*
* Protected by i_ceph_lock.
*/
-static void __take_cap_refs(struct ceph_inode_info *ci, int got)
+static void __take_cap_refs(struct ceph_inode_info *ci, int got,
+ bool snap_rwsem_locked)
{
if (got & CEPH_CAP_PIN)
ci->i_pin_ref++;
ci->i_rd_ref++;
if (got & CEPH_CAP_FILE_CACHE)
ci->i_rdcache_ref++;
- if (got & CEPH_CAP_FILE_WR)
+ if (got & CEPH_CAP_FILE_WR) {
+ if (ci->i_wr_ref == 0 && !ci->i_head_snapc) {
+ BUG_ON(!snap_rwsem_locked);
+ ci->i_head_snapc = ceph_get_snap_context(
+ ci->i_snap_realm->cached_context);
+ }
ci->i_wr_ref++;
+ }
if (got & CEPH_CAP_FILE_BUFFER) {
if (ci->i_wb_ref == 0)
ihold(&ci->vfs_inode);
* requested from the MDS.
*/
static int try_get_cap_refs(struct ceph_inode_info *ci, int need, int want,
- loff_t endoff, int *got, int *check_max, int *err)
+ loff_t endoff, bool nonblock, int *got, int *err)
{
struct inode *inode = &ci->vfs_inode;
+ struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
int ret = 0;
int have, implemented;
int file_wanted;
+ bool snap_rwsem_locked = false;
dout("get_cap_refs %p need %s want %s\n", inode,
ceph_cap_string(need), ceph_cap_string(want));
+again:
spin_lock(&ci->i_ceph_lock);
/* make sure file is actually open */
/* finish pending truncate */
while (ci->i_truncate_pending) {
spin_unlock(&ci->i_ceph_lock);
+ if (snap_rwsem_locked) {
+ up_read(&mdsc->snap_rwsem);
+ snap_rwsem_locked = false;
+ }
__ceph_do_pending_vmtruncate(inode);
spin_lock(&ci->i_ceph_lock);
}
dout("get_cap_refs %p endoff %llu > maxsize %llu\n",
inode, endoff, ci->i_max_size);
if (endoff > ci->i_requested_max_size) {
- *check_max = 1;
+ *err = -EAGAIN;
ret = 1;
}
goto out_unlock;
inode, ceph_cap_string(have), ceph_cap_string(not),
ceph_cap_string(revoking));
if ((revoking & not) == 0) {
+ if (!snap_rwsem_locked &&
+ !ci->i_head_snapc &&
+ (need & CEPH_CAP_FILE_WR)) {
+ if (!down_read_trylock(&mdsc->snap_rwsem)) {
+ /*
+ * we can not call down_read() when
+ * task isn't in TASK_RUNNING state
+ */
+ if (nonblock) {
+ *err = -EAGAIN;
+ ret = 1;
+ goto out_unlock;
+ }
+
+ spin_unlock(&ci->i_ceph_lock);
+ down_read(&mdsc->snap_rwsem);
+ snap_rwsem_locked = true;
+ goto again;
+ }
+ snap_rwsem_locked = true;
+ }
*got = need | (have & want);
- __take_cap_refs(ci, *got);
+ __take_cap_refs(ci, *got, true);
ret = 1;
}
} else {
}
out_unlock:
spin_unlock(&ci->i_ceph_lock);
+ if (snap_rwsem_locked)
+ up_read(&mdsc->snap_rwsem);
dout("get_cap_refs %p ret %d got %s\n", inode,
ret, ceph_cap_string(*got));
int ceph_get_caps(struct ceph_inode_info *ci, int need, int want,
loff_t endoff, int *got, struct page **pinned_page)
{
- int _got, check_max, ret, err = 0;
+ int _got, ret, err = 0;
ret = ceph_pool_perm_check(ci, need);
if (ret < 0)
return ret;
-retry:
- if (endoff > 0)
- check_max_size(&ci->vfs_inode, endoff);
- _got = 0;
- check_max = 0;
- ret = wait_event_interruptible(ci->i_cap_wq,
- try_get_cap_refs(ci, need, want, endoff,
- &_got, &check_max, &err));
- if (err)
- ret = err;
- if (ret < 0)
- return ret;
+ while (true) {
+ if (endoff > 0)
