From 63b6df14134ddd048984c8afadb46e721815bfc6 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 20 Apr 2016 17:08:21 -0400 Subject: [PATCH] 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 --- arch/alpha/kernel/osf_sys.c | 4 ++-- fs/compat.c | 12 ++++++------ fs/file.c | 5 +++++ fs/open.c | 2 +- fs/read_write.c | 12 ------------ fs/readdir.c | 12 ++++++------ include/linux/file.h | 13 +++++++++++++ 7 files changed, 33 insertions(+), 27 deletions(-) diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c index 6cc08166ff00..ffb93f499c83 100644 --- a/arch/alpha/kernel/osf_sys.c +++ b/arch/alpha/kernel/osf_sys.c @@ -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; } diff --git a/fs/compat.c b/fs/compat.c index a71936a3f4cb..8754e9aa14ad 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -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 */ diff --git a/fs/file.c b/fs/file.c index 1fbc5c0555a9..6b1acdfe59da 100644 --- a/fs/file.c +++ b/fs/file.c @@ -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 diff --git a/fs/open.c b/fs/open.c index 17cb6b1dab75..938a658a5c6d 100644 --- a/fs/open.c +++ b/fs/open.c @@ -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); diff --git a/fs/read_write.c b/fs/read_write.c index cf377cf9dfe3..69c7c3c2955c 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -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; diff --git a/fs/readdir.c b/fs/readdir.c index bf583e848a1a..d7308b8f6cf7 100644 --- a/fs/readdir.c +++ b/fs/readdir.c @@ -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; } diff --git a/include/linux/file.h b/include/linux/file.h index f87d30882a24..7444f5feda12 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -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); -- 2.20.1