* [PATCH 01/12] vfs: pull ext4's double-i_mutex-locking into common code
2013-04-17 1:46 [PATCH 00/12] Implement NFSv4 delegations, take 7 J. Bruce Fields
@ 2013-04-17 1:46 ` J. Bruce Fields
2013-04-17 1:46 ` [PATCH 03/12] vfs: rename I_MUTEX_QUOTA now that it's not used for quotas J. Bruce Fields
` (7 subsequent siblings)
8 siblings, 0 replies; 13+ messages in thread
From: J. Bruce Fields @ 2013-04-17 1:46 UTC (permalink / raw)
To: Al Viro
Cc: linux-nfs, linux-fsdevel, Linus Torvalds, J. Bruce Fields,
Theodore Ts'o, Andreas Dilger
From: "J. Bruce Fields" <bfields@redhat.com>
We want to do this elsewhere as well.
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
fs/ext4/move_extent.c | 40 ++--------------------------------------
fs/inode.c | 29 +++++++++++++++++++++++++++++
include/linux/fs.h | 3 +++
3 files changed, 34 insertions(+), 38 deletions(-)
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index 33e1c08..78f2c46 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -1209,42 +1209,6 @@ mext_check_arguments(struct inode *orig_inode,
}
/**
- * mext_inode_double_lock - Lock i_mutex on both @inode1 and @inode2
- *
- * @inode1: the inode structure
- * @inode2: the inode structure
- *
- * Lock two inodes' i_mutex
- */
-static void
-mext_inode_double_lock(struct inode *inode1, struct inode *inode2)
-{
- BUG_ON(inode1 == inode2);
- if (inode1 < inode2) {
- mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT);
- mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD);
- } else {
- mutex_lock_nested(&inode2->i_mutex, I_MUTEX_PARENT);
- mutex_lock_nested(&inode1->i_mutex, I_MUTEX_CHILD);
- }
-}
-
-/**
- * mext_inode_double_unlock - Release i_mutex on both @inode1 and @inode2
- *
- * @inode1: the inode that is released first
- * @inode2: the inode that is released second
- *
- */
-
-static void
-mext_inode_double_unlock(struct inode *inode1, struct inode *inode2)
-{
- mutex_unlock(&inode1->i_mutex);
- mutex_unlock(&inode2->i_mutex);
-}
-
-/**
* ext4_move_extents - Exchange the specified range of a file
*
* @o_filp: file structure of the original file
@@ -1333,7 +1297,7 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp,
return -EINVAL;
}
/* Protect orig and donor inodes against a truncate */
- mext_inode_double_lock(orig_inode, donor_inode);
+ lock_two_nondirectories(orig_inode, donor_inode);
/* Wait for all existing dio workers */
ext4_inode_block_unlocked_dio(orig_inode);
@@ -1541,7 +1505,7 @@ out:
double_up_write_data_sem(orig_inode, donor_inode);
ext4_inode_resume_unlocked_dio(orig_inode);
ext4_inode_resume_unlocked_dio(donor_inode);
- mext_inode_double_unlock(orig_inode, donor_inode);
+ unlock_two_nondirectories(orig_inode, donor_inode);
return ret;
}
diff --git a/fs/inode.c b/fs/inode.c
index f5f7c06..9815712 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -980,6 +980,35 @@ void unlock_new_inode(struct inode *inode)
EXPORT_SYMBOL(unlock_new_inode);
/**
+ * lock_two_nondirectories - take two i_mutexes on non-directory objects
+ * @inode1: first inode to lock
+ * @inode2: second inode to lock
+ */
+void lock_two_nondirectories(struct inode *inode1, struct inode *inode2)
+{
+ if (inode1 < inode2) {
+ mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT);
+ mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD);
+ } else {
+ mutex_lock_nested(&inode2->i_mutex, I_MUTEX_PARENT);
+ mutex_lock_nested(&inode1->i_mutex, I_MUTEX_CHILD);
+ }
+}
+EXPORT_SYMBOL(lock_two_nondirectories);
+
+/**
+ * unlock_two_nondirectories - release locks from lock_two_nondirectories()
+ * @inode1: first inode to unlock
+ * @inode2: second inode to unlock
+ */
+void unlock_two_nondirectories(struct inode *inode1, struct inode *inode2)
+{
+ mutex_unlock(&inode1->i_mutex);
+ mutex_unlock(&inode2->i_mutex);
+}
+EXPORT_SYMBOL(unlock_two_nondirectories);
+
+/**
* iget5_locked - obtain an inode from a mounted file system
* @sb: super block of file system
* @hashval: hash value (usually inode number) to get
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2c28271..356c676 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -634,6 +634,9 @@ enum inode_i_mutex_lock_class
I_MUTEX_QUOTA
};
+void lock_two_nondirectories(struct inode *, struct inode*);
+void unlock_two_nondirectories(struct inode *, struct inode*);
+
/*
* NOTE: in a 32bit arch with a preemptable kernel and
* an UP compile the i_size_read/write must be atomic
--
1.7.9.5
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 03/12] vfs: rename I_MUTEX_QUOTA now that it's not used for quotas
2013-04-17 1:46 [PATCH 00/12] Implement NFSv4 delegations, take 7 J. Bruce Fields
2013-04-17 1:46 ` [PATCH 01/12] vfs: pull ext4's double-i_mutex-locking into common code J. Bruce Fields
@ 2013-04-17 1:46 ` J. Bruce Fields
[not found] ` <1366163185-10317-1-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
` (6 subsequent siblings)
8 siblings, 0 replies; 13+ messages in thread
From: J. Bruce Fields @ 2013-04-17 1:46 UTC (permalink / raw)
To: Al Viro; +Cc: linux-nfs, linux-fsdevel, Linus Torvalds, J. Bruce Fields
From: "J. Bruce Fields" <bfields@redhat.com>
I_MUTEX_QUOTA is now just being used whenever we want to lock two
non-directories. So the name isn't right. I_MUTEX_NONDIR2 isn't
especially elegant but it's the best I could think of.
Also fix some outdated documentation.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
fs/inode.c | 4 ++--
include/linux/fs.h | 9 ++++++---
2 files changed, 8 insertions(+), 5 deletions(-)
diff --git a/fs/inode.c b/fs/inode.c
index 07af7be..4a00662 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -988,10 +988,10 @@ void lock_two_nondirectories(struct inode *inode1, struct inode *inode2)
{
if (inode1 < inode2) {
mutex_lock(&inode1->i_mutex);
- mutex_lock_nested(&inode2->i_mutex, I_MUTEX_QUOTA);
+ mutex_lock_nested(&inode2->i_mutex, I_MUTEX_NONDIR2);
} else {
mutex_lock(&inode2->i_mutex);
- mutex_lock_nested(&inode1->i_mutex, I_MUTEX_QUOTA);
+ mutex_lock_nested(&inode1->i_mutex, I_MUTEX_NONDIR2);
}
}
EXPORT_SYMBOL(lock_two_nondirectories);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 356c676..6e45aa6 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -620,10 +620,13 @@ static inline int inode_unhashed(struct inode *inode)
* 0: the object of the current VFS operation
* 1: parent
* 2: child/target
- * 3: quota file
+ * 3: xattr
+ * 4: second non-directory
+ * The last is for certain operations (such as rename) which lock two
+ * non-directories at once.
