The patch titled
vfs: add d_ancestor()
has been removed from the -mm tree. Its filename was
vfs-add-d_ancestor.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: vfs: add d_ancestor()
From: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
This adds d_ancestor() instead of d_isparent(), then use it.
If new_dentry == old_dentry, is_subdir() returns 1, looks strange.
"new_dentry == old_dentry" is not subdir obviously. But I'm not
checking callers for now, so this keeps current behavior.
Signed-off-by: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/dcache.c | 45 +++++++++++++++++++--------------------
fs/namei.c | 22 ++++++++-----------
include/linux/dcache.h | 1
3 files changed, 34 insertions(+), 34 deletions(-)
diff -puN fs/dcache.c~vfs-add-d_ancestor fs/dcache.c
--- a/fs/dcache.c~vfs-add-d_ancestor
+++ a/fs/dcache.c
@@ -1720,18 +1720,23 @@ void d_move(struct dentry * dentry, stru
spin_unlock(&dcache_lock);
}
-/*
- * Helper that returns 1 if p1 is a parent of p2, else 0
+/**
+ * d_ancestor - search for an ancestor
+ * @p1: ancestor dentry
+ * @p2: child dentry
+ *
+ * Returns the ancestor dentry of p2 which is a child of p1, if p1 is
+ * an ancestor of p2, else NULL.
*/
-static int d_isparent(struct dentry *p1, struct dentry *p2)
+struct dentry *d_ancestor(struct dentry *p1, struct dentry *p2)
{
struct dentry *p;
for (p = p2; !IS_ROOT(p); p = p->d_parent) {
if (p->d_parent == p1)
- return 1;
+ return p;
}
- return 0;
+ return NULL;
}
/*
@@ -1755,7 +1760,7 @@ static struct dentry *__d_unalias(struct
/* Check for loops */
ret = ERR_PTR(-ELOOP);
- if (d_isparent(alias, dentry))
+ if (d_ancestor(alias, dentry))
goto out_err;
/* See lock_rename() */
@@ -2155,31 +2160,27 @@ out:
* Caller must ensure that "new_dentry" is pinned before calling is_subdir()
*/
-int is_subdir(struct dentry * new_dentry, struct dentry * old_dentry)
+int is_subdir(struct dentry *new_dentry, struct dentry *old_dentry)
{
int result;
- struct dentry * saved = new_dentry;
unsigned long seq;
- /* need rcu_readlock to protect against the d_parent trashing due to
- * d_move
+ /* FIXME: This is old behavior, needed? Please check callers. */
+ if (new_dentry == old_dentry)
+ return 1;
+
+ /*
+ * Need rcu_readlock to protect against the d_parent trashing
+ * due to d_move
*/
rcu_read_lock();
- do {
+ do {
/* for restarting inner loop in case of seq retry */
- new_dentry = saved;
- result = 0;
seq = read_seqbegin(&rename_lock);
- for (;;) {
- if (new_dentry != old_dentry) {
- if (IS_ROOT(new_dentry))
- break;
- new_dentry = new_dentry->d_parent;
- continue;
- }
+ if (d_ancestor(old_dentry, new_dentry))
result = 1;
- break;
- }
+ else
+ result = 0;
} while (read_seqretry(&rename_lock, seq));
rcu_read_unlock();
diff -puN fs/namei.c~vfs-add-d_ancestor fs/namei.c
--- a/fs/namei.c~vfs-add-d_ancestor
+++ a/fs/namei.c
@@ -1454,20 +1454,18 @@ struct dentry *lock_rename(struct dentry
mutex_lock(&p1->d_inode->i_sb->s_vfs_rename_mutex);
- for (p = p1; !IS_ROOT(p); p = p->d_parent) {
- if (p->d_parent == p2) {
- mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT);
- mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_CHILD);
- return p;
- }
+ p = d_ancestor(p2, p1);
+ if (p) {
+ mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT);
+ mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_CHILD);
+ return p;
}
- for (p = p2; !IS_ROOT(p); p = p->d_parent) {
- if (p->d_parent == p1) {
- mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT);
- mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD);
- return p;
- }
+ p = d_ancestor(p1, p2);
+ if (p) {
+ mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT);
+ mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD);
+ return p;
}
mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT);
diff -puN include/linux/dcache.h~vfs-add-d_ancestor include/linux/dcache.h
--- a/include/linux/dcache.h~vfs-add-d_ancestor
+++ a/include/linux/dcache.h
@@ -287,6 +287,7 @@ static inline struct dentry *d_add_uniqu
/* used for rename() and baskets */
extern void d_move(struct dentry *, struct dentry *);
+extern struct dentry *d_ancestor(struct dentry *, struct dentry *);
/* appendix may either be NULL or be used for transname suffixes */
extern struct dentry * d_lookup(struct dentry *, struct qstr *);
_
Patches currently in -mm which might be from hirofumi@xxxxxxxxxxxxxxxxxx are
linux-next.patch
fat-document-additional-vfat-mount-options.patch
fat-move-fs-vfat-and-fs-msdos-to-fs-fat.patch
fat-split-include-msdos_fsh.patch
fat-fix-and-cleanup-timestamp-conversion.patch
fat-use-generic_file_llseek-for-directory.patch
fat-cleanup-fat_parse_long-error-handling.patch
fat-improve-fat_hash.patch
fat-fix-fat_ent_update_ptr-for-fat12.patch
fat-use-fat_detach-in-fat_clear_inode.patch
vfat-fix-vfat_find-error-path-in-vfat_lookup.patch
fat-fix-cleanup-dcache-handling-for-vfat.patch
fat-kill-d_invalidate-in-vfat_lookup.patch
fat-cleanup-msdos_lookup.patch
fat-cleanup-fat-attribute-stuff.patch
fat-fix-attr_ro-in-the-case-of-umask-s_wugo-==-0.patch
fat-fix-attr_ro-for-directory.patch
fat-fix-_fat_bmap-race.patch
fat-add-printf-attribute-to-fat_fs_panic.patch
fat-mmu_private-race-fix.patch
fat-i_pos-race-fix.patch
fat-i_blocks-warning-fix.patch
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