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give readdir(2)/getdents(2)/etc. uniform exclusion with lseek() 

same as read() on regular files has, and for the same reason.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
steinar/wifi_calib_4_9_kernel
Al Viro 2016-04-20 17:08:21 -04:00
parent 9902af79c0
commit 63b6df1413
7 changed files with 33 additions and 27 deletions
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4
arch/alpha/kernel/osf_sys.c
View File

@ -147,7 +147,7 @@ SYSCALL_DEFINE4(osf_getdirentries, unsigned int, fd,
long __user *, basep)
{
int error;
struct fd arg = fdget(fd);
struct fd arg = fdget_pos(fd);
struct osf_dirent_callback buf = {
.ctx.actor = osf_filldir,
.dirent = dirent,
@ -164,7 +164,7 @@ SYSCALL_DEFINE4(osf_getdirentries, unsigned int, fd,
if (count != buf.count)
error = count - buf.count;
fdput(arg);
fdput_pos(arg);
return error;
}

12
fs/compat.c
View File

@ -884,7 +884,7 @@ COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
struct compat_old_linux_dirent __user *, dirent, unsigned int, count)
{
int error;
struct fd f = fdget(fd);
struct fd f = fdget_pos(fd);
struct compat_readdir_callback buf = {
.ctx.actor = compat_fillonedir,
.dirent = dirent
@ -897,7 +897,7 @@ COMPAT_SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
if (buf.result)
error = buf.result;
fdput(f);
fdput_pos(f);
return error;
}
@ -975,7 +975,7 @@ COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd,
if (!access_ok(VERIFY_WRITE, dirent, count))
return -EFAULT;
f = fdget(fd);
f = fdget_pos(fd);
if (!f.file)
return -EBADF;
@ -989,7 +989,7 @@ COMPAT_SYSCALL_DEFINE3(getdents, unsigned int, fd,
else
error = count - buf.count;
}
fdput(f);
fdput_pos(f);
return error;
}
@ -1062,7 +1062,7 @@ COMPAT_SYSCALL_DEFINE3(getdents64, unsigned int, fd,
if (!access_ok(VERIFY_WRITE, dirent, count))
return -EFAULT;
f = fdget(fd);
f = fdget_pos(fd);
if (!f.file)
return -EBADF;
@ -1077,7 +1077,7 @@ COMPAT_SYSCALL_DEFINE3(getdents64, unsigned int, fd,
else
error = count - buf.count;
}
fdput(f);
fdput_pos(f);
return error;
}
#endif /* __ARCH_WANT_COMPAT_SYS_GETDENTS64 */

5
fs/file.c
View File

@ -784,6 +784,11 @@ unsigned long __fdget_pos(unsigned int fd)
return v;
}
void __f_unlock_pos(struct file *f)
{
mutex_unlock(&f->f_pos_lock);
}
/*
* We only lock f_pos if we have threads or if the file might be
* shared with another process. In both cases we'll have an elevated

2
fs/open.c
View File

@ -713,7 +713,7 @@ static int do_dentry_open(struct file *f,
}
/* POSIX.1-2008/SUSv4 Section XSI 2.9.7 */
if (S_ISREG(inode->i_mode))
if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))
f->f_mode |= FMODE_ATOMIC_POS;
f->f_op = fops_get(inode->i_fop);

12
fs/read_write.c
View File

@ -302,18 +302,6 @@ loff_t vfs_llseek(struct file *file, loff_t offset, int whence)
}
EXPORT_SYMBOL(vfs_llseek);
static inline struct fd fdget_pos(int fd)
{
return __to_fd(__fdget_pos(fd));
}
static inline void fdput_pos(struct fd f)
{
if (f.flags & FDPUT_POS_UNLOCK)
mutex_unlock(&f.file->f_pos_lock);
fdput(f);
}
SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence)
{
off_t retval;

12
fs/readdir.c
View File

@ -112,7 +112,7 @@ SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
struct old_linux_dirent __user *, dirent, unsigned int, count)
{
int error;
struct fd f = fdget(fd);
struct fd f = fdget_pos(fd);
struct readdir_callback buf = {
.ctx.actor = fillonedir,
.dirent = dirent
@ -125,7 +125,7 @@ SYSCALL_DEFINE3(old_readdir, unsigned int, fd,
if (buf.result)
error = buf.result;
fdput(f);
fdput_pos(f);
return error;
}
@ -209,7 +209,7 @@ SYSCALL_DEFINE3(getdents, unsigned int, fd,
if (!access_ok(VERIFY_WRITE, dirent, count))
return -EFAULT;
f = fdget(fd);
f = fdget_pos(fd);
if (!f.file)
return -EBADF;
@ -223,7 +223,7 @@ SYSCALL_DEFINE3(getdents, unsigned int, fd,
else
error = count - buf.count;
}
fdput(f);
fdput_pos(f);
return error;
}
@ -290,7 +290,7 @@ SYSCALL_DEFINE3(getdents64, unsigned int, fd,
if (!access_ok(VERIFY_WRITE, dirent, count))
return -EFAULT;
f = fdget(fd);
f = fdget_pos(fd);
if (!f.file)
return -EBADF;
@ -305,6 +305,6 @@ SYSCALL_DEFINE3(getdents64, unsigned int, fd,
else
error = count - buf.count;
}
fdput(f);
fdput_pos(f);
return error;
}

13
include/linux/file.h
View File

@ -44,6 +44,7 @@ extern struct file *fget_raw(unsigned int fd);
extern unsigned long __fdget(unsigned int fd);
extern unsigned long __fdget_raw(unsigned int fd);
extern unsigned long __fdget_pos(unsigned int fd);
extern void __f_unlock_pos(struct file *);
static inline struct fd __to_fd(unsigned long v)
{
@ -60,6 +61,18 @@ static inline struct fd fdget_raw(unsigned int fd)
return __to_fd(__fdget_raw(fd));
}
static inline struct fd fdget_pos(int fd)
{
return __to_fd(__fdget_pos(fd));
}
static inline void fdput_pos(struct fd f)
{
if (f.flags & FDPUT_POS_UNLOCK)
__f_unlock_pos(f.file);
fdput(f);
}
extern int f_dupfd(unsigned int from, struct file *file, unsigned flags);
extern int replace_fd(unsigned fd, struct file *file, unsigned flags);
extern void set_close_on_exec(unsigned int fd, int flag);