From 55f09ec0087c160533eab791607d92c9ce6222ae Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 9 Aug 2004 03:28:42 -0700 Subject: [PATCH] read/write: pass down a copy of f_pos, not f_pos itself. This allows the VFS layer to the update rather than the low-level drivers. --- fs/read_write.c | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) diff --git a/fs/read_write.c b/fs/read_write.c index d53bfe726a8d1..d85431d5d09ea 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -270,6 +270,16 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_ EXPORT_SYMBOL(vfs_write); +static inline loff_t file_pos_read(struct file *file) +{ + return file->f_pos; +} + +static inline void file_pos_write(struct file *file, loff_t pos) +{ + file->f_pos = pos; +} + asmlinkage ssize_t sys_read(unsigned int fd, char __user * buf, size_t count) { struct file *file; @@ -278,7 +288,9 @@ asmlinkage ssize_t sys_read(unsigned int fd, char __user * buf, size_t count) file = fget_light(fd, &fput_needed); if (file) { - ret = vfs_read(file, buf, count, &file->f_pos); + loff_t pos = file_pos_read(file); + ret = vfs_read(file, buf, count, &pos); + file_pos_write(file, pos); fput_light(file, fput_needed); } @@ -294,7 +306,9 @@ asmlinkage ssize_t sys_write(unsigned int fd, const char __user * buf, size_t co file = fget_light(fd, &fput_needed); if (file) { - ret = vfs_write(file, buf, count, &file->f_pos); + loff_t pos = file_pos_read(file); + ret = vfs_write(file, buf, count, &pos); + file_pos_write(file, pos); fput_light(file, fput_needed); } @@ -520,7 +534,9 @@ sys_readv(unsigned long fd, const struct iovec __user *vec, unsigned long vlen) file = fget_light(fd, &fput_needed); if (file) { - ret = vfs_readv(file, vec, vlen, &file->f_pos); + loff_t pos = file_pos_read(file); + ret = vfs_readv(file, vec, vlen, &pos); + file_pos_write(file, pos); fput_light(file, fput_needed); } @@ -536,7 +552,9 @@ sys_writev(unsigned long fd, const struct iovec __user *vec, unsigned long vlen) file = fget_light(fd, &fput_needed); if (file) { - ret = vfs_writev(file, vec, vlen, &file->f_pos); + loff_t pos = file_pos_read(file); + ret = vfs_writev(file, vec, vlen, &pos); + file_pos_write(file, pos); fput_light(file, fput_needed); } -- 2.53.0