From df1a085af1f652a02238168c4f2b730c8c90dd4a Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Thu, 29 Jan 2015 12:02:28 +0000
Subject: VFS: Add a fallthrough flag for marking virtual dentries
Add a DCACHE_FALLTHRU flag to indicate that, in a layered filesystem, this is
a virtual dentry that covers another one in a lower layer that should be used
instead. This may be recorded on medium if directory integration is stored
there.
The flag can be set with d_set_fallthru() and tested with d_is_fallthru().
Original-author: Valerie Aurora <vaurora@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/dcache.c | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
(limited to 'fs/dcache.c')
diff --git a/fs/dcache.c b/fs/dcache.c
index dc400fd29f4d..e33a0934efd7 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1659,6 +1659,22 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op)
}
EXPORT_SYMBOL(d_set_d_op);
+
+/*
+ * d_set_fallthru - Mark a dentry as falling through to a lower layer
+ * @dentry - The dentry to mark
+ *
+ * Mark a dentry as falling through to the lower layer (as set with
+ * d_pin_lower()). This flag may be recorded on the medium.
+ */
+void d_set_fallthru(struct dentry *dentry)
+{
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags |= DCACHE_FALLTHRU;
+ spin_unlock(&dentry->d_lock);
+}
+EXPORT_SYMBOL(d_set_fallthru);
+
static unsigned d_flags_for_inode(struct inode *inode)
{
unsigned add_flags = DCACHE_FILE_TYPE;
@@ -1691,7 +1707,8 @@ static void __d_instantiate(struct dentry *dentry, struct inode *inode)
unsigned add_flags = d_flags_for_inode(inode);
spin_lock(&dentry->d_lock);
- __d_set_type(dentry, add_flags);
+ dentry->d_flags &= ~(DCACHE_ENTRY_TYPE | DCACHE_FALLTHRU);
+ dentry->d_flags |= add_flags;
if (inode)
hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry);
dentry->d_inode = inode;
--
cgit v1.2.3
From 44bdb5e5f6382ba88f7678d6f535f879324522ae Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Thu, 29 Jan 2015 12:02:29 +0000
Subject: VFS: Split DCACHE_FILE_TYPE into regular and special types
Split DCACHE_FILE_TYPE into DCACHE_REGULAR_TYPE (dentries representing regular
files) and DCACHE_SPECIAL_TYPE (representing blockdev, chardev, FIFO and
socket files).
d_is_reg() and d_is_special() are added to detect these subtypes and
d_is_file() is left as the union of the two.
This allows a number of places that use S_ISREG(dentry->d_inode->i_mode) to
use d_is_reg(dentry) instead.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/dcache.c | 18 +++++++++++++-----
include/linux/dcache.h | 17 ++++++++++++++---
2 files changed, 27 insertions(+), 8 deletions(-)
(limited to 'fs/dcache.c')
diff --git a/fs/dcache.c b/fs/dcache.c
index e33a0934efd7..c71e3732e53b 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -1677,7 +1677,7 @@ EXPORT_SYMBOL(d_set_fallthru);
static unsigned d_flags_for_inode(struct inode *inode)
{
- unsigned add_flags = DCACHE_FILE_TYPE;
+ unsigned add_flags = DCACHE_REGULAR_TYPE;
if (!inode)
return DCACHE_MISS_TYPE;
@@ -1690,13 +1690,21 @@ static unsigned d_flags_for_inode(struct inode *inode)
else
inode->i_opflags |= IOP_LOOKUP;
}
- } else if (unlikely(!(inode->i_opflags & IOP_NOFOLLOW))) {
- if (unlikely(inode->i_op->follow_link))
+ goto type_determined;
+ }
+
+ if (unlikely(!(inode->i_opflags & IOP_NOFOLLOW))) {
+ if (unlikely(inode->i_op->follow_link)) {
add_flags = DCACHE_SYMLINK_TYPE;
- else
- inode->i_opflags |= IOP_NOFOLLOW;
+ goto type_determined;
+ }
+ inode->i_opflags |= IOP_NOFOLLOW;
}
+ if (unlikely(!S_ISREG(inode->i_mode)))
+ add_flags = DCACHE_SPECIAL_TYPE;
+
+type_determined:
if (unlikely(IS_AUTOMOUNT(inode)))
add_flags |= DCACHE_NEED_AUTOMOUNT;
return add_flags;
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 728f5d31b5e6..d8358799c594 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -219,8 +219,9 @@ struct dentry_operations {
#define DCACHE_WHITEOUT_TYPE 0x00100000 /* Whiteout dentry (stop pathwalk) */
#define DCACHE_DIRECTORY_TYPE 0x00200000 /* Normal directory */
#define DCACHE_AUTODIR_TYPE 0x00300000 /* Lookupless directory (presumed automount) */
-#define DCACHE_SYMLINK_TYPE 0x00400000 /* Symlink (or fallthru to such) */
-#define DCACHE_FILE_TYPE 0x00500000 /* Other file type (or fallthru to such) */
+#define DCACHE_REGULAR_TYPE 0x00400000 /* Regular file type (or fallthru to such) */
+#define DCACHE_SPECIAL_TYPE 0x00500000 /* Other file type (or fallthru to such) */
+#define DCACHE_SYMLINK_TYPE 0x00600000 /* Symlink (or fallthru to such) */
#define DCACHE_MAY_FREE 0x00800000
#define DCACHE_FALLTHRU 0x01000000 /* Fall through to lower layer */
@@ -455,9 +456,19 @@ static inline bool d_is_symlink(const struct dentry *dentry)
return __d_entry_type(dentry) == DCACHE_SYMLINK_TYPE;
}
+static inline bool d_is_reg(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_REGULAR_TYPE;
+}
+
+static inline bool d_is_special(const struct dentry *dentry)
+{
+ return __d_entry_type(dentry) == DCACHE_SPECIAL_TYPE;
+}
+
static inline bool d_is_file(const struct dentry *dentry)
{
- return __d_entry_type(dentry) == DCACHE_FILE_TYPE;
+ return d_is_reg(dentry) || d_is_special(dentry);
}
static inline bool d_is_negative(const struct dentry *dentry)
--
cgit v1.2.3