History

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull VFS fixes from Al Viro: "A bunch of assorted fixes, most of them followups to overlayfs merge" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ovl: initialize ->is_cursor Return short read or 0 at end of a raw device, not EIO isofs: don't bother with ->d_op for normal case isofs_cmp(): we'll never see a dentry for . or .. overlayfs: fix lockdep misannotation ovl: fix check for cursor overlayfs: barriers for opening upper-layer directory rcu: Provide counterpart to rcu_dereference() for non-RCU situations staging: android: logger: Fix log corruption regression

Linus Torvalds committed 12 years ago

Commit 7e05b802 parents 4cb8c35 9f2f7d49 files · +50 −58Browse files

Unified · Split

9 files
  1. drivers/char/raw.c +1 −1
  2. drivers/staging/android/logger.c +8 −5
  3. fs/block_dev.c +2 −1
  4. fs/isofs/inode.c +2 −22
  5. fs/isofs/namei.c +4 −18
  6. fs/namei.c +1 −1
  7. fs/overlayfs/readdir.c +10 −7
  8. include/linux/fs.h +7 −3
  9. include/linux/rcupdate.h +15 −0
drivers/char/raw.c+1−1
@@ -285,7 +285,7 @@ static long raw_ctl_compat_ioctl(struct file *file, unsigned int cmd, · 284 unmodified lines
285285
286286 static const struct file_operations raw_fops = {
287287 .read = new_sync_read,
288− .read_iter = generic_file_read_iter,
288+ .read_iter = blkdev_read_iter,
289289 .write = new_sync_write,
290290 .write_iter = blkdev_write_iter,
291291 .fsync = blkdev_fsync,
drivers/staging/android/logger.c+8−5
@@ -420,7 +420,7 @@ static ssize_t logger_write_iter(struct kiocb *iocb, struct iov_iter *from) · 419 unmodified lines
420420 struct logger_log *log = file_get_log(iocb->ki_filp);
421421 struct logger_entry header;
422422 struct timespec now;
423− size_t len, count;
423+ size_t len, count, w_off;
424424
425425 count = min_t(size_t, iocb->ki_nbytes, LOGGER_ENTRY_MAX_PAYLOAD);
426426
@@ -452,11 +452,14 @@ static ssize_t logger_write_iter(struct kiocb *iocb, struct iov_iter *from) · 25 unmodified lines
452452 memcpy(log->buffer + log->w_off, &header, len);
453453 memcpy(log->buffer, (char *)&header + len, sizeof(header) - len);
454454
455− len = min(count, log->size - log->w_off);
455+ /* Work with a copy until we are ready to commit the whole entry */
456+ w_off = logger_offset(log, log->w_off + sizeof(struct logger_entry));
456457
457− if (copy_from_iter(log->buffer + log->w_off, len, from) != len) {
458+ len = min(count, log->size - w_off);
459+
460+ if (copy_from_iter(log->buffer + w_off, len, from) != len) {
458461 /*
459− * Note that by not updating w_off, this abandons the
462+ * Note that by not updating log->w_off, this abandons the
460463 * portion of the new entry that *was* successfully
461464 * copied, just above. This is intentional to avoid
462465 * message corruption from missing fragments.
@@ -470,7 +473,7 @@ static ssize_t logger_write_iter(struct kiocb *iocb, struct iov_iter *from) · 7 unmodified lines
470473 return -EFAULT;
471474 }
472475
473− log->w_off = logger_offset(log, log->w_off + count);
476+ log->w_off = logger_offset(log, w_off + count);
474477 mutex_unlock(&log->mutex);
475478
476479 /* wake up any blocked readers */
fs/block_dev.c+2−1
@@ -1585,7 +1585,7 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) · 1584 unmodified lines
15851585 }
15861586 EXPORT_SYMBOL_GPL(blkdev_write_iter);
15871587
1588−static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
1588+ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
15891589 {
15901590 struct file *file = iocb->ki_filp;
15911591 struct inode *bd_inode = file->f_mapping->host;
@@ -1599,6 +1599,7 @@ static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) · 7 unmodified lines
15991599 iov_iter_truncate(to, size);
16001600 return generic_file_read_iter(iocb, to);
16011601 }
1602+EXPORT_SYMBOL_GPL(blkdev_read_iter);
16021603
16031604 /*
16041605 * Try to release a page associated with block device when the system
fs/isofs/inode.c+2−22
@@ -29,13 +29,9 @@ · 28 unmodified lines
2929 #define BEQUIET
3030
3131 static int isofs_hashi(const struct dentry *parent, struct qstr *qstr);
32−static int isofs_hash(const struct dentry *parent, struct qstr *qstr);
3332 static int isofs_dentry_cmpi(const struct dentry *parent,
3433 const struct dentry *dentry,
3534 unsigned int len, const char *str, const struct qstr *name);
