* truncate in ecryptfs
@ 2009-10-14 15:12 Christoph Hellwig
2009-10-14 15:37 ` Tyler Hicks
0 siblings, 1 reply; 5+ messages in thread
From: Christoph Hellwig @ 2009-10-14 15:12 UTC (permalink / raw)
To: tyhicks, kirkland; +Cc: linux-fsdevel
It looks like ecryptfs calls vmtruncate directly on the lower filesystem,
which is quite wrong. Vmtruncate is only a helper for the filesystem,
and while most filesystems end up calling vmtruncate from their
->setattr implementation if ATTR_SIZE is set there are many that require
additional work. I think ecryptfs needs to got through notify_change()
/ ->setattr if it wants truncate to work reliably and without silent
corruption or leaking blocks on a variety of filesystems.
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: truncate in ecryptfs
2009-10-14 15:12 truncate in ecryptfs Christoph Hellwig
@ 2009-10-14 15:37 ` Tyler Hicks
2009-10-15 4:19 ` [PATCH] eCryptfs: Use notify_change for truncating lower inodes Tyler Hicks
0 siblings, 1 reply; 5+ messages in thread
From: Tyler Hicks @ 2009-10-14 15:37 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: kirkland, linux-fsdevel
On 10/14/2009 10:12 AM, Christoph Hellwig wrote:
> It looks like ecryptfs calls vmtruncate directly on the lower filesystem,
> which is quite wrong. Vmtruncate is only a helper for the filesystem,
> and while most filesystems end up calling vmtruncate from their
> ->setattr implementation if ATTR_SIZE is set there are many that require
> additional work. I think ecryptfs needs to got through notify_change()
> / ->setattr if it wants truncate to work reliably and without silent
> corruption or leaking blocks on a variety of filesystems.
Thanks Christoph! I agree and will write up a patch shortly. I also
opened a bug to track the progress:
https://bugs.launchpad.net/ecryptfs/+bug/451368
Tyler
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH] eCryptfs: Use notify_change for truncating lower inodes
2009-10-14 15:37 ` Tyler Hicks
@ 2009-10-15 4:19 ` Tyler Hicks
2009-10-15 16:55 ` Dustin Kirkland
2009-10-25 7:22 ` Christoph Hellwig
0 siblings, 2 replies; 5+ messages in thread
From: Tyler Hicks @ 2009-10-15 4:19 UTC (permalink / raw)
To: linux-fsdevel; +Cc: Christoph Hellwig, Dustin Kirkland, ecryptfs-devel
When truncating inodes in the lower filesystem, eCryptfs directly
invoked vmtruncate(). As Christoph Hellwig pointed out, vmtruncate() is
a filesystem helper function, but filesystems may need to do more than
just a call to vmtruncate().
This patch moves the lower inode truncation out of ecryptfs_truncate()
and renames the function to truncate_upper(). truncate_upper() updates
an iattr for the lower inode to indicate if the lower inode needs to be
truncated upon return. ecryptfs_setattr() then calls notify_change(),
using the updated iattr for the lower inode, to complete the truncation.
For eCryptfs functions needing to truncate, ecryptfs_truncate() is
reintroduced as a simple way to truncate the upper inode to a specified
size and then truncate the lower inode accordingly.
https://bugs.launchpad.net/bugs/451368
Reported-by: Christoph Hellwig <hch@lst.de>
Cc: Dustin Kirkland <kirkland@canonical.com>
Cc: ecryptfs-devel@lists.launchpad.net
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
---
fs/ecryptfs/inode.c | 97 ++++++++++++++++++++++++++++++++++-----------------
1 files changed, 65 insertions(+), 32 deletions(-)
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 056fed6..371e92e 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -772,18 +772,23 @@ upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
}
/**
- * ecryptfs_truncate
+ * truncate_upper
* @dentry: The ecryptfs layer dentry
- * @new_length: The length to expand the file to
+ * @ia: Address of the ecryptfs inode's attributes
+ * @lower_ia: Address of the lower inode's attributes
*
* Function to handle truncations modifying the size of the file. Note
* that the file sizes are interpolated. When expanding, we are simply
- * writing strings of 0's out. When truncating, we need to modify the
- * underlying file size according to the page index interpolations.
+ * writing strings of 0's out. When truncating, we truncate the upper
+ * inode and update the lower_ia according to the page index
+ * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
+ * the caller must use lower_ia in a call to notify_change() to perform
+ * the truncation of the lower inode.
