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-rw-r--r--fs/locks.c3
-rw-r--r--fs/open.c15
2 files changed, 15 insertions, 3 deletions
diff --git a/fs/locks.c b/fs/locks.c
index c1656cff53ee..b242d5b99589 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1618,7 +1618,8 @@ check_conflicting_open(const struct dentry *dentry, const long arg, int flags)
if (flags & FL_LAYOUT)
return 0;
- if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
+ if ((arg == F_RDLCK) &&
+ (atomic_read(&d_real_inode(dentry)->i_writecount) > 0))
return -EAGAIN;
if ((arg == F_WRLCK) && ((d_count(dentry) > 1) ||
diff --git a/fs/open.c b/fs/open.c
index 648fb9d3e97a..8aeb08bb278b 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -68,6 +68,7 @@ int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
long vfs_truncate(const struct path *path, loff_t length)
{
struct inode *inode;
+ struct dentry *upperdentry;
long error;
inode = path->dentry->d_inode;
@@ -90,7 +91,17 @@ long vfs_truncate(const struct path *path, loff_t length)
if (IS_APPEND(inode))
goto mnt_drop_write_and_out;
- error = get_write_access(inode);
+ /*
+ * If this is an overlayfs then do as if opening the file so we get
+ * write access on the upper inode, not on the overlay inode. For
+ * non-overlay filesystems d_real() is an identity function.
+ */
+ upperdentry = d_real(path->dentry, NULL, O_WRONLY);
+ error = PTR_ERR(upperdentry);
+ if (IS_ERR(upperdentry))
+ goto mnt_drop_write_and_out;
+
+ error = get_write_access(upperdentry->d_inode);
if (error)
goto mnt_drop_write_and_out;
@@ -109,7 +120,7 @@ long vfs_truncate(const struct path *path, loff_t length)
error = do_truncate(path->dentry, length, 0, NULL);
put_write_and_out:
- put_write_access(inode);
+ put_write_access(upperdentry->d_inode);
mnt_drop_write_and_out:
mnt_drop_write(path->mnt);
out: