1 files changed, 1220 insertions, 0 deletions

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
new file mode 100644
index 000000000000..5107384ee029
--- /dev/null
+++ b/fs/ceph/dir.c
@@ -0,0 +1,1220 @@
+#include "ceph_debug.h"
+
+#include <linux/spinlock.h>
+#include <linux/fs_struct.h>
+#include <linux/namei.h>
+#include <linux/sched.h>
+
+#include "super.h"
+
+/*
+ * Directory operations: readdir, lookup, create, link, unlink,
+ * rename, etc.
+ */
+
+/*
+ * Ceph MDS operations are specified in terms of a base ino and
+ * relative path.  Thus, the client can specify an operation on a
+ * specific inode (e.g., a getattr due to fstat(2)), or as a path
+ * relative to, say, the root directory.
+ *
+ * Normally, we limit ourselves to strict inode ops (no path component)
+ * or dentry operations (a single path component relative to an ino).  The
+ * exception to this is open_root_dentry(), which will open the mount
+ * point by name.
+ */
+
+const struct inode_operations ceph_dir_iops;
+const struct file_operations ceph_dir_fops;
+struct dentry_operations ceph_dentry_ops;
+
+/*
+ * Initialize ceph dentry state.
+ */
+int ceph_init_dentry(struct dentry *dentry)
+{
+        struct ceph_dentry_info *di;
+
+        if (dentry->d_fsdata)
+                return 0;
+
+        if (ceph_snap(dentry->d_parent->d_inode) == CEPH_NOSNAP)
+                dentry->d_op = &ceph_dentry_ops;
+        else if (ceph_snap(dentry->d_parent->d_inode) == CEPH_SNAPDIR)
+                dentry->d_op = &ceph_snapdir_dentry_ops;
+        else
+                dentry->d_op = &ceph_snap_dentry_ops;
+
+        di = kmem_cache_alloc(ceph_dentry_cachep, GFP_NOFS);
+        if (!di)
+                return -ENOMEM;          /* oh well */
+
+        spin_lock(&dentry->d_lock);
+        if (dentry->d_fsdata) /* lost a race */
+                goto out_unlock;
+        di->dentry = dentry;
+        di->lease_session = NULL;
+        dentry->d_fsdata = di;
+        dentry->d_time = jiffies;
+        ceph_dentry_lru_add(dentry);
+out_unlock:
+        spin_unlock(&dentry->d_lock);
+        return 0;
+}
+
+
+
+/*
+ * for readdir, we encode the directory frag and offset within that
+ * frag into f_pos.
+ */
+static unsigned fpos_frag(loff_t p)
+{
+        return p >> 32;
+}
+static unsigned fpos_off(loff_t p)
+{
+        return p & 0xffffffff;
+}
+
+/*
+ * When possible, we try to satisfy a readdir by peeking at the
+ * dcache.  We make this work by carefully ordering dentries on
+ * d_u.d_child when we initially get results back from the MDS, and
+ * falling back to a "normal" sync readdir if any dentries in the dir
+ * are dropped.
+ *
+ * I_COMPLETE tells indicates we have all dentries in the dir.  It is
+ * defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
+ * the MDS if/when the directory is modified).
+ */
+static int __dcache_readdir(struct file *filp,
+                            void *dirent, filldir_t filldir)
+{
+        struct inode *inode = filp->f_dentry->d_inode;
+        struct ceph_file_info *fi = filp->private_data;
+        struct dentry *parent = filp->f_dentry;
+        struct inode *dir = parent->d_inode;
+        struct list_head *p;
+        struct dentry *dentry, *last;
+        struct ceph_dentry_info *di;
+        int err = 0;
+
+        /* claim ref on last dentry we returned */
+        last = fi->dentry;
+        fi->dentry = NULL;
+
+        dout("__dcache_readdir %p at %llu (last %p)\n", dir, filp->f_pos,
+             last);
+
+        spin_lock(&dcache_lock);
+
+        /* start at beginning? */
+        if (filp->f_pos == 2 || (last &&
+                                 filp->f_pos < ceph_dentry(last)->offset)) {
+                if (list_empty(&parent->d_subdirs))
+                        goto out_unlock;
+                p = parent->d_subdirs.prev;
+                dout(" initial p %p/%p\n", p->prev, p->next);
+        } else {
+                p = last->d_u.d_child.prev;
+        }
+
+more:
+        dentry = list_entry(p, struct dentry, d_u.d_child);
+        di = ceph_dentry(dentry);
+        while (1) {
+                dout(" p %p/%p d_subdirs %p/%p\n", p->prev, p->next,
+                     parent->d_subdirs.prev, parent->d_subdirs.next);
+                if (p == &parent->d_subdirs) {
+                        fi->at_end = 1;
+                        goto out_unlock;
+                }
+                if (!d_unhashed(dentry) && dentry->d_inode &&
+                    ceph_snap(dentry->d_inode) != CEPH_SNAPDIR &&
+                    ceph_ino(dentry->d_inode) != CEPH_INO_CEPH &&
+                    filp->f_pos <= di->offset)
+                        break;
+                dout(" skipping %p %.*s at %llu (%llu)%s%s\n", dentry,
+                     dentry->d_name.len, dentry->d_name.name, di->offset,
+                     filp->f_pos, d_unhashed(dentry) ? " unhashed" : "",
+                     !dentry->d_inode ? " null" : "");
+                p = p->prev;
+                dentry = list_entry(p, struct dentry, d_u.d_child);
+                di = ceph_dentry(dentry);
+        }
+
+        atomic_inc(&dentry->d_count);
+        spin_unlock(&dcache_lock);
+        spin_unlock(&inode->i_lock);
+
+        dout(" %llu (%llu) dentry %p %.*s %p\n", di->offset, filp->f_pos,
+             dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
+        filp->f_pos = di->offset;
+        err = filldir(dirent, dentry->d_name.name,
+                      dentry->d_name.len, di->offset,
+                      dentry->d_inode->i_ino,
+                      dentry->d_inode->i_mode >> 12);
+
+        if (last) {
+                if (err < 0) {
+                        /* remember our position */
+                        fi->dentry = last;
+                        fi->next_offset = di->offset;
+                } else {
+                        dput(last);
+                }
+                last = NULL;
+        }
+
+        spin_lock(&inode->i_lock);
+        spin_lock(&dcache_lock);
+
+        if (err < 0)
+                goto out_unlock;
+
+        last = dentry;
+
+        p = p->prev;
+        filp->f_pos++;
+
+        /* make sure a dentry wasn't dropped while we didn't have dcache_lock */
+        if ((ceph_inode(dir)->i_ceph_flags & CEPH_I_COMPLETE))
+                goto more;
+        dout(" lost I_COMPLETE on %p; falling back to mds\n", dir);
+        err = -EAGAIN;
+
+out_unlock:
+        spin_unlock(&dcache_lock);
+
+        if (last) {
+                spin_unlock(&inode->i_lock);
+                dput(last);
+                spin_lock(&inode->i_lock);
+        }
+
+        return err;
+}
+
+/*
+ * make note of the last dentry we read, so we can
+ * continue at the same lexicographical point,
+ * regardless of what dir changes take place on the
+ * server.