*
* The locking order between these classes is
- * parent -> child -> normal -> xattr -> quota
+ * parent -> child -> normal -> xattr -> second non-directory
*/
enum inode_i_mutex_lock_class
{
@@ -631,7 +634,7 @@ enum inode_i_mutex_lock_class
I_MUTEX_PARENT,
I_MUTEX_CHILD,
I_MUTEX_XATTR,
- I_MUTEX_QUOTA
+ I_MUTEX_NONDIR2
};
void lock_two_nondirectories(struct inode *, struct inode*);
--
1.7.9.5
^ permalink raw reply related [flat|nested] 13+ messages in thread[parent not found: <1366163185-10317-1-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]
* [PATCH 02/12] vfs: don't use PARENT/CHILD lock classes for non-directories
[not found] ` <1366163185-10317-1-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
@ 2013-04-17 1:46 ` J. Bruce Fields
2013-04-17 1:46 ` [PATCH 04/12] vfs: take i_mutex on renamed file J. Bruce Fields
` (2 subsequent siblings)
3 siblings, 0 replies; 13+ messages in thread
From: J. Bruce Fields @ 2013-04-17 1:46 UTC (permalink / raw)
To: Al Viro
Cc: linux-nfs-u79uwXL29TY76Z2rM5mHXA,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA, Linus Torvalds,
J. Bruce Fields
From: "J. Bruce Fields" <bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Reserve I_MUTEX_PARENT and I_MUTEX_CHILD for locking of actual
directories.
(Also I_MUTEX_QUOTA isn't really a meaningful name for this locking
class any more; fixed in a later patch.)
Signed-off-by: J. Bruce Fields <bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
fs/inode.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/inode.c b/fs/inode.c
index 9815712..07af7be 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -987,11 +987,11 @@ EXPORT_SYMBOL(unlock_new_inode);
void lock_two_nondirectories(struct inode *inode1, struct inode *inode2)
{
if (inode1 < inode2) {
- mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT);
- mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD);
+ mutex_lock(&inode1->i_mutex);
+ mutex_lock_nested(&inode2->i_mutex, I_MUTEX_QUOTA);
} else {
- mutex_lock_nested(&inode2->i_mutex, I_MUTEX_PARENT);
- mutex_lock_nested(&inode1->i_mutex, I_MUTEX_CHILD);
+ mutex_lock(&inode2->i_mutex);
+ mutex_lock_nested(&inode1->i_mutex, I_MUTEX_QUOTA);
}
}
EXPORT_SYMBOL(lock_two_nondirectories);
--
1.7.9.5
--
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^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 04/12] vfs: take i_mutex on renamed file
[not found] ` <1366163185-10317-1-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2013-04-17 1:46 ` [PATCH 02/12] vfs: don't use PARENT/CHILD lock classes for non-directories J. Bruce Fields
@ 2013-04-17 1:46 ` J. Bruce Fields
2013-04-17 1:46 ` [PATCH 07/12] namei: minor vfs_unlink cleanup J. Bruce Fields
2013-04-17 1:46 ` [PATCH 10/12] locks: break delegations on rename J. Bruce Fields
3 siblings, 0 replies; 13+ messages in thread
From: J. Bruce Fields @ 2013-04-17 1:46 UTC (permalink / raw)
To: Al Viro
Cc: linux-nfs-u79uwXL29TY76Z2rM5mHXA,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA, Linus Torvalds,
J. Bruce Fields
From: "J. Bruce Fields" <bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
A read delegation is used by NFSv4 as a guarantee that a client can
perform local read opens without informing the server.
The open operation takes the last component of the pathname as an
argument, thus is also a lookup operation, and giving the client the
above guarantee means informing the client before we allow anything that
would change the set of names pointing to the inode.
Therefore, we need to break delegations on rename, link, and unlink.
We also need to prevent new delegations from being acquired while one of
these operations is in progress.
We could add some completely new locking for that purpose, but it's
simpler to use the i_mutex, since that's already taken by all the
operations we care about.
The single exception is rename. So, modify rename to take the i_mutex
on the file that is being renamed.
Also fix up lockdep and Documentation/filesystems/directory-locking to
reflect the change.
Signed-off-by: J. Bruce Fields <bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
Documentation/filesystems/directory-locking | 31 +++++++++++++++++++--------
fs/namei.c | 12 ++++++++---
2 files changed, 31 insertions(+), 12 deletions(-)
diff --git a/Documentation/filesystems/directory-locking b/Documentation/filesystems/directory-locking
index ff7b611..09bbf9a 100644
--- a/Documentation/filesystems/directory-locking
+++ b/Documentation/filesystems/directory-locking
@@ -2,6 +2,10 @@
kinds of locks - per-inode (->i_mutex) and per-filesystem
(->s_vfs_rename_mutex).
+ When taking the i_mutex on multiple non-directory objects, we
+always acquire the locks in order by increasing address. We'll call
+that "inode pointer" order in the following.
+
For our purposes all operations fall in 5 classes:
1) read access. Locking rules: caller locks directory we are accessing.
@@ -12,8 +16,9 @@ kinds of locks - per-inode (->i_mutex) and per-filesystem
locks victim and calls the method.
4) rename() that is _not_ cross-directory. Locking rules: caller locks
-the parent, finds source and target, if target already exists - locks it
-and then calls the method.
+the parent and finds source and target. If target already exists, lock
+it. If source is a non-directory, lock it. If that means we need to
+lock both, lock them in inode pointer order.
5) link creation. Locking rules:
* lock parent
@@ -30,7 +35,9 @@ rules:
fail with -ENOTEMPTY
* if new parent is equal to or is a descendent of source
fail with -ELOOP
- * if target exists - lock it.
+ * If target exists, lock it. If source is a non-directory, lock
+ it. In case that means we need to lock both source and target,
+ do so in inode pointer order.
* call the method.
@@ -56,9 +63,11 @@ objects - A < B iff A is an ancestor of B.
renames will be blocked on filesystem lock and we don't start changing
the order until we had acquired all locks).
-(3) any operation holds at most one lock on non-directory object and
- that lock is acquired after all other locks. (Proof: see descriptions
- of operations).
+(3) locks on non-directory objects are acquired only after locks on
+ directory objects, and are acquired in inode pointer order.
+ (Proof: all operations but renames take lock on at most one
+ non-directory object, except renames, which take locks on source and
+ target in inode pointer order in the case they are not directories.)
Now consider the minimal deadlock. Each process is blocked on
attempt to acquire some lock and already holds at least one lock. Let's
@@ -66,9 +75,13 @@ consider the set of contended locks. First of all, filesystem lock is
not contended, since any process blocked on it is not holding any locks.
Thus all processes are blocked on ->i_mutex.
- Non-directory objects are not contended due to (3). Thus link
-creation can't be a part of deadlock - it can't be blocked on source
-and it means that it doesn't hold any locks.
+ By (3), any process holding a non-directory lock can only be
+waiting on another non-directory lock with a larger address. Therefore
+the process holding the "largest" such lock can always make progress, and
+non-directory objects are not included in the set of contended locks.
+
+ Thus link creation can't be a part of deadlock - it can't be
+blocked on source and it means that it doesn't hold any locks.
