[PATCH 24/29] Unionfs: debugging infrastructure

From: Erez Zadok
Date: Thu Jan 10 2008 - 10:08:37 EST


Signed-off-by: Erez Zadok <ezk@xxxxxxxxxxxxx>
---
fs/unionfs/debug.c | 533 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 533 insertions(+), 0 deletions(-)
create mode 100644 fs/unionfs/debug.c

diff --git a/fs/unionfs/debug.c b/fs/unionfs/debug.c
new file mode 100644
index 0000000..d154c32
--- /dev/null
+++ b/fs/unionfs/debug.c
@@ -0,0 +1,533 @@
+/*
+ * Copyright (c) 2003-2007 Erez Zadok
+ * Copyright (c) 2005-2007 Josef 'Jeff' Sipek
+ * Copyright (c) 2003-2007 Stony Brook University
+ * Copyright (c) 2003-2007 The Research Foundation of SUNY
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include "union.h"
+
+/*
+ * Helper debugging functions for maintainers (and for users to report back
+ * useful information back to maintainers)
+ */
+
+/* it's always useful to know what part of the code called us */
+#define PRINT_CALLER(fname, fxn, line) \
+ do { \
+ if (!printed_caller) { \
+ pr_debug("PC:%s:%s:%d\n", (fname), (fxn), (line)); \
+ printed_caller = 1; \
+ } \
+ } while (0)
+
+/*
+ * __unionfs_check_{inode,dentry,file} perform exhaustive sanity checking on
+ * the fan-out of various Unionfs objects. We check that no lower objects
+ * exist outside the start/end branch range; that all objects within are
+ * non-NULL (with some allowed exceptions); that for every lower file
+ * there's a lower dentry+inode; that the start/end ranges match for all
+ * corresponding lower objects; that open files/symlinks have only one lower
+ * objects, but directories can have several; and more.
+ */
+void __unionfs_check_inode(const struct inode *inode,
+ const char *fname, const char *fxn, int line)
+{
+ int bindex;
+ int istart, iend;
+ struct inode *lower_inode;
+ struct super_block *sb;
+ int printed_caller = 0;
+ void *poison_ptr;
+
+ /* for inodes now */
+ BUG_ON(!inode);
+ sb = inode->i_sb;
+ istart = ibstart(inode);
+ iend = ibend(inode);
+ /* don't check inode if no lower branches */
+ if (istart < 0 && iend < 0)
+ return;
+ if (unlikely(istart > iend)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" Ci0: inode=%p istart/end=%d:%d\n",
+ inode, istart, iend);
+ }
+ if (unlikely((istart == -1 && iend != -1) ||
+ (istart != -1 && iend == -1))) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" Ci1: inode=%p istart/end=%d:%d\n",
+ inode, istart, iend);
+ }
+ if (!S_ISDIR(inode->i_mode)) {
+ if (unlikely(iend != istart)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" Ci2: inode=%p istart=%d iend=%d\n",
+ inode, istart, iend);
+ }
+ }
+
+ for (bindex = sbstart(sb); bindex < sbmax(sb); bindex++) {
+ if (unlikely(!UNIONFS_I(inode))) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" Ci3: no inode_info %p\n", inode);
+ return;
+ }
+ if (unlikely(!UNIONFS_I(inode)->lower_inodes)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" Ci4: no lower_inodes %p\n", inode);
+ return;
+ }
+ lower_inode = unionfs_lower_inode_idx(inode, bindex);
+ if (lower_inode) {
+ memset(&poison_ptr, POISON_INUSE, sizeof(void *));
+ if (unlikely(bindex < istart || bindex > iend)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" Ci5: inode/linode=%p:%p bindex=%d "
+ "istart/end=%d:%d\n", inode,
+ lower_inode, bindex, istart, iend);
+ } else if (unlikely(lower_inode == poison_ptr)) {
+ /* freed inode! */
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" Ci6: inode/linode=%p:%p bindex=%d "
+ "istart/end=%d:%d\n", inode,
+ lower_inode, bindex, istart, iend);
+ }
+ continue;
+ }
+ /* if we get here, then lower_inode == NULL */
+ if (bindex < istart || bindex > iend)
+ continue;
+ /*
+ * directories can have NULL lower inodes in b/t start/end,
+ * but NOT if at the start/end range.