36−static int isofs_dentry_cmp(const struct dentry *parent,
37− const struct dentry *dentry,
38− unsigned int len, const char *str, const struct qstr *name);
3935
4036 #ifdef CONFIG_JOLIET
4137 static int isofs_hashi_ms(const struct dentry *parent, struct qstr *qstr);
@@ -134,10 +130,6 @@ static const struct super_operations isofs_sops = { · 92 unmodified lines
134130
135131
136132 static const struct dentry_operations isofs_dentry_ops[] = {
137− {
138− .d_hash = isofs_hash,
139− .d_compare = isofs_dentry_cmp,
140− },
141133 {
142134 .d_hash = isofs_hashi,
143135 .d_compare = isofs_dentry_cmpi,
@@ -257,25 +249,12 @@ static int isofs_dentry_cmp_common( · 113 unmodified lines
257249 return 1;
258250 }
259251
260−static int
261−isofs_hash(const struct dentry *dentry, struct qstr *qstr)
262−{
263− return isofs_hash_common(qstr, 0);
264−}
265−
266252 static int
267253 isofs_hashi(const struct dentry *dentry, struct qstr *qstr)
268254 {
269255 return isofs_hashi_common(qstr, 0);
270256 }
271257
272−static int
273−isofs_dentry_cmp(const struct dentry *parent, const struct dentry *dentry,
274− unsigned int len, const char *str, const struct qstr *name)
275−{
276− return isofs_dentry_cmp_common(len, str, name, 0, 0);
277−}
278−
279258 static int
280259 isofs_dentry_cmpi(const struct dentry *parent, const struct dentry *dentry,
281260 unsigned int len, const char *str, const struct qstr *name)
@@ -930,7 +909,8 @@ root_found: · 648 unmodified lines
930909 if (opt.check == 'r')
931910 table++;
932911
933− s->s_d_op = &isofs_dentry_ops[table];
912+ if (table)
913+ s->s_d_op = &isofs_dentry_ops[table - 1];
934914
935915 /* get the root dentry */
936916 s->s_root = d_make_root(inode);
fs/isofs/namei.c+4−18
@@ -18,25 +18,10 @@ static int · 17 unmodified lines
1818 isofs_cmp(struct dentry *dentry, const char *compare, int dlen)
1919 {
2020 struct qstr qstr;
21−
22− if (!compare)
23− return 1;
24−
25− /* check special "." and ".." files */
26− if (dlen == 1) {
27− /* "." */
28− if (compare[0] == 0) {
29− if (!dentry->d_name.len)
30− return 0;
31− compare = ".";
32− } else if (compare[0] == 1) {
33− compare = "..";
34− dlen = 2;
35− }
36− }
37−
3821 qstr.name = compare;
3922 qstr.len = dlen;
23+ if (likely(!dentry->d_op))
24+ return dentry->d_name.len != dlen || memcmp(dentry->d_name.name, compare, dlen);
4025 return dentry->d_op->d_compare(NULL, NULL, dentry->d_name.len, dentry->d_name.name, &qstr);
4126 }
4227
@@ -146,7 +131,8 @@ isofs_find_entry(struct inode *dir, struct dentry *dentry, · 103 unmodified lines
146131 (!(de->flags[-sbi->s_high_sierra] & 1))) &&
147132 (sbi->s_showassoc ||
148133 (!(de->flags[-sbi->s_high_sierra] & 4)))) {
149− match = (isofs_cmp(dentry, dpnt, dlen) == 0);
134+ if (dpnt && (dlen > 1 || dpnt[0] > 1))
135+ match = (isofs_cmp(dentry, dpnt, dlen) == 0);
150136 }
151137 if (match) {
152138 isofs_normalize_block_and_offset(de,
fs/namei.c+1−1
@@ -2497,7 +2497,7 @@ struct dentry *lock_rename(struct dentry *p1, struct dentry *p2) · 2496 unmodified lines
24972497 }
24982498
24992499 mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT);
2500− mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD);
2500+ mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT2);
25012501 return NULL;
25022502 }
25032503 EXPORT_SYMBOL(lock_rename);
fs/overlayfs/readdir.c+10−7
@@ -21,9 +21,10 @@ struct ovl_cache_entry { · 20 unmodified lines
2121 unsigned int len;
2222 unsigned int type;
2323 u64 ino;
24− bool is_whiteout;
2524 struct list_head l_node;
2625 struct rb_node node;
26+ bool is_whiteout;
27+ bool is_cursor;
2728 char name[];
2829 };
2930
@@ -92,6 +93,7 @@ static struct ovl_cache_entry *ovl_cache_entry_new(const char *name, int len, · 62 unmodified lines
9293 p->type = d_type;
9394 p->ino = ino;
9495 p->is_whiteout = false;
96+ p->is_cursor = false;
9597 }
9698
9799 return p;
@@ -251,7 +253,7 @@ static int ovl_dir_mark_whiteouts(struct dentry *dir, · 153 unmodified lines
251253
252254 mutex_lock(&dir->d_inode->i_mutex);
253255 list_for_each_entry(p, rdd->list, l_node) {
254− if (!p->name)
256+ if (p->is_cursor)
255257 continue;
256258
257259 if (p->type != DT_CHR)
@@ -307,7 +309,6 @@ static inline int ovl_dir_read_merged(struct path *upperpath, · 49 unmodified lines
307309 }
308310 out:
309311 return err;
310−
311312 }
312313