Any contended object is either held by cross-directory rename or
has a child that is also contended. Indeed, suppose that it is held by
diff --git a/fs/namei.c b/fs/namei.c
index 57ae9c8..8d7ea1f 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3677,7 +3677,8 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname
* That's where 4.4 screws up. Current fix: serialization on
* sb->s_vfs_rename_mutex. We might be more accurate, but that's another
* story.
- * c) we have to lock _three_ objects - parents and victim (if it exists).
+ * c) we have to lock _four_ objects - parents and victim (if it exists),
+ * and source (if it is not a directory).
* And that - after we got ->i_mutex on parents (until then we don't know
* whether the target exists). Solution: try to be smart with locking
* order for inodes. We rely on the fact that tree topology may change
@@ -3753,6 +3754,7 @@ static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
struct inode *target = new_dentry->d_inode;
+ struct inode *source = old_dentry->d_inode;
int error;
error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry);
@@ -3761,7 +3763,9 @@ static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry,
dget(new_dentry);
if (target)
- mutex_lock(&target->i_mutex);
+ lock_two_nondirectories(source, target);
+ else
+ mutex_lock(&source->i_mutex);
error = -EBUSY;
if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry))
@@ -3777,7 +3781,9 @@ static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry,
d_move(old_dentry, new_dentry);
out:
if (target)
- mutex_unlock(&target->i_mutex);
+ unlock_two_nondirectories(source, target);
+ else
+ mutex_unlock(&source->i_mutex);
dput(new_dentry);
return error;
}
--
1.7.9.5
--
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^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 07/12] namei: minor vfs_unlink cleanup
[not found] ` <1366163185-10317-1-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2013-04-17 1:46 ` [PATCH 02/12] vfs: don't use PARENT/CHILD lock classes for non-directories J. Bruce Fields
2013-04-17 1:46 ` [PATCH 04/12] vfs: take i_mutex on renamed file J. Bruce Fields
@ 2013-04-17 1:46 ` J. Bruce Fields
2013-04-17 1:46 ` [PATCH 10/12] locks: break delegations on rename J. Bruce Fields
3 siblings, 0 replies; 13+ messages in thread
From: J. Bruce Fields @ 2013-04-17 1:46 UTC (permalink / raw)
To: Al Viro
Cc: linux-nfs-u79uwXL29TY76Z2rM5mHXA,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA, Linus Torvalds,
J. Bruce Fields
From: "J. Bruce Fields" <bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
We'll be using dentry->d_inode in one more place.
Signed-off-by: J. Bruce Fields <bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
fs/namei.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 8d7ea1f..0c2ee90 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3386,6 +3386,7 @@ SYSCALL_DEFINE1(rmdir, const char __user *, pathname)
int vfs_unlink(struct inode *dir, struct dentry *dentry)
{
+ struct inode *target = dentry->d_inode;
int error = may_delete(dir, dentry, 0);
if (error)
@@ -3394,7 +3395,7 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry)
if (!dir->i_op->unlink)
return -EPERM;
- mutex_lock(&dentry->d_inode->i_mutex);
+ mutex_lock(&target->i_mutex);
if (d_mountpoint(dentry))
error = -EBUSY;
else {
@@ -3405,11 +3406,11 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry)
dont_mount(dentry);
}
}
- mutex_unlock(&dentry->d_inode->i_mutex);
+ mutex_unlock(&target->i_mutex);
/* We don't d_delete() NFS sillyrenamed files--they still exist. */
if (!error && !(dentry->d_flags & DCACHE_NFSFS_RENAMED)) {
- fsnotify_link_count(dentry->d_inode);
+ fsnotify_link_count(target);
d_delete(dentry);
}
--
1.7.9.5
--
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^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 10/12] locks: break delegations on rename
[not found] ` <1366163185-10317-1-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
` (2 preceding siblings ...)
2013-04-17 1:46 ` [PATCH 07/12] namei: minor vfs_unlink cleanup J. Bruce Fields
@ 2013-04-17 1:46 ` J. Bruce Fields
3 siblings, 0 replies; 13+ messages in thread
From: J. Bruce Fields @ 2013-04-17 1:46 UTC (permalink / raw)
To: Al Viro
Cc: linux-nfs-u79uwXL29TY76Z2rM5mHXA,
linux-fsdevel-u79uwXL29TY76Z2rM5mHXA, Linus Torvalds,
J. Bruce Fields, David Howells
From: "J. Bruce Fields" <bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: David Howells <dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Signed-off-by: J. Bruce Fields <bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
---
fs/cachefiles/namei.c | 2 +-
fs/namei.c | 26 ++++++++++++++++++++++----
fs/nfsd/vfs.c | 2 +-
include/linux/fs.h | 2 +-
4 files changed, 25 insertions(+), 7 deletions(-)
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index d61d884..678a8af 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -396,7 +396,7 @@ try_again:
cachefiles_io_error(cache, "Rename security error %d", ret);
} else {
ret = vfs_rename(dir->d_inode, rep,
- cache->graveyard->d_inode, grave);
+ cache->graveyard->d_inode, grave, NULL);
if (ret != 0 && ret != -ENOMEM)
cachefiles_io_error(cache,
"Rename failed with error %d", ret);
diff --git a/fs/namei.c b/fs/namei.c
index f788c3c..394ea5f 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3763,7 +3763,8 @@ out:
}
static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry,
- struct inode *new_dir, struct dentry *new_dentry)
+ struct inode *new_dir, struct dentry *new_dentry,
+ struct inode **delegated_inode)
{
struct inode *target = new_dentry->d_inode;
struct inode *source = old_dentry->d_inode;
@@ -3783,6 +3784,14 @@ static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry,
if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry))
goto out;
+ error = try_break_deleg(source, delegated_inode);
+ if (error)
+ goto out;
+ if (target) {
+ error = try_break_deleg(target, delegated_inode);
+ if (error)
+ goto out;
+ }
error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry);
if (error)
goto out;
@@ -3801,7 +3810,8 @@ out:
}
int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
- struct inode *new_dir, struct dentry *new_dentry)
+ struct inode *new_dir, struct dentry *new_dentry,
+ struct inode **delegated_inode)
{
int error;
int is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
@@ -3829,7 +3839,7 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
if (is_dir)
error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry);
else
- error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry);
+ error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry,delegated_inode);
if (!error)
fsnotify_move(old_dir, new_dir, old_name, is_dir,
new_dentry->d_inode, old_dentry);
@@ -3845,6 +3855,7 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname,
struct dentry *old_dentry, *new_dentry;
struct dentry *trap;
struct nameidata oldnd, newnd;
+ struct inode *delegated_inode = NULL;
struct filename *from;
struct filename *to;
unsigned int lookup_flags = 0;
@@ -3884,6 +3895,7 @@ retry:
newnd.flags &= ~LOOKUP_PARENT;
newnd.flags |= LOOKUP_RENAME_TARGET;
+retry_deleg:
trap = lock_rename(new_dir, old_dir);
old_dentry = lookup_hash(&oldnd);
@@ -3920,13 +3932,19 @@ retry:
if (error)
goto exit5;
error = vfs_rename(old_dir->d_inode, old_dentry,
- new_dir->d_inode, new_dentry);
+ new_dir->d_inode, new_dentry,
+ &delegated_inode);
exit5:
dput(new_dentry);
exit4:
dput(old_dentry);
exit3:
unlock_rename(new_dir, old_dir);
+ if (delegated_inode) {
+ error = break_deleg_wait(&delegated_inode);
+ if (!error)
+ goto retry_deleg;
+ }
mnt_drop_write(oldnd.path.mnt);
exit2:
if (retry_estale(error, lookup_flags))
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index b32c66b..407e11c 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1811,7 +1811,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
if (host_err)
goto out_dput_new;
}
- host_err = vfs_rename(fdir, odentry, tdir, ndentry);
+ host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL);
if (!host_err) {
host_err = commit_metadata(tfhp);
if (!host_err)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index c2096ed..86b94bc 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1462,7 +1462,7 @@ extern int vfs_symlink(struct inode *, struct dentry *, const char *);
extern int vfs_link(struct dentry *, struct inode *, struct dentry *);
extern int vfs_rmdir(struct inode *, struct dentry *);
extern int vfs_unlink(struct inode *, struct dentry *, struct inode **);
-extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
+extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **);
/*
* VFS dentry helper functions.
