>From d70afd90149d0318c0fe51d05aaebe24c7def96a Mon Sep 17 00:00:00 2001 From: Jan Blunck Date: Mon, 2 Nov 2009 17:20:28 +0100 Subject: [PATCH 05/28] ext2: Add ext2_sb_info spinlock Add a spinlock that protects the ext2_sb_info from concurrent modifications. This is a preparation for removing the BKL later. Signed-off-by: Jan Blunck Cc: Andi Kleen --- fs/ext2/inode.c | 2 ++ fs/ext2/super.c | 41 ++++++++++++++++++++++++++++++++++++----- include/linux/ext2_fs_sb.h | 2 ++ 3 files changed, 40 insertions(+), 5 deletions(-) diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index ade6340..65a0d4b 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(); + spin_lock(&EXT2_SB(sb)->s_lock); ext2_update_dynamic_rev(sb); EXT2_SET_RO_COMPAT_FEATURE(sb, EXT2_FEATURE_RO_COMPAT_LARGE_FILE); + spin_unlock(&EXT2_SB(sb)->s_lock); unlock_kernel(); ext2_write_super(sb); } diff --git a/fs/ext2/super.c b/fs/ext2/super.c index 5af1775..70c326c 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -52,8 +52,10 @@ void ext2_error (struct super_block * sb, const char * function, struct ext2_super_block *es = sbi->s_es; if (!(sb->s_flags & MS_RDONLY)) { + spin_lock(&sbi->s_lock); sbi->s_mount_state |= EXT2_ERROR_FS; es->s_state |= cpu_to_le16(EXT2_ERROR_FS); + /* drops sbi->s_lock */ ext2_sync_super(sb, es); } @@ -84,6 +86,9 @@ void ext2_warning (struct super_block * sb, const char * function, va_end(args); } +/* + * This must be called with sbi->s_lock held. + */ void ext2_update_dynamic_rev(struct super_block *sb) { struct ext2_super_block *es = EXT2_SB(sb)->s_es; @@ -117,14 +122,16 @@ 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)) { struct ext2_super_block *es = sbi->s_es; + spin_lock(&sbi->s_lock); es->s_state = cpu_to_le16(sbi->s_mount_state); + /* drops sbi->s_lock */ ext2_sync_super(sb, es); } db_count = sbi->s_gdb_count; @@ -207,6 +214,7 @@ 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; + spin_lock(&sbi->s_lock); def_mount_opts = le32_to_cpu(es->s_default_mount_opts); if (sbi->s_sb_block != 1) @@ -279,6 +287,7 @@ static int ext2_show_options(struct seq_file *seq, struct vfsmount *vfs) if (!test_opt(sb, RESERVATION)) seq_puts(seq, ",noreservation"); + spin_unlock(&sbi->s_lock); return 0; } @@ -762,6 +771,12 @@ 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(). + */ + spin_lock_init(&sbi->s_lock); + + /* * 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. @@ -1103,11 +1118,14 @@ static void ext2_commit_super (struct super_block * sb, sb->s_dirt = 0; } -static void ext2_sync_super(struct super_block *sb, struct ext2_super_block *es) +static void ext2_sync_super(struct super_block *sb, + struct ext2_super_block *es) { es->s_free_blocks_count = cpu_to_le32(ext2_count_free_blocks(sb)); es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); es->s_wtime = cpu_to_le32(get_seconds()); + /* unlock before we do IO */ + spin_unlock(&EXT2_SB(sb)->s_lock); mark_buffer_dirty(EXT2_SB(sb)->s_sbh); sync_dirty_buffer(EXT2_SB(sb)->s_sbh); sb->s_dirt = 0; @@ -1122,13 +1140,16 @@ 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_lock held. */ - static int ext2_sync_fs(struct super_block *sb, int wait) { - struct ext2_super_block *es = EXT2_SB(sb)->s_es; + struct ext2_sb_info *sbi = EXT2_SB(sb); + struct ext2_super_block *es = sbi->s_es; lock_kernel(); + spin_lock(&sbi->s_lock); if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) { ext2_debug("setting valid to 0\n"); es->s_state &= cpu_to_le16(~EXT2_VALID_FS); @@ -1137,9 +1158,11 @@ static int ext2_sync_fs(struct super_block *sb, int wait) es->s_free_inodes_count = cpu_to_le32(ext2_count_free_inodes(sb)); es->s_mtime = cpu_to_le32(get_seconds()); + /* drops sbi->s_lock */ ext2_sync_super(sb, es); } else { ext2_commit_super(sb, es); + spin_unlock(&sbi->s_lock); } sb->s_dirt = 0; unlock_kernel(); @@ -1166,6 +1189,7 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data) int err; lock_kernel(); + spin_lock(&sbi->s_lock); /* Store the old options */ old_sb_flags = sb->s_flags; @@ -1203,12 +1227,14 @@ 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)) { + spin_unlock(&sbi->s_lock); 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)) { + spin_unlock(&sbi->s_lock); unlock_kernel(); return 0; } @@ -1237,6 +1263,7 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data) if (!ext2_setup_super (sb, es, 0)) sb->s_flags &= ~MS_RDONLY; } + /* drops sbi->s_lock */ ext2_sync_super(sb, es); unlock_kernel(); return 0; @@ -1245,6 +1272,7 @@ restore_opts: sbi->s_resuid = old_opts.s_resuid; sbi->s_resgid = old_opts.s_resgid; sb->s_flags = old_sb_flags; + spin_unlock(&sbi->s_lock); unlock_kernel(); return err; } @@ -1256,6 +1284,8 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) struct ext2_super_block *es = sbi->s_es; u64 fsid; + spin_lock(&sbi->s_lock); + 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 +1340,7 @@ 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; + spin_unlock(&sbi->s_lock); return 0; } diff --git a/include/linux/ext2_fs_sb.h b/include/linux/ext2_fs_sb.h index 1cdb663..0d20278 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 */ + spinlock_t s_lock; }; static inline spinlock_t * -- 1.6.4.2