+ */
+static int note_last_dentry(struct ceph_file_info *fi, const char *name,
+                            int len)
+{
+        kfree(fi->last_name);
+        fi->last_name = kmalloc(len+1, GFP_NOFS);
+        if (!fi->last_name)
+                return -ENOMEM;
+        memcpy(fi->last_name, name, len);
+        fi->last_name[len] = 0;
+        dout("note_last_dentry '%s'\n", fi->last_name);
+        return 0;
+}
+
+static int ceph_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+        struct ceph_file_info *fi = filp->private_data;
+        struct inode *inode = filp->f_dentry->d_inode;
+        struct ceph_inode_info *ci = ceph_inode(inode);
+        struct ceph_client *client = ceph_inode_to_client(inode);
+        struct ceph_mds_client *mdsc = &client->mdsc;
+        unsigned frag = fpos_frag(filp->f_pos);
+        int off = fpos_off(filp->f_pos);
+        int err;
+        u32 ftype;
+        struct ceph_mds_reply_info_parsed *rinfo;
+        const int max_entries = client->mount_args->max_readdir;
+
+        dout("readdir %p filp %p frag %u off %u\n", inode, filp, frag, off);
+        if (fi->at_end)
+                return 0;
+
+        /* always start with . and .. */
+        if (filp->f_pos == 0) {
+                /* note dir version at start of readdir so we can tell
+                 * if any dentries get dropped */
+                fi->dir_release_count = ci->i_release_count;
+
+                dout("readdir off 0 -> '.'\n");
+                if (filldir(dirent, ".", 1, ceph_make_fpos(0, 0),
+                            inode->i_ino, inode->i_mode >> 12) < 0)
+                        return 0;
+                filp->f_pos = 1;
+                off = 1;
+        }
+        if (filp->f_pos == 1) {
+                dout("readdir off 1 -> '..'\n");
+                if (filldir(dirent, "..", 2, ceph_make_fpos(0, 1),
+                            filp->f_dentry->d_parent->d_inode->i_ino,
+                            inode->i_mode >> 12) < 0)
+                        return 0;
+                filp->f_pos = 2;
+                off = 2;
+        }
+
+        /* can we use the dcache? */
+        spin_lock(&inode->i_lock);
+        if ((filp->f_pos == 2 || fi->dentry) &&
+            !ceph_test_opt(client, NOASYNCREADDIR) &&
+            (ci->i_ceph_flags & CEPH_I_COMPLETE) &&
+            __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
+                err = __dcache_readdir(filp, dirent, filldir);
+                if (err != -EAGAIN) {
+                        spin_unlock(&inode->i_lock);
+                        return err;
+                }
+        }
+        spin_unlock(&inode->i_lock);
+        if (fi->dentry) {
+                err = note_last_dentry(fi, fi->dentry->d_name.name,
+                                       fi->dentry->d_name.len);
+                if (err)
+                        return err;
+                dput(fi->dentry);
+                fi->dentry = NULL;
+        }
+
+        /* proceed with a normal readdir */
+
+more:
+        /* do we have the correct frag content buffered? */
+        if (fi->frag != frag || fi->last_readdir == NULL) {
+                struct ceph_mds_request *req;
+                int op = ceph_snap(inode) == CEPH_SNAPDIR ?