--
1.7.9.5
--
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^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH 05/12] locks: introduce new FL_DELEG lock flag
2013-04-17 1:46 [PATCH 00/12] Implement NFSv4 delegations, take 7 J. Bruce Fields
` (2 preceding siblings ...)
[not found] ` <1366163185-10317-1-git-send-email-bfields-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
@ 2013-04-17 1:46 ` J. Bruce Fields
2013-04-17 1:46 ` [PATCH 06/12] locks: implement delegations J. Bruce Fields
` (4 subsequent siblings)
8 siblings, 0 replies; 13+ messages in thread
From: J. Bruce Fields @ 2013-04-17 1:46 UTC (permalink / raw)
To: Al Viro; +Cc: linux-nfs, linux-fsdevel, Linus Torvalds, J. Bruce Fields
From: "J. Bruce Fields" <bfields@redhat.com>
For now FL_DELEG is just a synonym for FL_LEASE. So this patch doesn't
change behavior.
Next we'll modify break_lease to treat FL_DELEG leases differently, to
account for the fact that NFSv4 delegations should be broken in more
situations than Windows oplocks.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
fs/locks.c | 2 +-
fs/nfsd/nfs4state.c | 2 +-
include/linux/fs.h | 1 +
3 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/locks.c b/fs/locks.c
index cb424a4..deec4de 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -131,7 +131,7 @@
#define IS_POSIX(fl) (fl->fl_flags & FL_POSIX)
#define IS_FLOCK(fl) (fl->fl_flags & FL_FLOCK)
-#define IS_LEASE(fl) (fl->fl_flags & FL_LEASE)
+#define IS_LEASE(fl) (fl->fl_flags & (FL_LEASE|FL_DELEG))
static bool lease_breaking(struct file_lock *fl)
{
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 2e27430..6663352 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2842,7 +2842,7 @@ static struct file_lock *nfs4_alloc_init_lease(struct nfs4_delegation *dp, int f
return NULL;
locks_init_lock(fl);
fl->fl_lmops = &nfsd_lease_mng_ops;
- fl->fl_flags = FL_LEASE;
+ fl->fl_flags = FL_DELEG;
fl->fl_type = flag == NFS4_OPEN_DELEGATE_READ? F_RDLCK: F_WRLCK;
fl->fl_end = OFFSET_MAX;
fl->fl_owner = (fl_owner_t)(dp->dl_file);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 6e45aa6..15985f3 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -882,6 +882,7 @@ static inline int file_check_writeable(struct file *filp)
#define FL_POSIX 1
#define FL_FLOCK 2
+#define FL_DELEG 4 /* NFSv4 delegation */
#define FL_ACCESS 8 /* not trying to lock, just looking */
#define FL_EXISTS 16 /* when unlocking, test for existence */
#define FL_LEASE 32 /* lease held on this file */
--
1.7.9.5
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 06/12] locks: implement delegations
2013-04-17 1:46 [PATCH 00/12] Implement NFSv4 delegations, take 7 J. Bruce Fields
` (3 preceding siblings ...)
2013-04-17 1:46 ` [PATCH 05/12] locks: introduce new FL_DELEG lock flag J. Bruce Fields
@ 2013-04-17 1:46 ` J. Bruce Fields
2013-04-17 1:46 ` [PATCH 08/12] locks: break delegations on unlink J. Bruce Fields
` (3 subsequent siblings)
8 siblings, 0 replies; 13+ messages in thread
From: J. Bruce Fields @ 2013-04-17 1:46 UTC (permalink / raw)
To: Al Viro; +Cc: linux-nfs, linux-fsdevel, Linus Torvalds, J. Bruce Fields
From: "J. Bruce Fields" <bfields@redhat.com>
Implement NFSv4 delegations at the vfs level using the new FL_DELEG lock
type.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
fs/locks.c | 49 +++++++++++++++++++++++++++++++++++++++----------
include/linux/fs.h | 18 +++++++++++++++---
2 files changed, 54 insertions(+), 13 deletions(-)
diff --git a/fs/locks.c b/fs/locks.c
index deec4de..2b56954 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1176,28 +1176,40 @@ static void time_out_leases(struct inode *inode)
}
}
+static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker)
+{
+ if ((breaker->fl_flags & FL_DELEG) && (lease->fl_flags & FL_LEASE))
+ return false;
+ return locks_conflict(breaker, lease);
+}
+
/**
* __break_lease - revoke all outstanding leases on file
* @inode: the inode of the file to return
- * @mode: the open mode (read or write)
+ * @mode: O_RDONLY: break only write leases; O_WRONLY or O_RDWR:
+ * break all leases
+ * @type: FL_LEASE: break leases and delegations; FL_DELEG: break
+ * only delegations
*
* break_lease (inlined for speed) has checked there already is at least
* some kind of lock (maybe a lease) on this file. Leases are broken on
* a call to open() or truncate(). This function can sleep unless you
* specified %O_NONBLOCK to your open().
