diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-03-10 19:57:26 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-03-10 19:57:26 (GMT) |
commit | e6a4b6f5eaa8478b7a0b9a17e40c51463631db1a (patch) | |
tree | 35e164226b3a590481469a1739a2eb2a7b1217c1 | |
parent | 2b64c5434d1303646388e748b7add69624a1cfee (diff) | |
parent | bd2a31d522344b3ac2fb680bd2366e77a9bd8209 (diff) | |
download | linux-e6a4b6f5eaa8478b7a0b9a17e40c51463631db1a.tar.xz |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro.
Clean up file table accesses (get rid of fget_light() in favor of the
fdget() interface), add proper file position locking.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
get rid of fget_light()
sockfd_lookup_light(): switch to fdget^W^Waway from fget_light
vfs: atomic f_pos accesses as per POSIX
ocfs2 syncs the wrong range...
-rw-r--r-- | fs/file.c | 56 | ||||
-rw-r--r-- | fs/file_table.c | 1 | ||||
-rw-r--r-- | fs/namei.c | 2 | ||||
-rw-r--r-- | fs/ocfs2/file.c | 8 | ||||
-rw-r--r-- | fs/open.c | 4 | ||||
-rw-r--r-- | fs/read_write.c | 40 | ||||
-rw-r--r-- | include/linux/file.h | 27 | ||||
-rw-r--r-- | include/linux/fs.h | 8 | ||||
-rw-r--r-- | net/socket.c | 13 |
9 files changed, 107 insertions, 52 deletions
@@ -683,35 +683,65 @@ EXPORT_SYMBOL(fget_raw); * The fput_needed flag returned by fget_light should be passed to the * corresponding fput_light. */ -struct file *__fget_light(unsigned int fd, fmode_t mask, int *fput_needed) +static unsigned long __fget_light(unsigned int fd, fmode_t mask) { struct files_struct *files = current->files; struct file *file; - *fput_needed = 0; if (atomic_read(&files->count) == 1) { file = __fcheck_files(files, fd); - if (file && (file->f_mode & mask)) - file = NULL; + if (!file || unlikely(file->f_mode & mask)) + return 0; + return (unsigned long)file; } else { file = __fget(fd, mask); - if (file) - *fput_needed = 1; + if (!file) + return 0; + return FDPUT_FPUT | (unsigned long)file; } - - return file; } -struct file *fget_light(unsigned int fd, int *fput_needed) +unsigned long __fdget(unsigned int fd) { - return __fget_light(fd, FMODE_PATH, fput_needed); + return __fget_light(fd, FMODE_PATH); } -EXPORT_SYMBOL(fget_light); +EXPORT_SYMBOL(__fdget); -struct file *fget_raw_light(unsigned int fd, int *fput_needed) +unsigned long __fdget_raw(unsigned int fd) { - return __fget_light(fd, 0, fput_needed); + return __fget_light(fd, 0); +} + +unsigned long __fdget_pos(unsigned int fd) +{ + struct files_struct *files = current->files; + struct file *file; + unsigned long v; + + if (atomic_read(&files->count) == 1) { + file = __fcheck_files(files, fd); + v = 0; + } else { + file = __fget(fd, 0); + v = FDPUT_FPUT; + } + if (!file) + return 0; + + if (file->f_mode & FMODE_ATOMIC_POS) { + if (file_count(file) > 1) { + v |= FDPUT_POS_UNLOCK; + mutex_lock(&file->f_pos_lock); + } + } + return v | (unsigned long)file; } +/* + * 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 + * file count (done either by fdget() or by fork()). + */ + void set_close_on_exec(unsigned int fd, int flag) { struct files_struct *files = current->files; diff --git a/fs/file_table.c b/fs/file_table.c index 5fff903..5b24008 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -135,6 +135,7 @@ struct file *get_empty_filp(void) atomic_long_set(&f->f_count, 1); rwlock_init(&f->f_owner.lock); spin_lock_init(&f->f_lock); + mutex_init(&f->f_pos_lock); eventpoll_init_file(f); /* f->f_version: 0 */ return f; @@ -1884,7 +1884,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, nd->path = f.file->f_path; if (flags & LOOKUP_RCU) { - if (f.need_put) + if (f.flags & FDPUT_FPUT) *fp = f.file; nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq); rcu_read_lock(); diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 8450262bc..51632c4 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -2393,8 +2393,8 @@ out_dio: if (((file->f_flags & O_DSYNC) && !direct_io) || IS_SYNC(inode) || ((file->f_flags & O_DIRECT) && !direct_io)) { - ret = filemap_fdatawrite_range(file->f_mapping, pos, - pos + count - 1); + ret = filemap_fdatawrite_range(file->f_mapping, *ppos, + *ppos + count - 1); if (ret < 0) written = ret; @@ -2407,8 +2407,8 @@ out_dio: } if (!ret) - ret = filemap_fdatawait_range(file->f_mapping, pos, - pos + count - 1); + ret = filemap_fdatawait_range(file->f_mapping, *ppos, + *ppos + count - 1); } /* @@ -705,6 +705,10 @@ static int do_dentry_open(struct file *f, return 0; } + /* POSIX.1-2008/SUSv4 Section XSI 2.9.7 */ + if (S_ISREG(inode->i_mode)) + f->f_mode |= FMODE_ATOMIC_POS; + f->f_op = fops_get(inode->i_fop); if (unlikely(WARN_ON(!f->f_op))) { error = -ENODEV; diff --git a/fs/read_write.c b/fs/read_write.c index edc5746..54e19b9 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -264,10 +264,22 @@ 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; - struct fd f = fdget(fd); + struct fd f = fdget_pos(fd); if (!f.file) return -EBADF; @@ -278,7 +290,7 @@ SYSCALL_DEFINE3(lseek, unsigned int, fd, off_t, offset, unsigned int, whence) if (res != (loff_t)retval) retval = -EOVERFLOW; /* LFS: should only happen on 32 bit platforms */ } - fdput(f); + fdput_pos(f); return retval; } @@ -498,7 +510,7 @@ static inline void file_pos_write(struct file *file, loff_t pos) SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) { - struct fd f = fdget(fd); + struct fd f = fdget_pos(fd); ssize_t ret = -EBADF; if (f.file) { @@ -506,7 +518,7 @@ SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) ret = vfs_read(f.file, buf, count, &pos); if (ret >= 0) file_pos_write(f.file, pos); - fdput(f); + fdput_pos(f); } return ret; } @@ -514,7 +526,7 @@ SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, size_t, count) { - struct fd f = fdget(fd); + struct fd f = fdget_pos(fd); ssize_t ret = -EBADF; if (f.file) { @@ -522,7 +534,7 @@ SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, ret = vfs_write(f.file, buf, count, &pos); if (ret >= 0) file_pos_write(f.file, pos); - fdput(f); + fdput_pos(f); } return ret; @@ -797,7 +809,7 @@ EXPORT_SYMBOL(vfs_writev); SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen) { - struct fd f = fdget(fd); + struct fd f = fdget_pos(fd); ssize_t ret = -EBADF; if (f.file) { @@ -805,7 +817,7 @@ SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, ret = vfs_readv(f.file, vec, vlen, &pos); if (ret >= 0) file_pos_write(f.file, pos); - fdput(f); + fdput_pos(f); } if (ret > 0) @@ -817,7 +829,7 @@ SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, unsigned long, vlen) { - struct fd f = fdget(fd); + struct fd f = fdget_pos(fd); ssize_t ret = -EBADF; if (f.file) { @@ -825,7 +837,7 @@ SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, ret = vfs_writev(f.file, vec, vlen, &pos); if (ret >= 0) file_pos_write(f.file, pos); - fdput(f); + fdput_pos(f); } if (ret > 0) @@ -968,7 +980,7 @@ COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd, const struct compat_iovec __user *,vec, compat_ulong_t, vlen) { - struct fd f = fdget(fd); + struct fd f = fdget_pos(fd); ssize_t ret; loff_t pos; @@ -978,7 +990,7 @@ COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd, ret = compat_readv(f.file, vec, vlen, &pos); if (ret >= 0) f.file->f_pos = pos; - fdput(f); + fdput_pos(f); return ret; } @@ -1035,7 +1047,7 @@ COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd, const struct compat_iovec __user *, vec, compat_ulong_t, vlen) { - struct fd f = fdget(fd); + struct fd f = fdget_pos(fd); ssize_t ret; loff_t pos; @@ -1045,7 +1057,7 @@ COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd, ret = compat_writev(f.file, vec, vlen, &pos); if (ret >= 0) f.file->f_pos = pos; - fdput(f); + fdput_pos(f); return ret; } diff --git a/include/linux/file.h b/include/linux/file.h index cbacf4f..4d69123 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -28,33 +28,36 @@ static inline void fput_light(struct file *file, int fput_needed) struct fd { struct file *file; - int need_put; + unsigned int flags; }; +#define FDPUT_FPUT 1 +#define FDPUT_POS_UNLOCK 2 static inline void fdput(struct fd fd) { - if (fd.need_put) + if (fd.flags & FDPUT_FPUT) fput(fd.file); } extern struct file *fget(unsigned int fd); -extern struct file *fget_light(unsigned int fd, int *fput_needed); +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); -static inline struct fd fdget(unsigned int fd) +static inline struct fd __to_fd(unsigned long v) { - int b; - struct file *f = fget_light(fd, &b); - return (struct fd){f,b}; + return (struct fd){(struct file *)(v & ~3),v & 3}; } -extern struct file *fget_raw(unsigned int fd); -extern struct file *fget_raw_light(unsigned int fd, int *fput_needed); +static inline struct fd fdget(unsigned int fd) +{ + return __to_fd(__fdget(fd)); +} static inline struct fd fdget_raw(unsigned int fd) { - int b; - struct file *f = fget_raw_light(fd, &b); - return (struct fd){f,b}; + return __to_fd(__fdget_raw(fd)); } extern int f_dupfd(unsigned int from, struct file *file, unsigned flags); diff --git a/include/linux/fs.h b/include/linux/fs.h index 6082956..23b2a35 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -123,6 +123,9 @@ typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset, /* File is opened with O_PATH; almost nothing can be done with it */ #define FMODE_PATH ((__force fmode_t)0x4000) +/* File needs atomic accesses to f_pos */ +#define FMODE_ATOMIC_POS ((__force fmode_t)0x8000) + /* File was opened by fanotify and shouldn't generate fanotify events */ #define FMODE_NONOTIFY ((__force fmode_t)0x1000000) @@ -780,13 +783,14 @@ struct file { const struct file_operations *f_op; /* - * Protects f_ep_links, f_flags, f_pos vs i_size in lseek SEEK_CUR. + * Protects f_ep_links, f_flags. * Must not be taken from IRQ context. */ spinlock_t f_lock; atomic_long_t f_count; unsigned int f_flags; fmode_t f_mode; + struct mutex f_pos_lock; loff_t f_pos; struct fown_struct f_owner; const struct cred *f_cred; @@ -808,7 +812,7 @@ struct file { #ifdef CONFIG_DEBUG_WRITECOUNT unsigned long f_mnt_write_state; #endif -}; +} __attribute__((aligned(4))); /* lest something weird decides that 2 is OK */ struct file_handle { __u32 handle_bytes; diff --git a/net/socket.c b/net/socket.c index 879933a..fd8d86e 100644 --- a/net/socket.c +++ b/net/socket.c @@ -450,16 +450,17 @@ EXPORT_SYMBOL(sockfd_lookup); static struct socket *sockfd_lookup_light(int fd, int *err, int *fput_needed) { - struct file *file; + struct fd f = fdget(fd); struct socket *sock; *err = -EBADF; - file = fget_light(fd, fput_needed); - if (file) { - sock = sock_from_file(file, err); - if (sock) + if (f.file) { + sock = sock_from_file(f.file, err); + if (likely(sock)) { + *fput_needed = f.flags; return sock; - fput_light(file, *fput_needed); + } + fdput(f); } return NULL; } |