+                        CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
+
+                /* discard old result, if any */
+                if (fi->last_readdir)
+                        ceph_mdsc_put_request(fi->last_readdir);
+
+                /* requery frag tree, as the frag topology may have changed */
+                frag = ceph_choose_frag(ceph_inode(inode), frag, NULL, NULL);
+
+                dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
+                     ceph_vinop(inode), frag, fi->last_name);
+                req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
+                if (IS_ERR(req))
+                        return PTR_ERR(req);
+                req->r_inode = igrab(inode);
+                req->r_dentry = dget(filp->f_dentry);
+                /* hints to request -> mds selection code */
+                req->r_direct_mode = USE_AUTH_MDS;
+                req->r_direct_hash = ceph_frag_value(frag);
+                req->r_direct_is_hash = true;
+                req->r_path2 = kstrdup(fi->last_name, GFP_NOFS);
+                req->r_readdir_offset = fi->next_offset;
+                req->r_args.readdir.frag = cpu_to_le32(frag);
+                req->r_args.readdir.max_entries = cpu_to_le32(max_entries);
+                req->r_num_caps = max_entries;
+                err = ceph_mdsc_do_request(mdsc, NULL, req);
+                if (err < 0) {
+                        ceph_mdsc_put_request(req);
+                        return err;
+                }
+                dout("readdir got and parsed readdir result=%d"
+                     " on frag %x, end=%d, complete=%d\n", err, frag,
+                     (int)req->r_reply_info.dir_end,
+                     (int)req->r_reply_info.dir_complete);
+
+                if (!req->r_did_prepopulate) {
+                        dout("readdir !did_prepopulate");
+                        fi->dir_release_count--;    /* preclude I_COMPLETE */
+                }
+
+                /* note next offset and last dentry name */
+                fi->offset = fi->next_offset;
+                fi->last_readdir = req;
+
+                if (req->r_reply_info.dir_end) {
+                        kfree(fi->last_name);
+                        fi->last_name = NULL;
+                        fi->next_offset = 0;
+                } else {
+                        rinfo = &req->r_reply_info;
+                        err = note_last_dentry(fi,
+                                       rinfo->dir_dname[rinfo->dir_nr-1],
+                                       rinfo->dir_dname_len[rinfo->dir_nr-1]);
+                        if (err)
+                                return err;
+                        fi->next_offset += rinfo->dir_nr;
+                }
+        }
+
+        rinfo = &fi->last_readdir->r_reply_info;
+        dout("readdir frag %x num %d off %d chunkoff %d\n", frag,
+             rinfo->dir_nr, off, fi->offset);
+        while (off - fi->offset >= 0 && off - fi->offset < rinfo->dir_nr) {
+                u64 pos = ceph_make_fpos(frag, off);
+                struct ceph_mds_reply_inode *in =
+                        rinfo->dir_in[off - fi->offset].in;
+                dout("readdir off %d (%d/%d) -> %lld '%.*s' %p\n",
+                     off, off - fi->offset, rinfo->dir_nr, pos,
+                     rinfo->dir_dname_len[off - fi->offset],
+                     rinfo->dir_dname[off - fi->offset], in);
+                BUG_ON(!in);
+                ftype = le32_to_cpu(in->mode) >> 12;
+                if (filldir(dirent,
+                            rinfo->dir_dname[off - fi->offset],
+                            rinfo->dir_dname_len[off - fi->offset],
+                            pos,
+                            le64_to_cpu(in->ino),
+                            ftype) < 0) {
+                        dout("filldir stopping us...\n");
+                        return 0;
+                }
+                off++;
+                filp->f_pos = pos + 1;
+        }
+
+        if (fi->last_name) {
+                ceph_mdsc_put_request(fi->last_readdir);
+                fi->last_readdir = NULL;
+                goto more;
+        }
+
+        /* more frags? */
+        if (!ceph_frag_is_rightmost(frag)) {
+                frag = ceph_frag_next(frag);
+                off = 0;
+                filp->f_pos = ceph_make_fpos(frag, off);
+                dout("readdir next frag is %x\n", frag);
+                goto more;
+        }
+        fi->at_end = 1;
+
+        /*
+         * if dir_release_count still matches the dir, no dentries
+         * were released during the whole readdir, and we should have
+         * the complete dir contents in our cache.
+         */
+        spin_lock(&inode->i_lock);
+        if (ci->i_release_count == fi->dir_release_count) {
+                dout(" marking %p complete\n", inode);
+                ci->i_ceph_flags |= CEPH_I_COMPLETE;
+                ci->i_max_offset = filp->f_pos;
+        }
+        spin_unlock(&inode->i_lock);
+
+        dout("readdir %p filp %p done.\n", inode, filp);
+        return 0;
+}
+
+static void reset_readdir(struct ceph_file_info *fi)
+{
+        if (fi->last_readdir) {
+                ceph_mdsc_put_request(fi->last_readdir);
+                fi->last_readdir = NULL;
+        }
+        kfree(fi->last_name);
+        fi->next_offset = 2;  /* compensate for . and .. */
+        if (fi->dentry) {
+                dput(fi->dentry);
+                fi->dentry = NULL;
+        }
+        fi->at_end = 0;
+}
+
+static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int origin)
+{
+        struct ceph_file_info *fi = file->private_data;
+        struct inode *inode = file->f_mapping->host;
+        loff_t old_offset = offset;
+        loff_t retval;
+
+        mutex_lock(&inode->i_mutex);
+        switch (origin) {
+        case SEEK_END:
+                offset += inode->i_size + 2;   /* FIXME */
+                break;
+        case SEEK_CUR:
+                offset += file->f_pos;
+        }
+        retval = -EINVAL;
+        if (offset >= 0 && offset <= inode->i_sb->s_maxbytes) {
+                if (offset != file->f_pos) {
+                        file->f_pos = offset;
+                        file->f_version = 0;
+                        fi->at_end = 0;
+                }
+                retval = offset;
+
+                /*
+                 * discard buffered readdir content on seekdir(0), or
+                 * seek to new frag, or seek prior to current chunk.
+                 */
+                if (offset == 0 ||
+                    fpos_frag(offset) != fpos_frag(old_offset) ||
+                    fpos_off(offset) < fi->offset) {
+                        dout("dir_llseek dropping %p content\n", file);
+                        reset_readdir(fi);
+                }
+
+                /* bump dir_release_count if we did a forward seek */
+                if (offset > old_offset)
+                        fi->dir_release_count--;
+        }
+        mutex_unlock(&inode->i_mutex);
+        return retval;
+}
+
+/*
+ * Process result of a lookup/open request.
