[Qemu-devel] [PATCH] Fix bug with virtio-9p rename

[Qemu-devel] [PATCH] Fix bug with virtio-9p rename

[Sassan Panahinejad]

After renaming a file, any existing references to the file are updated.
However, in addition to this, it would update any files whos names began with that of the file being moved.
Therefore when renaming somefile.txt to somefile.txt-old, any references to somefile.txt-new became somefile.txt-old-new.
This breaks debconf and probably many other applications.
This patch fixes the problem. Now only files exactly matching, or files which are a subdirectory of a directory being moved are affected.

Signed-off-by: Sassan Panahinejad <sassan@sassan.me.uk>
---
 hw/virtio-9p.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
index 2530f6d..a2f096d 100644
--- a/hw/virtio-9p.c
+++ b/hw/virtio-9p.c
@@ -2810,8 +2810,15 @@ static int v9fs_complete_rename(V9fsState *s, V9fsRenameState *vs)
                     */
                     continue;
                 }
+                /*
+                * Fix the name if
+                * A: The file is the one we're moving
+                * Or B: The file is a subdirectory of one we're moving
+                */
                 if (!strncmp(vs->fidp->path.data, fidp->path.data,
-                    strlen(vs->fidp->path.data))) {
+                    strlen(vs->fidp->path.data)) &&
+                    (strlen(vs->fidp->path.data) == strlen(fidp->path.data) ||
+                    fidp->path.data[strlen(vs->fidp->path.data)] == '/')) {
                     /* replace the name */
                     v9fs_fix_path(&fidp->path, &vs->name,
                                   strlen(vs->fidp->path.data));
-- 
1.7.0.4

Re: [Qemu-devel] [PATCH] Fix bug with virtio-9p rename

[Sassan Panahinejad]

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Malahal Naineni's patch "Stop renaming files with similar name!" (posted
since this one) also fixes this bug.
I don't mind which one gets merged, as long as the bug gets fixed ;)

Sassan


On 27 April 2011 19:30, Sassan Panahinejad <sassan@sassan.me.uk> wrote:

> After renaming a file, any existing references to the file are updated.
> However, in addition to this, it would update any files whos names began
> with that of the file being moved.
> Therefore when renaming somefile.txt to somefile.txt-old, any references to
> somefile.txt-new became somefile.txt-old-new.
> This breaks debconf and probably many other applications.
> This patch fixes the problem. Now only files exactly matching, or files
> which are a subdirectory of a directory being moved are affected.
>
> Signed-off-by: Sassan Panahinejad <sassan@sassan.me.uk>
> ---
>  hw/virtio-9p.c |    9 ++++++++-
>  1 files changed, 8 insertions(+), 1 deletions(-)
>
> diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
> index 2530f6d..a2f096d 100644
> --- a/hw/virtio-9p.c
> +++ b/hw/virtio-9p.c
> @@ -2810,8 +2810,15 @@ static int v9fs_complete_rename(V9fsState *s,
> V9fsRenameState *vs)
>                     */
>                     continue;
>                 }
> +                /*
> +                * Fix the name if
> +                * A: The file is the one we're moving
> +                * Or B: The file is a subdirectory of one we're moving
> +                */
>                 if (!strncmp(vs->fidp->path.data, fidp->path.data,
> -                    strlen(vs->fidp->path.data))) {
> +                    strlen(vs->fidp->path.data)) &&
> +                    (strlen(vs->fidp->path.data) ==
> strlen(fidp->path.data) ||
> +                    fidp->path.data[strlen(vs->fidp->path.data)] == '/'))
> {
>                     /* replace the name */
>                     v9fs_fix_path(&fidp->path, &vs->name,
>                                   strlen(vs->fidp->path.data));
> --
> 1.7.0.4
>
>

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