From: Amir Goldstein amir73il@gmail.com
[ Upstream commit 65cd913ec9d9d71529665924c81015b7ab7d9381 ]
The test in ovl_dentry_version_inc() was out-dated and did not include the case where readdir cache is used on a non-merge dir that has origin xattr, indicating that it may contain leftover whiteouts.
To make the code more robust, use the same helper ovl_dir_is_real() to determine if readdir cache should be used and if readdir cache should be invalidated.
Fixes: b79e05aaa166 ("ovl: no direct iteration for dir with origin xattr") Link: https://lore.kernel.org/linux-unionfs/CAOQ4uxht70nODhNHNwGFMSqDyOKLXOKrY0H6g... Cc: Chris Murphy lists@colorremedies.com Signed-off-by: Amir Goldstein amir73il@gmail.com Signed-off-by: Miklos Szeredi mszeredi@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/overlayfs/overlayfs.h | 30 +++++++++++++++++++++++++++--- fs/overlayfs/readdir.c | 12 ------------ fs/overlayfs/util.c | 31 +++++++++---------------------- 3 files changed, 36 insertions(+), 37 deletions(-)
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index cb4e2d60ecf9..cf0c5ea2f2fc 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -310,9 +310,6 @@ int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry, enum ovl_xattr ox, const void *value, size_t size, int xerr); int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); -void ovl_set_flag(unsigned long flag, struct inode *inode); -void ovl_clear_flag(unsigned long flag, struct inode *inode); -bool ovl_test_flag(unsigned long flag, struct inode *inode); bool ovl_inuse_trylock(struct dentry *dentry); void ovl_inuse_unlock(struct dentry *dentry); bool ovl_is_inuse(struct dentry *dentry); @@ -326,6 +323,21 @@ char *ovl_get_redirect_xattr(struct ovl_fs *ofs, struct dentry *dentry, int padding); int ovl_sync_status(struct ovl_fs *ofs);
+static inline void ovl_set_flag(unsigned long flag, struct inode *inode) +{ + set_bit(flag, &OVL_I(inode)->flags); +} + +static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) +{ + clear_bit(flag, &OVL_I(inode)->flags); +} + +static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) +{ + return test_bit(flag, &OVL_I(inode)->flags); +} + static inline bool ovl_is_impuredir(struct super_block *sb, struct dentry *dentry) { @@ -430,6 +442,18 @@ int ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, struct dentry *dentry, int level); int ovl_indexdir_cleanup(struct ovl_fs *ofs);
+/* + * Can we iterate real dir directly? + * + * Non-merge dir may contain whiteouts from a time it was a merge upper, before + * lower dir was removed under it and possibly before it was rotated from upper + * to lower layer. + */ +static inline bool ovl_dir_is_real(struct dentry *dir) +{ + return !ovl_test_flag(OVL_WHITEOUTS, d_inode(dir)); +} + /* inode.c */ int ovl_set_nlink_upper(struct dentry *dentry); int ovl_set_nlink_lower(struct dentry *dentry); diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index f404a78e6b60..cc1e80257064 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -319,18 +319,6 @@ static inline int ovl_dir_read(struct path *realpath, return err; }
-/* - * Can we iterate real dir directly? - * - * Non-merge dir may contain whiteouts from a time it was a merge upper, before - * lower dir was removed under it and possibly before it was rotated from upper - * to lower layer. - */ -static bool ovl_dir_is_real(struct dentry *dir) -{ - return !ovl_test_flag(OVL_WHITEOUTS, d_inode(dir)); -} - static void ovl_dir_reset(struct file *file) { struct ovl_dir_file *od = file->private_data; diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 9826b003f1d2..47dab5a709db 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -422,18 +422,20 @@ void ovl_inode_update(struct inode *inode, struct dentry *upperdentry) } }
-static void ovl_dentry_version_inc(struct dentry *dentry, bool impurity) +static void ovl_dir_version_inc(struct dentry *dentry, bool impurity) { struct inode *inode = d_inode(dentry);
WARN_ON(!inode_is_locked(inode)); + WARN_ON(!d_is_dir(dentry)); /* - * Version is used by readdir code to keep cache consistent. For merge - * dirs all changes need to be noted. For non-merge dirs, cache only - * contains impure (ones which have been copied up and have origins) - * entries, so only need to note changes to impure entries. + * Version is used by readdir code to keep cache consistent. + * For merge dirs (or dirs with origin) all changes need to be noted. + * For non-merge dirs, cache contains only impure entries (i.e. ones + * which have been copied up and have origins), so only need to note + * changes to impure entries. */ - if (OVL_TYPE_MERGE(ovl_path_type(dentry)) || impurity) + if (!ovl_dir_is_real(dentry) || impurity) OVL_I(inode)->version++; }
@@ -442,7 +444,7 @@ void ovl_dir_modified(struct dentry *dentry, bool impurity) /* Copy mtime/ctime */ ovl_copyattr(d_inode(ovl_dentry_upper(dentry)), d_inode(dentry));
- ovl_dentry_version_inc(dentry, impurity); + ovl_dir_version_inc(dentry, impurity); }
u64 ovl_dentry_version_get(struct dentry *dentry) @@ -638,21 +640,6 @@ int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry) return err; }
-void ovl_set_flag(unsigned long flag, struct inode *inode) -{ - set_bit(flag, &OVL_I(inode)->flags); -} - -void ovl_clear_flag(unsigned long flag, struct inode *inode) -{ - clear_bit(flag, &OVL_I(inode)->flags); -} - -bool ovl_test_flag(unsigned long flag, struct inode *inode) -{ - return test_bit(flag, &OVL_I(inode)->flags); -} - /** * Caller must hold a reference to inode to prevent it from being freed while * it is marked inuse.