Merge tag 'v4.4.177' into toradex_vf_4.4-nextColibri-VF_LXDE-Image_2.8b6.183-20190331

This is the 4.4.177 stable release

7 files changed, 59 insertions, 36 deletions

diff --git a/fs/9p/cache.c b/fs/9p/cache.c
index a69260f27555..103ca5e1267b 100644
--- a/fs/9p/cache.c
+++ b/fs/9p/cache.c
@@ -243,14 +243,14 @@ void v9fs_cache_inode_set_cookie(struct inode *inode, struct file *filp)
 	if (!v9inode->fscache)
 		return;
 
-	spin_lock(&v9inode->fscache_lock);
+	mutex_lock(&v9inode->fscache_lock);
 
 	if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
 		v9fs_cache_inode_flush_cookie(inode);
 	else
 		v9fs_cache_inode_get_cookie(inode);
 
-	spin_unlock(&v9inode->fscache_lock);
+	mutex_unlock(&v9inode->fscache_lock);
 }
 
 void v9fs_cache_inode_reset_cookie(struct inode *inode)
@@ -264,7 +264,7 @@ void v9fs_cache_inode_reset_cookie(struct inode *inode)
 
 	old = v9inode->fscache;
 
-	spin_lock(&v9inode->fscache_lock);
+	mutex_lock(&v9inode->fscache_lock);
 	fscache_relinquish_cookie(v9inode->fscache, 1);
 
 	v9ses = v9fs_inode2v9ses(inode);
@@ -274,7 +274,7 @@ void v9fs_cache_inode_reset_cookie(struct inode *inode)
 	p9_debug(P9_DEBUG_FSC, "inode %p revalidating cookie old %p new %p\n",
 		 inode, old, v9inode->fscache);
 
-	spin_unlock(&v9inode->fscache_lock);
+	mutex_unlock(&v9inode->fscache_lock);
 }
 
 int __v9fs_fscache_release_page(struct page *page, gfp_t gfp)
diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h
index 0923f2cf3c80..6877050384a1 100644
--- a/fs/9p/v9fs.h
+++ b/fs/9p/v9fs.h
@@ -123,7 +123,7 @@ struct v9fs_session_info {
 
 struct v9fs_inode {
 #ifdef CONFIG_9P_FSCACHE
-	spinlock_t fscache_lock;
+	struct mutex fscache_lock;
 	struct fscache_cookie *fscache;
 #endif
 	struct p9_qid qid;
diff --git a/fs/9p/v9fs_vfs.h b/fs/9p/v9fs_vfs.h
index 5a0db6dec8d1..aaee1e6584e6 100644
--- a/fs/9p/v9fs_vfs.h
+++ b/fs/9p/v9fs_vfs.h
@@ -40,6 +40,9 @@
  */
 #define P9_LOCK_TIMEOUT (30*HZ)
 
+/* flags for v9fs_stat2inode() & v9fs_stat2inode_dotl() */
+#define V9FS_STAT2INODE_KEEP_ISIZE 1
+
 extern struct file_system_type v9fs_fs_type;
 extern const struct address_space_operations v9fs_addr_operations;
 extern const struct file_operations v9fs_file_operations;
@@ -61,8 +64,10 @@ int v9fs_init_inode(struct v9fs_session_info *v9ses,
 		    struct inode *inode, umode_t mode, dev_t);
 void v9fs_evict_inode(struct inode *inode);
 ino_t v9fs_qid2ino(struct p9_qid *qid);
-void v9fs_stat2inode(struct p9_wstat *, struct inode *, struct super_block *);
-void v9fs_stat2inode_dotl(struct p9_stat_dotl *, struct inode *);
+void v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
+		      struct super_block *sb, unsigned int flags);
+void v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
+			   unsigned int flags);
 int v9fs_dir_release(struct inode *inode, struct file *filp);
 int v9fs_file_open(struct inode *inode, struct file *file);
 void v9fs_inode2stat(struct inode *inode, struct p9_wstat *stat);
@@ -83,4 +88,18 @@ static inline void v9fs_invalidate_inode_attr(struct inode *inode)
 }
 
 int v9fs_open_to_dotl_flags(int flags);
+
+static inline void v9fs_i_size_write(struct inode *inode, loff_t i_size)
+{
+	/*
+	 * 32-bit need the lock, concurrent updates could break the
+	 * sequences and make i_size_read() loop forever.
+	 * 64-bit updates are atomic and can skip the locking.
+	 */
+	if (sizeof(i_size) > sizeof(long))
+		spin_lock(&inode->i_lock);
+	i_size_write(inode, i_size);
+	if (sizeof(i_size) > sizeof(long))
+		spin_unlock(&inode->i_lock);
+}
 #endif
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index e7b3d2c4472d..62ce8b4a7e5f 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -442,7 +442,11 @@ v9fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 		i_size = i_size_read(inode);
 		if (iocb->ki_pos > i_size) {
 			inode_add_bytes(inode, iocb->ki_pos - i_size);
-			i_size_write(inode, iocb->ki_pos);
+			/*
+			 * Need to serialize against i_size_write() in
+			 * v9fs_stat2inode()
+			 */
+			v9fs_i_size_write(inode, iocb->ki_pos);
 		}
 		return retval;
 	}
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 73f1d1b3a51c..2de1505aedfd 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -244,7 +244,7 @@ struct inode *v9fs_alloc_inode(struct super_block *sb)
 		return NULL;
 #ifdef CONFIG_9P_FSCACHE
 	v9inode->fscache = NULL;
-	spin_lock_init(&v9inode->fscache_lock);
+	mutex_init(&v9inode->fscache_lock);
 #endif
 	v9inode->writeback_fid = NULL;
 	v9inode->cache_validity = 0;
@@ -538,7 +538,7 @@ static struct inode *v9fs_qid_iget(struct super_block *sb,
 	if (retval)
 		goto error;
 
-	v9fs_stat2inode(st, inode, sb);
+	v9fs_stat2inode(st, inode, sb, 0);
 	v9fs_cache_inode_get_cookie(inode);
 	unlock_new_inode(inode);
 	return inode;
@@ -1074,7 +1074,7 @@ v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 	if (IS_ERR(st))
 		return PTR_ERR(st);
 
-	v9fs_stat2inode(st, d_inode(dentry), d_inode(dentry)->i_sb);
+	v9fs_stat2inode(st, d_inode(dentry), d_inode(dentry)->i_sb, 0);
 	generic_fillattr(d_inode(dentry), stat);
 
 	p9stat_free(st);
@@ -1152,12 +1152,13 @@ static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
  * @stat: Plan 9 metadata (mistat) structure
  * @inode: inode to populate
  * @sb: superblock of filesystem
+ * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
  *
  */
 
 void
 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
-	struct super_block *sb)
+		 struct super_block *sb, unsigned int flags)
 {
 	umode_t mode;
 	char ext[32];
@@ -1198,10 +1199,11 @@ v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
 	mode = p9mode2perm(v9ses, stat);
 	mode |= inode->i_mode & ~S_IALLUGO;
 	inode->i_mode = mode;
-	i_size_write(inode, stat->length);
 
+	if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
+		v9fs_i_size_write(inode, stat->length);
 	/* not real number of blocks, but 512 byte ones ... */
-	inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
+	inode->i_blocks = (stat->length + 512 - 1) >> 9;
 	v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
 }
 
@@ -1389,9 +1391,9 @@ int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
 {
 	int umode;
 	dev_t rdev;
-	loff_t i_size;
 	struct p9_wstat *st;
 	struct v9fs_session_info *v9ses;
+	unsigned int flags;
 
 	v9ses = v9fs_inode2v9ses(inode);
 	st = p9_client_stat(fid);
@@ -1404,16 +1406,13 @@ int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
 	if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
 		goto out;
 
-	spin_lock(&inode->i_lock);
 	/*
 	 * We don't want to refresh inode->i_size,
 	 * because we may have cached data
 	 */
-	i_size = inode->i_size;
-	v9fs_stat2inode(st, inode, inode->i_sb);
-	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
-		inode->i_size = i_size;
-	spin_unlock(&inode->i_lock);
+	flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ?
+		V9FS_STAT2INODE_KEEP_ISIZE : 0;
+	v9fs_stat2inode(st, inode, inode->i_sb, flags);
 out:
 	p9stat_free(st);
 	kfree(st);
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index 0b88744c6446..7ae67fcca031 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -143,7 +143,7 @@ static struct inode *v9fs_qid_iget_dotl(struct super_block *sb,
 	if (retval)
 		goto error;
 
