2008-10-31 10:47:40

by David Howells

Subject: Wrapping Ext4 credential accesses

Hi Ted,

Can you add the attached patch into the ext4 tree please? It wraps credential
accesses (current->fsuid -> current_fsuid() for example) so that moving to a
detached cred structure is easier. The prerequisite patch has been upstream
for a while. Hopefully we can get Linus to take the rest of the patches in
the next merge window.

This'll make it easier for Stephen Rothwell to maintain linux-next.

Thanks,
David
---
From: David Howells <[email protected]>

CRED: Wrap task credential accesses in the Ext4 filesystem

Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.

Signed-off-by: David Howells <[email protected]>
Reviewed-by: James Morris <[email protected]>
Acked-by: Serge Hallyn <[email protected]>
Cc: Stephen Tweedie <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: [email protected]
Cc: [email protected]
---

fs/ext4/balloc.c | 5 ++---
fs/ext4/ialloc.c | 4 ++--
2 files changed, 4 insertions(+), 5 deletions(-)


diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index b9821be..5ede818 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -601,7 +601,7 @@ int ext4_claim_free_blocks(struct ext4_sb_info *sbi,
dirty_blocks = percpu_counter_read_positive(dbc);

if (!capable(CAP_SYS_RESOURCE) &&
- sbi->s_resuid != current->fsuid &&
+ sbi->s_resuid != current_fsuid() &&
(sbi->s_resgid == 0 || !in_group_p(sbi->s_resgid)))
root_blocks = ext4_r_blocks_count(sbi->s_es);

@@ -648,7 +648,7 @@ ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi,
dirty_blocks = percpu_counter_read_positive(dbc);

if (!capable(CAP_SYS_RESOURCE) &&
- sbi->s_resuid != current->fsuid &&
+ sbi->s_resuid != current_fsuid() &&
(sbi->s_resgid == 0 || !in_group_p(sbi->s_resgid)))
root_blocks = ext4_r_blocks_count(sbi->s_es);

@@ -666,7 +666,6 @@ ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi,
return nblocks;
}

-
/**
* ext4_should_retry_alloc()
* @sb: super block
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index fe34d74..c8ea50e 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -785,7 +785,7 @@ got:
spin_unlock(sb_bgl_lock(sbi, flex_group));
}

- inode->i_uid = current->fsuid;
+ inode->i_uid = current_fsuid();
if (test_opt(sb, GRPID))
inode->i_gid = dir->i_gid;
else if (dir->i_mode & S_ISGID) {
@@ -793,7 +793,7 @@ got:
if (S_ISDIR(mode))
mode |= S_ISGID;
} else
- inode->i_gid = current->fsgid;
+ inode->i_gid = current_fsgid();
inode->i_mode = mode;

inode->i_ino = ino + group * EXT4_INODES_PER_GROUP(sb);

2008-10-31 14:10:49

by Theodore Ts'o

Subject: Re: Wrapping Ext4 credential accesses

On Fri, Oct 31, 2008 at 10:47:16AM +0000, David Howells wrote:
>
> Can you add the attached patch into the ext4 tree please? It wraps credential
> accesses (current->fsuid -> current_fsuid() for example) so that moving to a
> detached cred structure is easier. The prerequisite patch has been upstream
> for a while. Hopefully we can get Linus to take the rest of the patches in
> the next merge window.

Sure! You're not looking for this to be merged before the next merge
window, correct? So it will be Ok if I carry this patch and push this
at the next merge window?

- Ted

2008-10-31 15:08:59

by David Howells

Subject: Re: Wrapping Ext4 credential accesses

Theodore Tso <[email protected]> wrote:

> Sure! You're not looking for this to be merged before the next merge
> window, correct? So it will be Ok if I carry this patch and push this
> at the next merge window?

That's fine. It's mainly to make Stephen's life easier.

Thanks,
David