diff options
| author | Yan, Zheng <zyan@redhat.com> | 2016-10-25 10:51:55 +0800 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2016-12-12 23:54:27 +0100 |
| commit | 2b1ac852eb67a6e95595e576371d23519105559f (patch) | |
| tree | 076e01b89275932db841f55fb604744b5c84bc5a /fs/ceph/caps.c | |
| parent | 5c341ee32881c554727ec14b71ec3e8832f01989 (diff) | |
ceph: try getting buffer capability for readahead/fadvise
For readahead/fadvise cases, caller of ceph_readpages does not
hold buffer capability. Pages can be added to page cache while
there is no buffer capability. This can cause data integrity
issue.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
Diffstat (limited to 'fs/ceph/caps.c')
| -rw-r--r-- | fs/ceph/caps.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index 4037b389a7e9..edb407f38b40 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -2479,6 +2479,27 @@ static void check_max_size(struct inode *inode, loff_t endoff) ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL); } +int ceph_try_get_caps(struct ceph_inode_info *ci, int need, int want, int *got) +{ + int ret, err = 0; + + BUG_ON(need & ~CEPH_CAP_FILE_RD); + BUG_ON(want & ~(CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)); + ret = ceph_pool_perm_check(ci, need); + if (ret < 0) + return ret; + + ret = try_get_cap_refs(ci, need, want, 0, true, got, &err); + if (ret) { + if (err == -EAGAIN) { + ret = 0; + } else if (err < 0) { + ret = err; + } + } + return ret; +} + /* * Wait for caps, and take cap references. If we can't get a WR cap * due to a small max_size, make sure we check_max_size (and possibly |