+ *
+ * Mainly, make sure we return the final req->r_dentry (if it already
+ * existed) in place of the original VFS-provided dentry when they
+ * differ.
+ *
+ * Gracefully handle the case where the MDS replies with -ENOENT and
+ * no trace (which it may do, at its discretion, e.g., if it doesn't
+ * care to issue a lease on the negative dentry).
+ */
+struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
+                                  struct dentry *dentry, int err)
+{
+        struct ceph_client *client = ceph_client(dentry->d_sb);
+        struct inode *parent = dentry->d_parent->d_inode;
+
+        /* .snap dir? */
+        if (err == -ENOENT &&
+            ceph_vino(parent).ino != CEPH_INO_ROOT && /* no .snap in root dir */
+            strcmp(dentry->d_name.name,
+                   client->mount_args->snapdir_name) == 0) {
+                struct inode *inode = ceph_get_snapdir(parent);
+                dout("ENOENT on snapdir %p '%.*s', linking to snapdir %p\n",
+                     dentry, dentry->d_name.len, dentry->d_name.name, inode);
+                d_add(dentry, inode);
+                err = 0;
+        }
+
+        if (err == -ENOENT) {
+                /* no trace? */
+                err = 0;
+                if (!req->r_reply_info.head->is_dentry) {
+                        dout("ENOENT and no trace, dentry %p inode %p\n",
+                             dentry, dentry->d_inode);
+                        if (dentry->d_inode) {
+                                d_drop(dentry);
+                                err = -ENOENT;
+                        } else {
+                                d_add(dentry, NULL);
+                        }
+                }
+        }
+        if (err)
+                dentry = ERR_PTR(err);
+        else if (dentry != req->r_dentry)
+                dentry = dget(req->r_dentry);   /* we got spliced */
+        else
+                dentry = NULL;
+        return dentry;
+}
+
+static int is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
+{
+        return ceph_ino(inode) == CEPH_INO_ROOT &&
+                strncmp(dentry->d_name.name, ".ceph", 5) == 0;
+}
+
+/*
+ * Look up a single dir entry.  If there is a lookup intent, inform
+ * the MDS so that it gets our 'caps wanted' value in a single op.
+ */
+static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
+                                  struct nameidata *nd)
+{
+        struct ceph_client *client = ceph_sb_to_client(dir->i_sb);
+        struct ceph_mds_client *mdsc = &client->mdsc;
+        struct ceph_mds_request *req;
+        int op;
+        int err;
+
+        dout("lookup %p dentry %p '%.*s'\n",
+             dir, dentry, dentry->d_name.len, dentry->d_name.name);
+
+        if (dentry->d_name.len > NAME_MAX)
+                return ERR_PTR(-ENAMETOOLONG);
+
+        err = ceph_init_dentry(dentry);
+        if (err < 0)
+                return ERR_PTR(err);
+
+        /* open (but not create!) intent? */
+        if (nd &&
+            (nd->flags & LOOKUP_OPEN) &&
+            (nd->flags & LOOKUP_CONTINUE) == 0 && /* only open last component */
+            !(nd->intent.open.flags & O_CREAT)) {
+                int mode = nd->intent.open.create_mode & ~current->fs->umask;
+                return ceph_lookup_open(dir, dentry, nd, mode, 1);
+        }
+
+        /* can we conclude ENOENT locally? */
+        if (dentry->d_inode == NULL) {
+                struct ceph_inode_info *ci = ceph_inode(dir);
+                struct ceph_dentry_info *di = ceph_dentry(dentry);
+
+                spin_lock(&dir->i_lock);
+                dout(" dir %p flags are %d\n", dir, ci->i_ceph_flags);
+                if (strncmp(dentry->d_name.name,
+                            client->mount_args->snapdir_name,
+                            dentry->d_name.len) &&
+                    !is_root_ceph_dentry(dir, dentry) &&
+                    (ci->i_ceph_flags & CEPH_I_COMPLETE) &&
+                    (__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
+                        di->offset = ci->i_max_offset++;
+                        spin_unlock(&dir->i_lock);
+                        dout(" dir %p complete, -ENOENT\n", dir);
+                        d_add(dentry, NULL);
+                        di->lease_shared_gen = ci->i_shared_gen;
+                        return NULL;
+                }
+                spin_unlock(&dir->i_lock);
+        }
+
+        op = ceph_snap(dir) == CEPH_SNAPDIR ?
+                CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
+        req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
+        if (IS_ERR(req))
+                return ERR_PTR(PTR_ERR(req));
+        req->r_dentry = dget(dentry);
+        req->r_num_caps = 2;
+        /* we only need inode linkage */
+        req->r_args.getattr.mask = cpu_to_le32(CEPH_STAT_CAP_INODE);
+        req->r_locked_dir = dir;
+        err = ceph_mdsc_do_request(mdsc, NULL, req);
+        dentry = ceph_finish_lookup(req, dentry, err);
+        ceph_mdsc_put_request(req);  /* will dput(dentry) */
+        dout("lookup result=%p\n", dentry);
+        return dentry;
+}
+
+/*
+ * If we do a create but get no trace back from the MDS, follow up with
+ * a lookup (the VFS expects us to link up the provided dentry).
+ */
+int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
+{
+        struct dentry *result = ceph_lookup(dir, dentry, NULL);
+
+        if (result && !IS_ERR(result)) {
+                /*
+                 * We created the item, then did a lookup, and found
+                 * it was already linked to another inode we already
+                 * had in our cache (and thus got spliced).  Link our
+                 * dentry to that inode, but don't hash it, just in
+                 * case the VFS wants to dereference it.
