Messages in this thread Patch in this message | | | From | Namhyung Kim <> | Subject | [RFC/PATCH 1/2] pstore: Protect unlink with read_mutex | Date | Wed, 19 Oct 2016 10:23:40 +0900 |
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When update_ms is set, pstore_get_records() will be called when there's a new entry. But unlink can be called at the same time and might contend with the open-read-close loop. Depending on the implementation of platform driver, it may be safe or not. But I think it'd be better to protect those race in the first place.
Cc: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- fs/pstore/inode.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index 1781dc50762e..75728dfae0a6 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -197,11 +197,14 @@ static int pstore_unlink(struct inode *dir, struct dentry *dentry) if (err) return err; - if (p->psi->erase) + if (p->psi->erase) { + mutex_lock(&p->psi->read_mutex); p->psi->erase(p->type, p->id, p->count, d_inode(dentry)->i_ctime, p->psi); - else + mutex_unlock(&p->psi->read_mutex); + } else { return -EPERM; + } return simple_unlink(dir, dentry); } -- 2.9.3
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