diff options
| author | Yan, Zheng <zyan@redhat.com> | 2017-12-15 11:15:36 +0800 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2018-01-29 18:36:08 +0100 |
| commit | 5d988308283ecf062fa88f20ae05c52cce0bcdca (patch) | |
| tree | fdc84f449e10eab2f74123d38fc0f3dcf26e5b54 /fs/ceph/file.c | |
| parent | 5495c2d04f85da09512f5f346ed24dc0261d905d (diff) | |
ceph: track read contexts in ceph_file_info
Previously ceph_read_iter() uses current->journal to pass context info
to ceph_readpages(), so that ceph_readpages() can distinguish read(2)
from readahead(2)/fadvise(2)/madvise(2). The problem is that page fault
can happen when copying data to userspace memory. Page fault may call
other filesystem's page_mkwrite() if the userspace memory is mapped to a
file. The later filesystem may also want to use current->journal.
The fix is define a on-stack data structure in ceph_read_iter(), add it
to context list in ceph_file_info. ceph_readpages() searches the list,
find if there is a context belongs to current thread.
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'fs/ceph/file.c')
| -rw-r--r-- | fs/ceph/file.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/fs/ceph/file.c b/fs/ceph/file.c index 770dd3b413e4..6639926eed4e 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -181,6 +181,10 @@ static int ceph_init_file(struct inode *inode, struct file *file, int fmode) return -ENOMEM; } cf->fmode = fmode; + + spin_lock_init(&cf->rw_contexts_lock); + INIT_LIST_HEAD(&cf->rw_contexts); + cf->next_offset = 2; cf->readdir_cache_idx = -1; file->private_data = cf; @@ -464,6 +468,7 @@ int ceph_release(struct inode *inode, struct file *file) ceph_mdsc_put_request(cf->last_readdir); kfree(cf->last_name); kfree(cf->dir_info); + WARN_ON(!list_empty(&cf->rw_contexts)); kmem_cache_free(ceph_file_cachep, cf); /* wake up anyone waiting for caps on this inode */ @@ -1199,12 +1204,13 @@ again: retry_op = READ_INLINE; } } else { + CEPH_DEFINE_RW_CONTEXT(rw_ctx, got); dout("aio_read %p %llx.%llx %llu~%u got cap refs on %s\n", inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len, ceph_cap_string(got)); - current->journal_info = filp; + ceph_add_rw_context(fi, &rw_ctx); ret = generic_file_read_iter(iocb, to); - current->journal_info = NULL; + ceph_del_rw_context(fi, &rw_ctx); } dout("aio_read %p %llx.%llx dropping cap refs on %s = %d\n", inode, ceph_vinop(inode), ceph_cap_string(got), (int)ret); |