+ */
+ if (unlikely(S_ISDIR(inode->i_mode) &&
+ bindex > istart && bindex < iend))
+ continue;
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" Ci7: inode/linode=%p:%p "
+ "bindex=%d istart/end=%d:%d\n",
+ inode, lower_inode, bindex, istart, iend);
+ }
+}
+
+void __unionfs_check_dentry(const struct dentry *dentry,
+ const char *fname, const char *fxn, int line)
+{
+ int bindex;
+ int dstart, dend, istart, iend;
+ struct dentry *lower_dentry;
+ struct inode *inode, *lower_inode;
+ struct super_block *sb;
+ struct vfsmount *lower_mnt;
+ int printed_caller = 0;
+ void *poison_ptr;
+
+ BUG_ON(!dentry);
+ sb = dentry->d_sb;
+ inode = dentry->d_inode;
+ dstart = dbstart(dentry);
+ dend = dbend(dentry);
+ /* don't check dentry/mnt if no lower branches */
+ if (dstart < 0 && dend < 0)
+ goto check_inode;
+ BUG_ON(dstart > dend);
+
+ if (unlikely((dstart == -1 && dend != -1) ||
+ (dstart != -1 && dend == -1))) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CD0: dentry=%p dstart/end=%d:%d\n",
+ dentry, dstart, dend);
+ }
+ /*
+ * check for NULL dentries inside the start/end range, or
+ * non-NULL dentries outside the start/end range.
+ */
+ for (bindex = sbstart(sb); bindex < sbmax(sb); bindex++) {
+ lower_dentry = unionfs_lower_dentry_idx(dentry, bindex);
+ if (lower_dentry) {
+ if (unlikely(bindex < dstart || bindex > dend)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CD1: dentry/lower=%p:%p(%p) "
+ "bindex=%d dstart/end=%d:%d\n",
+ dentry, lower_dentry,
+ (lower_dentry ? lower_dentry->d_inode :
+ (void *) -1L),
+ bindex, dstart, dend);
+ }
+ } else { /* lower_dentry == NULL */
+ if (bindex < dstart || bindex > dend)
+ continue;
+ /*
+ * Directories can have NULL lower inodes in b/t
+ * start/end, but NOT if at the start/end range.
+ * Ignore this rule, however, if this is a NULL
+ * dentry or a deleted dentry.
+ */
+ if (unlikely(!d_deleted((struct dentry *) dentry) &&
+ inode &&
+ !(inode && S_ISDIR(inode->i_mode) &&
+ bindex > dstart && bindex < dend))) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CD2: dentry/lower=%p:%p(%p) "
+ "bindex=%d dstart/end=%d:%d\n",
+ dentry, lower_dentry,
+ (lower_dentry ?
+ lower_dentry->d_inode :
+ (void *) -1L),
+ bindex, dstart, dend);
+ }
+ }
+ }
+
+ /* check for vfsmounts same as for dentries */
+ for (bindex = sbstart(sb); bindex < sbmax(sb); bindex++) {
+ lower_mnt = unionfs_lower_mnt_idx(dentry, bindex);
+ if (lower_mnt) {
+ if (unlikely(bindex < dstart || bindex > dend)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CM0: dentry/lmnt=%p:%p bindex=%d "
+ "dstart/end=%d:%d\n", dentry,
+ lower_mnt, bindex, dstart, dend);
+ }
+ } else { /* lower_mnt == NULL */
+ if (bindex < dstart || bindex > dend)
+ continue;
+ /*
+ * Directories can have NULL lower inodes in b/t
+ * start/end, but NOT if at the start/end range.
+ * Ignore this rule, however, if this is a NULL
+ * dentry.
