[PATCH 2/4] sysfs: make the sysfs_addrm_cxt->removed list FIFO

Tejun Heo
2007-09-20T07:27:37Z

Add sysfs_addrm_cxt->removed_tail to make the ->removed list FIFO.
This will be used to implement care-free suicide.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---
fs/sysfs/dir.c | 7 +++++--
fs/sysfs/sysfs.h | 2 +-
2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index ad3394a..c902bdc 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -361,6 +361,7 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,

memset(acxt, 0, sizeof(*acxt));
acxt->parent_sd = parent_sd;
+ acxt->removed_tail = &acxt->removed;

/* Lookup parent inode. inode initialization and I_NEW
* clearing are protected by sysfs_mutex. By grabbing it and
@@ -448,8 +449,10 @@ void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
sysfs_unlink_sibling(sd);

sd->s_flags |= SYSFS_FLAG_REMOVED;
- sd->s_sibling = acxt->removed;
- acxt->removed = sd;
+ *acxt->removed_tail = sd;
+ /* keep them in FIFO order, suicide check depends on it */
+ acxt->removed_tail = &sd->s_sibling;
+ *acxt->removed_tail = NULL;

if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode)
drop_nlink(acxt->parent_inode);
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 269c845..be16947 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -71,7 +71,7 @@ static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
struct sysfs_addrm_cxt {
struct sysfs_dirent *parent_sd;
struct inode *parent_inode;
- struct sysfs_dirent *removed;
+ struct sysfs_dirent *removed, **removed_tail;
int cnt;
};

--
1.5.0.3