+                 */
+                BUG_ON(!result->d_inode);
+                d_instantiate(dentry, result->d_inode);
+                return 0;
+        }
+        return PTR_ERR(result);
+}
+
+static int ceph_mknod(struct inode *dir, struct dentry *dentry,
+                      int mode, dev_t rdev)
+{
+        struct ceph_client *client = ceph_sb_to_client(dir->i_sb);
+        struct ceph_mds_client *mdsc = &client->mdsc;
+        struct ceph_mds_request *req;
+        int err;
+
+        if (ceph_snap(dir) != CEPH_NOSNAP)
+                return -EROFS;
+
+        dout("mknod in dir %p dentry %p mode 0%o rdev %d\n",
+             dir, dentry, mode, rdev);
+        req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
+        if (IS_ERR(req)) {
+                d_drop(dentry);
+                return PTR_ERR(req);
+        }
+        req->r_dentry = dget(dentry);
+        req->r_num_caps = 2;
+        req->r_locked_dir = dir;
+        req->r_args.mknod.mode = cpu_to_le32(mode);
+        req->r_args.mknod.rdev = cpu_to_le32(rdev);
+        req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
+        req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
+        err = ceph_mdsc_do_request(mdsc, dir, req);
+        if (!err && !req->r_reply_info.head->is_dentry)
+                err = ceph_handle_notrace_create(dir, dentry);
+        ceph_mdsc_put_request(req);
+        if (err)
+                d_drop(dentry);
+        return err;
+}
+
+static int ceph_create(struct inode *dir, struct dentry *dentry, int mode,
+                       struct nameidata *nd)
+{
+        dout("create in dir %p dentry %p name '%.*s'\n",
+             dir, dentry, dentry->d_name.len, dentry->d_name.name);
+
+        if (ceph_snap(dir) != CEPH_NOSNAP)
+                return -EROFS;
+
+        if (nd) {
+                BUG_ON((nd->flags & LOOKUP_OPEN) == 0);
+                dentry = ceph_lookup_open(dir, dentry, nd, mode, 0);
+                /* hrm, what should i do here if we get aliased? */
+                if (IS_ERR(dentry))
+                        return PTR_ERR(dentry);
+                return 0;
+        }
+
+        /* fall back to mknod */
+        return ceph_mknod(dir, dentry, (mode & ~S_IFMT) | S_IFREG, 0);
+}
+
+static int ceph_symlink(struct inode *dir, struct dentry *dentry,
+                            const char *dest)
+{
+        struct ceph_client *client = ceph_sb_to_client(dir->i_sb);
+        struct ceph_mds_client *mdsc = &client->mdsc;
+        struct ceph_mds_request *req;
+        int err;
+
+        if (ceph_snap(dir) != CEPH_NOSNAP)
+                return -EROFS;
+
+        dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
+        req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
+        if (IS_ERR(req)) {
+                d_drop(dentry);
+                return PTR_ERR(req);
+        }
+        req->r_dentry = dget(dentry);
+        req->r_num_caps = 2;
+        req->r_path2 = kstrdup(dest, GFP_NOFS);
+        req->r_locked_dir = dir;
+        req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
+        req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
+        err = ceph_mdsc_do_request(mdsc, dir, req);
+        if (!err && !req->r_reply_info.head->is_dentry)
+                err = ceph_handle_notrace_create(dir, dentry);
+        ceph_mdsc_put_request(req);
+        if (err)
+                d_drop(dentry);
+        return err;
+}
+
+static int ceph_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+        struct ceph_client *client = ceph_sb_to_client(dir->i_sb);
+        struct ceph_mds_client *mdsc = &client->mdsc;
+        struct ceph_mds_request *req;
+        int err = -EROFS;
+        int op;
+
+        if (ceph_snap(dir) == CEPH_SNAPDIR) {
+                /* mkdir .snap/foo is a MKSNAP */
+                op = CEPH_MDS_OP_MKSNAP;
+                dout("mksnap dir %p snap '%.*s' dn %p\n", dir,
+                     dentry->d_name.len, dentry->d_name.name, dentry);
+        } else if (ceph_snap(dir) == CEPH_NOSNAP) {
+                dout("mkdir dir %p dn %p mode 0%o\n", dir, dentry, mode);
+                op = CEPH_MDS_OP_MKDIR;
+        } else {
+                goto out;
+        }
+        req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
+        if (IS_ERR(req)) {
+                err = PTR_ERR(req);
+                goto out;
+        }
+
+        req->r_dentry = dget(dentry);
+        req->r_num_caps = 2;
+        req->r_locked_dir = dir;
+        req->r_args.mkdir.mode = cpu_to_le32(mode);
+        req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
+        req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
+        err = ceph_mdsc_do_request(mdsc, dir, req);
+        if (!err && !req->r_reply_info.head->is_dentry)
+                err = ceph_handle_notrace_create(dir, dentry);
+        ceph_mdsc_put_request(req);
+out:
+        if (err < 0)
+                d_drop(dentry);
+        return err;
+}
+
+static int ceph_link(struct dentry *old_dentry, struct inode *dir,
+                     struct dentry *dentry)
+{
+        struct ceph_client *client = ceph_sb_to_client(dir->i_sb);
+        struct ceph_mds_client *mdsc = &client->mdsc;
+        struct ceph_mds_request *req;
+        int err;
+
+        if (ceph_snap(dir) != CEPH_NOSNAP)
+                return -EROFS;
+
+        dout("link in dir %p old_dentry %p dentry %p\n", dir,
+             old_dentry, dentry);
+        req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
+        if (IS_ERR(req)) {
+                d_drop(dentry);
+                return PTR_ERR(req);
+        }
+        req->r_dentry = dget(dentry);
+        req->r_num_caps = 2;
+        req->r_old_dentry = dget(old_dentry); /* or inode? hrm. */
+        req->r_locked_dir = dir;
+        req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
+        req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
+        err = ceph_mdsc_do_request(mdsc, dir, req);
+        if (err)
+                d_drop(dentry);
+        else if (!req->r_reply_info.head->is_dentry)
+                d_instantiate(dentry, igrab(old_dentry->d_inode));
+        ceph_mdsc_put_request(req);
+        return err;
+}
+
+/*
+ * For a soon-to-be unlinked file, drop the AUTH_RDCACHE caps.  If it
+ * looks like the link count will hit 0, drop any other caps (other
+ * than PIN) we don't specifically want (due to the file still being
+ * open).
