Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 4 Jul 2002 04:31:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 4 Jul 2002 04:31:33 -0400 Received: from gateway2.ensim.com ([65.164.64.250]:26121 "EHLO nasdaq.ms.ensim.com") by vger.kernel.org with ESMTP id ; Thu, 4 Jul 2002 04:31:23 -0400 X-Mailer: exmh version 2.5 01/15/2001 with nmh-1.0 From: Paul Menage To: torvalds@transmeta.com, viro@math.psu.edu, linux-fsdevel@vger.kernel.org cc: pmenage@ensim.com, linux-kernel@vger.kernel.org Subject: [PATCH] Shift BKL into ->statfs() (trimmed) Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 04 Jul 2002 01:33:30 -0700 Message-Id: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 11229 Lines: 355 This patch removes BKL protection from the invocation of the super_operations ->statfs() method, and shifts it into the filesystems where necessary. Any out-of-tree filesystems may need to take the BKL in their statfs() methods if they were relying on it for synchronisation. Several ->statfs() implementation changes in the previous version of the patch have been dropped following assurances from Oleg Drokin, Anton Altaparmakov and Matthew Wilcox that they were unnecessary. All ->statfs() implementations have been modified to take the BKL, except for the following: - those that don't reference any external mutable data: simple_statfs isofs_statfs ncp_statfs cramfs_statfs romfs_statfs efs_statfs vxfs_statfs ntfs_statfs adfs_statfs - those that already have their own locking: ext2_statfs shmem_statfs fat_statfs UMSDOS_statfs minix_statfs sysv_statfs reiserfs_statfs affs_statfs bfs_statfs ext3_statfs hfs_statfs jffs2_statfs jfs_statfs Additionally, capifs is changed to use simple_statfs rather than its own home-grown version. The BKL change has been flagged at the end of Documentation/filesystems/porting, along with the recent change to ->permission BKL usage. Paul diff -Naur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.24/Documentation/filesystems/Locking linux-2.5.24-statfs2/Documentation/filesystems/Locking --- linux-2.5.24/Documentation/filesystems/Locking Tue Jun 18 19:11:52 2002 +++ linux-2.5.24-statfs2/Documentation/filesystems/Locking Wed Jul 3 00:22:36 2002 @@ -108,7 +108,7 @@ clear_inode: no put_super: yes yes maybe (see below) write_super: no yes maybe (see below) -statfs: yes no no +statfs: no no no remount_fs: yes yes maybe (see below) umount_begin: yes no maybe (see below) diff -Naur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.24/Documentation/filesystems/porting linux-2.5.24-statfs2/Documentation/filesystems/porting --- linux-2.5.24/Documentation/filesystems/porting Tue Jun 18 19:11:51 2002 +++ linux-2.5.24-statfs2/Documentation/filesystems/porting Wed Jul 3 00:26:49 2002 @@ -81,7 +81,7 @@ [mandatory] ->lookup(), ->truncate(), ->create(), ->unlink(), ->mknod(), ->mkdir(), -->rmdir(), ->link(), ->lseek(), ->symlink(), ->rename(), ->permission() +->rmdir(), ->link(), ->lseek(), ->symlink(), ->rename() and ->readdir() are called without BKL now. Grab it on entry, drop upon return - that will guarantee the same locking you used to have. If your method or its parts do not need BKL - better yet, now you can shift lock_kernel() and @@ -228,3 +228,19 @@ Use bdev_read_only(bdev) instead of is_read_only(kdev). The latter is still alive, but only because of the mess in drivers/s390/block/dasd.c. As soon as it gets fixed is_read_only() will die. + +--- +[mandatory] + +->permission() is called without BKL now. Grab it on entry, drop upon +return - that will guarantee the same locking you used to have. If +your method or its parts do not need BKL - better yet, now you can +shift lock_kernel() and unlock_kernel() so that they would protect +exactly what needs to be protected. + +--- +[mandatory] + +->statfs() is now called without BKL held. BKL should have