*
* Returns zero on success; non-zero otherwise
*/
-int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
+static int truncate_upper(struct dentry *dentry, struct iattr *ia,
+ struct iattr *lower_ia)
{
int rc = 0;
struct inode *inode = dentry->d_inode;
@@ -794,7 +799,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
loff_t lower_size_before_truncate;
loff_t lower_size_after_truncate;
- if (unlikely((new_length == i_size)))
+ if (unlikely((ia->ia_size == i_size)))
goto out;
crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
/* Set up a fake ecryptfs file, this is used to interface with
@@ -815,28 +820,30 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
&fake_ecryptfs_file,
ecryptfs_inode_to_private(dentry->d_inode)->lower_file);
/* Switch on growing or shrinking file */
- if (new_length > i_size) {
+ if (ia->ia_size > i_size) {
char zero[] = { 0x00 };
+ lower_ia->ia_valid &= ~ATTR_SIZE;
/* Write a single 0 at the last position of the file;
* this triggers code that will fill in 0's throughout
* the intermediate portion of the previous end of the
* file and the new and of the file */
rc = ecryptfs_write(&fake_ecryptfs_file, zero,
- (new_length - 1), 1);
- } else { /* new_length < i_size_read(inode) */
- /* We're chopping off all the pages down do the page
- * in which new_length is located. Fill in the end of
- * that page from (new_length & ~PAGE_CACHE_MASK) to
+ (ia->ia_size - 1), 1);
+ } else { /* ia->ia_size < i_size_read(inode) */
+ /* We're chopping off all the pages down to the page
+ * in which ia->ia_size is located. Fill in the end of
+ * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
* PAGE_CACHE_SIZE with zeros. */
size_t num_zeros = (PAGE_CACHE_SIZE
- - (new_length & ~PAGE_CACHE_MASK));
+ - (ia->ia_size & ~PAGE_CACHE_MASK));
if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
- rc = vmtruncate(inode, new_length);
+ rc = vmtruncate(inode, ia->ia_size);
if (rc)
goto out_free;
- rc = vmtruncate(lower_dentry->d_inode, new_length);
+ lower_ia->ia_size = ia->ia_size;
+ lower_ia->ia_valid |= ATTR_SIZE;
goto out_free;
}
if (num_zeros) {
@@ -848,7 +855,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
goto out_free;
}
rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt,
- new_length, num_zeros);
+ ia->ia_size, num_zeros);
kfree(zeros_virt);
if (rc) {
printk(KERN_ERR "Error attempting to zero out "
@@ -857,7 +864,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
goto out_free;
}
}
- vmtruncate(inode, new_length);
+ vmtruncate(inode, ia->ia_size);
rc = ecryptfs_write_inode_size_to_metadata(inode);
if (rc) {
printk(KERN_ERR "Problem with "
@@ -870,10 +877,12 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
lower_size_before_truncate =
upper_size_to_lower_size(crypt_stat, i_size);
lower_size_after_truncate =
- upper_size_to_lower_size(crypt_stat, new_length);
- if (lower_size_after_truncate < lower_size_before_truncate)
- vmtruncate(lower_dentry->d_inode,
- lower_size_after_truncate);
+ upper_size_to_lower_size(crypt_stat, ia->ia_size);
+ if (lower_size_after_truncate < lower_size_before_truncate) {
+ lower_ia->ia_size = lower_size_after_truncate;
+ lower_ia->ia_valid |= ATTR_SIZE;
+ } else
+ lower_ia->ia_valid &= ~ATTR_SIZE;
}
out_free:
if (ecryptfs_file_to_private(&fake_ecryptfs_file))
@@ -883,6 +892,33 @@ out:
return rc;
}
+/**
+ * ecryptfs_truncate
+ * @dentry: The ecryptfs layer dentry
+ * @new_length: The length to expand the file to
+ *
+ * Simple function that handles the truncation of an eCryptfs inode and
+ * its corresponding lower inode.