+ check_max_size(&ci->vfs_inode, endoff);
- if (check_max)
- goto retry;
+ err = 0;
+ _got = 0;
+ ret = try_get_cap_refs(ci, need, want, endoff,
+ false, &_got, &err);
+ if (ret) {
+ if (err == -EAGAIN)
+ continue;
+ if (err < 0)
+ return err;
+ } else {
+ ret = wait_event_interruptible(ci->i_cap_wq,
+ try_get_cap_refs(ci, need, want, endoff,
+ true, &_got, &err));
+ if (err == -EAGAIN)
+ continue;
+ if (err < 0)
+ ret = err;
+ if (ret < 0)
+ return ret;
+ }
- if (ci->i_inline_version != CEPH_INLINE_NONE &&
- (_got & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) &&
- i_size_read(&ci->vfs_inode) > 0) {
- struct page *page = find_get_page(ci->vfs_inode.i_mapping, 0);
- if (page) {
- if (PageUptodate(page)) {
- *pinned_page = page;
- goto out;
+ if (ci->i_inline_version != CEPH_INLINE_NONE &&
+ (_got & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) &&
+ i_size_read(&ci->vfs_inode) > 0) {
+ struct page *page =
+ find_get_page(ci->vfs_inode.i_mapping, 0);
+ if (page) {
+ if (PageUptodate(page)) {
+ *pinned_page = page;
+ break;
+ }
+ page_cache_release(page);
}
- page_cache_release(page);
- }
- /*
- * drop cap refs first because getattr while holding
- * caps refs can cause deadlock.
- */
- ceph_put_cap_refs(ci, _got);
- _got = 0;
+ /*
+ * drop cap refs first because getattr while
+ * holding * caps refs can cause deadlock.
+ */
+ ceph_put_cap_refs(ci, _got);
+ _got = 0;
- /* getattr request will bring inline data into page cache */
- ret = __ceph_do_getattr(&ci->vfs_inode, NULL,
- CEPH_STAT_CAP_INLINE_DATA, true);
- if (ret < 0)
- return ret;
- goto retry;
+ /*
+ * getattr request will bring inline data into
+ * page cache
+ */
+ ret = __ceph_do_getattr(&ci->vfs_inode, NULL,
+ CEPH_STAT_CAP_INLINE_DATA,
+ true);
+ if (ret < 0)
+ return ret;
+ continue;
+ }
+ break;
}
-out:
+
*got = _got;
return 0;
}
void ceph_get_cap_refs(struct ceph_inode_info *ci, int caps)
{
spin_lock(&ci->i_ceph_lock);
- __take_cap_refs(ci, caps);
+ __take_cap_refs(ci, caps, false);
spin_unlock(&ci->i_ceph_lock);
}
wake = 1;
}
}
+ if (ci->i_wrbuffer_ref_head == 0 &&
+ ci->i_dirty_caps == 0 &&
+ ci->i_flushing_caps == 0) {
+ BUG_ON(!ci->i_head_snapc);
+ ceph_put_snap_context(ci->i_head_snapc);
+ ci->i_head_snapc = NULL;
+ }
/* see comment in __ceph_remove_cap() */
if (!__ceph_is_any_caps(ci) && ci->i_snap_realm)
drop_inode_snap_realm(ci);
if (ci->i_head_snapc == snapc) {
ci->i_wrbuffer_ref_head -= nr;
if (ci->i_wrbuffer_ref_head == 0 &&
- ci->i_dirty_caps == 0 && ci->i_flushing_caps == 0) {
+ ci->i_wr_ref == 0 &&
+ ci->i_dirty_caps == 0 &&
+ ci->i_flushing_caps == 0) {
BUG_ON(!ci->i_head_snapc);
ceph_put_snap_context(ci->i_head_snapc);
ci->i_head_snapc = NULL;
dout(" inode %p now clean\n", inode);
BUG_ON(!list_empty(&ci->i_dirty_item));
drop = 1;
- if (ci->i_wrbuffer_ref_head == 0) {
+ if (ci->i_wr_ref == 0 &&
+ ci->i_wrbuffer_ref_head == 0) {
BUG_ON(!ci->i_head_snapc);
ceph_put_snap_context(ci->i_head_snapc);
ci->i_head_snapc = NULL;
projects / firefly-linux-kernel-4.4.55.git / blobdiff