313314 static void ovl_seek_cursor(struct ovl_dir_file *od, loff_t pos)
@@ -316,7 +317,7 @@ static void ovl_seek_cursor(struct ovl_dir_file *od, loff_t pos) · 2 unmodified lines
316317 loff_t off = 0;
317318
318319 list_for_each_entry(p, &od->cache->entries, l_node) {
319− if (!p->name)
320+ if (p->is_cursor)
320321 continue;
321322 if (off >= pos)
322323 break;
@@ -389,7 +390,7 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx) · 66 unmodified lines
389390
390391 p = list_entry(od->cursor.l_node.next, struct ovl_cache_entry, l_node);
391392 /* Skip cursors */
392− if (p->name) {
393+ if (!p->is_cursor) {
393394 if (!p->is_whiteout) {
394395 if (!dir_emit(ctx, p->name, p->len, p->ino, p->type))
395396 break;
@@ -454,12 +455,13 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end, · 58 unmodified lines
454455 if (!od->is_upper && ovl_path_type(dentry) == OVL_PATH_MERGE) {
455456 struct inode *inode = file_inode(file);
456457
457− realfile = od->upperfile;
458+ realfile =lockless_dereference(od->upperfile);
458459 if (!realfile) {
459460 struct path upperpath;
460461
461462 ovl_path_upper(dentry, &upperpath);
462463 realfile = ovl_path_open(&upperpath, O_RDONLY);
464+ smp_mb__before_spinlock();
463465 mutex_lock(&inode->i_mutex);
464466 if (!od->upperfile) {
465467 if (IS_ERR(realfile)) {
@@ -518,6 +520,7 @@ static int ovl_dir_open(struct inode *inode, struct file *file) · 52 unmodified lines
518520 od->realfile = realfile;
519521 od->is_real = (type != OVL_PATH_MERGE);
520522 od->is_upper = (type != OVL_PATH_LOWER);
523+ od->cursor.is_cursor = true;
521524 file->private_data = od;
522525
523526 return 0;
@@ -569,7 +572,7 @@ void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list) · 45 unmodified lines
569572 {
570573 struct ovl_cache_entry *p;
571574
572− mutex_lock_nested(&upper->d_inode->i_mutex, I_MUTEX_PARENT);
575+ mutex_lock_nested(&upper->d_inode->i_mutex, I_MUTEX_CHILD);
573576 list_for_each_entry(p, list, l_node) {
574577 struct dentry *dentry;
575578
include/linux/fs.h+7−3
@@ -639,11 +639,13 @@ static inline int inode_unhashed(struct inode *inode) · 638 unmodified lines
639639 * 2: child/target
640640 * 3: xattr
641641 * 4: second non-directory
642− * The last is for certain operations (such as rename) which lock two
642+ * 5: second parent (when locking independent directories in rename)
643+ *
644+ * I_MUTEX_NONDIR2 is for certain operations (such as rename) which lock two
643645 * non-directories at once.
644646 *
645647 * The locking order between these classes is
646− * parent -> child -> normal -> xattr -> second non-directory
648+ * parent[2] -> child -> grandchild -> normal -> xattr -> second non-directory
647649 */
648650 enum inode_i_mutex_lock_class
649651 {
@@ -651,7 +653,8 @@ enum inode_i_mutex_lock_class · 1 unmodified line
651653 I_MUTEX_PARENT,
652654 I_MUTEX_CHILD,
653655 I_MUTEX_XATTR,
654− I_MUTEX_NONDIR2
656+ I_MUTEX_NONDIR2,
657+ I_MUTEX_PARENT2,
655658 };
656659
657660 void lock_two_nondirectories(struct inode *, struct inode*);
@@ -2466,6 +2469,7 @@ extern ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, lo · 1808 unmodified lines
24662469 extern ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos);
24672470
24682471 /* fs/block_dev.c */
2472+extern ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to);
24692473 extern ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from);
24702474 extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
24712475 int datasync);
include/linux/rcupdate.h+15−0
@@ -616,6 +616,21 @@ static inline void rcu_preempt_sleep_check(void) · 615 unmodified lines
616616 */
617617 #define RCU_INITIALIZER(v) (typeof(*(v)) __force __rcu *)(v)
618618
619+/**
620+ * lockless_dereference() - safely load a pointer for later dereference
621+ * @p: The pointer to load
622+ *
623+ * Similar to rcu_dereference(), but for situations where the pointed-to
624+ * object's lifetime is managed by something other than RCU. That
625+ * "something other" might be reference counting or simple immortality.
626+ */
627+#define lockless_dereference(p) \
628+({ \
629+ typeof(p) _________p1 = ACCESS_ONCE(p); \
630+ smp_read_barrier_depends(); /* Dependency order vs. p above. */ \
631+ (_________p1); \
632+})
633+
619634 /**
620635 * rcu_assign_pointer() - assign to RCU-protected pointer
621636 * @p: pointer to assign to