+ */
+static int drop_caps_for_unlink(struct inode *inode)
+{
+        struct ceph_inode_info *ci = ceph_inode(inode);
+        int drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
+
+        spin_lock(&inode->i_lock);
+        if (inode->i_nlink == 1) {
+                drop |= ~(__ceph_caps_wanted(ci) | CEPH_CAP_PIN);
+                ci->i_ceph_flags |= CEPH_I_NODELAY;
+        }
+        spin_unlock(&inode->i_lock);
+        return drop;
+}
+
+/*
+ * rmdir and unlink are differ only by the metadata op code
+ */
+static int ceph_unlink(struct inode *dir, struct dentry *dentry)
+{
+        struct ceph_client *client = ceph_sb_to_client(dir->i_sb);
+        struct ceph_mds_client *mdsc = &client->mdsc;
+        struct inode *inode = dentry->d_inode;
+        struct ceph_mds_request *req;
+        int err = -EROFS;
+        int op;
+
+        if (ceph_snap(dir) == CEPH_SNAPDIR) {
+                /* rmdir .snap/foo is RMSNAP */
+                dout("rmsnap dir %p '%.*s' dn %p\n", dir, dentry->d_name.len,
+                     dentry->d_name.name, dentry);
+                op = CEPH_MDS_OP_RMSNAP;
+        } else if (ceph_snap(dir) == CEPH_NOSNAP) {
+                dout("unlink/rmdir dir %p dn %p inode %p\n",
+                     dir, dentry, inode);
+                op = ((dentry->d_inode->i_mode & S_IFMT) == S_IFDIR) ?
+                        CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
+        } else
+                goto out;
+        req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
+        if (IS_ERR(req)) {
+                err = PTR_ERR(req);
+                goto out;
+        }
+        req->r_dentry = dget(dentry);
+        req->r_num_caps = 2;
+        req->r_locked_dir = dir;
+        req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
+        req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
+        req->r_inode_drop = drop_caps_for_unlink(inode);
+        err = ceph_mdsc_do_request(mdsc, dir, req);
+        if (!err && !req->r_reply_info.head->is_dentry)
+                d_delete(dentry);
+        ceph_mdsc_put_request(req);
+out:
+        return err;
+}
+
+static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
+                       struct inode *new_dir, struct dentry *new_dentry)
+{
+        struct ceph_client *client = ceph_sb_to_client(old_dir->i_sb);
+        struct ceph_mds_client *mdsc = &client->mdsc;
+        struct ceph_mds_request *req;
+        int err;
+
+        if (ceph_snap(old_dir) != ceph_snap(new_dir))
+                return -EXDEV;
+        if (ceph_snap(old_dir) != CEPH_NOSNAP ||
+            ceph_snap(new_dir) != CEPH_NOSNAP)
+                return -EROFS;
+        dout("rename dir %p dentry %p to dir %p dentry %p\n",
+             old_dir, old_dentry, new_dir, new_dentry);
+        req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_RENAME, USE_AUTH_MDS);
+        if (IS_ERR(req))
+                return PTR_ERR(req);
+        req->r_dentry = dget(new_dentry);
+        req->r_num_caps = 2;
+        req->r_old_dentry = dget(old_dentry);
+        req->r_locked_dir = new_dir;
+        req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
+        req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
+        req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
+        req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
+        /* release LINK_RDCACHE on source inode (mds will lock it) */
+        req->r_old_inode_drop = CEPH_CAP_LINK_SHARED;
+        if (new_dentry->d_inode)
+                req->r_inode_drop = drop_caps_for_unlink(new_dentry->d_inode);
+        err = ceph_mdsc_do_request(mdsc, old_dir, req);
+        if (!err && !req->r_reply_info.head->is_dentry) {
+                /*
+                 * Normally d_move() is done by fill_trace (called by
+                 * do_request, above).  If there is no trace, we need
+                 * to do it here.
+                 */
+                d_move(old_dentry, new_dentry);
+        }
+        ceph_mdsc_put_request(req);
+        return err;
+}
+
+
+/*
+ * Check if dentry lease is valid.  If not, delete the lease.  Try to
+ * renew if the least is more than half up.