+ */
+ if (unlikely(inode &&
+ !(inode && S_ISDIR(inode->i_mode) &&
+ bindex > dstart && bindex < dend))) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CM1: dentry/lmnt=%p:%p "
+ "bindex=%d dstart/end=%d:%d\n",
+ dentry, lower_mnt, bindex,
+ dstart, dend);
+ }
+ }
+ }
+
+check_inode:
+ /* for inodes now */
+ if (!inode)
+ return;
+ istart = ibstart(inode);
+ iend = ibend(inode);
+ /* don't check inode if no lower branches */
+ if (istart < 0 && iend < 0)
+ return;
+ BUG_ON(istart > iend);
+ if (unlikely((istart == -1 && iend != -1) ||
+ (istart != -1 && iend == -1))) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CI0: dentry/inode=%p:%p istart/end=%d:%d\n",
+ dentry, inode, istart, iend);
+ }
+ if (unlikely(istart != dstart)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CI1: dentry/inode=%p:%p istart=%d dstart=%d\n",
+ dentry, inode, istart, dstart);
+ }
+ if (unlikely(iend != dend)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CI2: dentry/inode=%p:%p iend=%d dend=%d\n",
+ dentry, inode, iend, dend);
+ }
+
+ if (!S_ISDIR(inode->i_mode)) {
+ if (unlikely(dend != dstart)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CI3: dentry/inode=%p:%p dstart=%d dend=%d\n",
+ dentry, inode, dstart, dend);
+ }
+ if (unlikely(iend != istart)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CI4: dentry/inode=%p:%p istart=%d iend=%d\n",
+ dentry, inode, istart, iend);
+ }
+ }
+
+ for (bindex = sbstart(sb); bindex < sbmax(sb); bindex++) {
+ lower_inode = unionfs_lower_inode_idx(inode, bindex);
+ if (lower_inode) {
+ memset(&poison_ptr, POISON_INUSE, sizeof(void *));
+ if (unlikely(bindex < istart || bindex > iend)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CI5: dentry/linode=%p:%p bindex=%d "
+ "istart/end=%d:%d\n", dentry,
+ lower_inode, bindex, istart, iend);
+ } else if (unlikely(lower_inode == poison_ptr)) {
+ /* freed inode! */
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CI6: dentry/linode=%p:%p bindex=%d "
+ "istart/end=%d:%d\n", dentry,
+ lower_inode, bindex, istart, iend);
+ }
+ continue;
+ }
+ /* if we get here, then lower_inode == NULL */
+ if (bindex < istart || bindex > iend)
+ continue;
+ /*
+ * directories can have NULL lower inodes in b/t start/end,
+ * but NOT if at the start/end range.
+ */
+ if (unlikely(S_ISDIR(inode->i_mode) &&
+ bindex > istart && bindex < iend))
+ continue;
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CI7: dentry/linode=%p:%p "
+ "bindex=%d istart/end=%d:%d\n",
+ dentry, lower_inode, bindex, istart, iend);
+ }
+
+ /*
+ * If it's a directory, then intermediate objects b/t start/end can
+ * be NULL. But, check that all three are NULL: lower dentry, mnt,
+ * and inode.