+ *
+ * Returns zero on success; non-zero otherwise
+ */
+int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
+{
+ struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
+ struct iattr lower_ia = { .ia_valid = 0 };
+ int rc;
+
+ rc = truncate_upper(dentry, &ia, &lower_ia);
+ if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
+ struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
+
+ mutex_lock(&lower_dentry->d_inode->i_mutex);
+ rc = notify_change(lower_dentry, &lower_ia);
+ mutex_unlock(&lower_dentry->d_inode->i_mutex);
+ }
+ return rc;
+}
+
static int
ecryptfs_permission(struct inode *inode, int mask)
{
@@ -905,6 +941,7 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
{
int rc = 0;
struct dentry *lower_dentry;
+ struct iattr lower_ia;
struct inode *inode;
struct inode *lower_inode;
struct ecryptfs_crypt_stat *crypt_stat;
@@ -943,15 +980,11 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
}
}
mutex_unlock(&crypt_stat->cs_mutex);
+ memcpy(&lower_ia, ia, sizeof(lower_ia));
+ if (ia->ia_valid & ATTR_FILE)
+ lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
if (ia->ia_valid & ATTR_SIZE) {
- ecryptfs_printk(KERN_DEBUG,
- "ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n",
- ia->ia_valid, ATTR_SIZE);
- rc = ecryptfs_truncate(dentry, ia->ia_size);
- /* ecryptfs_truncate handles resizing of the lower file */
- ia->ia_valid &= ~ATTR_SIZE;
- ecryptfs_printk(KERN_DEBUG, "ia->ia_valid = [%x]\n",
- ia->ia_valid);
+ rc = truncate_upper(dentry, ia, &lower_ia);
if (rc < 0)
goto out;
}
@@ -960,11 +993,11 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
* mode change is for clearing setuid/setgid bits. Allow lower fs
* to interpret this in its own way.
*/
- if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
- ia->ia_valid &= ~ATTR_MODE;
+ if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
+ lower_ia.ia_valid &= ~ATTR_MODE;
mutex_lock(&lower_dentry->d_inode->i_mutex);
- rc = notify_change(lower_dentry, ia);
+ rc = notify_change(lower_dentry, &lower_ia);
mutex_unlock(&lower_dentry->d_inode->i_mutex);
out:
fsstack_copy_attr_all(inode, lower_inode, NULL);
--
1.6.2.5
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] eCryptfs: Use notify_change for truncating lower inodes
2009-10-15 4:19 ` [PATCH] eCryptfs: Use notify_change for truncating lower inodes Tyler Hicks
@ 2009-10-15 16:55 ` Dustin Kirkland
2009-10-25 7:22 ` Christoph Hellwig
1 sibling, 0 replies; 5+ messages in thread
From: Dustin Kirkland @ 2009-10-15 16:55 UTC (permalink / raw)
To: Tyler Hicks; +Cc: linux-fsdevel, Christoph Hellwig, ecryptfs-devel
[-- Attachment #1: Type: text/plain, Size: 9239 bytes --]
On Wed, 2009-10-14 at 23:19 -0500, Tyler Hicks wrote:
> When truncating inodes in the lower filesystem, eCryptfs directly
> invoked vmtruncate(). As Christoph Hellwig pointed out, vmtruncate() is
> a filesystem helper function, but filesystems may need to do more than
> just a call to vmtruncate().
>
> This patch moves the lower inode truncation out of ecryptfs_truncate()
> and renames the function to truncate_upper(). truncate_upper() updates
> an iattr for the lower inode to indicate if the lower inode needs to be
> truncated upon return. ecryptfs_setattr() then calls notify_change(),
> using the updated iattr for the lower inode, to complete the truncation.
>
> For eCryptfs functions needing to truncate, ecryptfs_truncate() is
> reintroduced as a simple way to truncate the upper inode to a specified
> size and then truncate the lower inode accordingly.
>
> https://bugs.launchpad.net/bugs/451368
>
> Reported-by: Christoph Hellwig <hch@lst.de>
> Cc: Dustin Kirkland <kirkland@canonical.com>
> Cc: ecryptfs-devel@lists.launchpad.net
> Cc: linux-fsdevel@vger.kernel.org
> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Thanks for tackling, this, Tyler. Looks good to me.
Acked-by: Dustin Kirkland <kirkland@canonical.com>
> ---
> fs/ecryptfs/inode.c | 97 ++++++++++++++++++++++++++++++++++-----------------
> 1 files changed, 65 insertions(+), 32 deletions(-)
>
> diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
> index 056fed6..371e92e 100644
> --- a/fs/ecryptfs/inode.c
> +++ b/fs/ecryptfs/inode.c
> @@ -772,18 +772,23 @@ upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
> }
>
> /**
> - * ecryptfs_truncate
> + * truncate_upper
> * @dentry: The ecryptfs layer dentry
> - * @new_length: The length to expand the file to
> + * @ia: Address of the ecryptfs inode's attributes
> + * @lower_ia: Address of the lower inode's attributes
> *
> * Function to handle truncations modifying the size of the file. Note
> * that the file sizes are interpolated. When expanding, we are simply
> - * writing strings of 0's out. When truncating, we need to modify the
> - * underlying file size according to the page index interpolations.
