ceph: tolerate bad i_size for symlink inode

A mds bug can cause symlink's size to be truncated to zero.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 7ba8e1c2557bbb5e8ca979fcb661cd4ad8d8a685..89d08155986dfc43c96d1fa81f48ccb7af0c0e3c 100644 (file)
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -582,6 +582,11 @@ int ceph_drop_inode(struct inode *inode)
        return 1;
 }
 
+static inline blkcnt_t calc_inode_blocks(u64 size)
+{
+       return (size + (1<<9) - 1) >> 9;
+}
+
 /*
  * Helpers to fill in size, ctime, mtime, and atime.  We have to be
  * careful because either the client or MDS may have more up to date
@@ -604,7 +609,7 @@ int ceph_fill_file_size(struct inode *inode, int issued,
                        size = 0;
                }
                i_size_write(inode, size);
-               inode->i_blocks = (size + (1<<9) - 1) >> 9;
+               inode->i_blocks = calc_inode_blocks(size);
                ci->i_reported_size = size;
                if (truncate_seq != ci->i_truncate_seq) {
                        dout("truncate_seq %u -> %u\n",
@@ -863,9 +868,13 @@ static int fill_inode(struct inode *inode, struct page *locked_page,
 
                        spin_unlock(&ci->i_ceph_lock);
 
-                       err = -EINVAL;
-                       if (WARN_ON(symlen != i_size_read(inode)))
-                               goto out;
+                       if (symlen != i_size_read(inode)) {
+                               pr_err("fill_inode %llx.%llx BAD symlink "
+                                       "size %lld\n", ceph_vinop(inode),
+                                       i_size_read(inode));
+                               i_size_write(inode, symlen);
+                               inode->i_blocks = calc_inode_blocks(symlen);
+                       }
 
                        err = -ENOMEM;
                        sym = kstrndup(iinfo->symlink, symlen, GFP_NOFS);
@@ -1629,7 +1638,7 @@ int ceph_inode_set_size(struct inode *inode, loff_t size)
        spin_lock(&ci->i_ceph_lock);
        dout("set_size %p %llu -> %llu\n", inode, inode->i_size, size);
        i_size_write(inode, size);
-       inode->i_blocks = (size + (1 << 9) - 1) >> 9;
+       inode->i_blocks = calc_inode_blocks(size);
 
        /* tell the MDS if we are approaching max_size */
        if ((size << 1) >= ci->i_max_size &&
@@ -2002,8 +2011,7 @@ int ceph_setattr(struct dentry *dentry, struct iattr *attr)
                if ((issued & CEPH_CAP_FILE_EXCL) &&
                    attr->ia_size > inode->i_size) {
                        i_size_write(inode, attr->ia_size);
-                       inode->i_blocks =
-                               (attr->ia_size + (1 << 9) - 1) >> 9;
+                       inode->i_blocks = calc_inode_blocks(attr->ia_size);
                        inode->i_ctime = attr->ia_ctime;
                        ci->i_reported_size = attr->ia_size;
                        dirtied |= CEPH_CAP_FILE_EXCL;