Skip to content

Commit 5822b7f

Browse files
albertitoLinus Torvalds
albertito
authored and
Linus Torvalds
committed
uml: make hostfs_setattr() support operations on unlinked open files
This patch allows hostfs_setattr() to work on unlinked open files by calling set_attr() (the userspace part) with the inode's fd. Without this, applications that depend on doing attribute changes to unlinked open files will fail. It works by using the fd versions instead of the path ones (for example fchmod() instead of chmod(), fchown() instead of chown()) when an fd is available. Signed-off-by: Alberto Bertogli <albertito@gmail.com> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 0e6b9c9 commit 5822b7f

File tree

3 files changed

+74
-44
lines changed

3 files changed

+74
-44
lines changed

‎fs/hostfs/hostfs.h‎

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -55,7 +55,7 @@ extern int stat_file(const char *path, unsigned long long *inode_out,
5555
int *mode_out, int *nlink_out, int *uid_out, int *gid_out,
5656
unsigned long long *size_out, struct timespec *atime_out,
5757
struct timespec *mtime_out, struct timespec *ctime_out,
58-
int *blksize_out, unsigned long long *blocks_out);
58+
int *blksize_out, unsigned long long *blocks_out, int fd);
5959
extern int access_file(char *path, int r, int w, int x);
6060
extern int open_file(char *path, int r, int w, int append);
6161
extern int file_type(const char *path, int *maj, int *min);
@@ -71,7 +71,7 @@ extern int lseek_file(int fd, long long offset, int whence);
7171
extern int fsync_file(int fd, int datasync);
7272
extern int file_create(char *name, int ur, int uw, int ux, int gr,
7373
int gw, int gx, int or, int ow, int ox);
74-
extern int set_attr(const char *file, struct hostfs_iattr *attrs);
74+
extern int set_attr(const char *file, struct hostfs_iattr *attrs, int fd);
7575
extern int make_symlink(const char *from, const char *to);
7676
extern int unlink_file(const char *file);
7777
extern int do_mkdir(const char *file, int mode);

‎fs/hostfs/hostfs_kern.c‎

Lines changed: 4 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -147,7 +147,7 @@ static int read_name(struct inode *ino, char *name)
147147

148148
err = stat_file(name, &i_ino, &i_mode, &i_nlink, &ino->i_uid,
149149
&ino->i_gid, &i_size, &ino->i_atime, &ino->i_mtime,
150-
&ino->i_ctime, &i_blksize, &i_blocks);
150+
&ino->i_ctime, &i_blksize, &i_blocks, -1);
151151
if(err)
152152
return(err);
153153

@@ -820,6 +820,8 @@ int hostfs_setattr(struct dentry *dentry, struct iattr *attr)
820820
char *name;
821821
int err;
822822

823+
int fd = HOSTFS_I(dentry->d_inode)->fd;
824+
823825
err = inode_change_ok(dentry->d_inode, attr);
824826
if (err)
825827
return err;
@@ -864,7 +866,7 @@ int hostfs_setattr(struct dentry *dentry, struct iattr *attr)
864866
}
865867
name = dentry_name(dentry, 0);
866868
if(name == NULL) return(-ENOMEM);
867-
err = set_attr(name, &attrs);
869+
err = set_attr(name, &attrs, fd);
868870
kfree(name);
869871
if(err)
870872
return(err);

‎fs/hostfs/hostfs_user.c‎

Lines changed: 68 additions & 40 deletions
Original file line numberDiff line numberDiff line change
@@ -21,12 +21,16 @@ int stat_file(const char *path, unsigned long long *inode_out, int *mode_out,
2121
int *nlink_out, int *uid_out, int *gid_out,
2222
unsigned long long *size_out, struct timespec *atime_out,
2323
struct timespec *mtime_out, struct timespec *ctime_out,
24-
int *blksize_out, unsigned long long *blocks_out)
24+
int *blksize_out, unsigned long long *blocks_out, int fd)
2525
{
2626
struct stat64 buf;
2727

28-
if(lstat64(path, &buf) < 0)
28+
if(fd >= 0) {
29+
if (fstat64(fd, &buf) < 0)
30+
return(-errno);
31+
} else if(lstat64(path, &buf) < 0) {
2932
return(-errno);
33+
}
3034

3135
if(inode_out != NULL) *inode_out = buf.st_ino;
3236
if(mode_out != NULL) *mode_out = buf.st_mode;
@@ -202,58 +206,82 @@ int file_create(char *name, int ur, int uw, int ux, int gr,
202206
return(fd);
203207
}
204208

205-
int set_attr(const char *file, struct hostfs_iattr *attrs)
209+
int set_attr(const char *file, struct hostfs_iattr *attrs, int fd)
206210
{
207-
struct utimbuf buf;
211+
struct timeval times[2];
212+
struct timespec atime_ts, mtime_ts;
208213
int err, ma;
209214