> + * writing strings of 0's out. When truncating, we truncate the upper
> + * inode and update the lower_ia according to the page index
> + * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
> + * the caller must use lower_ia in a call to notify_change() to perform
> + * the truncation of the lower inode.
> *
> * Returns zero on success; non-zero otherwise
> */
> -int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
> +static int truncate_upper(struct dentry *dentry, struct iattr *ia,
> + struct iattr *lower_ia)
> {
> int rc = 0;
> struct inode *inode = dentry->d_inode;
> @@ -794,7 +799,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
> loff_t lower_size_before_truncate;
> loff_t lower_size_after_truncate;
>
> - if (unlikely((new_length == i_size)))
> + if (unlikely((ia->ia_size == i_size)))
> goto out;
> crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
> /* Set up a fake ecryptfs file, this is used to interface with
> @@ -815,28 +820,30 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
> &fake_ecryptfs_file,
> ecryptfs_inode_to_private(dentry->d_inode)->lower_file);
> /* Switch on growing or shrinking file */
> - if (new_length > i_size) {
> + if (ia->ia_size > i_size) {
> char zero[] = { 0x00 };
>
> + lower_ia->ia_valid &= ~ATTR_SIZE;
> /* Write a single 0 at the last position of the file;
> * this triggers code that will fill in 0's throughout
> * the intermediate portion of the previous end of the
> * file and the new and of the file */
> rc = ecryptfs_write(&fake_ecryptfs_file, zero,
> - (new_length - 1), 1);
> - } else { /* new_length < i_size_read(inode) */
> - /* We're chopping off all the pages down do the page
> - * in which new_length is located. Fill in the end of
> - * that page from (new_length & ~PAGE_CACHE_MASK) to
> + (ia->ia_size - 1), 1);
> + } else { /* ia->ia_size < i_size_read(inode) */
> + /* We're chopping off all the pages down to the page
> + * in which ia->ia_size is located. Fill in the end of
> + * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
> * PAGE_CACHE_SIZE with zeros. */
> size_t num_zeros = (PAGE_CACHE_SIZE
> - - (new_length & ~PAGE_CACHE_MASK));
> + - (ia->ia_size & ~PAGE_CACHE_MASK));
>
> if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
> - rc = vmtruncate(inode, new_length);
> + rc = vmtruncate(inode, ia->ia_size);
> if (rc)
> goto out_free;
> - rc = vmtruncate(lower_dentry->d_inode, new_length);
> + lower_ia->ia_size = ia->ia_size;
> + lower_ia->ia_valid |= ATTR_SIZE;
> goto out_free;
> }
> if (num_zeros) {
> @@ -848,7 +855,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
> goto out_free;
> }
> rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt,
> - new_length, num_zeros);
> + ia->ia_size, num_zeros);
> kfree(zeros_virt);
> if (rc) {
> printk(KERN_ERR "Error attempting to zero out "
> @@ -857,7 +864,7 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
> goto out_free;
> }
> }
> - vmtruncate(inode, new_length);
> + vmtruncate(inode, ia->ia_size);
> rc = ecryptfs_write_inode_size_to_metadata(inode);
> if (rc) {
> printk(KERN_ERR "Problem with "
> @@ -870,10 +877,12 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
> lower_size_before_truncate =
> upper_size_to_lower_size(crypt_stat, i_size);
> lower_size_after_truncate =
> - upper_size_to_lower_size(crypt_stat, new_length);
> - if (lower_size_after_truncate < lower_size_before_truncate)
> - vmtruncate(lower_dentry->d_inode,
> - lower_size_after_truncate);
> + upper_size_to_lower_size(crypt_stat, ia->ia_size);
> + if (lower_size_after_truncate < lower_size_before_truncate) {
> + lower_ia->ia_size = lower_size_after_truncate;
> + lower_ia->ia_valid |= ATTR_SIZE;
> + } else
> + lower_ia->ia_valid &= ~ATTR_SIZE;
> }
> out_free:
> if (ecryptfs_file_to_private(&fake_ecryptfs_file))
> @@ -883,6 +892,33 @@ out:
> return rc;
> }
>
> +/**
> + * ecryptfs_truncate
> + * @dentry: The ecryptfs layer dentry
> + * @new_length: The length to expand the file to
> + *
> + * Simple function that handles the truncation of an eCryptfs inode and
> + * its corresponding lower inode.