*/
-int __break_lease(struct inode *inode, unsigned int mode)
+int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
{
int error = 0;
struct file_lock *new_fl, *flock;
struct file_lock *fl;
unsigned long break_time;
int i_have_this_lease = 0;
+ bool lease_conflict = false;
int want_write = (mode & O_ACCMODE) != O_RDONLY;
new_fl = lease_alloc(NULL, want_write ? F_WRLCK : F_RDLCK);
if (IS_ERR(new_fl))
return PTR_ERR(new_fl);
+ new_fl->fl_flags = type;
lock_flocks();
@@ -1207,13 +1219,16 @@ int __break_lease(struct inode *inode, unsigned int mode)
if ((flock == NULL) || !IS_LEASE(flock))
goto out;
- if (!locks_conflict(flock, new_fl))
+ for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) {
+ if (leases_conflict(fl, new_fl)) {
+ lease_conflict = true;
+ if (fl->fl_owner == current->files)
+ i_have_this_lease = 1;
+ }
+ }
+ if (!lease_conflict)
goto out;
- for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next)
- if (fl->fl_owner == current->files)
- i_have_this_lease = 1;
-
break_time = 0;
if (lease_break_time > 0) {
break_time = jiffies + lease_break_time * HZ;
@@ -1222,6 +1237,8 @@ int __break_lease(struct inode *inode, unsigned int mode)
}
for (fl = flock; fl && IS_LEASE(fl); fl = fl->fl_next) {
+ if (!leases_conflict(fl, new_fl))
+ continue;
if (want_write) {
if (fl->fl_flags & FL_UNLOCK_PENDING)
continue;
@@ -1263,7 +1280,7 @@ restart:
*/
for (flock = inode->i_flock; flock && IS_LEASE(flock);
flock = flock->fl_next) {
- if (locks_conflict(new_fl, flock))
+ if (leases_conflict(new_fl, flock))
goto restart;
}
error = 0;
@@ -1343,9 +1360,20 @@ int generic_add_lease(struct file *filp, long arg, struct file_lock **flp)
struct file_lock *fl, **before, **my_before = NULL, *lease;
struct dentry *dentry = filp->f_path.dentry;
struct inode *inode = dentry->d_inode;
+ bool is_deleg = (*flp)->fl_flags & FL_DELEG;
int error;
lease = *flp;
+ /*
+ * In the delegation case we need mutual exclusion with
+ * a number of operations that take the i_mutex. We trylock
+ * because delegations are an optional optimization, and if
+ * there's some chance of a conflict--we'd rather not
+ * bother, maybe that's a sign this just isn't a good file to
+ * hand out a delegation on.
+ */
+ if (is_deleg && !mutex_trylock(&inode->i_mutex))
+ return -EAGAIN;
error = -EAGAIN;
if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
@@ -1397,9 +1425,10 @@ int generic_add_lease(struct file *filp, long arg, struct file_lock **flp)
goto out;
locks_insert_lock(before, lease);
- return 0;
-
+ error = 0;
out:
+ if (is_deleg)
+ mutex_unlock(&inode->i_mutex);
return error;
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 15985f3..8c78d0d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1004,7 +1004,7 @@ extern int vfs_test_lock(struct file *, struct file_lock *);
extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl);
-extern int __break_lease(struct inode *inode, unsigned int flags);
+extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type);
extern void lease_get_mtime(struct inode *, struct timespec *time);
extern int generic_setlease(struct file *, long, struct file_lock **);
extern int vfs_setlease(struct file *, long, struct file_lock **);
@@ -1117,7 +1117,7 @@ static inline int flock_lock_file_wait(struct file *filp,
return -ENOLCK;
}
-static inline int __break_lease(struct inode *inode, unsigned int mode)
+static inline int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
{
return 0;
}
@@ -1949,9 +1949,17 @@ static inline int locks_verify_truncate(struct inode *inode,
static inline int break_lease(struct inode *inode, unsigned int mode)
{
if (inode->i_flock)
- return __break_lease(inode, mode);
+ return __break_lease(inode, mode, FL_LEASE);
return 0;
}
+
+static inline int break_deleg(struct inode *inode, unsigned int mode)
+{
+ if (inode->i_flock)
+ return __break_lease(inode, mode, FL_DELEG);
+ return 0;
+}
+
#else /* !CONFIG_FILE_LOCKING */
static inline int locks_mandatory_locked(struct inode *inode)
{
@@ -1991,6 +1999,10 @@ static inline int break_lease(struct inode *inode, unsigned int mode)
return 0;
}
+static inline int break_deleg(struct inode *inode, unsigned int mode)
+{
+ return 0;
+}
#endif /* CONFIG_FILE_LOCKING */
/* fs/open.c */
--
1.7.9.5
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 08/12] locks: break delegations on unlink
2013-04-17 1:46 [PATCH 00/12] Implement NFSv4 delegations, take 7 J. Bruce Fields
` (4 preceding siblings ...)
2013-04-17 1:46 ` [PATCH 06/12] locks: implement delegations J. Bruce Fields
@ 2013-04-17 1:46 ` J. Bruce Fields
2013-04-17 1:46 ` [PATCH 09/12] locks: helper functions for delegation breaking J. Bruce Fields
` (2 subsequent siblings)
8 siblings, 0 replies; 13+ messages in thread
From: J. Bruce Fields @ 2013-04-17 1:46 UTC (permalink / raw)
To: Al Viro
Cc: linux-nfs, linux-fsdevel, Linus Torvalds, J. Bruce Fields,
David Howells, Tyler Hicks, Dustin Kirkland
From: "J. Bruce Fields" <bfields@redhat.com>
We need to break delegations on any operation that changes the set of
links pointing to an inode. Start with unlink.
Such operations also hold the i_mutex on a parent directory. Breaking a
delegation may require waiting for a timeout (by default 90 seconds) in
the case of a unresponsive NFS client. To avoid blocking all directory
operations, we therefore drop locks before waiting for the delegation.
The logic then looks like:
acquire locks
...
test for delegation; if found:
take reference on inode
release locks
wait for delegation break
drop reference on inode
retry
It is possible this could never terminate. (Even if we take precautions
to prevent another delegation being acquired on the same inode, we could
get a different inode on each retry.) But this seems very unlikely.
The initial test for a delegation happens after the lock on the target
inode is acquired, but the directory inode may have been acquired
further up the call stack. We therefore add a "struct inode **"
argument to any intervening functions, which we use to pass the inode
back up to the caller in the case it needs a delegation synchronously
broken.
