* [PATCH] procfs: stop using vmtruncate
@ 2011-06-20 22:47 Christoph Hellwig
2011-06-21 2:05 ` Al Viro
0 siblings, 1 reply; 3+ messages in thread
From: Christoph Hellwig @ 2011-06-20 22:47 UTC (permalink / raw)
To: viro; +Cc: linux-fsdevel
Procfs doens't have any ->truncate instances, so all vmtruncate calls can
be replaced with truncate_setsize, given that we've just done the
inode_newsize_ok check as part of inode_change_ok just before.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Index: linux-2.6/fs/proc/base.c
===================================================================
--- linux-2.6.orig/fs/proc/base.c 2011-06-10 11:51:06.203880498 +0200
+++ linux-2.6/fs/proc/base.c 2011-06-21 00:39:37.454049407 +0200
@@ -615,12 +615,8 @@ int proc_setattr(struct dentry *dentry,
if (error)
return error;
- if ((attr->ia_valid & ATTR_SIZE) &&
- attr->ia_size != i_size_read(inode)) {
- error = vmtruncate(inode, attr->ia_size);
- if (error)
- return error;
- }
+ if ((attr->ia_valid & ATTR_SIZE) && attr->ia_size != i_size_read(inode))
+ truncate_setsize(inode, attr->ia_size);
setattr_copy(inode, attr);
mark_inode_dirty(inode);
Index: linux-2.6/fs/proc/generic.c
===================================================================
--- linux-2.6.orig/fs/proc/generic.c 2011-06-10 11:51:06.203880498 +0200
+++ linux-2.6/fs/proc/generic.c 2011-06-21 00:39:27.764049898 +0200
@@ -251,7 +251,7 @@ static const struct file_operations proc
.write = proc_file_write,
};
-static int proc_notify_change(struct dentry *dentry, struct iattr *iattr)
+static int proc_file_setattr(struct dentry *dentry, struct iattr *iattr)
{
struct inode *inode = dentry->d_inode;
struct proc_dir_entry *de = PDE(inode);
@@ -262,11 +262,8 @@ static int proc_notify_change(struct den
return error;
if ((iattr->ia_valid & ATTR_SIZE) &&
- iattr->ia_size != i_size_read(inode)) {
- error = vmtruncate(inode, iattr->ia_size);
- if (error)
- return error;
- }
+ iattr->ia_size != i_size_read(inode))
+ truncate_setsize(inode, iattr->ia_size);
setattr_copy(inode, iattr);
mark_inode_dirty(inode);
@@ -290,7 +287,7 @@ static int proc_getattr(struct vfsmount
}
static const struct inode_operations proc_file_inode_operations = {
- .setattr = proc_notify_change,
+ .setattr = proc_file_setattr,
};
/*
@@ -549,7 +546,7 @@ static const struct file_operations proc
static const struct inode_operations proc_dir_inode_operations = {
.lookup = proc_lookup,
.getattr = proc_getattr,
- .setattr = proc_notify_change,
+ .setattr = proc_file_setattr,
};
static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
Index: linux-2.6/fs/proc/proc_sysctl.c
===================================================================
--- linux-2.6.orig/fs/proc/proc_sysctl.c 2011-06-10 11:51:06.203880498 +0200
+++ linux-2.6/fs/proc/proc_sysctl.c 2011-06-21 00:39:45.980715641 +0200
@@ -337,12 +337,8 @@ static int proc_sys_setattr(struct dentr
if (error)
return error;
- if ((attr->ia_valid & ATTR_SIZE) &&
- attr->ia_size != i_size_read(inode)) {
- error = vmtruncate(inode, attr->ia_size);
- if (error)
- return error;
- }
+ if ((attr->ia_valid & ATTR_SIZE) && attr->ia_size != i_size_read(inode))
+ truncate_setsize(inode, attr->ia_size);
setattr_copy(inode, attr);
mark_inode_dirty(inode);
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] procfs: stop using vmtruncate
2011-06-20 22:47 [PATCH] procfs: stop using vmtruncate Christoph Hellwig
@ 2011-06-21 2:05 ` Al Viro
2011-06-21 7:43 ` Christoph Hellwig
0 siblings, 1 reply; 3+ messages in thread
From: Al Viro @ 2011-06-21 2:05 UTC (permalink / raw)
To: Christoph Hellwig; +Cc: linux-fsdevel
On Mon, Jun 20, 2011 at 06:47:27PM -0400, Christoph Hellwig wrote:
> Procfs doens't have any ->truncate instances, so all vmtruncate calls can
> be replaced with truncate_setsize, given that we've just done the
> inode_newsize_ok check as part of inode_change_ok just before.
What files on procfs allow meaningful truncate anyway? I agree that
vmtruncate() there is bogus, but AFAICT we have the following picture:
* there are files with non-zero i_size (/proc/kcore and
/proc/bus/pci/*/*); for any of those ATTR_SIZE should fail and I don't
think it should fail silently.
* the rest has size 0 and for those ATTR_SIZE to non-0 length
should definitely fail with an error.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] procfs: stop using vmtruncate
2011-06-21 2:05 ` Al Viro
@ 2011-06-21 7:43 ` Christoph Hellwig
0 siblings, 0 replies; 3+ messages in thread
From: Christoph Hellwig @ 2011-06-21 7:43 UTC (permalink / raw)
To: Al Viro; +Cc: linux-fsdevel
On Tue, Jun 21, 2011 at 03:05:26AM +0100, Al Viro wrote:
> On Mon, Jun 20, 2011 at 06:47:27PM -0400, Christoph Hellwig wrote:
> > Procfs doens't have any ->truncate instances, so all vmtruncate calls can
> > be replaced with truncate_setsize, given that we've just done the
> > inode_newsize_ok check as part of inode_change_ok just before.
>
> What files on procfs allow meaningful truncate anyway? I agree that
> vmtruncate() there is bogus, but AFAICT we have the following picture:
> * there are files with non-zero i_size (/proc/kcore and
> /proc/bus/pci/*/*); for any of those ATTR_SIZE should fail and I don't
> think it should fail silently.
> * the rest has size 0 and for those ATTR_SIZE to non-0 length
> should definitely fail with an error.
True. We probably should simply refuse any ATTR_SIZE calls.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2011-06-21 2:05 ` Al Viro
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