ceph: protect access to d_parent
[deliverable/linux.git] / fs / ceph / file.c
index 9542f07d0b9306774e7172afed25b6f809503c06..45fbd69daabe97a7dbf93ffc4a4cc08042a087a4 100644 (file)
@@ -122,7 +122,7 @@ int ceph_open(struct inode *inode, struct file *file)
        struct ceph_mds_client *mdsc = fsc->mdsc;
        struct ceph_mds_request *req;
        struct ceph_file_info *cf = file->private_data;
-       struct inode *parent_inode = file->f_dentry->d_parent->d_inode;
+       struct inode *parent_inode = NULL;
        int err;
        int flags, fmode, wanted;
 
@@ -194,7 +194,10 @@ int ceph_open(struct inode *inode, struct file *file)
        req->r_inode = inode;
        ihold(inode);
        req->r_num_caps = 1;
+       if (flags & (O_CREAT|O_TRUNC))
+               parent_inode = ceph_get_dentry_parent_inode(file->f_dentry);
        err = ceph_mdsc_do_request(mdsc, parent_inode, req);
+       iput(parent_inode);
        if (!err)
                err = ceph_init_file(inode, file, req->r_fmode);
        ceph_mdsc_put_request(req);
@@ -222,9 +225,9 @@ struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
 {
        struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
        struct ceph_mds_client *mdsc = fsc->mdsc;
-       struct file *file = nd->intent.open.file;
-       struct inode *parent_inode = get_dentry_parent_inode(file->f_dentry);
+       struct file *file;
        struct ceph_mds_request *req;
+       struct dentry *ret;
        int err;
        int flags = nd->intent.open.flags - 1;  /* silly vfs! */
 
@@ -242,16 +245,24 @@ struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
                req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
        }
        req->r_locked_dir = dir;           /* caller holds dir->i_mutex */
-       err = ceph_mdsc_do_request(mdsc, parent_inode, req);
-       dentry = ceph_finish_lookup(req, dentry, err);
-       if (!err && (flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
+       err = ceph_mdsc_do_request(mdsc,
+                                  (flags & (O_CREAT|O_TRUNC)) ? dir : NULL,
+                                  req);
+       err = ceph_handle_snapdir(req, dentry, err);
+       if (err)
+               goto out;
+       if ((flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
                err = ceph_handle_notrace_create(dir, dentry);
-       if (!err)
-               err = ceph_init_file(req->r_dentry->d_inode, file,
-                                    req->r_fmode);
+       if (err)
+               goto out;
+       file = lookup_instantiate_filp(nd, req->r_dentry, ceph_open);
+       if (IS_ERR(file))
+               err = PTR_ERR(file);
+out:
+       ret = ceph_finish_lookup(req, dentry, err);
        ceph_mdsc_put_request(req);
-       dout("ceph_lookup_open result=%p\n", dentry);
-       return dentry;
+       dout("ceph_lookup_open result=%p\n", ret);
+       return ret;
 }
 
 int ceph_release(struct inode *inode, struct file *file)
@@ -290,7 +301,6 @@ static int striped_read(struct inode *inode,
        struct ceph_inode_info *ci = ceph_inode(inode);
        u64 pos, this_len;
        int io_align, page_align;
-       int page_off = off & ~PAGE_CACHE_MASK; /* first byte's offset in page */
        int left, pages_left;
        int read;
        struct page **page_pos;
@@ -326,12 +336,11 @@ more:
             ret, hit_stripe ? " HITSTRIPE" : "", was_short ? " SHORT" : "");
 
        if (ret > 0) {
-               int didpages =
-                       ((pos & ~PAGE_CACHE_MASK) + ret) >> PAGE_CACHE_SHIFT;
+               int didpages = (page_align + ret) >> PAGE_CACHE_SHIFT;
 
                if (read < pos - off) {
                        dout(" zero gap %llu to %llu\n", off + read, pos);
-                       ceph_zero_page_vector_range(page_off + read,
+                       ceph_zero_page_vector_range(page_align + read,
                                                    pos - off - read, pages);
                }
                pos += ret;
@@ -356,7 +365,7 @@ more:
                                left = inode->i_size - pos;
 
