diff --git a/fs/ceph/export.c b/fs/ceph/export.c index baa6368bece5..042bb4a02c0a 100644 --- a/fs/ceph/export.c +++ b/fs/ceph/export.c @@ -129,6 +129,10 @@ static struct inode *__lookup_inode(struct super_block *sb, u64 ino) vino.ino = ino; vino.snap = CEPH_NOSNAP; + + if (ceph_vino_is_reserved(vino)) + return ERR_PTR(-ESTALE); + inode = ceph_find_inode(sb, vino); if (!inode) { struct ceph_mds_request *req; @@ -214,6 +218,10 @@ static struct dentry *__snapfh_to_dentry(struct super_block *sb, vino.ino = sfh->ino; vino.snap = sfh->snapid; } + + if (ceph_vino_is_reserved(vino)) + return ERR_PTR(-ESTALE); + inode = ceph_find_inode(sb, vino); if (inode) return d_obtain_alias(inode); diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index 8b96370306cf..8c6811e3682d 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -56,6 +56,9 @@ struct inode *ceph_get_inode(struct super_block *sb, struct ceph_vino vino) { struct inode *inode; + if (ceph_vino_is_reserved(vino)) + return ERR_PTR(-EREMOTEIO); + inode = iget5_locked(sb, (unsigned long)vino.ino, ceph_ino_compare, ceph_set_ino_cb, &vino); if (!inode) diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 63b53098360c..e5af591d3bd4 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -440,6 +440,13 @@ static int ceph_parse_deleg_inos(void **p, void *end, ceph_decode_64_safe(p, end, start, bad); ceph_decode_64_safe(p, end, len, bad); + + /* Don't accept a delegation of system inodes */ + if (start < CEPH_INO_SYSTEM_BASE) { + pr_warn_ratelimited("ceph: ignoring reserved inode range delegation (start=0x%llx len=0x%llx)\n", + start, len); + continue; + } while (len--) { int err = xa_insert(&s->s_delegated_inos, ino = start++, DELEGATED_INO_AVAILABLE, diff --git a/fs/ceph/super.h b/fs/ceph/super.h index df0851b9240e..db80d89556b1 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -529,10 +529,34 @@ static inline int ceph_ino_compare(struct inode *inode, void *data) ci->i_vino.snap == pvino->snap; } +/* + * The MDS reserves a set of inodes for its own usage. These should never + * be accessible by clients, and so the MDS has no reason to ever hand these + * out. The range is CEPH_MDS_INO_MDSDIR_OFFSET..CEPH_INO_SYSTEM_BASE. + * + * These come from src/mds/mdstypes.h in the ceph sources. + */ +#define CEPH_MAX_MDS 0x100 +#define CEPH_NUM_STRAY 10 +#define CEPH_MDS_INO_MDSDIR_OFFSET (1 * CEPH_MAX_MDS) +#define CEPH_INO_SYSTEM_BASE ((6*CEPH_MAX_MDS) + (CEPH_MAX_MDS * CEPH_NUM_STRAY)) + +static inline bool ceph_vino_is_reserved(const struct ceph_vino vino) +{ + if (vino.ino < CEPH_INO_SYSTEM_BASE && + vino.ino >= CEPH_MDS_INO_MDSDIR_OFFSET) { + WARN_RATELIMIT(1, "Attempt to access reserved inode number 0x%llx", vino.ino); + return true; + } + return false; +} static inline struct inode *ceph_find_inode(struct super_block *sb, struct ceph_vino vino) { + if (ceph_vino_is_reserved(vino)) + return NULL; + /* * NB: The hashval will be run through the fs/inode.c hash function * anyway, so there is no need to squash the inode number down to