Cc: David Howells <dhowells@redhat.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
drivers/base/devtmpfs.c | 2 +-
fs/cachefiles/namei.c | 2 +-
fs/ecryptfs/inode.c | 2 +-
fs/namei.c | 24 +++++++++++++++++++++---
fs/nfsd/vfs.c | 2 +-
include/linux/fs.h | 2 +-
ipc/mqueue.c | 2 +-
7 files changed, 27 insertions(+), 9 deletions(-)
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 01fc5b0..288f64b 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -318,7 +318,7 @@ static int handle_remove(const char *nodename, struct device *dev)
mutex_lock(&dentry->d_inode->i_mutex);
notify_change(dentry, &newattrs);
mutex_unlock(&dentry->d_inode->i_mutex);
- err = vfs_unlink(parent.dentry->d_inode, dentry);
+ err = vfs_unlink(parent.dentry->d_inode, dentry, NULL);
if (!err || err == -ENOENT)
deleted = 1;
}
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index 8c01c5fc..d61d884 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -294,7 +294,7 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache,
if (ret < 0) {
cachefiles_io_error(cache, "Unlink security error");
} else {
- ret = vfs_unlink(dir->d_inode, rep);
+ ret = vfs_unlink(dir->d_inode, rep, NULL);
if (preemptive)
cachefiles_mark_object_buried(cache, rep);
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 5eab400..af42d88 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -153,7 +153,7 @@ static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
dget(lower_dentry);
lower_dir_dentry = lock_parent(lower_dentry);
- rc = vfs_unlink(lower_dir_inode, lower_dentry);
+ rc = vfs_unlink(lower_dir_inode, lower_dentry, NULL);
if (rc) {
printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
goto out_unlock;
diff --git a/fs/namei.c b/fs/namei.c
index 0c2ee90..6b8698f 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3384,7 +3384,7 @@ SYSCALL_DEFINE1(rmdir, const char __user *, pathname)
return do_rmdir(AT_FDCWD, pathname);
}
-int vfs_unlink(struct inode *dir, struct dentry *dentry)
+int vfs_unlink(struct inode *dir, struct dentry *dentry, struct inode **delegated_inode)
{
struct inode *target = dentry->d_inode;
int error = may_delete(dir, dentry, 0);
@@ -3401,11 +3401,20 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry)
else {
error = security_inode_unlink(dir, dentry);
if (!error) {
+ error = break_deleg(target, O_WRONLY|O_NONBLOCK);
+ if (error) {
+ if (error == -EWOULDBLOCK && delegated_inode) {
+ *delegated_inode = target;
+ ihold(target);
+ }
+ goto out;
+ }
error = dir->i_op->unlink(dir, dentry);
if (!error)
dont_mount(dentry);
}
}
+out:
mutex_unlock(&target->i_mutex);
/* We don't d_delete() NFS sillyrenamed files--they still exist. */
@@ -3430,6 +3439,7 @@ static long do_unlinkat(int dfd, const char __user *pathname)
struct dentry *dentry;
struct nameidata nd;
struct inode *inode = NULL;
+ struct inode *delegated_inode = NULL;
unsigned int lookup_flags = 0;
retry:
name = user_path_parent(dfd, pathname, &nd, lookup_flags);
@@ -3444,7 +3454,7 @@ retry:
error = mnt_want_write(nd.path.mnt);
if (error)
goto exit1;
-
+retry_deleg:
mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
dentry = lookup_hash(&nd);
error = PTR_ERR(dentry);
@@ -3459,13 +3469,21 @@ retry:
error = security_path_unlink(&nd.path, dentry);
if (error)
goto exit2;
- error = vfs_unlink(nd.path.dentry->d_inode, dentry);
+ error = vfs_unlink(nd.path.dentry->d_inode, dentry, &delegated_inode);
exit2:
dput(dentry);
}
mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
if (inode)
iput(inode); /* truncate the inode here */
+ inode = NULL;
+ if (delegated_inode) {
+ error = break_deleg(delegated_inode, O_WRONLY);
+ iput(delegated_inode);
+ delegated_inode = NULL;
+ if (!error)
+ goto retry_deleg;
+ }
mnt_drop_write(nd.path.mnt);
exit1:
path_put(&nd.path);
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 2b2e239..b32c66b 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1884,7 +1884,7 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
if (host_err)
goto out_put;
if (type != S_IFDIR)
- host_err = vfs_unlink(dirp, rdentry);
+ host_err = vfs_unlink(dirp, rdentry, NULL);
else
host_err = vfs_rmdir(dirp, rdentry);
if (!host_err)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 8c78d0d..f2d0194 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1461,7 +1461,7 @@ extern int vfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
extern int vfs_symlink(struct inode *, struct dentry *, const char *);
extern int vfs_link(struct dentry *, struct inode *, struct dentry *);
extern int vfs_rmdir(struct inode *, struct dentry *);
-extern int vfs_unlink(struct inode *, struct dentry *);
+extern int vfs_unlink(struct inode *, struct dentry *, struct inode **);
extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
/*
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index e4e47f6..384eb35 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -884,7 +884,7 @@ SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
err = -ENOENT;
} else {
ihold(inode);
- err = vfs_unlink(dentry->d_parent->d_inode, dentry);
+ err = vfs_unlink(dentry->d_parent->d_inode, dentry, NULL);
}
dput(dentry);
--
1.7.9.5
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 09/12] locks: helper functions for delegation breaking
2013-04-17 1:46 [PATCH 00/12] Implement NFSv4 delegations, take 7 J. Bruce Fields
` (5 preceding siblings ...)
2013-04-17 1:46 ` [PATCH 08/12] locks: break delegations on unlink J. Bruce Fields
@ 2013-04-17 1:46 ` J. Bruce Fields
2013-04-17 1:46 ` [PATCH 11/12] locks: break delegations on link J. Bruce Fields
2013-04-17 1:46 ` [PATCH 12/12] locks: break delegations on any attribute modification J. Bruce Fields
8 siblings, 0 replies; 13+ messages in thread
From: J. Bruce Fields @ 2013-04-17 1:46 UTC (permalink / raw)
To: Al Viro; +Cc: linux-nfs, linux-fsdevel, Linus Torvalds, J. Bruce Fields
From: "J. Bruce Fields" <bfields@redhat.com>
We'll need the same logic for rename and link.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
fs/namei.c | 13 +++----------
include/linux/fs.h | 33 +++++++++++++++++++++++++++++++--
2 files changed, 34 insertions(+), 12 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 6b8698f..f788c3c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3401,14 +3401,9 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry, struct inode **delegate
else {
error = security_inode_unlink(dir, dentry);
if (!error) {
- error = break_deleg(target, O_WRONLY|O_NONBLOCK);
- if (error) {
- if (error == -EWOULDBLOCK && delegated_inode) {
- *delegated_inode = target;
- ihold(target);
- }
+ error = try_break_deleg(target, delegated_inode);
+ if (error)
goto out;
- }
error = dir->i_op->unlink(dir, dentry);
if (!error)
dont_mount(dentry);
@@ -3478,9 +3473,7 @@ exit2:
iput(inode); /* truncate the inode here */
inode = NULL;
if (delegated_inode) {
- error = break_deleg(delegated_inode, O_WRONLY);
- iput(delegated_inode);
- delegated_inode = NULL;
+ error = break_deleg_wait(&delegated_inode);
if (!error)
goto retry_deleg;
}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f2d0194..c2096ed 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1892,6 +1892,9 @@ extern bool our_mnt(struct vfsmount *mnt);
extern int current_umask(void);
+extern void ihold(struct inode * inode);
+extern void iput(struct inode *);
+
/* /sys/fs */
extern struct kobject *fs_kobj;
@@ -1960,6 +1963,28 @@ static inline int break_deleg(struct inode *inode, unsigned int mode)
return 0;
}
+static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
+{
+ int ret;
+
+ ret = break_deleg(inode, O_WRONLY|O_NONBLOCK);
+ if (ret == -EWOULDBLOCK && delegated_inode) {
+ *delegated_inode = inode;
+ ihold(inode);
+ }
+ return ret;
+}
+
+static inline int break_deleg_wait(struct inode **delegated_inode)
+{
+ int ret;
+
+ ret = break_deleg(*delegated_inode, O_WRONLY);
+ iput(*delegated_inode);
+ *delegated_inode = NULL;
+ return ret;
+}
+
#else /* !CONFIG_FILE_LOCKING */
static inline int locks_mandatory_locked(struct inode *inode)
{
@@ -2003,6 +2028,12 @@ static inline int break_deleg(struct inode *inode, unsigned int mode)
{
return 0;
}
+
+static inline int try_break_deleg(struct inode *inode, struct delegated_inode **inode)
+{
+ return 0;
+}
+
#endif /* CONFIG_FILE_LOCKING */
/* fs/open.c */
@@ -2317,8 +2348,6 @@ extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence);
extern int inode_init_always(struct super_block *, struct inode *);
extern void inode_init_once(struct inode *);
extern void address_space_init_once(struct address_space *mapping);
-extern void ihold(struct inode * inode);
-extern void iput(struct inode *);
extern struct inode * igrab(struct inode *);
extern ino_t iunique(struct super_block *, ino_t);
extern int inode_needs_sync(struct inode *inode);
--
1.7.9.5
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 11/12] locks: break delegations on link
2013-04-17 1:46 [PATCH 00/12] Implement NFSv4 delegations, take 7 J. Bruce Fields
` (6 preceding siblings ...)
