From: Jan Blunck Subject: [PATCH 04/27] ext2: Add ext2_sb_info mutex Date: Mon, 2 Nov 2009 11:04:44 +0100 Message-ID: <1257156307-24175-5-git-send-email-jblunck@suse.de> References: <1257156307-24175-1-git-send-email-jblunck@suse.de> Cc: Matthew Wilcox , linux-kernel@vger.kernel.org, Jan Blunck , Andi Kleen , Jan Kara , Al Viro , Andrew Morton , Andi Kleen , Christoph Hellwig , Pekka Enberg , Andreas Dilger , linux-ext4@vger.kernel.org To: linux-fsdevel@vger.kernel.org Return-path: In-Reply-To: <1257156307-24175-1-git-send-email-jblunck@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Add a mutex that protects the ext2_sb_info from concurrent modifications. This is a preparation for removing the BKL later. Signed-off-by: Jan Blunck --- fs/ext2/inode.c | 2 ++ fs/ext2/super.c | 30 +++++++++++++++++++++++++++--- include/linux/ext2_fs_sb.h | 2 ++ 3 files changed, 31 insertions(+), 3 deletions(-) diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index ade6340..057074e 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -1401,9 +1401,11 @@ int ext2_write_inode(struct inode *inode, int do_sync) * created, add a flag to the superblock. */ lock_kernel(); + mutex_lock(&EXT2_SB(sb)->s_mutex); ext2_update_dynamic_rev(sb); EXT2_SET_RO_COMPAT_FEATURE(sb, EXT2_FEATURE_RO_COMPAT_LARGE_FILE); + mutex_unlock(&EXT2_SB(sb)->s_mutex); unlock_kernel(); ext2_write_super(sb); } diff --git a/fs/ext2/super.c b/fs/ext2/super.c index 5af1775..d610eb9 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -84,6 +84,9 @@ void ext2_warning (struct super_block * sb, const char * function, va_end(args); } +/* + * This must be called with sbi->s_mutex held. + */ void ext2_update_dynamic_rev(struct super_block *sb) { struct ext2_super_block *es = EXT2_SB(sb)->s_es; @@ -117,8 +120,8 @@ static void ext2_put_super (struct super_block * sb) lock_kernel(); - if (sb->s_dirt) - ext2_write_super(sb); + if (sb->s_dirt && !(sb->s_flags & MS_RDONLY)) + ext2_sync_fs(sb, 1); ext2_xattr_put_super(sb); if (!(sb->s_flags & MS_RDONLY)) { @@ -207,6 +210,7 @@ static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) struct ext2_super_block *es = sbi->s_es; unsigned long def_mount_opts; + mutex_lock(&sbi->s_mutex); def_mount_opts = le32_to_cpu(es->s_default_mount_opts); if (sbi->s_sb_block != 1) @@ -279,6 +283,7 @@ static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) if (!test_opt(sb, RESERVATION)) seq_puts(seq, ",noreservation"); + mutex_unlock(&sbi->s_mutex); return 0; } @@ -762,6 +767,12 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent) sbi->s_sb_block = sb_block; /* + * mutex for protection of modifications of the superblock while being + * write out by ext2_write_super() or ext2_sync_fs(). + */ + mutex_init(&sbi->s_mutex); + + /* * See what the current blocksize for the device is, and * use that as the blocksize. Otherwise (or if the blocksize * is smaller than the default) use the default. @@ -1122,8 +1133,9 @@ static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es) * flags to 0. We need to set this flag to 0 since the fs * may have been checked while mounted and e2fsck may have * set s_state to EXT2_VALID_FS after some corrections. + * + * This must be called with sbi->s_mutex held. */ - static int ext2_sync_fs(struct super_block *sb, int wait) { struct ext2_super_block *es = EXT2_SB(sb)->s_es; @@ -1150,10 +1162,14 @@ static int ext2_sync_fs(struct super_block *sb, int wait) void ext2_write_super(struct super_block *sb) { + struct ext2_sb_info * sbi = EXT2_SB(sb); + + mutex_lock(&sbi->s_mutex); if (!(sb->s_flags & MS_RDONLY)) ext2_sync_fs(sb, 1); else sb->s_dirt = 0; + mutex_unlock(&sbi->s_mutex); } static int ext2_remount (struct super_block * sb, int * flags, char * data) @@ -1166,6 +1182,7 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data) int err; lock_kernel(); + mutex_lock(&sbi->s_mutex); /* Store the old options */ old_sb_flags = sb->s_flags; @@ -1203,12 +1220,14 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data) sbi->s_mount_opt |= old_mount_opt & EXT2_MOUNT_XIP; } if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) { + mutex_unlock(&sbi->s_mutex); unlock_kernel(); return 0; } if (*flags & MS_RDONLY) { if (le16_to_cpu(es->s_state) & EXT2_VALID_FS || !(sbi->s_mount_state & EXT2_VALID_FS)) { + mutex_unlock(&sbi->s_mutex); unlock_kernel(); return 0; } @@ -1238,6 +1257,7 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data) sb->s_flags &= ~MS_RDONLY; } ext2_sync_super(sb, es); + mutex_unlock(&sbi->s_mutex); unlock_kernel(); return 0; restore_opts: @@ -1245,6 +1265,7 @@ restore_opts: sbi->s_resuid = old_opts.s_resuid; sbi->s_resgid = old_opts.s_resgid; sb->s_flags = old_sb_flags; + mutex_unlock(&sbi->s_mutex); unlock_kernel(); return err; } @@ -1256,6 +1277,8 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) struct ext2_super_block *es = sbi->s_es; u64 fsid; + mutex_lock(&sbi->s_mutex); + if (test_opt (sb, MINIX_DF)) sbi->s_overhead_last = 0; else if (sbi->s_blocks_last != le32_to_cpu(es->s_blocks_count)) { @@ -1310,6 +1333,7 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) le64_to_cpup((void *)es->s_uuid + sizeof(u64)); buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL; buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL; + mutex_unlock(&sbi->s_mutex); return 0; } diff --git a/include/linux/ext2_fs_sb.h b/include/linux/ext2_fs_sb.h index 1cdb663..8518361 100644 --- a/include/linux/ext2_fs_sb.h +++ b/include/linux/ext2_fs_sb.h @@ -106,6 +106,8 @@ struct ext2_sb_info { spinlock_t s_rsv_window_lock; struct rb_root s_rsv_window_root; struct ext2_reserve_window_node s_rsv_window_head; + /* protect against concurrent modifications of this structure */ + struct mutex s_mutex; }; static inline spinlock_t * -- 1.6.4.2