Commit 65547661 authored by Jan Kara's avatar Jan Kara
Browse files

ext2: Call dquot_writeback_dquots() with s_umount held 



ext2_sync_fs() could be called without s_umount semaphore held when
called through ext2_write_super() from __ext2_write_inode(). This
function then calls dquot_writeback_dquots() which relies on s_umount to
be held for protection against other quota operations.

In fact __ext2_write_inode() does not need all the functionality
ext2_write_super() provides. It is enough to just write the superblock.
So use ext2_sync_super() instead.

Fixes: 9d1ccbe7
Reported-by: default avatarJan Beulich <jbeulich@suse.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent ab494964

fs/ext2/ext2.h

+2 −1
Original line number Diff line number Diff line
@@ -796,7 +796,8 @@ void ext2_error(struct super_block *, const char *, const char *, ...); 
extern __printf(3, 4)

void ext2_msg(struct super_block *, const char *, const char *, ...);

extern void ext2_update_dynamic_rev (struct super_block *sb);

extern void ext2_write_super (struct super_block *);

extern void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,

			    int wait);



/*

 * Inodes and files operations

fs/ext2/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -1615,7 +1615,7 @@ static int __ext2_write_inode(struct inode *inode, int do_sync) 
				EXT2_SET_RO_COMPAT_FEATURE(sb,

					EXT2_FEATURE_RO_COMPAT_LARGE_FILE);

				spin_unlock(&EXT2_SB(sb)->s_lock);

				ext2_write_super(sb);

				ext2_sync_super(sb, EXT2_SB(sb)->s_es, 1);

			}

		}

	}

fs/ext2/super.c

+4 −5
Original line number Diff line number Diff line
@@ -36,8 +36,7 @@ 
#include "xattr.h"

#include "acl.h"



static void ext2_sync_super(struct super_block *sb,

			    struct ext2_super_block *es, int wait);

static void ext2_write_super(struct super_block *sb);

static int ext2_remount (struct super_block * sb, int * flags, char * data);

static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf);

static int ext2_sync_fs(struct super_block *sb, int wait);
@@ -1194,7 +1193,7 @@ static void ext2_clear_super_error(struct super_block *sb) 
	}

}



static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,

void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es,

		     int wait)

{

	ext2_clear_super_error(sb);
@@ -1270,7 +1269,7 @@ static int ext2_unfreeze(struct super_block *sb) 
	return 0;

}



void ext2_write_super(struct super_block *sb)

static void ext2_write_super(struct super_block *sb)

{

	if (!(sb->s_flags & MS_RDONLY))

		ext2_sync_fs(sb, 1);

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