+ */
+static int dentry_lease_is_valid(struct dentry *dentry)
+{
+        struct ceph_dentry_info *di;
+        struct ceph_mds_session *s;
+        int valid = 0;
+        u32 gen;
+        unsigned long ttl;
+        struct ceph_mds_session *session = NULL;
+        struct inode *dir = NULL;
+        u32 seq = 0;
+
+        spin_lock(&dentry->d_lock);
+        di = ceph_dentry(dentry);
+        if (di && di->lease_session) {
+                s = di->lease_session;
+                spin_lock(&s->s_cap_lock);
+                gen = s->s_cap_gen;
+                ttl = s->s_cap_ttl;
+                spin_unlock(&s->s_cap_lock);
+
+                if (di->lease_gen == gen &&
+                    time_before(jiffies, dentry->d_time) &&
+                    time_before(jiffies, ttl)) {
+                        valid = 1;
+                        if (di->lease_renew_after &&
+                            time_after(jiffies, di->lease_renew_after)) {
+                                /* we should renew */
+                                dir = dentry->d_parent->d_inode;
+                                session = ceph_get_mds_session(s);
+                                seq = di->lease_seq;
+                                di->lease_renew_after = 0;
+                                di->lease_renew_from = jiffies;
+                        }
+                }
+        }
+        spin_unlock(&dentry->d_lock);
+
+        if (session) {
+                ceph_mdsc_lease_send_msg(session, dir, dentry,
+                                         CEPH_MDS_LEASE_RENEW, seq);
+                ceph_put_mds_session(session);
+        }
+        dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
+        return valid;
+}
+
+/*
+ * Check if directory-wide content lease/cap is valid.
+ */
+static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry)
+{
+        struct ceph_inode_info *ci = ceph_inode(dir);
+        struct ceph_dentry_info *di = ceph_dentry(dentry);
+        int valid = 0;
+
+        spin_lock(&dir->i_lock);
+        if (ci->i_shared_gen == di->lease_shared_gen)
+                valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
+        spin_unlock(&dir->i_lock);
+        dout("dir_lease_is_valid dir %p v%u dentry %p v%u = %d\n",
+             dir, (unsigned)ci->i_shared_gen, dentry,
+             (unsigned)di->lease_shared_gen, valid);
+        return valid;
+}
+
+/*
+ * Check if cached dentry can be trusted.
+ */
+static int ceph_d_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+        struct inode *dir = dentry->d_parent->d_inode;
+
+        dout("d_revalidate %p '%.*s' inode %p\n", dentry,
+             dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
+
+        /* always trust cached snapped dentries, snapdir dentry */
+        if (ceph_snap(dir) != CEPH_NOSNAP) {
+                dout("d_revalidate %p '%.*s' inode %p is SNAPPED\n", dentry,
+                     dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
+                goto out_touch;
+        }
+        if (dentry->d_inode && ceph_snap(dentry->d_inode) == CEPH_SNAPDIR)
+                goto out_touch;
+
+        if (dentry_lease_is_valid(dentry) ||
+            dir_lease_is_valid(dir, dentry))
+                goto out_touch;
+
+        dout("d_revalidate %p invalid\n", dentry);
+        d_drop(dentry);
+        return 0;
+out_touch:
+        ceph_dentry_lru_touch(dentry);
+        return 1;
+}
+
+/*
+ * When a dentry is released, clear the dir I_COMPLETE if it was part
+ * of the current dir gen.
+ */
+static void ceph_dentry_release(struct dentry *dentry)
+{
+        struct ceph_dentry_info *di = ceph_dentry(dentry);
+        struct inode *parent_inode = dentry->d_parent->d_inode;
+
+        if (parent_inode) {
+                struct ceph_inode_info *ci = ceph_inode(parent_inode);
+
+                spin_lock(&parent_inode->i_lock);
+                if (ci->i_shared_gen == di->lease_shared_gen) {
+                        dout(" clearing %p complete (d_release)\n",
+                             parent_inode);
+                        ci->i_ceph_flags &= ~CEPH_I_COMPLETE;
+                        ci->i_release_count++;
+                }
+                spin_unlock(&parent_inode->i_lock);
+        }
+        if (di) {
+                ceph_dentry_lru_del(dentry);
+                if (di->lease_session)
+                        ceph_put_mds_session(di->lease_session);
+                kmem_cache_free(ceph_dentry_cachep, di);
+                dentry->d_fsdata = NULL;
+        }
+}
+
+static int ceph_snapdir_d_revalidate(struct dentry *dentry,
+                                          struct nameidata *nd)
+{
+        /*
+         * Eventually, we'll want to revalidate snapped metadata
+         * too... probably...
+         */
+        return 1;
+}
+
+
+
+/*
+ * read() on a dir.  This weird interface hack only works if mounted
+ * with '-o dirstat'.
+ */
+static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
+                             loff_t *ppos)
+{
+        struct ceph_file_info *cf = file->private_data;
+        struct inode *inode = file->f_dentry->d_inode;
+        struct ceph_inode_info *ci = ceph_inode(inode);
+        int left;
+
+        if (!ceph_test_opt(ceph_client(inode->i_sb), DIRSTAT))
+                return -EISDIR;
+
+        if (!cf->dir_info) {
+                cf->dir_info = kmalloc(1024, GFP_NOFS);
+                if (!cf->dir_info)
+                        return -ENOMEM;
+                cf->dir_info_len =
+                        sprintf(cf->dir_info,
+                                "entries:   %20lld\n"
+                                " files:    %20lld\n"
+                                " subdirs:  %20lld\n"
+                                "rentries:  %20lld\n"
+                                " rfiles:   %20lld\n"
+                                " rsubdirs: %20lld\n"
+                                "rbytes:    %20lld\n"
+                                "rctime:    %10ld.%09ld\n",
+                                ci->i_files + ci->i_subdirs,
+                                ci->i_files,
+                                ci->i_subdirs,
+                                ci->i_rfiles + ci->i_rsubdirs,
+                                ci->i_rfiles,
+                                ci->i_rsubdirs,
+                                ci->i_rbytes,
+                                (long)ci->i_rctime.tv_sec,
+                                (long)ci->i_rctime.tv_nsec);
+        }
+
+        if (*ppos >= cf->dir_info_len)
+                return 0;
+        size = min_t(unsigned, size, cf->dir_info_len-*ppos);
+        left = copy_to_user(buf, cf->dir_info + *ppos, size);
+        if (left == size)
+                return -EFAULT;
+        *ppos += (size - left);
+        return size - left;
+}
+
+/*
+ * an fsync() on a dir will wait for any uncommitted directory
+ * operations to commit.