> + *
> + * Returns zero on success; non-zero otherwise
> + */
> +int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
> +{
> + struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
> + struct iattr lower_ia = { .ia_valid = 0 };
> + int rc;
> +
> + rc = truncate_upper(dentry, &ia, &lower_ia);
> + if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
> + struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
> +
> + mutex_lock(&lower_dentry->d_inode->i_mutex);
> + rc = notify_change(lower_dentry, &lower_ia);
> + mutex_unlock(&lower_dentry->d_inode->i_mutex);
> + }
> + return rc;
> +}
> +
> static int
> ecryptfs_permission(struct inode *inode, int mask)
> {
> @@ -905,6 +941,7 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
> {
> int rc = 0;
> struct dentry *lower_dentry;
> + struct iattr lower_ia;
> struct inode *inode;
> struct inode *lower_inode;
> struct ecryptfs_crypt_stat *crypt_stat;
> @@ -943,15 +980,11 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
> }
> }
> mutex_unlock(&crypt_stat->cs_mutex);
> + memcpy(&lower_ia, ia, sizeof(lower_ia));
> + if (ia->ia_valid & ATTR_FILE)
> + lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
> if (ia->ia_valid & ATTR_SIZE) {
> - ecryptfs_printk(KERN_DEBUG,
> - "ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n",
> - ia->ia_valid, ATTR_SIZE);
> - rc = ecryptfs_truncate(dentry, ia->ia_size);
> - /* ecryptfs_truncate handles resizing of the lower file */
> - ia->ia_valid &= ~ATTR_SIZE;
> - ecryptfs_printk(KERN_DEBUG, "ia->ia_valid = [%x]\n",
> - ia->ia_valid);
> + rc = truncate_upper(dentry, ia, &lower_ia);
> if (rc < 0)
> goto out;
> }
> @@ -960,11 +993,11 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
> * mode change is for clearing setuid/setgid bits. Allow lower fs
> * to interpret this in its own way.
> */
> - if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
> - ia->ia_valid &= ~ATTR_MODE;
> + if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
> + lower_ia.ia_valid &= ~ATTR_MODE;
>
> mutex_lock(&lower_dentry->d_inode->i_mutex);
> - rc = notify_change(lower_dentry, ia);
> + rc = notify_change(lower_dentry, &lower_ia);
> mutex_unlock(&lower_dentry->d_inode->i_mutex);
> out:
> fsstack_copy_attr_all(inode, lower_inode, NULL);
[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 197 bytes --]
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] eCryptfs: Use notify_change for truncating lower inodes
2009-10-15 4:19 ` [PATCH] eCryptfs: Use notify_change for truncating lower inodes Tyler Hicks
2009-10-15 16:55 ` Dustin Kirkland
@ 2009-10-25 7:22 ` Christoph Hellwig
1 sibling, 0 replies; 5+ messages in thread
From: Christoph Hellwig @ 2009-10-25 7:22 UTC (permalink / raw)
To: Tyler Hicks
Cc: linux-fsdevel, Christoph Hellwig, Dustin Kirkland, ecryptfs-devel
On Wed, Oct 14, 2009 at 11:19:37PM -0500, Tyler Hicks wrote:
> When truncating inodes in the lower filesystem, eCryptfs directly
> invoked vmtruncate(). As Christoph Hellwig pointed out, vmtruncate() is
> a filesystem helper function, but filesystems may need to do more than
> just a call to vmtruncate().
>
> This patch moves the lower inode truncation out of ecryptfs_truncate()
> and renames the function to truncate_upper(). truncate_upper() updates
> an iattr for the lower inode to indicate if the lower inode needs to be
> truncated upon return. ecryptfs_setattr() then calls notify_change(),
> using the updated iattr for the lower inode, to complete the truncation.
>
> For eCryptfs functions needing to truncate, ecryptfs_truncate() is
> reintroduced as a simple way to truncate the upper inode to a specified
> size and then truncate the lower inode accordingly.
Thanks, this looks correct to me from glacing over it.
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2009-10-25 7:22 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2009-10-14 15:12 truncate in ecryptfs Christoph Hellwig
2009-10-14 15:37 ` Tyler Hicks
2009-10-15 4:19 ` [PATCH] eCryptfs: Use notify_change for truncating lower inodes Tyler Hicks
2009-10-15 16:55 ` Dustin Kirkland
2009-10-25 7:22 ` Christoph Hellwig
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