nfsd: fix double-locks of directory mutex (9a8d248e) · Commits · 戴 / test

A number of nfsd operations depend on the i_mutex to cover more code than just the fsync, so the approach of "add a vfs_fsync helper" doesn't work for nfsd. Revert the parts of those patches that touch nfsd. Note: we can't, however, remove the logic from vfs_fsync that was needed only for the special case of nfsd, because a vfs_fsync(NULL,...) call can still result indirectly from a stackable filesystem that was called by nfsd. (Thanks to Christoph Hellwig for pointing this out.) Reported-by:

Eric Sesterhenn <snakebyte@gmx.de> Signed-off-by:

J. Bruce Fields <bfields@citi.umich.edu>

fs/nfsd/vfs.c

+31 −3

Original line number	Diff line number	Diff line
		@@ -744,16 +744,44 @@ nfsd_close(struct file *filp)
		fput(filp);
		}

		/*
		* Sync a file
		* As this calls fsync (not fdatasync) there is no need for a write_inode
		* after it.
		*/
		static inline int nfsd_dosync(struct file filp, struct dentry dp,
		const struct file_operations *fop)
		{
		struct inode *inode = dp->d_inode;
		int (fsync) (struct file , struct dentry *, int);
		int err;

		err = filemap_fdatawrite(inode->i_mapping);
		if (err == 0 && fop && (fsync = fop->fsync))
		err = fsync(filp, dp, 0);
		if (err == 0)
		err = filemap_fdatawait(inode->i_mapping);

		return err;
		}

		static int
		nfsd_sync(struct file *filp)
		{
		return vfs_fsync(filp, filp->f_path.dentry, 0);
		int err;
		struct inode *inode = filp->f_path.dentry->d_inode;
		dprintk("nfsd: sync file %s\n", filp->f_path.dentry->d_name.name);
		mutex_lock(&inode->i_mutex);
		err=nfsd_dosync(filp, filp->f_path.dentry, filp->f_op);
		mutex_unlock(&inode->i_mutex);

		return err;
		}

		int
		nfsd_sync_dir(struct dentry *dentry)
		nfsd_sync_dir(struct dentry *dp)
		{
		return vfs_fsync(NULL, dentry, 0);
		return nfsd_dosync(NULL, dp, dp->d_inode->i_fop);
		}

		/*

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