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authorDavid Howells <dhowells@redhat.com>2006-10-03 01:13:46 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-03 08:03:40 -0700
commitafefdbb28a0a2af689926c30b94a14aea6036719 (patch)
tree6ee500575cac928cd90045bcf5b691cf2b8daa09 /fs/readdir.c
parent1d32849b14bc8792e6f35ab27dd990d74b16126c (diff)
downloadlinux-afefdbb28a0a2af689926c30b94a14aea6036719.tar.gz
[PATCH] VFS: Make filldir_t and struct kstat deal in 64-bit inode numbers
These patches make the kernel pass 64-bit inode numbers internally when communicating to userspace, even on a 32-bit system. They are required because some filesystems have intrinsic 64-bit inode numbers: NFS3+ and XFS for example. The 64-bit inode numbers are then propagated to userspace automatically where the arch supports it. Problems have been seen with userspace (eg: ld.so) using the 64-bit inode number returned by stat64() or getdents64() to differentiate files, and failing because the 64-bit inode number space was compressed to 32-bits, and so overlaps occur. This patch: Make filldir_t take a 64-bit inode number and struct kstat carry a 64-bit inode number so that 64-bit inode numbers can be passed back to userspace. The stat functions then returns the full 64-bit inode number where available and where possible. If it is not possible to represent the inode number supplied by the filesystem in the field provided by userspace, then error EOVERFLOW will be issued. Similarly, the getdents/readdir functions now pass the full 64-bit inode number to userspace where possible, returning EOVERFLOW instead when a directory entry is encountered that can't be properly represented. Note that this means that some inodes will not be stat'able on a 32-bit system with old libraries where they were before - but it does mean that there will be no ambiguity over what a 32-bit inode number refers to. Note similarly that directory scans may be cut short with an error on a 32-bit system with old libraries where the scan would work before for the same reasons. It is judged unlikely that this situation will occur because modern glibc uses 64-bit capable versions of stat and getdents class functions exclusively, and that older systems are unlikely to encounter unrepresentable inode numbers anyway. [akpm: alpha build fix] Signed-off-by: David Howells <dhowells@redhat.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/readdir.c')
-rw-r--r--fs/readdir.c18
1 files changed, 13 insertions, 5 deletions
diff --git a/fs/readdir.c b/fs/readdir.c
index b6109329b60..bff3ee58e2f 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -69,20 +69,24 @@ struct readdir_callback {
};
static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset,
- ino_t ino, unsigned int d_type)
+ u64 ino, unsigned int d_type)
{
struct readdir_callback * buf = (struct readdir_callback *) __buf;
struct old_linux_dirent __user * dirent;
+ unsigned long d_ino;
if (buf->result)
return -EINVAL;
+ d_ino = ino;
+ if (sizeof(d_ino) < sizeof(ino) && d_ino != ino)
+ return -EOVERFLOW;
buf->result++;
dirent = buf->dirent;
if (!access_ok(VERIFY_WRITE, dirent,
(unsigned long)(dirent->d_name + namlen + 1) -
(unsigned long)dirent))
goto efault;
- if ( __put_user(ino, &dirent->d_ino) ||
+ if ( __put_user(d_ino, &dirent->d_ino) ||
__put_user(offset, &dirent->d_offset) ||
__put_user(namlen, &dirent->d_namlen) ||
__copy_to_user(dirent->d_name, name, namlen) ||
@@ -138,22 +142,26 @@ struct getdents_callback {
};
static int filldir(void * __buf, const char * name, int namlen, loff_t offset,
- ino_t ino, unsigned int d_type)
+ u64 ino, unsigned int d_type)
{
struct linux_dirent __user * dirent;
struct getdents_callback * buf = (struct getdents_callback *) __buf;
+ unsigned long d_ino;
int reclen = ROUND_UP(NAME_OFFSET(dirent) + namlen + 2);
buf->error = -EINVAL; /* only used if we fail.. */
if (reclen > buf->count)
return -EINVAL;
+ d_ino = ino;
+ if (sizeof(d_ino) < sizeof(ino) && d_ino != ino)
+ return -EOVERFLOW;
dirent = buf->previous;
if (dirent) {
if (__put_user(offset, &dirent->d_off))
goto efault;
}
dirent = buf->current_dir;
- if (__put_user(ino, &dirent->d_ino))
+ if (__put_user(d_ino, &dirent->d_ino))
goto efault;
if (__put_user(reclen, &dirent->d_reclen))
goto efault;
@@ -222,7 +230,7 @@ struct getdents_callback64 {
};
static int filldir64(void * __buf, const char * name, int namlen, loff_t offset,
- ino_t ino, unsigned int d_type)
+ u64 ino, unsigned int d_type)
{
struct linux_dirent64 __user *dirent;
struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf;