encrypted */
1054 -                       err = ext4_fname_disk_to_usr(ctx, hinfo, de,
1055 +                       err = ext4_fname_disk_to_usr(dir, hinfo, de,
1056                                                      &fname_crypto_str);
1057                         if (err < 0) {
1058                                 count = err;
1059 @@ -1021,7 +1012,6 @@ static int htree_dirblock_to_tree(struct file *dir_file,
1060  errout:
1061         brelse(bh);
1062  #ifdef CONFIG_EXT4_FS_ENCRYPTION
1063 -       ext4_put_fname_crypto_ctx(&ctx);
1064         ext4_fname_crypto_free_buffer(&fname_crypto_str);
1065  #endif
1066         return count;
1067 @@ -3107,7 +3097,6 @@ static int ext4_symlink(struct inode *dir,
1068         }
1070         if (encryption_required) {
1071 -               struct ext4_fname_crypto_ctx *ctx = NULL;
1072                 struct qstr istr;
1073                 struct ext4_str ostr;
1075 @@ -3119,19 +3108,14 @@ static int ext4_symlink(struct inode *dir,
1076                 err = ext4_inherit_context(dir, inode);
1077                 if (err)
1078                         goto err_drop_inode;
1079 -               ctx = ext4_get_fname_crypto_ctx(inode,
1080 -                                               inode->i_sb->s_blocksize);
1081 -               if (IS_ERR_OR_NULL(ctx)) {
1082 -                       /* We just set the policy, so ctx should not be NULL */
1083 -                       err = (ctx == NULL) ? -EIO : PTR_ERR(ctx);
1084 +               err = ext4_setup_fname_crypto(inode);
1085 +               if (err)
1086                         goto err_drop_inode;
1087 -               }
1088                 istr.name = (const unsigned char *) symname;
1089                 istr.len = len;
1090                 ostr.name = sd->encrypted_path;
1091                 ostr.len = disk_link.len;
1092 -               err = ext4_fname_usr_to_disk(ctx, &istr, &ostr);
1093 -               ext4_put_fname_crypto_ctx(&ctx);
1094 +               err = ext4_fname_usr_to_disk(inode, &istr, &ostr);
1095                 if (err < 0)
1096                         goto err_drop_inode;
1097                 sd->len = cpu_to_le16(ostr.len);
1098 diff --git a/fs/ext4/super.c b/fs/ext4/super.c
1099 index a9ebe3d..1850553 100644
1100 --- a/fs/ext4/super.c
1101 +++ b/fs/ext4/super.c
1102 @@ -877,9 +877,8 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
1103         atomic_set(&ei->i_unwritten, 0);
1104         INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work);
1105  #ifdef CONFIG_EXT4_FS_ENCRYPTION
1106 -       ei->i_crypt_info.ci_mode = EXT4_ENCRYPTION_MODE_INVALID;
1107 +       ei->i_crypt_info = NULL;
1108  #endif
1110         return &ei->vfs_inode;
1113 @@ -956,6 +955,8 @@ void ext4_clear_inode(struct inode *inode)
1114                 jbd2_free_inode(EXT4_I(inode)->jinode);
1115                 EXT4_I(inode)->jinode = NULL;
1116         }
1117 +       if (EXT4_I(inode)->i_crypt_info)
1118 +               ext4_free_encryption_info(inode);
1121  static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1122 diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
1123 index ca65d45..3287088 100644
1124 --- a/fs/ext4/symlink.c
1125 +++ b/fs/ext4/symlink.c
1126 @@ -29,7 +29,6 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd)
1127         char *caddr, *paddr = NULL;
1128         struct ext4_str cstr, pstr;
1129         struct inode *inode = d_inode(dentry);
1130 -       struct ext4_fname_crypto_ctx *ctx = NULL;
1131         struct ext4_encrypted_symlink_data *sd;
1132         loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1);
1133         int res;
1134 @@ -38,19 +37,17 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd)
1135         if (!ext4_encrypted_inode(inode))
1136                 return page_follow_link_light(dentry, nd);
1138 -       ctx = ext4_get_fname_crypto_ctx(inode, inode->i_sb->s_blocksize);
1139 -       if (IS_ERR(ctx))
1140 -               return ctx;
1141 +       res = ext4_setup_fname_crypto(inode);
1142 +       if (res)
1143 +               return ERR_PTR(res);
1145         if (ext4_inode_is_fast_symlink(inode)) {
1146                 caddr = (char *) EXT4_I(inode)->i_data;
1147                 max_size = sizeof(EXT4_I(inode)->i_data);
1148         } else {
1149                 cpage = read_mapping_page(inode->i_mapping, 0, NULL);
1150 -               if (IS_ERR(cpage)) {
1151 -                       ext4_put_fname_crypto_ctx(&ctx);
1152 +               if (IS_ERR(cpage))
1153                         return cpage;
1154 -               }
1155                 caddr = kmap(cpage);
1156                 caddr[size] = 0;
1157         }
1158 @@ -75,21 +72,19 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd)
1159         }
1160         pstr.name = paddr;
1161         pstr.len = plen;
1162 -       res = _ext4_fname_disk_to_usr(ctx, NULL, &cstr, &pstr);
1163 +       res = _ext4_fname_disk_to_usr(inode, NULL, &cstr, &pstr);
1164         if (res < 0)
1165                 goto errout;
1166         /* Null-terminate the name */
1167         if (res <= plen)
1168                 paddr[res] = '\0';
1169         nd_set_link(nd, paddr);
1170 -       ext4_put_fname_crypto_ctx(&ctx);
1171         if (cpage) {
1172                 kunmap(cpage);
1173                 page_cache_release(cpage);
1174         }
1175         return NULL;
1176  errout:
1177 -       ext4_put_fname_crypto_ctx(&ctx);
1178         if (cpage) {
1179                 kunmap(cpage);
1180                 page_cache_release(cpage);