+ */
+ if (dstart >= 0 && dend >= 0 && S_ISDIR(inode->i_mode))
+ for (bindex = dstart+1; bindex < dend; bindex++) {
+ lower_inode = unionfs_lower_inode_idx(inode, bindex);
+ lower_dentry = unionfs_lower_dentry_idx(dentry,
+ bindex);
+ lower_mnt = unionfs_lower_mnt_idx(dentry, bindex);
+ if (unlikely(!((lower_inode && lower_dentry &&
+ lower_mnt) ||
+ (!lower_inode &&
+ !lower_dentry && !lower_mnt)))) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" Cx: lmnt/ldentry/linode=%p:%p:%p "
+ "bindex=%d dstart/end=%d:%d\n",
+ lower_mnt, lower_dentry, lower_inode,
+ bindex, dstart, dend);
+ }
+ }
+ /* check if lower inode is newer than upper one (it shouldn't) */
+ if (unlikely(is_newer_lower(dentry))) {
+ PRINT_CALLER(fname, fxn, line);
+ for (bindex = ibstart(inode); bindex <= ibend(inode);
+ bindex++) {
+ lower_inode = unionfs_lower_inode_idx(inode, bindex);
+ if (unlikely(!lower_inode))
+ continue;
+ pr_debug(" CI8: bindex=%d mtime/lmtime=%lu.%lu/%lu.%lu "
+ "ctime/lctime=%lu.%lu/%lu.%lu\n",
+ bindex,
+ inode->i_mtime.tv_sec,
+ inode->i_mtime.tv_nsec,
+ lower_inode->i_mtime.tv_sec,
+ lower_inode->i_mtime.tv_nsec,
+ inode->i_ctime.tv_sec,
+ inode->i_ctime.tv_nsec,
+ lower_inode->i_ctime.tv_sec,
+ lower_inode->i_ctime.tv_nsec);
+ }
+ }
+}
+
+void __unionfs_check_file(const struct file *file,
+ const char *fname, const char *fxn, int line)
+{
+ int bindex;
+ int dstart, dend, fstart, fend;
+ struct dentry *dentry;
+ struct file *lower_file;
+ struct inode *inode;
+ struct super_block *sb;
+ int printed_caller = 0;
+
+ BUG_ON(!file);
+ dentry = file->f_path.dentry;
+ sb = dentry->d_sb;
+ dstart = dbstart(dentry);
+ dend = dbend(dentry);
+ BUG_ON(dstart > dend);
+ fstart = fbstart(file);
+ fend = fbend(file);
+ BUG_ON(fstart > fend);
+
+ if (unlikely((fstart == -1 && fend != -1) ||
+ (fstart != -1 && fend == -1))) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CF0: file/dentry=%p:%p fstart/end=%d:%d\n",
+ file, dentry, fstart, fend);
+ }
+ if (unlikely(fstart != dstart)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CF1: file/dentry=%p:%p fstart=%d dstart=%d\n",
+ file, dentry, fstart, dstart);
+ }
+ if (unlikely(fend != dend)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CF2: file/dentry=%p:%p fend=%d dend=%d\n",
+ file, dentry, fend, dend);
+ }
+ inode = dentry->d_inode;
+ if (!S_ISDIR(inode->i_mode)) {
+ if (unlikely(fend != fstart)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CF3: file/inode=%p:%p fstart=%d fend=%d\n",
+ file, inode, fstart, fend);
+ }
+ if (unlikely(dend != dstart)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CF4: file/dentry=%p:%p dstart=%d dend=%d\n",
+ file, dentry, dstart, dend);
+ }
+ }
+
+ /*
+ * check for NULL dentries inside the start/end range, or
+ * non-NULL dentries outside the start/end range.
+ */
+ for (bindex = sbstart(sb); bindex < sbmax(sb); bindex++) {
+ lower_file = unionfs_lower_file_idx(file, bindex);
+ if (lower_file) {
+ if (unlikely(bindex < fstart || bindex > fend)) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CF5: file/lower=%p:%p bindex=%d "
+ "fstart/end=%d:%d\n", file,
+ lower_file, bindex, fstart, fend);
+ }
+ } else { /* lower_file == NULL */
+ if (bindex >= fstart && bindex <= fend) {
+ /*
+ * directories can have NULL lower inodes in
+ * b/t start/end, but NOT if at the
+ * start/end range.
