..compiled without LFS support, but running on 64-bit kernel.
Currently, when a broken (compiled without LFS support) 32-bit application on
a 64-bit kernel tries to do a stat(), it fails with -EOVERFLOW error. This
problem happens because the 32-bit application is unable to fit the huge
64-bit inode number in its target structure field.
This problem could be reproduced by mounting a filesystem that supports 64-bit
inodes (in my case it is a Windows 2003 Server with NTFS) and using the below
reproducer to stat files/dir in the mounted filesystem.
Reproducer
----------
#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
int
main(int argc, char *argv[])
{
struct stat sb;
if (argc != 2) {
fprintf(stderr, "Usage: %s <pathname>\n", argv[0]);
exit(EXIT_FAILURE);
}
if (stat(argv[1], &sb) == -1) {
perror("stat");
exit(EXIT_FAILURE);
}
printf("File type: ");
switch (sb.st_mode & S_IFMT) {
case S_IFDIR: printf("directory\n"); break;
case S_IFLNK: printf("link\n"); break;
case S_IFREG: printf("regular file\n"); break;
default: printf("not a regular file or directory or symlink\n");
}
printf("inode number: %ld\n", (long) sb.st_ino);
exit(EXIT_SUCCESS);
}
Ideally, these 32-bit applications should be built with -D_FILE_OFFSET_BITS=64
if they are running on a 64-bit kernel and they should be considered broken if
they are not.i However, there are quite a few applications that are not doing
so.
To workaround this issue, this patch introduces a mount option:
-o noinode64 - squashes 64-bit inode number to 32-bits for such applications
-o inode64 - supports 64-bit inodes (default behavior)
Testing: This patch has been tested using the above mentioned reproducer. Also,
verified that the hardlinks are seen properly.
Cc: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Suresh Jayaraman <sjayaraman@xxxxxxx>
---
fs/cifs/cifs_fs_sb.h | 1 +
fs/cifs/cifsfs.c | 4 ++++
fs/cifs/cifsfs.h | 16 ++++++++++++++++
fs/cifs/connect.c | 10 ++++++++++
fs/cifs/inode.c | 4 ++++
fs/cifs/readdir.c | 5 ++++-
6 files changed, 39 insertions(+), 1 deletions(-)
diff --git a/fs/cifs/cifs_fs_sb.h b/fs/cifs/cifs_fs_sb.h
index 7852cd6..2563d26 100644
--- a/fs/cifs/cifs_fs_sb.h
+++ b/fs/cifs/cifs_fs_sb.h
@@ -40,6 +40,7 @@
#define CIFS_MOUNT_FSCACHE 0x8000 /* local caching enabled */
#define CIFS_MOUNT_MF_SYMLINKS 0x10000 /* Minshall+French Symlinks enabled */
#define CIFS_MOUNT_MULTIUSER 0x20000 /* multiuser mount */
+#define CIFS_MOUNT_32BIT_INODES 0x40000 /* squash to 32-bits */
struct cifs_sb_info {
struct rb_root tlink_tree;
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 5e7075d..6b370e8 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -473,6 +473,10 @@ cifs_show_options(struct seq_file *s, struct vfsmount *m)
seq_printf(s, ",mfsymlinks");
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
seq_printf(s, ",fsc");
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_32BIT_INODES)
+ seq_printf(s, ",noinode64");
+ else
+ seq_printf(s, ",inode64");
seq_printf(s, ",rsize=%d", cifs_sb->rsize);
seq_printf(s, ",wsize=%d", cifs_sb->wsize);
diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h
index 897b2b2..e01d9e3 100644
--- a/fs/cifs/cifsfs.h
+++ b/fs/cifs/cifsfs.h
@@ -22,6 +22,8 @@
#ifndef _CIFSFS_H
#define _CIFSFS_H
+#include <linux/compat.h>
+
#define ROOT_I 2
/*
@@ -37,6 +39,20 @@ cifs_uniqueid_to_ino_t(u64 fileid)
return ino;
}
+static inline u64
+cifs_compat_user_ino64(u64 fileid)
+{
+#ifdef CONFIG_COMPAT
+ compat_ulong_t ino;
+#else
+ unsigned long ino;
+#endif
+ ino = fileid;
+ if (sizeof(ino) < sizeof(u64))
+ ino ^= fileid >> (sizeof(u64)-sizeof(ino)) * 8;
+ return ino;
+}
+
extern struct file_system_type cifs_fs_type;
extern const struct address_space_operations cifs_addr_ops;
extern const struct address_space_operations cifs_addr_ops_smallbuf;
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index a65d311..7fdb361 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -101,6 +101,7 @@ struct smb_vol {
bool fsc:1; /* enable fscache */
bool mfsymlinks:1; /* use Minshall+French Symlinks */
bool multiuser:1;
+ bool inode64:1;
unsigned int rsize;
unsigned int wsize;
bool sockopt_tcp_nodelay:1;
@@ -836,6 +837,8 @@ cifs_parse_mount_options(char *options, const char *devname,
vol->posix_paths = 1;
/* default to using server inode numbers where available */
vol->server_ino = 1;
+ /* default to support 64-bit inode numbers */
+ vol->inode64 = 1;
vol->actimeo = CIFS_DEF_ACTIMEO;
@@ -1368,6 +1371,10 @@ cifs_parse_mount_options(char *options, const char *devname,
vol->mfsymlinks = true;
} else if (strnicmp(data, "multiuser", 8) == 0) {
vol->multiuser = true;
+ } else if (strnicmp(data, "inode64", 7) == 0) {
+ vol->inode64 = 1;
+ } else if (strnicmp(data, "noinode64", 9) == 0) {
+ vol->inode64 = 0;
} else
printk(KERN_WARNING "CIFS: Unknown mount option %s\n",
data);
@@ -2578,6 +2585,9 @@ static void setup_cifs_sb(struct smb_vol *pvolume_info,
if (pvolume_info->multiuser)
cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_MULTIUSER |
CIFS_MOUNT_NO_PERM);
+ if (!pvolume_info->inode64)
+ cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_32BIT_INODES;
+
if (pvolume_info->direct_io) {
cFYI(1, "mounting share using direct i/o");
cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_DIRECT_IO;
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 0c7e369..b31c8d9 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -1791,6 +1791,10 @@ int cifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_OVERR_GID))
stat->gid = current_fsgid();
}
+
+ /* squash to 32-bits if 'noinode64' option is enabled */
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_32BIT_INODES)
+ stat->ino = cifs_uniqueid_to_ino_t(stat->ino);
}
return err;
}
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index 76b1b37..b902fd0 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -754,7 +754,10 @@ static int cifs_filldir(char *pfindEntry, struct file *file, filldir_t filldir,
*/
fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
- ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_32BIT_INODES)
+ ino = cifs_compat_user_ino64(fattr.cf_uniqueid);
+ else
+ ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
tmp_dentry = cifs_readdir_lookup(file->f_dentry, &qstring, &fattr);
rc = filldir(direntry, qstring.name, qstring.len, file->f_pos,
--
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