-	v9fs_stat2inode_dotl(st, inode);
+	v9fs_stat2inode_dotl(st, inode, 0);
 	v9fs_cache_inode_get_cookie(inode);
 	retval = v9fs_get_acl(inode, fid);
 	if (retval)
@@ -498,7 +498,7 @@ v9fs_vfs_getattr_dotl(struct vfsmount *mnt, struct dentry *dentry,
 	if (IS_ERR(st))
 		return PTR_ERR(st);
 
-	v9fs_stat2inode_dotl(st, d_inode(dentry));
+	v9fs_stat2inode_dotl(st, d_inode(dentry), 0);
 	generic_fillattr(d_inode(dentry), stat);
 	/* Change block size to what the server returned */
 	stat->blksize = st->st_blksize;
@@ -609,11 +609,13 @@ int v9fs_vfs_setattr_dotl(struct dentry *dentry, struct iattr *iattr)
  * v9fs_stat2inode_dotl - populate an inode structure with stat info
  * @stat: stat structure
  * @inode: inode to populate
+ * @flags: ctrl flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
  *
  */
 
 void
-v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
+v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode,
+		      unsigned int flags)
 {
 	umode_t mode;
 	struct v9fs_inode *v9inode = V9FS_I(inode);
@@ -633,7 +635,8 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
 		mode |= inode->i_mode & ~S_IALLUGO;
 		inode->i_mode = mode;
 
-		i_size_write(inode, stat->st_size);
+		if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
+			v9fs_i_size_write(inode, stat->st_size);
 		inode->i_blocks = stat->st_blocks;
 	} else {
 		if (stat->st_result_mask & P9_STATS_ATIME) {
@@ -663,8 +666,9 @@ v9fs_stat2inode_dotl(struct p9_stat_dotl *stat, struct inode *inode)
 		}
 		if (stat->st_result_mask & P9_STATS_RDEV)
 			inode->i_rdev = new_decode_dev(stat->st_rdev);
-		if (stat->st_result_mask & P9_STATS_SIZE)
-			i_size_write(inode, stat->st_size);
+		if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE) &&
+		    stat->st_result_mask & P9_STATS_SIZE)
+			v9fs_i_size_write(inode, stat->st_size);
 		if (stat->st_result_mask & P9_STATS_BLOCKS)
 			inode->i_blocks = stat->st_blocks;
 	}
@@ -926,9 +930,9 @@ v9fs_vfs_follow_link_dotl(struct dentry *dentry, void **cookie)
 
 int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)
 {
-	loff_t i_size;
 	struct p9_stat_dotl *st;
 	struct v9fs_session_info *v9ses;
+	unsigned int flags;
 
 	v9ses = v9fs_inode2v9ses(inode);
 	st = p9_client_getattr_dotl(fid, P9_STATS_ALL);
@@ -940,16 +944,13 @@ int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)
 	if ((inode->i_mode & S_IFMT) != (st->st_mode & S_IFMT))
 		goto out;
 
-	spin_lock(&inode->i_lock);
 	/*
 	 * We don't want to refresh inode->i_size,
 	 * because we may have cached data
 	 */
-	i_size = inode->i_size;
-	v9fs_stat2inode_dotl(st, inode);
-	if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
-		inode->i_size = i_size;
-	spin_unlock(&inode->i_lock);
+	flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ?
+		V9FS_STAT2INODE_KEEP_ISIZE : 0;
+	v9fs_stat2inode_dotl(st, inode, flags);
 out:
 	kfree(st);
 	return 0;
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index bf495cedec26..ccf935d9e722 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -165,7 +165,7 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
 			goto release_sb;
 		}
 		d_inode(root)->i_ino = v9fs_qid2ino(&st->qid);
-		v9fs_stat2inode_dotl(st, d_inode(root));
+		v9fs_stat2inode_dotl(st, d_inode(root), 0);
 		kfree(st);
 	} else {
 		struct p9_wstat *st = NULL;
@@ -176,7 +176,7 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
 		}
 
 		d_inode(root)->i_ino = v9fs_qid2ino(&st->qid);
-		v9fs_stat2inode(st, d_inode(root), sb);
+		v9fs_stat2inode(st, d_inode(root), sb, 0);
 
 		p9stat_free(st);
 		kfree(st);