210-
if(attrs->ia_valid & HOSTFS_ATTR_MODE){
211-
if(chmod(file, attrs->ia_mode) != 0) return(-errno);
212-
}
213-
if(attrs->ia_valid & HOSTFS_ATTR_UID){
214-
if(chown(file, attrs->ia_uid, -1)) return(-errno);
215+
if (attrs->ia_valid & HOSTFS_ATTR_MODE) {
216+
if (fd >= 0) {
217+
if (fchmod(fd, attrs->ia_mode) != 0)
218+
return (-errno);
219+
} else if (chmod(file, attrs->ia_mode) != 0) {
220+
return (-errno);
221+
}
215222
}
216-
if(attrs->ia_valid & HOSTFS_ATTR_GID){
217-
if(chown(file, -1, attrs->ia_gid)) return(-errno);
223+
if (attrs->ia_valid & HOSTFS_ATTR_UID) {
224+
if (fd >= 0) {
225+
if (fchown(fd, attrs->ia_uid, -1))
226+
return (-errno);
227+
} else if(chown(file, attrs->ia_uid, -1)) {
228+
return (-errno);
229+
}
218230
}
219-
if(attrs->ia_valid & HOSTFS_ATTR_SIZE){
220-
if(truncate(file, attrs->ia_size)) return(-errno);
231+
if (attrs->ia_valid & HOSTFS_ATTR_GID) {
232+
if (fd >= 0) {
233+
if (fchown(fd, -1, attrs->ia_gid))
234+
return (-errno);
235+
} else if (chown(file, -1, attrs->ia_gid)) {
236+
return (-errno);
237+
}
221238
}
222-
ma = HOSTFS_ATTR_ATIME_SET | HOSTFS_ATTR_MTIME_SET;
223-
if((attrs->ia_valid & ma) == ma){
224-
buf.actime = attrs->ia_atime.tv_sec;
225-
buf.modtime = attrs->ia_mtime.tv_sec;
226-
if(utime(file, &buf) != 0) return(-errno);
239+
if (attrs->ia_valid & HOSTFS_ATTR_SIZE) {
240+
if (fd >= 0) {
241+
if (ftruncate(fd, attrs->ia_size))
242+
return (-errno);
243+
} else if (truncate(file, attrs->ia_size)) {
244+
return (-errno);
245+
}
227246
}
228-
else {
229-
struct timespec ts;
230-
231-
if(attrs->ia_valid & HOSTFS_ATTR_ATIME_SET){
232-
err = stat_file(file, NULL, NULL, NULL, NULL, NULL,
233-
NULL, NULL, &ts, NULL, NULL, NULL);
234-
if(err != 0)
235-
return(err);
236-
buf.actime = attrs->ia_atime.tv_sec;
237-
buf.modtime = ts.tv_sec;
238-
if(utime(file, &buf) != 0)
239-
return(-errno);
247+
248+
/* Update accessed and/or modified time, in two parts: first set
249+
* times according to the changes to perform, and then call futimes()
250+
* or utimes() to apply them. */
251+
ma = (HOSTFS_ATTR_ATIME_SET | HOSTFS_ATTR_MTIME_SET);
252+
if (attrs->ia_valid & ma) {
253+
err = stat_file(file, NULL, NULL, NULL, NULL, NULL, NULL,
254+
&atime_ts, &mtime_ts, NULL, NULL, NULL, fd);
255+
if (err != 0)
256+
return err;
257+
258+
times[0].tv_sec = atime_ts.tv_sec;
259+
times[0].tv_usec = atime_ts.tv_nsec * 1000;
260+
times[1].tv_sec = mtime_ts.tv_sec;
261+
times[1].tv_usec = mtime_ts.tv_nsec * 1000;
262+
263+
if (attrs->ia_valid & HOSTFS_ATTR_ATIME_SET) {
264+
times[0].tv_sec = attrs->ia_atime.tv_sec;
265+
times[0].tv_usec = attrs->ia_atime.tv_nsec * 1000;
240266
}
241-
if(attrs->ia_valid & HOSTFS_ATTR_MTIME_SET){
242-
err = stat_file(file, NULL, NULL, NULL, NULL, NULL,
243-
NULL, &ts, NULL, NULL, NULL, NULL);
244-
if(err != 0)
245-
return(err);
246-
buf.actime = ts.tv_sec;
247-
buf.modtime = attrs->ia_mtime.tv_sec;
248-
if(utime(file, &buf) != 0)
249-
return(-errno);
267+
if (attrs->ia_valid & HOSTFS_ATTR_MTIME_SET) {
268+
times[1].tv_sec = attrs->ia_mtime.tv_sec;
269+
times[1].tv_usec = attrs->ia_mtime.tv_nsec * 1000;
270+
}
271+
272+
if (fd >= 0) {
273+
if (futimes(fd, times) != 0)
274+
return (-errno);
275+
} else if (utimes(file, times) != 0) {
276+
return (-errno);
250277
}
251278
}
279+
252280
if(attrs->ia_valid & HOSTFS_ATTR_CTIME) ;
253281
if(attrs->ia_valid & (HOSTFS_ATTR_ATIME | HOSTFS_ATTR_MTIME)){
254282
err = stat_file(file, NULL, NULL, NULL, NULL, NULL, NULL,
255283
&attrs->ia_atime, &attrs->ia_mtime, NULL,
256-
NULL, NULL);
284+
NULL, NULL, fd);
257285
if(err != 0) return(err);
258286
}
259287
return(0);

0 commit comments

Comments
 (0)