Patchwork [1/1] eCryptfs: Handle failed metadata read in lookup

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Submitter Colin King
Date March 1, 2012, 7:22 p.m.
Message ID <1330629749-12911-2-git-send-email-colin.king@canonical.com>
Download mbox | patch
Permalink /patch/144095/
State New
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Comments

Colin King - March 1, 2012, 7:22 p.m.
From: Colin Ian King <colin.king@canonical.com>

When failing to read the lower file's crypto metadata during a lookup,
eCryptfs must continue on without throwing an error. For example, there
may be a plaintext file in the lower mount point that the user wants to
delete through the eCryptfs mount.

If an error is encountered while reading the metadata in lookup(), the
eCryptfs inode's size could be incorrect. We must be sure to reread the
plaintext inode size from the metadata when performing an open() or
setattr(). The metadata is already being read in those paths, so this
adds minimal performance overhead.

This patch introduces a flag which will track whether or not the
plaintext inode size has been read so that an incorrect i_size can be
fixed in the open() or setattr() paths.

BugLink: http://bugs.launchpad.net/bugs/509180

Cc: <stable@kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>

(backported from 3aeb86ea4cd15f728147a3bd5469a205ada8c767)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 fs/ecryptfs/crypto.c          |   21 +++++++++++++++++++++
 fs/ecryptfs/ecryptfs_kernel.h |    2 ++
 fs/ecryptfs/file.c            |    3 ++-
 fs/ecryptfs/inode.c           |   18 +++---------------
 4 files changed, 28 insertions(+), 16 deletions(-)
Brad Figg - March 1, 2012, 7:42 p.m.
On 03/01/2012 11:22 AM, Colin King wrote:
> From: Colin Ian King<colin.king@canonical.com>
>
> When failing to read the lower file's crypto metadata during a lookup,
> eCryptfs must continue on without throwing an error. For example, there
> may be a plaintext file in the lower mount point that the user wants to
> delete through the eCryptfs mount.
>
> If an error is encountered while reading the metadata in lookup(), the
> eCryptfs inode's size could be incorrect. We must be sure to reread the
> plaintext inode size from the metadata when performing an open() or
> setattr(). The metadata is already being read in those paths, so this
> adds minimal performance overhead.
>
> This patch introduces a flag which will track whether or not the
> plaintext inode size has been read so that an incorrect i_size can be
> fixed in the open() or setattr() paths.
>
> BugLink: http://bugs.launchpad.net/bugs/509180
>
> Cc:<stable@kernel.org>
> Signed-off-by: Tyler Hicks<tyhicks@linux.vnet.ibm.com>
>
> (backported from 3aeb86ea4cd15f728147a3bd5469a205ada8c767)
> Signed-off-by: Tim Gardner<tim.gardner@canonical.com>
> Signed-off-by: Colin Ian King<colin.king@canonical.com>
> ---
>   fs/ecryptfs/crypto.c          |   21 +++++++++++++++++++++
>   fs/ecryptfs/ecryptfs_kernel.h |    2 ++
>   fs/ecryptfs/file.c            |    3 ++-
>   fs/ecryptfs/inode.c           |   18 +++---------------
>   4 files changed, 28 insertions(+), 16 deletions(-)
>
> diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
> index 98a2a31..c0fe342 100644
> --- a/fs/ecryptfs/crypto.c
> +++ b/fs/ecryptfs/crypto.c
> @@ -1453,6 +1453,25 @@ static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat)
>   	crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
>   }
>
> +void ecryptfs_i_size_init(const char *page_virt, struct inode *inode)
> +{
> +	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
> +	struct ecryptfs_crypt_stat *crypt_stat;
> +	u64 file_size;
> +
> +	crypt_stat =&ecryptfs_inode_to_private(inode)->crypt_stat;
> +	mount_crypt_stat =
> +		&ecryptfs_superblock_to_private(inode->i_sb)->mount_crypt_stat;
> +	if (mount_crypt_stat->flags&  ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
> +		file_size = i_size_read(ecryptfs_inode_to_lower(inode));
> +		if (crypt_stat->flags&  ECRYPTFS_METADATA_IN_XATTR)
> +			file_size += crypt_stat->metadata_size;
> +	} else
> +		file_size = get_unaligned_be64(page_virt);
> +	i_size_write(inode, (loff_t)file_size);
> +	crypt_stat->flags |= ECRYPTFS_I_SIZE_INITIALIZED;
> +}
> +
>   /**
>    * ecryptfs_read_headers_virt
>    * @page_virt: The virtual address into which to read the headers
> @@ -1483,6 +1502,8 @@ static int ecryptfs_read_headers_virt(char *page_virt,
>   		rc = -EINVAL;
>   		goto out;
>   	}
> +	if (!(crypt_stat->flags&  ECRYPTFS_I_SIZE_INITIALIZED))
> +		ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode);
>   	offset += MAGIC_ECRYPTFS_MARKER_SIZE_BYTES;
>   	rc = ecryptfs_process_flags(crypt_stat, (page_virt + offset),
>   				&bytes_read);
> diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
> index 427478e..507500f 100644
> --- a/fs/ecryptfs/ecryptfs_kernel.h
> +++ b/fs/ecryptfs/ecryptfs_kernel.h
> @@ -269,6 +269,7 @@ struct ecryptfs_crypt_stat {
>   #define ECRYPTFS_ENCFN_USE_MOUNT_FNEK 0x00000800
>   #define ECRYPTFS_ENCFN_USE_FEK        0x00001000
>   #define ECRYPTFS_UNLINK_SIGS          0x00002000
> +#define ECRYPTFS_I_SIZE_INITIALIZED   0x00008000
>   	u32 flags;
>   	unsigned int file_version;
>   	size_t iv_bytes;
> @@ -629,6 +630,7 @@ struct ecryptfs_open_req {
>   int ecryptfs_interpose(struct dentry *hidden_dentry,
>   		       struct dentry *this_dentry, struct super_block *sb,
>   		       u32 flags);
> +void ecryptfs_i_size_init(const char *page_virt, struct inode *inode);
>   int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
>   					struct dentry *lower_dentry,
>   					struct inode *ecryptfs_dir_inode);
> diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
> index 7d1050e..d30aac2 100644
> --- a/fs/ecryptfs/file.c
> +++ b/fs/ecryptfs/file.c
> @@ -211,7 +211,8 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
>   	if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
>   		ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
>   		mutex_lock(&crypt_stat->cs_mutex);
> -		crypt_stat->flags&= ~(ECRYPTFS_ENCRYPTED);
> +		crypt_stat->flags&= ~(ECRYPTFS_I_SIZE_INITIALIZED
> +					| ECRYPTFS_ENCRYPTED);
>   		mutex_unlock(&crypt_stat->cs_mutex);
>   		rc = 0;
>   		goto out;
> diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
> index f99051b..442947f 100644
> --- a/fs/ecryptfs/inode.c
> +++ b/fs/ecryptfs/inode.c
> @@ -226,10 +226,8 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
>   	struct dentry *lower_dir_dentry;
>   	struct vfsmount *lower_mnt;
>   	struct inode *lower_inode;
> -	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
>   	struct ecryptfs_crypt_stat *crypt_stat;
>   	char *page_virt = NULL;
> -	u64 file_size;
>   	int rc = 0;
>
>   	lower_dir_dentry = lower_dentry->d_parent;
> @@ -302,18 +300,7 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
>   		}
>   		crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
>   	}
> -	mount_crypt_stat =&ecryptfs_superblock_to_private(
> -		ecryptfs_dentry->d_sb)->mount_crypt_stat;
> -	if (mount_crypt_stat->flags&  ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
> -		if (crypt_stat->flags&  ECRYPTFS_METADATA_IN_XATTR)
> -			file_size = (crypt_stat->metadata_size
> -				     + i_size_read(lower_dentry->d_inode));
> -		else
> -			file_size = i_size_read(lower_dentry->d_inode);
> -	} else {
> -		file_size = get_unaligned_be64(page_virt);
> -	}
> -	i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
> +	ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode);
>   out_free_kmem:
>   	kmem_cache_free(ecryptfs_header_cache_2, page_virt);
>   	goto out;
> @@ -927,7 +914,8 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
>   				goto out;
>   			}
>   			rc = 0;
> -			crypt_stat->flags&= ~(ECRYPTFS_ENCRYPTED);
> +			crypt_stat->flags&= ~(ECRYPTFS_I_SIZE_INITIALIZED
> +						| ECRYPTFS_ENCRYPTED);
>   		}
>   	}
>   	mutex_unlock(&crypt_stat->cs_mutex);
Herton Ronaldo Krzesinski - March 1, 2012, 8:14 p.m.
On Thu, Mar 01, 2012 at 07:22:29PM +0000, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
> 
> When failing to read the lower file's crypto metadata during a lookup,
> eCryptfs must continue on without throwing an error. For example, there
> may be a plaintext file in the lower mount point that the user wants to
> delete through the eCryptfs mount.
> 
> If an error is encountered while reading the metadata in lookup(), the
> eCryptfs inode's size could be incorrect. We must be sure to reread the
> plaintext inode size from the metadata when performing an open() or
> setattr(). The metadata is already being read in those paths, so this
> adds minimal performance overhead.
> 
> This patch introduces a flag which will track whether or not the
> plaintext inode size has been read so that an incorrect i_size can be
> fixed in the open() or setattr() paths.
> 
> BugLink: http://bugs.launchpad.net/bugs/509180
> 
> Cc: <stable@kernel.org>
> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
> 
> (backported from 3aeb86ea4cd15f728147a3bd5469a205ada8c767)
> Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  fs/ecryptfs/crypto.c          |   21 +++++++++++++++++++++
>  fs/ecryptfs/ecryptfs_kernel.h |    2 ++
>  fs/ecryptfs/file.c            |    3 ++-
>  fs/ecryptfs/inode.c           |   18 +++---------------
>  4 files changed, 28 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
> index 98a2a31..c0fe342 100644
> --- a/fs/ecryptfs/crypto.c
