Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
"These four commits are obvious fixes (a couple of fdget_pos()-related
ones from Eric Biggers, prepend_name() fix, missing checks for false
negatives from __lookup_mnt() in fs/namei.c)"
For now I'm pulling just the four obvious fixes, there's another four
pending in Al's 'for-linus' branch wrt the mnt_hash list that were more
involved.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
rcuwalk: recheck mount_lock after mountpoint crossing attempts
make prepend_name() work correctly when called with negative *buflen
vfs: Don't let __fdget_pos() get FMODE_PATH files
vfs: atomic f_pos access in llseek()
diff --git a/fs/dcache.c b/fs/dcache.c
index 265e0ce..ca02c13 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2833,9 +2833,9 @@
u32 dlen = ACCESS_ONCE(name->len);
char *p;
- if (*buflen < dlen + 1)
- return -ENAMETOOLONG;
*buflen -= dlen + 1;
+ if (*buflen < 0)
+ return -ENAMETOOLONG;
p = *buffer -= dlen + 1;
*p++ = '/';
while (dlen--) {
diff --git a/fs/file.c b/fs/file.c
index 60a45e9..eb56a13 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -713,27 +713,16 @@
unsigned long __fdget_pos(unsigned int fd)
{
- struct files_struct *files = current->files;
- struct file *file;
- unsigned long v;
+ unsigned long v = __fdget(fd);
+ struct file *file = (struct file *)(v & ~3);
- if (atomic_read(&files->count) == 1) {
- file = __fcheck_files(files, fd);
- v = 0;
- } else {
- file = __fget(fd, 0);
- v = FDPUT_FPUT;
- }
- if (!file)
- return 0;
-
- if (file->f_mode & FMODE_ATOMIC_POS) {
+ if (file && (file->f_mode & FMODE_ATOMIC_POS)) {
if (file_count(file) > 1) {
v |= FDPUT_POS_UNLOCK;
mutex_lock(&file->f_pos_lock);
}
}
- return v | (unsigned long)file;
+ return v;
}
/*
diff --git a/fs/namei.c b/fs/namei.c
index 2f730ef..4b491b4 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1109,7 +1109,7 @@
return false;
if (!d_mountpoint(path->dentry))
- break;
+ return true;
mounted = __lookup_mnt(path->mnt, path->dentry);
if (!mounted)
@@ -1125,20 +1125,7 @@
*/
*inode = path->dentry->d_inode;
}
- return true;
-}
-
-static void follow_mount_rcu(struct nameidata *nd)
-{
- while (d_mountpoint(nd->path.dentry)) {
- struct mount *mounted;
- mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry);
- if (!mounted)
- break;
- nd->path.mnt = &mounted->mnt;
- nd->path.dentry = mounted->mnt.mnt_root;
- nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
- }
+ return read_seqretry(&mount_lock, nd->m_seq);
}
static int follow_dotdot_rcu(struct nameidata *nd)
@@ -1166,7 +1153,17 @@
break;
nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
}
- follow_mount_rcu(nd);
+ while (d_mountpoint(nd->path.dentry)) {
+ struct mount *mounted;
+ mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry);
+ if (!mounted)
+ break;
+ nd->path.mnt = &mounted->mnt;
+ nd->path.dentry = mounted->mnt.mnt_root;
+ nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
+ if (!read_seqretry(&mount_lock, nd->m_seq))
+ goto failed;
+ }
nd->inode = nd->path.dentry->d_inode;
return 0;
diff --git a/fs/read_write.c b/fs/read_write.c
index 54e19b9..28cc9c8 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -307,7 +307,7 @@
unsigned int, whence)
{
int retval;
- struct fd f = fdget(fd);
+ struct fd f = fdget_pos(fd);
loff_t offset;
if (!f.file)
@@ -327,7 +327,7 @@
retval = 0;
}
out_putf:
- fdput(f);
+ fdput_pos(f);
return retval;
}
#endif