From e36cb0b89ce20b4f8786a57e8a6bc8476f577650 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 29 Jan 2015 12:02:35 +0000 Subject: VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry) Convert the following where appropriate: (1) S_ISLNK(dentry->d_inode) to d_is_symlink(dentry). (2) S_ISREG(dentry->d_inode) to d_is_reg(dentry). (3) S_ISDIR(dentry->d_inode) to d_is_dir(dentry). This is actually more complicated than it appears as some calls should be converted to d_can_lookup() instead. The difference is whether the directory in question is a real dir with a ->lookup op or whether it's a fake dir with a ->d_automount op. In some circumstances, we can subsume checks for dentry->d_inode not being NULL into this, provided we the code isn't in a filesystem that expects d_inode to be NULL if the dirent really *is* negative (ie. if we're going to use d_inode() rather than d_backing_inode() to get the inode pointer). Note that the dentry type field may be set to something other than DCACHE_MISS_TYPE when d_inode is NULL in the case of unionmount, where the VFS manages the fall-through from a negative dentry to a lower layer. In such a case, the dentry type of the negative union dentry is set to the same as the type of the lower dentry. However, if you know d_inode is not NULL at the call site, then you can use the d_is_xxx() functions even in a filesystem. There is one further complication: a 0,0 chardev dentry may be labelled DCACHE_WHITEOUT_TYPE rather than DCACHE_SPECIAL_TYPE. Strictly, this was intended for special directory entry types that don't have attached inodes. The following perl+coccinelle script was used: use strict; my @callers; open($fd, 'git grep -l \'S_IS[A-Z].*->d_inode\' |') || die "Can't grep for S_ISDIR and co. callers"; @callers = <$fd>; close($fd); unless (@callers) { print "No matches\n"; exit(0); } my @cocci = ( '@@', 'expression E;', '@@', '', '- S_ISLNK(E->d_inode->i_mode)', '+ d_is_symlink(E)', '', '@@', 'expression E;', '@@', '', '- S_ISDIR(E->d_inode->i_mode)', '+ d_is_dir(E)', '', '@@', 'expression E;', '@@', '', '- S_ISREG(E->d_inode->i_mode)', '+ d_is_reg(E)' ); my $coccifile = "tmp.sp.cocci"; open($fd, ">$coccifile") || die $coccifile; print($fd "$_\n") || die $coccifile foreach (@cocci); close($fd); foreach my $file (@callers) { chomp $file; print "Processing ", $file, "\n"; system("spatch", "--sp-file", $coccifile, $file, "--in-place", "--no-show-diff") == 0 || die "spatch failed"; } [AV: overlayfs parts skipped] Signed-off-by: David Howells Signed-off-by: Al Viro --- fs/debugfs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/debugfs/inode.c') diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 45b18a5e225..90933645298 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -690,7 +690,7 @@ struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, } d_move(old_dentry, dentry); fsnotify_move(old_dir->d_inode, new_dir->d_inode, old_name, - S_ISDIR(old_dentry->d_inode->i_mode), + d_is_dir(old_dentry), NULL, old_dentry); fsnotify_oldname_free(old_name); unlock_rename(new_dir, old_dir); -- cgit v1.2.3-70-g09d2 From 0db59e59299f0b67450c5db21f7f316c8fb04e84 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 21 Feb 2015 22:05:11 -0500 Subject: debugfs: leave freeing a symlink body until inode eviction As it is, we have debugfs_remove() racing with symlink traversals. Supply ->evict_inode() and do freeing there - inode will remain pinned until we are done with the symlink body. And rip the idiocy with checking if dentry is positive right after we'd verified debugfs_positive(), which is a stronger check... Cc: stable@vger.kernel.org Signed-off-by: Al Viro --- fs/debugfs/inode.c | 34 +++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) (limited to 'fs/debugfs/inode.c') diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 90933645298..96400ab42d1 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -169,10 +169,19 @@ static int debugfs_show_options(struct seq_file *m, struct dentry *root) return 0; } +static void debugfs_evict_inode(struct inode *inode) +{ + truncate_inode_pages_final(&inode->i_data); + clear_inode(inode); + if (S_ISLNK(inode->i_mode)) + kfree(inode->i_private); +} + static const struct super_operations debugfs_super_operations = { .statfs = simple_statfs, .remount_fs = debugfs_remount, .show_options = debugfs_show_options, + .evict_inode = debugfs_evict_inode, }; static struct vfsmount *debugfs_automount(struct path *path) @@ -511,23 +520,14 @@ static int __debugfs_remove(struct dentry *dentry, struct dentry *parent) int ret = 0; if (debugfs_positive(dentry)) { - if (dentry->d_inode) { - dget(dentry); - switch (dentry->d_inode->i_mode & S_IFMT) { - case S_IFDIR: - ret = simple_rmdir(parent->d_inode, dentry); - break; - case S_IFLNK: - kfree(dentry->d_inode->i_private); - /* fall through */ - default: - simple_unlink(parent->d_inode, dentry); - break; - } - if (!ret) - d_delete(dentry); - dput(dentry); - } + dget(dentry); + if (S_ISDIR(dentry->d_inode->i_mode)) + ret = simple_rmdir(parent->d_inode, dentry); + else + simple_unlink(parent->d_inode, dentry); + if (!ret) + d_delete(dentry); + dput(dentry); } return ret; } -- cgit v1.2.3-70-g09d2