> +++ b/fs/ecryptfs/crypto.c
> @@ -1453,6 +1453,25 @@ static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat)
>  	crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
>  }
>  
> +void ecryptfs_i_size_init(const char *page_virt, struct inode *inode)
> +{
> +	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
> +	struct ecryptfs_crypt_stat *crypt_stat;
> +	u64 file_size;
> +
> +	crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
> +	mount_crypt_stat =
> +		&ecryptfs_superblock_to_private(inode->i_sb)->mount_crypt_stat;
> +	if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
> +		file_size = i_size_read(ecryptfs_inode_to_lower(inode));
> +		if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
> +			file_size += crypt_stat->metadata_size;
> +	} else
> +		file_size = get_unaligned_be64(page_virt);
> +	i_size_write(inode, (loff_t)file_size);
> +	crypt_stat->flags |= ECRYPTFS_I_SIZE_INITIALIZED;
> +}
> +
>  /**
>   * ecryptfs_read_headers_virt
>   * @page_virt: The virtual address into which to read the headers
> @@ -1483,6 +1502,8 @@ static int ecryptfs_read_headers_virt(char *page_virt,
>  		rc = -EINVAL;
>  		goto out;
>  	}
> +	if (!(crypt_stat->flags & ECRYPTFS_I_SIZE_INITIALIZED))
> +		ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode);
>  	offset += MAGIC_ECRYPTFS_MARKER_SIZE_BYTES;
>  	rc = ecryptfs_process_flags(crypt_stat, (page_virt + offset),
>  				    &bytes_read);
> diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
> index 427478e..507500f 100644
> --- a/fs/ecryptfs/ecryptfs_kernel.h
> +++ b/fs/ecryptfs/ecryptfs_kernel.h
> @@ -269,6 +269,7 @@ struct ecryptfs_crypt_stat {
>  #define ECRYPTFS_ENCFN_USE_MOUNT_FNEK 0x00000800
>  #define ECRYPTFS_ENCFN_USE_FEK        0x00001000
>  #define ECRYPTFS_UNLINK_SIGS          0x00002000
> +#define ECRYPTFS_I_SIZE_INITIALIZED   0x00008000
>  	u32 flags;
>  	unsigned int file_version;
>  	size_t iv_bytes;
> @@ -629,6 +630,7 @@ struct ecryptfs_open_req {
>  int ecryptfs_interpose(struct dentry *hidden_dentry,
>  		       struct dentry *this_dentry, struct super_block *sb,
>  		       u32 flags);
> +void ecryptfs_i_size_init(const char *page_virt, struct inode *inode);
>  int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
>  					struct dentry *lower_dentry,
>  					struct inode *ecryptfs_dir_inode);
> diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
> index 7d1050e..d30aac2 100644
> --- a/fs/ecryptfs/file.c
> +++ b/fs/ecryptfs/file.c
> @@ -211,7 +211,8 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
>  	if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
>  		ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
>  		mutex_lock(&crypt_stat->cs_mutex);
> -		crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
> +		crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
> +					| ECRYPTFS_ENCRYPTED);
>  		mutex_unlock(&crypt_stat->cs_mutex);
>  		rc = 0;
>  		goto out;
> diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
> index f99051b..442947f 100644
> --- a/fs/ecryptfs/inode.c
> +++ b/fs/ecryptfs/inode.c
> @@ -226,10 +226,8 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
>  	struct dentry *lower_dir_dentry;
>  	struct vfsmount *lower_mnt;
>  	struct inode *lower_inode;
> -	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
>  	struct ecryptfs_crypt_stat *crypt_stat;
>  	char *page_virt = NULL;
> -	u64 file_size;
>  	int rc = 0;
>  
>  	lower_dir_dentry = lower_dentry->d_parent;
> @@ -302,18 +300,7 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
>  		}
>  		crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
>  	}
> -	mount_crypt_stat = &ecryptfs_superblock_to_private(
> -		ecryptfs_dentry->d_sb)->mount_crypt_stat;
> -	if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
> -		if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
> -			file_size = (crypt_stat->metadata_size
> -				     + i_size_read(lower_dentry->d_inode));
> -		else
> -			file_size = i_size_read(lower_dentry->d_inode);
> -	} else {
> -		file_size = get_unaligned_be64(page_virt);
> -	}
> -	i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
> +	ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode);
>  out_free_kmem:
>  	kmem_cache_free(ecryptfs_header_cache_2, page_virt);
>  	goto out;
> @@ -927,7 +914,8 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
>  				goto out;
>  			}
>  			rc = 0;
> -			crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
> +			crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
> +						| ECRYPTFS_ENCRYPTED);
>  		}
>  	}
>  	mutex_unlock(&crypt_stat->cs_mutex);
> -- 
> 1.7.4.1
> 
> 
> -- 
> kernel-team mailing list
> kernel-team@lists.ubuntu.com
> https://lists.ubuntu.com/mailman/listinfo/kernel-team
>