+ */
+static int ceph_dir_fsync(struct file *file, struct dentry *dentry,
+                          int datasync)
+{
+        struct inode *inode = dentry->d_inode;
+        struct ceph_inode_info *ci = ceph_inode(inode);
+        struct list_head *head = &ci->i_unsafe_dirops;
+        struct ceph_mds_request *req;
+        u64 last_tid;
+        int ret = 0;
+
+        dout("dir_fsync %p\n", inode);
+        spin_lock(&ci->i_unsafe_lock);
+        if (list_empty(head))
+                goto out;
+
+        req = list_entry(head->prev,
+                         struct ceph_mds_request, r_unsafe_dir_item);
+        last_tid = req->r_tid;
+
+        do {
+                ceph_mdsc_get_request(req);
+                spin_unlock(&ci->i_unsafe_lock);
+                dout("dir_fsync %p wait on tid %llu (until %llu)\n",
+                     inode, req->r_tid, last_tid);
+                if (req->r_timeout) {
+                        ret = wait_for_completion_timeout(
+                                &req->r_safe_completion, req->r_timeout);
+                        if (ret > 0)
+                                ret = 0;
+                        else if (ret == 0)
+                                ret = -EIO;  /* timed out */
+                } else {
+                        wait_for_completion(&req->r_safe_completion);
+                }
+                spin_lock(&ci->i_unsafe_lock);
+                ceph_mdsc_put_request(req);
+
+                if (ret || list_empty(head))
+                        break;
+                req = list_entry(head->next,
+                                 struct ceph_mds_request, r_unsafe_dir_item);
+        } while (req->r_tid < last_tid);
+out:
+        spin_unlock(&ci->i_unsafe_lock);
+        return ret;
+}
+
+/*
+ * We maintain a private dentry LRU.
+ *
+ * FIXME: this needs to be changed to a per-mds lru to be useful.
+ */
+void ceph_dentry_lru_add(struct dentry *dn)
+{
+        struct ceph_dentry_info *di = ceph_dentry(dn);
+        struct ceph_mds_client *mdsc;
+
+        dout("dentry_lru_add %p %p '%.*s'\n", di, dn,
+             dn->d_name.len, dn->d_name.name);
+        if (di) {
+                mdsc = &ceph_client(dn->d_sb)->mdsc;
+                spin_lock(&mdsc->dentry_lru_lock);
+                list_add_tail(&di->lru, &mdsc->dentry_lru);
+                mdsc->num_dentry++;
+                spin_unlock(&mdsc->dentry_lru_lock);
+        }
+}
+
+void ceph_dentry_lru_touch(struct dentry *dn)
+{
+        struct ceph_dentry_info *di = ceph_dentry(dn);
+        struct ceph_mds_client *mdsc;
+
+        dout("dentry_lru_touch %p %p '%.*s'\n", di, dn,
+             dn->d_name.len, dn->d_name.name);
+        if (di) {
+                mdsc = &ceph_client(dn->d_sb)->mdsc;
+                spin_lock(&mdsc->dentry_lru_lock);
+                list_move_tail(&di->lru, &mdsc->dentry_lru);
+                spin_unlock(&mdsc->dentry_lru_lock);
+        }
+}
+
+void ceph_dentry_lru_del(struct dentry *dn)
+{
+        struct ceph_dentry_info *di = ceph_dentry(dn);
+        struct ceph_mds_client *mdsc;
+
+        dout("dentry_lru_del %p %p '%.*s'\n", di, dn,
+             dn->d_name.len, dn->d_name.name);
+        if (di) {
+                mdsc = &ceph_client(dn->d_sb)->mdsc;
+                spin_lock(&mdsc->dentry_lru_lock);
+                list_del_init(&di->lru);
+                mdsc->num_dentry--;
+                spin_unlock(&mdsc->dentry_lru_lock);
+        }
+}
+
+const struct file_operations ceph_dir_fops = {
+        .read = ceph_read_dir,
+        .readdir = ceph_readdir,
+        .llseek = ceph_dir_llseek,
+        .open = ceph_open,
+        .release = ceph_release,
+        .unlocked_ioctl = ceph_ioctl,
+        .fsync = ceph_dir_fsync,
+};
+
+const struct inode_operations ceph_dir_iops = {
+        .lookup = ceph_lookup,
+        .permission = ceph_permission,
+        .getattr = ceph_getattr,
+        .setattr = ceph_setattr,
+        .setxattr = ceph_setxattr,
+        .getxattr = ceph_getxattr,
+        .listxattr = ceph_listxattr,
+        .removexattr = ceph_removexattr,
+        .mknod = ceph_mknod,
+        .symlink = ceph_symlink,
+        .mkdir = ceph_mkdir,
+        .link = ceph_link,
+        .unlink = ceph_unlink,
+        .rmdir = ceph_unlink,
+        .rename = ceph_rename,
+        .create = ceph_create,
+};
+
+struct dentry_operations ceph_dentry_ops = {
+        .d_revalidate = ceph_d_revalidate,
+        .d_release = ceph_dentry_release,
+};
+
+struct dentry_operations ceph_snapdir_dentry_ops = {
+        .d_revalidate = ceph_snapdir_d_revalidate,
+};
+
+struct dentry_operations ceph_snap_dentry_ops = {
+};