2013-04-17 1:46 ` [PATCH 09/12] locks: helper functions for delegation breaking J. Bruce Fields
@ 2013-04-17 1:46 ` J. Bruce Fields
2013-04-17 1:46 ` [PATCH 12/12] locks: break delegations on any attribute modification J. Bruce Fields
8 siblings, 0 replies; 13+ messages in thread
From: J. Bruce Fields @ 2013-04-17 1:46 UTC (permalink / raw)
To: Al Viro
Cc: linux-nfs, linux-fsdevel, Linus Torvalds, J. Bruce Fields,
Tyler Hicks, Dustin Kirkland
From: "J. Bruce Fields" <bfields@redhat.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
fs/ecryptfs/inode.c | 2 +-
fs/namei.c | 17 +++++++++++++----
fs/nfsd/vfs.c | 2 +-
include/linux/fs.h | 2 +-
4 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index af42d88..19e4435 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -475,7 +475,7 @@ static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
dget(lower_new_dentry);
lower_dir_dentry = lock_parent(lower_new_dentry);
rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
- lower_new_dentry);
+ lower_new_dentry, NULL);
if (rc || !lower_new_dentry->d_inode)
goto out_lock;
rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
diff --git a/fs/namei.c b/fs/namei.c
index 394ea5f..4ad5a0e 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3566,7 +3566,7 @@ SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newn
return sys_symlinkat(oldname, AT_FDCWD, newname);
}
-int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
+int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry, struct inode **delegated_inode)
{
struct inode *inode = old_dentry->d_inode;
unsigned max_links = dir->i_sb->s_max_links;
@@ -3602,8 +3602,11 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de
error = -ENOENT;
else if (max_links && inode->i_nlink >= max_links)
error = -EMLINK;
- else
- error = dir->i_op->link(old_dentry, dir, new_dentry);
+ else {
+ error = try_break_deleg(inode, delegated_inode);
+ if (!error)
+ error = dir->i_op->link(old_dentry, dir, new_dentry);
+ }
mutex_unlock(&inode->i_mutex);
if (!error)
fsnotify_link(dir, inode, new_dentry);
@@ -3624,6 +3627,7 @@ SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname,
{
struct dentry *new_dentry;
struct path old_path, new_path;
+ struct inode *delegated_inode = NULL;
int how = 0;
int error;
@@ -3662,9 +3666,14 @@ retry:
error = security_path_link(old_path.dentry, &new_path, new_dentry);
if (error)
goto out_dput;
- error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry);
+ error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry, &delegated_inode);
out_dput:
done_path_create(&new_path, new_dentry);
+ if (delegated_inode) {
+ error = break_deleg_wait(&delegated_inode);
+ if (!error)
+ goto retry;
+ }
if (retry_estale(error, how)) {
how |= LOOKUP_REVAL;
goto retry;
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 407e11c..64255a0 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1708,7 +1708,7 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
err = nfserrno(host_err);
goto out_dput;
}
- host_err = vfs_link(dold, dirp, dnew);
+ host_err = vfs_link(dold, dirp, dnew, NULL);
if (!host_err) {
err = nfserrno(commit_metadata(ffhp));
if (!err)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 86b94bc..0244cb1 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1459,7 +1459,7 @@ extern int vfs_create(struct inode *, struct dentry *, umode_t, bool);
extern int vfs_mkdir(struct inode *, struct dentry *, umode_t);
extern int vfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
extern int vfs_symlink(struct inode *, struct dentry *, const char *);
-extern int vfs_link(struct dentry *, struct inode *, struct dentry *);
+extern int vfs_link(struct dentry *, struct inode *, struct dentry *, struct inode **);
extern int vfs_rmdir(struct inode *, struct dentry *);
extern int vfs_unlink(struct inode *, struct dentry *, struct inode **);
extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **);
--
1.7.9.5
^ permalink raw reply related [flat|nested] 13+ messages in thread* [PATCH 12/12] locks: break delegations on any attribute modification
2013-04-17 1:46 [PATCH 00/12] Implement NFSv4 delegations, take 7 J. Bruce Fields
` (7 preceding siblings ...)
2013-04-17 1:46 ` [PATCH 11/12] locks: break delegations on link J. Bruce Fields
@ 2013-04-17 1:46 ` J. Bruce Fields
8 siblings, 0 replies; 13+ messages in thread
From: J. Bruce Fields @ 2013-04-17 1:46 UTC (permalink / raw)
To: Al Viro
Cc: linux-nfs, linux-fsdevel, Linus Torvalds, J. Bruce Fields,
Mikulas Patocka, David Howells, Tyler Hicks, Dustin Kirkland
From: "J. Bruce Fields" <bfields@redhat.com>
NFSv4 uses leases to guarantee that clients can cache metadata as well
as data.
