Depending on the synchronization state of the lower filesystem during a
power cut it can happen that a lower file is empty after that power cut.
An inode_operations::setattr operation fails with -EIO on such files,
because ecryptfs_read_metadata() fails. In e3ccaa976120 ("eCryptfs:
Initialize empty lower files when opening them") a similar problem was
solved in the open() path:
| To transparently solve this problem, this patch initializes empty lower
| files in the ecryptfs_open() error path. If the metadata is unreadable
| due to the lower inode size being 0, plaintext passthrough support is
| not in use, and the metadata is stored in the header of the file (as
| opposed to the user.ecryptfs extended attribute), the lower file will be
| initialized.
Do the same in inode_operations::setattr to allow setattr on empty lower
files.
Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
---
fs/ecryptfs/crypto.c | 42 +++++++++++++++++++++++++++++++++
fs/ecryptfs/ecryptfs_kernel.h | 1 +
fs/ecryptfs/file.c | 44 +----------------------------------
fs/ecryptfs/inode.c | 2 +-
4 files changed, 45 insertions(+), 44 deletions(-)
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 0681540c48d9..a48116aae02c 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1448,6 +1448,48 @@ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry)
return rc;
}
+int ecryptfs_read_or_initialize_metadata(struct dentry *dentry)
+{
+ struct inode *inode = d_inode(dentry);
+ struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+ struct ecryptfs_crypt_stat *crypt_stat;
+ int rc;
+
+ crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
+ mount_crypt_stat = &ecryptfs_superblock_to_private(
+ inode->i_sb)->mount_crypt_stat;
+ mutex_lock(&crypt_stat->cs_mutex);
+
+ if (crypt_stat->flags & ECRYPTFS_POLICY_APPLIED &&
+ crypt_stat->flags & ECRYPTFS_KEY_VALID) {
+ rc = 0;
+ goto out;
+ }
+
+ rc = ecryptfs_read_metadata(dentry);
+ if (!rc)
+ goto out;
+
+ if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED) {
+ crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
+ | ECRYPTFS_ENCRYPTED);
+ rc = 0;
+ goto out;
+ }
+
+ if (!(mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) &&
+ !i_size_read(ecryptfs_inode_to_lower(inode))) {
+ rc = ecryptfs_initialize_file(dentry, inode);
+ if (!rc)
+ goto out;
+ }
+
+ rc = -EIO;
+out:
+ mutex_unlock(&crypt_stat->cs_mutex);
+ return rc;
+}
+
/**
* ecryptfs_encrypt_filename - encrypt filename
*
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index e6ac78c62ca4..3815b3cc4c33 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -589,6 +589,7 @@ int ecryptfs_decrypt_page(struct page *page);
int ecryptfs_write_metadata(struct dentry *ecryptfs_dentry,
struct inode *ecryptfs_inode);
int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry);
+int ecryptfs_read_or_initialize_metadata(struct dentry *dentry);
int ecryptfs_new_file_context(struct inode *ecryptfs_inode);
void ecryptfs_write_crypt_stat_flags(char *page_virt,
struct ecryptfs_crypt_stat *crypt_stat,
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 5fb45d865ce5..14157b312f06 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -124,48 +124,6 @@ static int ecryptfs_readdir(struct file *file, struct dir_context *ctx)
struct kmem_cache *ecryptfs_file_info_cache;
-static int read_or_initialize_metadata(struct dentry *dentry)
-{
- struct inode *inode = d_inode(dentry);
- struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
- struct ecryptfs_crypt_stat *crypt_stat;
- int rc;
-
- crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
- mount_crypt_stat = &ecryptfs_superblock_to_private(
- inode->i_sb)->mount_crypt_stat;
- mutex_lock(&crypt_stat->cs_mutex);
-
- if (crypt_stat->flags & ECRYPTFS_POLICY_APPLIED &&
- crypt_stat->flags & ECRYPTFS_KEY_VALID) {
- rc = 0;
- goto out;
- }
-
- rc = ecryptfs_read_metadata(dentry);
- if (!rc)
- goto out;
-
- if (mount_crypt_stat->flags & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED) {
- crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
- | ECRYPTFS_ENCRYPTED);
- rc = 0;
- goto out;
- }
-
- if (!(mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED) &&
- !i_size_read(ecryptfs_inode_to_lower(inode))) {
- rc = ecryptfs_initialize_file(dentry, inode);
- if (!rc)
- goto out;
- }
-
- rc = -EIO;
-out:
- mutex_unlock(&crypt_stat->cs_mutex);
- return rc;
-}
-
static int ecryptfs_mmap(struct file *file, struct vm_area_struct *vma)
{
struct file *lower_file = ecryptfs_file_to_lower(file);
@@ -232,7 +190,7 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
}
ecryptfs_set_file_lower(
file, ecryptfs_inode_to_private(inode)->lower_file);
- rc = read_or_initialize_metadata(ecryptfs_dentry);
+ rc = ecryptfs_read_or_initialize_metadata(ecryptfs_dentry);
if (rc)
goto out_put;
ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = "
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 58d0f7187997..230fee828059 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -912,7 +912,7 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
mutex_unlock(&crypt_stat->cs_mutex);
goto out;
}
- rc = ecryptfs_read_metadata(dentry);
+ rc = ecryptfs_read_or_initialize_metadata(dentry);
ecryptfs_put_lower_file(inode);
if (rc) {
if (!(mount_crypt_stat->flags
--
2.29.2
