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torvaldstorvalds
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Merge tag '9p-for-5.1' of git://github.com/martinetd/linux
Pull 9p updates from Dominique Martinet: "Here is a 9p update for 5.1; there honestly hasn't been much. Two fixes (leak on invalid mount argument and possible deadlock on i_size update on 32bit smp) and a fall-through warning cleanup" * tag '9p-for-5.1' of git://github.com/martinetd/linux: 9p/net: fix memory leak in p9_client_create 9p: use inode->i_lock to protect i_size_write() under 32-bit 9p: mark expected switch fall-through
2 parents a9dce66 + bb06c38 commit db77bef

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7 files changed

+55
-32
lines changed

7 files changed

+55
-32
lines changed

‎fs/9p/v9fs_vfs.h

Lines changed: 21 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -40,6 +40,9 @@
4040
*/
4141
#define P9_LOCK_TIMEOUT (30*HZ)
4242

43+
/* flags for v9fs_stat2inode() & v9fs_stat2inode_dotl() */
44+
#define V9FS_STAT2INODE_KEEP_ISIZE 1
45+
4346
extern struct file_system_type v9fs_fs_type;
4447
extern const struct address_space_operations v9fs_addr_operations;
4548
extern const struct file_operations v9fs_file_operations;
@@ -61,8 +64,10 @@ int v9fs_init_inode(struct v9fs_session_info *v9ses,
6164
struct inode *inode, umode_t mode, dev_t);
6265
void v9fs_evict_inode(struct inode *inode);
6366
ino_t v9fs_qid2ino(struct p9_qid *qid);
64-
void v9fs_stat2inode(struct p9_wstat *, struct inode *, struct super_block *);
65-
void v9fs_stat2inode_dotl(struct p9_stat_dotl *, struct inode *);
67+
void v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
68+
struct super_block *sb, unsigned int flags);
69+
void v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
70+
unsigned int flags);
6671
int v9fs_dir_release(struct inode *inode, struct file *filp);
6772
int v9fs_file_open(struct inode *inode, struct file *file);
6873
void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);
@@ -83,4 +88,18 @@ static inline void v9fs_invalidate_inode_attr(struct inode *inode)
8388
}
8489

8590
int v9fs_open_to_dotl_flags(int flags);
91+
92+
static inline void v9fs_i_size_write(struct inode *inode, loff_t i_size)
93+
{
94+
/*
95+
* 32-bit need the lock, concurrent updates could break the
96+
* sequences and make i_size_read() loop forever.
97+
* 64-bit updates are atomic and can skip the locking.
98+
*/
99+
if (sizeof(i_size) > sizeof(long))
100+
spin_lock(&inode->i_lock);
101+
i_size_write(inode, i_size);
102+
if (sizeof(i_size) > sizeof(long))
103+
spin_unlock(&inode->i_lock);
104+
}
86105
#endif

‎fs/9p/vfs_file.c

Lines changed: 5 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -446,7 +446,11 @@ v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
446446
i_size = i_size_read(inode);
447447
if (iocb->ki_pos > i_size) {
448448
inode_add_bytes(inode, iocb->ki_pos - i_size);
449-
i_size_write(inode, iocb->ki_pos);
449+
/*
450+
* Need to serialize against i_size_write() in
451+
* v9fs_stat2inode()
452+
*/
453+
v9fs_i_size_write(inode, iocb->ki_pos);
450454
}
451455
return retval;
452456
}

‎fs/9p/vfs_inode.c

Lines changed: 11 additions & 12 deletions
Original file line numberDiff line numberDiff line change
@@ -538,7 +538,7 @@ static struct inode *v9fs_qid_iget(struct super_block *sb,
538538
if (retval)
539539
goto error;
540540

541-
v9fs_stat2inode(st, inode, sb);
541+
v9fs_stat2inode(st, inode, sb, 0);
542542
v9fs_cache_inode_get_cookie(inode);
543543
unlock_new_inode(inode);
544544
return inode;
@@ -1092,7 +1092,7 @@ v9fs_vfs_getattr(const struct path *path, struct kstat *stat,
10921092
if (IS_ERR(st))
10931093
return PTR_ERR(st);
10941094

1095-
v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb);
1095+
v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0);
10961096
generic_fillattr(d_inode(dentry), stat);
10971097

10981098
p9stat_free(st);
@@ -1170,12 +1170,13 @@ static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
11701170
* @stat: Plan 9 metadata (mistat) structure
11711171
* @inode: inode to populate
11721172
* @sb: superblock of filesystem
1173+
* @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
11731174
*
11741175
*/
11751176

11761177
void
11771178
v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1178-
struct super_block *sb)
1179+
struct super_block *sb, unsigned int flags)
11791180
{
11801181
umode_t mode;
11811182
char ext[32];
@@ -1216,10 +1217,11 @@ v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
12161217
mode = p9mode2perm(v9ses, stat);
12171218
mode |= inode->i_mode & ~S_IALLUGO;
12181219
inode->i_mode = mode;
1219-
i_size_write(inode, stat->length);
12201220

1221+
if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
1222+
v9fs_i_size_write(inode, stat->length);
12211223
/* not real number of blocks, but 512 byte ones ... */
1222-
inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1224+
inode->i_blocks = (stat->length + 512 - 1) >> 9;
12231225
v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
12241226
}
12251227

@@ -1416,9 +1418,9 @@ int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
14161418
{
14171419
int umode;
14181420
dev_t rdev;
1419-
loff_t i_size;
14201421
struct p9_wstat *st;
14211422
struct v9fs_session_info *v9ses;
1423+
unsigned int flags;
14221424

14231425
v9ses = v9fs_inode2v9ses(inode);
14241426
st = p9_client_stat(fid);
@@ -1431,16 +1433,13 @@ int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
14311433
if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
14321434
goto out;
14331435

1434-
spin_lock(&inode->i_lock);
14351436
/*
14361437
* We don't want to refresh inode->i_size,
14371438
* because we may have cached data
14381439
*/
1439-
i_size = inode->i_size;
1440-
v9fs_stat2inode(st, inode, inode->i_sb);
1441-
if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
1442-
inode->i_size = i_size;
1443-
spin_unlock(&inode->i_lock);
1440+
flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ?
1441+
V9FS_STAT2INODE_KEEP_ISIZE : 0;
1442+
v9fs_stat2inode(st, inode, inode->i_sb, flags);
14441443
out:
14451444
p9stat_free(st);
14461445
kfree(st);

‎fs/9p/vfs_inode_dotl.c

Lines changed: 14 additions & 13 deletions
Original file line numberDiff line numberDiff line change
@@ -143,7 +143,7 @@ static struct inode *v9fs_qid_iget_dotl(struct super_block *sb,
143143
if (retval)
144144
goto error;
145145

146-
v9fs_stat2inode_dotl(st, inode);
146+
v9fs_stat2inode_dotl(st, inode, 0);
147147
v9fs_cache_inode_get_cookie(inode);
148148
retval = v9fs_get_acl(inode, fid);
149149
if (retval)
@@ -496,7 +496,7 @@ v9fs_vfs_getattr_dotl(const struct path *path, struct kstat *stat,
496496
if (IS_ERR(st))
497497
return PTR_ERR(st);
498498

499-
v9fs_stat2inode_dotl(st, d_inode(dentry));
499+
v9fs_stat2inode_dotl(st, d_inode(dentry), 0);
500500
generic_fillattr(d_inode(dentry), stat);
501501
/* Change block size to what the server returned */
502502
stat->blksize = st->st_blksize;
@@ -607,11 +607,13 @@ int v9fs_vfs_setattr_dotl(struct dentry *dentry, struct iattr *iattr)
607607
* v9fs_stat2inode_dotl - populate an inode structure with stat info
608608
* @stat: stat structure
609609
* @inode: inode to populate
610+
* @flags: ctrl flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
610611
*
611612
*/
612613