+ */
+ if (unlikely(!(S_ISDIR(inode->i_mode) &&
+ bindex > fstart &&
+ bindex < fend))) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CF6: file/lower=%p:%p "
+ "bindex=%d fstart/end=%d:%d\n",
+ file, lower_file, bindex,
+ fstart, fend);
+ }
+ }
+ }
+ }
+
+ __unionfs_check_dentry(dentry, fname, fxn, line);
+}
+
+void __unionfs_check_nd(const struct nameidata *nd,
+ const char *fname, const char *fxn, int line)
+{
+ struct file *file;
+ int printed_caller = 0;
+
+ if (unlikely(!nd))
+ return;
+ if (nd->flags & LOOKUP_OPEN) {
+ file = nd->intent.open.file;
+ if (unlikely(file->f_path.dentry &&
+ strcmp(file->f_path.dentry->d_sb->s_type->name,
+ UNIONFS_NAME))) {
+ PRINT_CALLER(fname, fxn, line);
+ pr_debug(" CND1: lower_file of type %s\n",
+ file->f_path.dentry->d_sb->s_type->name);
+ BUG();
+ }
+ }
+}
+
+/* useful to track vfsmount leaks that could cause EBUSY on unmount */
+void __show_branch_counts(const struct super_block *sb,
+ const char *file, const char *fxn, int line)
+{
+ int i;
+ struct vfsmount *mnt;
+
+ pr_debug("BC:");
+ for (i = 0; i < sbmax(sb); i++) {
+ if (likely(sb->s_root))
+ mnt = UNIONFS_D(sb->s_root)->lower_paths[i].mnt;
+ else
+ mnt = NULL;
+ printk(KERN_CONT "%d:",
+ (mnt ? atomic_read(&mnt->mnt_count) : -99));
+ }
+ printk(KERN_CONT "%s:%s:%d\n", file, fxn, line);
+}
+
+void __show_inode_times(const struct inode *inode,
+ const char *file, const char *fxn, int line)
+{
+ struct inode *lower_inode;
+ int bindex;
+
+ for (bindex = ibstart(inode); bindex <= ibend(inode); bindex++) {
+ lower_inode = unionfs_lower_inode_idx(inode, bindex);
+ if (unlikely(!lower_inode))
+ continue;
+ pr_debug("IT(%lu:%d): %s:%s:%d "
+ "um=%lu/%lu lm=%lu/%lu uc=%lu/%lu lc=%lu/%lu\n",
+ inode->i_ino, bindex,
+ file, fxn, line,
+ inode->i_mtime.tv_sec, inode->i_mtime.tv_nsec,
+ lower_inode->i_mtime.tv_sec,
+ lower_inode->i_mtime.tv_nsec,
+ inode->i_ctime.tv_sec, inode->i_ctime.tv_nsec,
+ lower_inode->i_ctime.tv_sec,
+ lower_inode->i_ctime.tv_nsec);
+ }
+}
+
+void __show_dinode_times(const struct dentry *dentry,
+ const char *file, const char *fxn, int line)
+{
+ struct inode *inode = dentry->d_inode;
+ struct inode *lower_inode;
+ int bindex;
+
+ for (bindex = ibstart(inode); bindex <= ibend(inode); bindex++) {
+ lower_inode = unionfs_lower_inode_idx(inode, bindex);
+ if (!lower_inode)
+ continue;
+ pr_debug("DT(%s:%lu:%d): %s:%s:%d "
+ "um=%lu/%lu lm=%lu/%lu uc=%lu/%lu lc=%lu/%lu\n",
+ dentry->d_name.name, inode->i_ino, bindex,
+ file, fxn, line,
+ inode->i_mtime.tv_sec, inode->i_mtime.tv_nsec,
+ lower_inode->i_mtime.tv_sec,
+ lower_inode->i_mtime.tv_nsec,
+ inode->i_ctime.tv_sec, inode->i_ctime.tv_nsec,
+ lower_inode->i_ctime.tv_sec,
+ lower_inode->i_ctime.tv_nsec);
+ }
+}
+
+void __show_inode_counts(const struct inode *inode,
+ const char *file, const char *fxn, int line)
+{
+ struct inode *lower_inode;
+ int bindex;
+
+ if (unlikely(!inode)) {
+ pr_debug("SiC: Null inode\n");
+ return;
+ }
+ for (bindex = sbstart(inode->i_sb); bindex <= sbend(inode->i_sb);
+ bindex++) {
+ lower_inode = unionfs_lower_inode_idx(inode, bindex);
+ if (unlikely(!lower_inode))
+ continue;
+ pr_debug("SIC(%lu:%d:%d): lc=%d %s:%s:%d\n",
+ inode->i_ino, bindex,
+ atomic_read(&(inode)->i_count),
+ atomic_read(&(lower_inode)->i_count),
+ file, fxn, line);
+ }
+}
--
1.5.2.2

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