                        dout("zero tail %d\n", left);
-                       ceph_zero_page_vector_range(page_off + read, left,
+                       ceph_zero_page_vector_range(page_align + read, left,
                                                    pages);
                        read += left;
                }
@@ -478,9 +487,6 @@ static ssize_t ceph_sync_write(struct file *file, const char __user *data,
        else
                pos = *offset;
 
-       io_align = pos & ~PAGE_MASK;
-       buf_align = (unsigned long)data & ~PAGE_MASK;
-
        ret = filemap_write_and_wait_range(inode->i_mapping, pos, pos + left);
        if (ret < 0)
                return ret;
@@ -504,6 +510,8 @@ static ssize_t ceph_sync_write(struct file *file, const char __user *data,
         * boundary.  this isn't atomic, unfortunately.  :(
         */
 more:
+       io_align = pos & ~PAGE_MASK;
+       buf_align = (unsigned long)data & ~PAGE_MASK;
        len = left;
        if (file->f_flags & O_DIRECT) {
                /* write from beginning of first page, regardless of
@@ -593,6 +601,7 @@ out:
                pos += len;
                written += len;
                left -= len;
+               data += written;
                if (left)
                        goto more;
 
@@ -645,7 +654,8 @@ again:
 
        if ((got & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0 ||
            (iocb->ki_filp->f_flags & O_DIRECT) ||
-           (inode->i_sb->s_flags & MS_SYNCHRONOUS))
+           (inode->i_sb->s_flags & MS_SYNCHRONOUS) ||
+           (fi->flags & CEPH_F_SYNC))
                /* hmm, this isn't really async... */
                ret = ceph_sync_read(filp, base, len, ppos, &checkeof);
        else
@@ -714,7 +724,7 @@ retry_snap:
                want = CEPH_CAP_FILE_BUFFER;
        ret = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, &got, endoff);
        if (ret < 0)
-               goto out;
+               goto out_put;
 
        dout("aio_write %p %llx.%llx %llu~%u  got cap refs on %s\n",
             inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len,
@@ -722,12 +732,23 @@ retry_snap:
 
        if ((got & (CEPH_CAP_FILE_BUFFER|CEPH_CAP_FILE_LAZYIO)) == 0 ||
            (iocb->ki_filp->f_flags & O_DIRECT) ||
-           (inode->i_sb->s_flags & MS_SYNCHRONOUS)) {
+           (inode->i_sb->s_flags & MS_SYNCHRONOUS) ||
+           (fi->flags & CEPH_F_SYNC)) {
                ret = ceph_sync_write(file, iov->iov_base, iov->iov_len,
                        &iocb->ki_pos);
        } else {
-               ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
+               /*
+                * buffered write; drop Fw early to avoid slow
+                * revocation if we get stuck on balance_dirty_pages
+                */
+               int dirty;
 
+               spin_lock(&inode->i_lock);
+               dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR);
+               spin_unlock(&inode->i_lock);
+               ceph_put_cap_refs(ci, got);
+
+               ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
                if ((ret >= 0 || ret == -EIOCBQUEUED) &&
                    ((file->f_flags & O_SYNC) || IS_SYNC(file->f_mapping->host)
                     || ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_NEARFULL))) {
@@ -735,7 +756,12 @@ retry_snap:
                        if (err < 0)
                                ret = err;
                }
+
+               if (dirty)
+                       __mark_inode_dirty(inode, dirty);
+               goto out;
        }
+
        if (ret >= 0) {
                int dirty;
                spin_lock(&inode->i_lock);
@@ -745,12 +771,13 @@ retry_snap:
                        __mark_inode_dirty(inode, dirty);
        }
 
-out:
+out_put:
        dout("aio_write %p %llx.%llx %llu~%u  dropping cap refs on %s\n",
             inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len,
             ceph_cap_string(got));
        ceph_put_cap_refs(ci, got);
 
+out:
        if (ret == -EOLDSNAPC) {
                dout("aio_write %p %llx.%llx %llu~%u got EOLDSNAPC, retrying\n",
                     inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len);
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