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: David Howells <dhowells@redhat.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
drivers/base/devtmpfs.c | 4 ++--
fs/attr.c | 5 ++++-
fs/cachefiles/interface.c | 4 ++--
fs/ecryptfs/inode.c | 2 +-
fs/hpfs/namei.c | 2 +-
fs/inode.c | 6 +++++-
fs/nfsd/vfs.c | 8 ++++++--
fs/open.c | 21 +++++++++++++++++----
fs/utimes.c | 9 ++++++++-
include/linux/fs.h | 2 +-
10 files changed, 47 insertions(+), 16 deletions(-)
diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c
index 288f64b..b08d0dd 100644
--- a/drivers/base/devtmpfs.c
+++ b/drivers/base/devtmpfs.c
@@ -210,7 +210,7 @@ static int handle_create(const char *nodename, umode_t mode, struct device *dev)
newattrs.ia_mode = mode;
newattrs.ia_valid = ATTR_MODE;
mutex_lock(&dentry->d_inode->i_mutex);
- notify_change(dentry, &newattrs);
+ notify_change(dentry, &newattrs, NULL);
mutex_unlock(&dentry->d_inode->i_mutex);
/* mark as kernel-created inode */
@@ -316,7 +316,7 @@ static int handle_remove(const char *nodename, struct device *dev)
newattrs.ia_valid =
ATTR_UID|ATTR_GID|ATTR_MODE;
mutex_lock(&dentry->d_inode->i_mutex);
- notify_change(dentry, &newattrs);
+ notify_change(dentry, &newattrs, NULL);
mutex_unlock(&dentry->d_inode->i_mutex);
err = vfs_unlink(parent.dentry->d_inode, dentry, NULL);
if (!err || err == -ENOENT)
diff --git a/fs/attr.c b/fs/attr.c
index 1449adb..261f5c9 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -167,7 +167,7 @@ void setattr_copy(struct inode *inode, const struct iattr *attr)
}
EXPORT_SYMBOL(setattr_copy);
-int notify_change(struct dentry * dentry, struct iattr * attr)
+int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **delegated_inode)
{
struct inode *inode = dentry->d_inode;
umode_t mode = inode->i_mode;
@@ -243,6 +243,9 @@ int notify_change(struct dentry * dentry, struct iattr * attr)
error = security_inode_setattr(dentry, attr);
if (error)
return error;
+ error = try_break_deleg(inode, delegated_inode);
+ if (error)
+ return error;
if (inode->i_op->setattr)
error = inode->i_op->setattr(dentry, attr);
diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c
index 746ce53..40f5917 100644
--- a/fs/cachefiles/interface.c
+++ b/fs/cachefiles/interface.c
@@ -417,14 +417,14 @@ static int cachefiles_attr_changed(struct fscache_object *_object)
_debug("discard tail %llx", oi_size);
newattrs.ia_valid = ATTR_SIZE;
newattrs.ia_size = oi_size & PAGE_MASK;
- ret = notify_change(object->backer, &newattrs);
+ ret = notify_change(object->backer, &newattrs, NULL);
if (ret < 0)
goto truncate_failed;
}
newattrs.ia_valid = ATTR_SIZE;
newattrs.ia_size = ni_size;
- ret = notify_change(object->backer, &newattrs);
+ ret = notify_change(object->backer, &newattrs, NULL);
truncate_failed:
mutex_unlock(&object->backer->d_inode->i_mutex);
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 19e4435..bd54575 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -992,7 +992,7 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
lower_ia.ia_valid &= ~ATTR_MODE;
mutex_lock(&lower_dentry->d_inode->i_mutex);
- rc = notify_change(lower_dentry, &lower_ia);
+ rc = notify_change(lower_dentry, &lower_ia, NULL);
mutex_unlock(&lower_dentry->d_inode->i_mutex);
out:
fsstack_copy_attr_all(inode, lower_inode);
diff --git a/fs/hpfs/namei.c b/fs/hpfs/namei.c
index 345713d..1b39afd 100644
--- a/fs/hpfs/namei.c
+++ b/fs/hpfs/namei.c
@@ -407,7 +407,7 @@ again:
/*printk("HPFS: truncating file before delete.\n");*/
newattrs.ia_size = 0;
newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
- err = notify_change(dentry, &newattrs);
+ err = notify_change(dentry, &newattrs, NULL);
put_write_access(inode);
if (!err)
goto again;
diff --git a/fs/inode.c b/fs/inode.c
index 4a00662..d648863 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1633,7 +1633,11 @@ static int __remove_suid(struct dentry *dentry, int kill)
struct iattr newattrs;
newattrs.ia_valid = ATTR_FORCE | kill;
- return notify_change(dentry, &newattrs);
+ /*
+ * Note we call this on write, so notify_change will not
+ * encounter any conflicting delegations:
+ */
+ return notify_change(dentry, &newattrs, NULL);
}
int file_remove_suid(struct file *file)
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 64255a0..64adad2 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -426,7 +426,7 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
goto out_nfserr;
fh_lock(fhp);
- host_err = notify_change(dentry, iap);
+ host_err = notify_change(dentry, iap, NULL);
err = nfserrno(host_err);
fh_unlock(fhp);
}
@@ -959,7 +959,11 @@ static void kill_suid(struct dentry *dentry)
ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
mutex_lock(&dentry->d_inode->i_mutex);
- notify_change(dentry, &ia);
+ /*
+ * Note we call this on write, so notify_change will not
+ * encounter any conflicting delegations:
+ */
+ notify_change(dentry, &ia, NULL);
mutex_unlock(&dentry->d_inode->i_mutex);
}
diff --git a/fs/open.c b/fs/open.c
index 6835446..2547a17 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -57,7 +57,7 @@ int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
newattrs.ia_valid |= ret | ATTR_FORCE;
mutex_lock(&dentry->d_inode->i_mutex);
- ret = notify_change(dentry, &newattrs);
+ ret = notify_change(dentry, &newattrs, NULL);
mutex_unlock(&dentry->d_inode->i_mutex);
return ret;
}
@@ -492,21 +492,28 @@ out:
static int chmod_common(struct path *path, umode_t mode)
{
struct inode *inode = path->dentry->d_inode;
+ struct inode *delegated_inode = NULL;
struct iattr newattrs;
int error;
error = mnt_want_write(path->mnt);
if (error)
return error;
+retry_deleg:
mutex_lock(&inode->i_mutex);
error = security_path_chmod(path, mode);
if (error)
goto out_unlock;
newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
- error = notify_change(path->dentry, &newattrs);
+ error = notify_change(path->dentry, &newattrs, &delegated_inode);
out_unlock:
mutex_unlock(&inode->i_mutex);
+ if (delegated_inode) {
+ error = break_deleg_wait(&delegated_inode);
+ if (!error)
+ goto retry_deleg;
+ }
mnt_drop_write(path->mnt);
return error;
}
@@ -551,6 +558,7 @@ SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode)
static int chown_common(struct path *path, uid_t user, gid_t group)
{
struct inode *inode = path->dentry->d_inode;
+ struct inode *delegated_inode = NULL;
int error;
struct iattr newattrs;
kuid_t uid;
@@ -575,12 +583,17 @@ static int chown_common(struct path *path, uid_t user, gid_t group)
if (!S_ISDIR(inode->i_mode))
newattrs.ia_valid |=
ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
+retry_deleg:
mutex_lock(&inode->i_mutex);
error = security_path_chown(path, uid, gid);
if (!error)
- error = notify_change(path->dentry, &newattrs);
+ error = notify_change(path->dentry, &newattrs, &delegated_inode);
mutex_unlock(&inode->i_mutex);
-
+ if (delegated_inode) {
+ error = break_deleg_wait(&delegated_inode);
+ if (!error)
+ goto retry_deleg;
+ }
return error;
}
diff --git a/fs/utimes.c b/fs/utimes.c
index f4fb7ec..aa138d6 100644
--- a/fs/utimes.c
+++ b/fs/utimes.c
@@ -53,6 +53,7 @@ static int utimes_common(struct path *path, struct timespec *times)
int error;
struct iattr newattrs;
struct inode *inode = path->dentry->d_inode;
+ struct inode *delegated_inode = NULL;
error = mnt_want_write(path->mnt);
if (error)
@@ -101,9 +102,15 @@ static int utimes_common(struct path *path, struct timespec *times)
goto mnt_drop_write_and_out;
}
}
+retry_deleg:
mutex_lock(&inode->i_mutex);
- error = notify_change(path->dentry, &newattrs);
+ error = notify_change(path->dentry, &newattrs, &delegated_inode);
mutex_unlock(&inode->i_mutex);
+ if (delegated_inode) {
+ error = break_deleg_wait(&delegated_inode);
+ if (!error)
+ goto retry_deleg;
+ }
mnt_drop_write_and_out:
mnt_drop_write(path->mnt);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0244cb1..bf488b5 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2259,7 +2259,7 @@ extern void emergency_remount(void);
#ifdef CONFIG_BLOCK
extern sector_t bmap(struct inode *, sector_t);
#endif
-extern int notify_change(struct dentry *, struct iattr *);
+extern int notify_change(struct dentry *, struct iattr *, struct inode **);
extern int inode_permission(struct inode *, int);
extern int generic_permission(struct inode *, int);
--
1.7.9.5
^ permalink raw reply related [flat|nested] 13+ messages in thread