Patch

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 98a2a31..c0fe342 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1453,6 +1453,25 @@  static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat)
 	crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
 }
 
+void ecryptfs_i_size_init(const char *page_virt, struct inode *inode)
+{
+	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+	struct ecryptfs_crypt_stat *crypt_stat;
+	u64 file_size;
+
+	crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
+	mount_crypt_stat =
+		&ecryptfs_superblock_to_private(inode->i_sb)->mount_crypt_stat;
+	if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
+		file_size = i_size_read(ecryptfs_inode_to_lower(inode));
+		if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
+			file_size += crypt_stat->metadata_size;
+	} else
+		file_size = get_unaligned_be64(page_virt);
+	i_size_write(inode, (loff_t)file_size);
+	crypt_stat->flags |= ECRYPTFS_I_SIZE_INITIALIZED;
+}
+
 /**
  * ecryptfs_read_headers_virt
  * @page_virt: The virtual address into which to read the headers
@@ -1483,6 +1502,8 @@  static int ecryptfs_read_headers_virt(char *page_virt,
 		rc = -EINVAL;
 		goto out;
 	}
+	if (!(crypt_stat->flags & ECRYPTFS_I_SIZE_INITIALIZED))
+		ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode);
 	offset += MAGIC_ECRYPTFS_MARKER_SIZE_BYTES;
 	rc = ecryptfs_process_flags(crypt_stat, (page_virt + offset),
 				    &bytes_read);
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 427478e..507500f 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -269,6 +269,7 @@  struct ecryptfs_crypt_stat {
 #define ECRYPTFS_ENCFN_USE_MOUNT_FNEK 0x00000800
 #define ECRYPTFS_ENCFN_USE_FEK        0x00001000
 #define ECRYPTFS_UNLINK_SIGS          0x00002000
+#define ECRYPTFS_I_SIZE_INITIALIZED   0x00008000
 	u32 flags;
 	unsigned int file_version;
 	size_t iv_bytes;
@@ -629,6 +630,7 @@  struct ecryptfs_open_req {
 int ecryptfs_interpose(struct dentry *hidden_dentry,
 		       struct dentry *this_dentry, struct super_block *sb,
 		       u32 flags);
+void ecryptfs_i_size_init(const char *page_virt, struct inode *inode);
 int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
 					struct dentry *lower_dentry,
 					struct inode *ecryptfs_dir_inode);
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 7d1050e..d30aac2 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -211,7 +211,8 @@  static int ecryptfs_open(struct inode *inode, struct file *file)
 	if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
 		ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
 		mutex_lock(&crypt_stat->cs_mutex);
-		crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
+		crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
+					| ECRYPTFS_ENCRYPTED);
 		mutex_unlock(&crypt_stat->cs_mutex);
 		rc = 0;
 		goto out;
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index f99051b..442947f 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -226,10 +226,8 @@  int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
 	struct dentry *lower_dir_dentry;
 	struct vfsmount *lower_mnt;
 	struct inode *lower_inode;
-	struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
 	struct ecryptfs_crypt_stat *crypt_stat;
 	char *page_virt = NULL;
-	u64 file_size;
 	int rc = 0;
 
 	lower_dir_dentry = lower_dentry->d_parent;
@@ -302,18 +300,7 @@  int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
 		}
 		crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
 	}
-	mount_crypt_stat = &ecryptfs_superblock_to_private(
-		ecryptfs_dentry->d_sb)->mount_crypt_stat;
-	if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
-		if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
-			file_size = (crypt_stat->metadata_size
-				     + i_size_read(lower_dentry->d_inode));
-		else
-			file_size = i_size_read(lower_dentry->d_inode);
-	} else {
-		file_size = get_unaligned_be64(page_virt);
-	}
-	i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
+	ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode);
 out_free_kmem:
 	kmem_cache_free(ecryptfs_header_cache_2, page_virt);
 	goto out;
@@ -927,7 +914,8 @@  static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
 				goto out;
 			}
 			rc = 0;
-			crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
+			crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
+						| ECRYPTFS_ENCRYPTED);
 		}
 	}
 	mutex_unlock(&crypt_stat->cs_mutex);