ocfs2: Block signals for mkdir/link/symlink/O_CREAT.

Once file or link creation gets going, it can't be interrupted by a
signal.  They're not idempotent.

This blocks signals in ocfs2_mknod(), ocfs2_link(), and ocfs2_symlink()
once we start actually changing things.  ocfs2_mknod() covers mknod(),
creat(), mkdir(), and open(O_CREAT).

Signed-off-by: Joel Becker <joel.becker@oracle.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index 21d4a33d0f0e..607084b349d4 100644
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -239,6 +239,8 @@ static int ocfs2_mknod(struct inode *dir,
         };
         int did_quota_inode = 0;
         struct ocfs2_dir_lookup_result lookup = { NULL, };
+        sigset_t oldset;
+        int did_block_signals = 0;
 
         mlog_entry("(0x%p, 0x%p, %d, %lu, '%.*s')\n", dir, dentry, mode,
                    (unsigned long)dev, dentry->d_name.len,
@@ -350,6 +352,10 @@ static int ocfs2_mknod(struct inode *dir,
                 goto leave;
         }
 
+        /* Starting to change things, restart is no longer possible. */
+        ocfs2_block_signals(&oldset);
+        did_block_signals = 1;
+
         status = dquot_alloc_inode(inode);
         if (status)
                 goto leave;
@@ -430,6 +436,8 @@ leave:
                 ocfs2_commit_trans(osb, handle);
 
         ocfs2_inode_unlock(dir, 1);
+        if (did_block_signals)
+                ocfs2_unblock_signals(&oldset);
 
         if (status == -ENOSPC)
                 mlog(0, "Disk is full\n");
@@ -618,6 +626,7 @@ static int ocfs2_link(struct dentry *old_dentry,
         struct ocfs2_dinode *fe = NULL;
         struct ocfs2_super *osb = OCFS2_SB(dir->i_sb);
         struct ocfs2_dir_lookup_result lookup = { NULL, };
+        sigset_t oldset;
 
         mlog_entry("(inode=%lu, old='%.*s' new='%.*s')\n", inode->i_ino,
                    old_dentry->d_name.len, old_dentry->d_name.name,
@@ -674,6 +683,9 @@ static int ocfs2_link(struct dentry *old_dentry,
                 goto out_unlock_inode;
         }
 
+        /* Starting to change things, restart is no longer possible. */
+        ocfs2_block_signals(&oldset);
+
         err = ocfs2_journal_access_di(handle, INODE_CACHE(inode), fe_bh,
                                       OCFS2_JOURNAL_ACCESS_WRITE);
         if (err < 0) {
@@ -710,6 +722,7 @@ static int ocfs2_link(struct dentry *old_dentry,
 
 out_commit:
         ocfs2_commit_trans(osb, handle);
+        ocfs2_unblock_signals(&oldset);
 out_unlock_inode:
         ocfs2_inode_unlock(inode, 1);
 
@@ -1568,6 +1581,8 @@ static int ocfs2_symlink(struct inode *dir,
         };
         int did_quota = 0, did_quota_inode = 0;
         struct ocfs2_dir_lookup_result lookup = { NULL, };
+        sigset_t oldset;
+        int did_block_signals = 0;
 
         mlog_entry("(0x%p, 0x%p, symname='%s' actual='%.*s')\n", dir,
                    dentry, symname, dentry->d_name.len, dentry->d_name.name);
@@ -1663,6 +1678,10 @@ static int ocfs2_symlink(struct inode *dir,
                 goto bail;
         }
 
+        /* Starting to change things, restart is no longer possible. */
+        ocfs2_block_signals(&oldset);
+        did_block_signals = 1;
+
         status = dquot_alloc_inode(inode);
         if (status)
                 goto bail;
@@ -1766,6 +1785,8 @@ bail:
                 ocfs2_commit_trans(osb, handle);
 
         ocfs2_inode_unlock(dir, 1);
+        if (did_block_signals)
+                ocfs2_unblock_signals(&oldset);
 
         brelse(new_fe_bh);
         brelse(parent_fe_bh);