been +shifted into individual fs sb_op functions where it's not clear that +it's safe to remove it. If you don't need it, remove it. diff -Naur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.24/drivers/isdn/capi/capifs.c linux-2.5.24-statfs2/drivers/isdn/capi/capifs.c --- linux-2.5.24/drivers/isdn/capi/capifs.c Tue Jun 18 19:11:50 2002 +++ linux-2.5.24-statfs2/drivers/isdn/capi/capifs.c Wed Jul 3 00:22:36 2002 @@ -221,11 +221,9 @@ kfree(sbi); } -static int capifs_statfs(struct super_block *sb, struct statfs *buf); - static struct super_operations capifs_sops = { put_super: capifs_put_super, - statfs: capifs_statfs, + statfs: simple_statfs, }; static int capifs_parse_options(char *options, struct capifs_sb_info *sbi) @@ -354,19 +352,6 @@ return -EINVAL; } -static int capifs_statfs(struct super_block *sb, struct statfs *buf) -{ - buf->f_type = CAPIFS_SUPER_MAGIC; - buf->f_bsize = 1024; - buf->f_blocks = 0; - buf->f_bfree = 0; - buf->f_bavail = 0; - buf->f_files = 0; - buf->f_ffree = 0; - buf->f_namelen = NAME_MAX; - return 0; -} - static struct inode *capifs_new_inode(struct super_block *sb) { struct inode *inode = new_inode(sb); diff -Naur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.24/fs/coda/inode.c linux-2.5.24-statfs2/fs/coda/inode.c --- linux-2.5.24/fs/coda/inode.c Tue Jun 18 19:11:55 2002 +++ linux-2.5.24-statfs2/fs/coda/inode.c Wed Jul 3 00:22:36 2002 @@ -281,9 +281,13 @@ static int coda_statfs(struct super_block *sb, struct statfs *buf) { int error; + + lock_kernel(); error = venus_statfs(sb, buf); + unlock_kernel(); + if (error) { /* fake something like AFS does */ buf->f_blocks = 9000000; diff -Naur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.24/fs/ext3/super.c linux-2.5.24-statfs2/fs/ext3/super.c --- linux-2.5.24/fs/ext3/super.c Tue Jun 18 19:11:58 2002 +++ linux-2.5.24-statfs2/fs/ext3/super.c Wed Jul 3 00:28:00 2002 @@ -504,7 +504,7 @@ write_super: ext3_write_super, /* BKL not held. We take it. Needed? */ write_super_lockfs: ext3_write_super_lockfs, /* BKL not held. Take it */ unlockfs: ext3_unlockfs, /* BKL not held. We take it */ - statfs: ext3_statfs, /* BKL held */ + statfs: ext3_statfs, /* BKL not held. */ remount_fs: ext3_remount, /* BKL held */ }; diff -Naur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.24/fs/freevxfs/vxfs_super.c linux-2.5.24-statfs2/fs/freevxfs/vxfs_super.c --- linux-2.5.24/fs/freevxfs/vxfs_super.c Tue Jun 18 19:11:51 2002 +++ linux-2.5.24-statfs2/fs/freevxfs/vxfs_super.c Wed Jul 3 00:22:36 2002 @@ -98,7 +98,7 @@ * Zero. * * Locking: - * We are under bkl and @sbp->s_lock. + * No locks held. * * Notes: * This is everything but complete... diff -Naur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.24/fs/hpfs/super.c linux-2.5.24-statfs2/fs/hpfs/super.c --- linux-2.5.24/fs/hpfs/super.c Tue Jun 18 19:11:56 2002 +++ linux-2.5.24-statfs2/fs/hpfs/super.c Wed Jul 3 00:28:21 2002 @@ -134,6 +134,8 @@ int hpfs_statfs(struct super_block *s, struct statfs *buf) { + lock_kernel(); + /*if (s->s_hpfs_n_free == -1) {*/ s->s_hpfs_n_free = count_bitmaps(s); s->s_hpfs_n_free_dnodes = hpfs_count_one_bitmap(s, s->s_hpfs_dmap); @@ -146,6 +148,9 @@ buf->f_files = s->s_hpfs_dirband_size / 4; buf->f_ffree = s->s_hpfs_n_free_dnodes; buf->f_namelen = 254; + + unlock_kernel(); + return 0; } diff -Naur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.24/fs/jffs/inode-v23.c linux-2.5.24-statfs2/fs/jffs/inode-v23.c --- linux-2.5.24/fs/jffs/inode-v23.c Tue Jun 18 19:11:56 2002 +++ linux-2.5.24-statfs2/fs/jffs/inode-v23.c Wed Jul 3 00:22:36 2002 @@ -383,7 +383,11 @@ jffs_statfs(struct super_block *sb, struct statfs *buf) { struct jffs_control *c = (struct jffs_control *) sb->u.generic_sbp; - struct jffs_fmcontrol *fmc = c->fmc; + struct jffs_fmcontrol *fmc; + + lock_kernel(); + + fmc = c->fmc; D2(printk("jffs_statfs()\n")); @@ -401,6 +405,9 @@ buf->f_ffree = buf->f_bfree; /* buf->f_fsid = 0; */ buf->f_namelen = JFFS_MAX_NAME_LEN; + + unlock_kernel(); + return 0; } diff -Naur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.24/fs/nfs/inode.c linux-2.5.24-statfs2/fs/nfs/inode.c --- linux-2.5.24/fs/nfs/inode.c Tue Jun 18 19:11:57 2002 +++ linux-2.5.24-statfs2/fs/nfs/inode.c Wed Jul 3 00:28:52 2002 @@ -474,6 +474,8 @@ struct nfs_fsinfo res; int error; + lock_kernel(); + error = server->rpc_ops->statfs(server, NFS_FH(sb->s_root->d_inode), &res); buf->f_type = NFS_SUPER_MAGIC; if (error < 0) @@ -491,11 +493,17 @@ if (res.namelen == 0 || res.namelen > server->namelen) res.namelen = server->namelen; buf->f_namelen = res.namelen; + + out: + unlock_kernel(); + return 0; + out_err: - printk("nfs_statfs: statfs error = %d\n", -error); + printk(KERN_WARNING "nfs_statfs: statfs error = %d\n", -error); buf->f_bsize = buf->f_blocks = buf->f_bfree = buf->f_bavail = -1; - return 0; + goto out; + } static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt) diff -Naur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.24/fs/open.c linux-2.5.24-statfs2/fs/open.c --- linux-2.5.24/fs/open.c Tue Jun 18 19:11:46 2002 +++ linux-2.5.24-statfs2/fs/open.c Wed Jul 3 00:22:36 2002 @@ -30,9 +30,7 @@ retval = -ENOSYS; if (sb->s_op && sb->s_op->statfs) { memset(buf, 0, sizeof(struct statfs)); - lock_kernel(); retval = sb->s_op->statfs(sb, buf); - unlock_kernel(); } } return retval; diff -Naur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.24/fs/qnx4/inode.c linux-2.5.24-statfs2/fs/qnx4/inode.c --- linux-2.5.24/fs/qnx4/inode.c Tue Jun 18 19:11:52 2002 +++ linux-2.5.24-statfs2/fs/qnx4/inode.c Wed Jul 3 00:29:20 2002 @@ -281,6 +281,8 @@ static int qnx4_statfs(struct super_block *sb, struct statfs *buf) { + lock_kernel(); + buf->f_type = sb->s_magic; buf->f_bsize = sb->s_blocksize; buf->f_blocks = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size) * 8; @@ -288,6 +290,8 @@ buf->f_bavail = buf->f_bfree; buf->f_namelen = QNX4_NAME_MAX; + unlock_kernel(); + return 0; } diff -Naur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.24/fs/smbfs/inode.c linux-2.5.24-statfs2/fs/smbfs/inode.c --- linux-2.5.24/fs/smbfs/inode.c Tue Jun 18 19:11:48 2002 +++ linux-2.5.24-statfs2/fs/smbfs/inode.c Wed Jul 3 00:22:36 2002 @@ -604,7 +604,13 @@ static int smb_statfs(struct super_block *sb, struct statfs *buf) { - int result = smb_proc_dskattr(sb, buf); + int result; + + lock_kernel(); + + result = smb_proc_dskattr(sb, buf); + + unlock_kernel(); buf->f_type = SMB_SUPER_MAGIC; buf->f_namelen = SMB_MAXPATHLEN; diff -Naur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.24/fs/udf/super.c linux-2.5.24-statfs2/fs/udf/super.c --- linux-2.5.24/fs/udf/super.c Tue Jun 18 19:11:56 2002 +++ linux-2.5.24-statfs2/fs/udf/super.c Wed Jul 3 00:29:44 2002 @@ -1726,6 +1726,8 @@ static int udf_statfs(struct super_block *sb, struct statfs *buf) { + lock_kernel(); + buf->f_type = UDF_SUPER_MAGIC; buf->f_bsize = sb->s_blocksize; buf->f_blocks = UDF_SB_PARTLEN(sb, UDF_SB_PARTITION(sb)); @@ -1738,6 +1740,8 @@ /* __kernel_fsid_t f_fsid */ buf->f_namelen = UDF_NAME_LEN; + unlock_kernel(); + return 0; } diff -Naur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.24/fs/ufs/super.c linux-2.5.24-statfs2/fs/ufs/super.c --- linux-2.5.24/fs/ufs/super.c Tue Jun 18 19:11:44 2002 +++ linux-2.5.24-statfs2/fs/ufs/super.c Wed Jul 3 00:22:36 2002 @@ -959,6 +959,8 @@ struct ufs_sb_private_info * uspi; struct ufs_super_block_first * usb1; + lock_kernel(); + uspi = sb->u.ufs_sb.s_uspi; usb1 = ubh_get_usb_first (USPI_UBH); @@ -972,6 +974,9 @@ buf->f_files = uspi->s_ncg * uspi->s_ipg; buf->f_ffree = fs32_to_cpu(sb, usb1->fs_cstotal.cs_nifree); buf->f_namelen = UFS_MAXNAMLEN; + + unlock_kernel(); + return 0; } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/