[PATCH -mm 3/10] unshare system call -v5 : unshare filesystem info

From: JANAK DESAI
Date: Wed Jan 11 2006 - 23:15:21 EST


[PATCH -mm 3/10] unshare system call: allow unsharing of filesystem info

If filesystem structure is being shared, allocate a new one and
copy information from the current, shared, structure.

Changes since -v4 of this patch submitted on 12/13/05:
- none

Signed-off-by: Janak Desai <janak@xxxxxxxxxx>

---

fork.c | 9 ++++++---
1 files changed, 6 insertions(+), 3 deletions(-)

diff -Naurp 2.6.15-mm3+unsh-base/kernel/fork.c 2.6.15-mm3+unsh-fs/kernel/fork.c
--- 2.6.15-mm3+unsh-base/kernel/fork.c 2006-01-11 22:46:49.000000000 +0000
+++ 2.6.15-mm3+unsh-fs/kernel/fork.c 2006-01-12 00:26:46.000000000 +0000
@@ -1371,15 +1371,18 @@ static int unshare_thread(unsigned long
}

/*
- * Unsharing of fs info for tasks created with CLONE_FS is not supported yet
+ * Unshare the filesystem structure if it is being shared
*/
static int unshare_fs(unsigned long unshare_flags, struct fs_struct **new_fsp)
{
struct fs_struct *fs = current->fs;

if ((unshare_flags & CLONE_FS) &&
- (fs && atomic_read(&fs->count) > 1))
- return -EINVAL;
+ (fs && atomic_read(&fs->count) > 1)) {
+ *new_fsp = __copy_fs_struct(current->fs);
+ if (!*new_fsp)
+ return -ENOMEM;
+ }

return 0;
}


-
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