613614
void
614-
v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
615+
v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
616+
unsigned int flags)
615617
{
616618
umode_t mode;
617619
struct v9fs_inode *v9inode = V9FS_I(inode);
@@ -631,7 +633,8 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
631633
mode |= inode->i_mode & ~S_IALLUGO;
632634
inode->i_mode = mode;
633635

634-
i_size_write(inode, stat->st_size);
636+
if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
637+
v9fs_i_size_write(inode, stat->st_size);
635638
inode->i_blocks = stat->st_blocks;
636639
} else {
637640
if (stat->st_result_mask & P9_STATS_ATIME) {
@@ -661,8 +664,9 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
661664
}
662665
if (stat->st_result_mask & P9_STATS_RDEV)
663666
inode->i_rdev = new_decode_dev(stat->st_rdev);
664-
if (stat->st_result_mask & P9_STATS_SIZE)
665-
i_size_write(inode, stat->st_size);
667+
if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE) &&
668+
stat->st_result_mask & P9_STATS_SIZE)
669+
v9fs_i_size_write(inode, stat->st_size);
666670
if (stat->st_result_mask & P9_STATS_BLOCKS)
667671
inode->i_blocks = stat->st_blocks;
668672
}
@@ -928,9 +932,9 @@ v9fs_vfs_get_link_dotl(struct dentry *dentry,
928932

929933
int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)
930934
{
931-
loff_t i_size;
932935
struct p9_stat_dotl *st;
933936
struct v9fs_session_info *v9ses;
937+
unsigned int flags;
934938

935939
v9ses = v9fs_inode2v9ses(inode);
936940
st = p9_client_getattr_dotl(fid, P9_STATS_ALL);
@@ -942,16 +946,13 @@ int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)
942946
if ((inode->i_mode & S_IFMT) != (st->st_mode & S_IFMT))
943947
goto out;
944948

945-
spin_lock(&inode->i_lock);
946949
/*
947950
* We don't want to refresh inode->i_size,
948951
* because we may have cached data
949952
*/
950-
i_size = inode->i_size;
951-
v9fs_stat2inode_dotl(st, inode);
952-
if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
953-
inode->i_size = i_size;
954-
spin_unlock(&inode->i_lock);
953+
flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ?
954+
V9FS_STAT2INODE_KEEP_ISIZE : 0;
955+
v9fs_stat2inode_dotl(st, inode, flags);
955956
out:
956957
kfree(st);
957958
return 0;

‎fs/9p/vfs_super.c

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -172,7 +172,7 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
172172
goto release_sb;
173173
}
174174
d_inode(root)->i_ino = v9fs_qid2ino(&st->qid);
175-
v9fs_stat2inode_dotl(st, d_inode(root));
175+
v9fs_stat2inode_dotl(st, d_inode(root), 0);
176176
kfree(st);
177177
} else {
178178
struct p9_wstat *st = NULL;
@@ -183,7 +183,7 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
183183
}
184184

185185
d_inode(root)->i_ino = v9fs_qid2ino(&st->qid);
186-
v9fs_stat2inode(st, d_inode(root), sb);
186+
v9fs_stat2inode(st, d_inode(root), sb, 0);
187187

188188
p9stat_free(st);
189189
kfree(st);

‎net/9p/client.c

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1061,7 +1061,7 @@ struct p9_client *p9_client_create(const char *dev_name, char *options)
10611061
p9_debug(P9_DEBUG_ERROR,
10621062
"Please specify a msize of at least 4k\n");
10631063
err = -EINVAL;
1064-
goto free_client;
1064+
goto close_trans;
10651065
}
10661066

10671067
err = p9_client_version(clnt);

‎net/9p/trans_xen.c

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -513,7 +513,7 @@ static void xen_9pfs_front_changed(struct xenbus_device *dev,
513513
case XenbusStateClosed:
514514
if (dev->state == XenbusStateClosed)
515515
break;
516-
/* Missed the backend's CLOSING state -- fallthrough */
516+
/* fall through - Missed the backend's CLOSING state */
517517
case XenbusStateClosing:
518518
xenbus_frontend_closed(dev);
519519
break;

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