diff options
Diffstat (limited to 'fs/read_write.c')
-rw-r--r-- | fs/read_write.c | 89 |
1 files changed, 67 insertions, 22 deletions
diff --git a/fs/read_write.c b/fs/read_write.c index 03430008704e..122a3846d9e1 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -41,8 +41,19 @@ static inline int unsigned_offsets(struct file *file) return file->f_mode & FMODE_UNSIGNED_OFFSET; } -static loff_t lseek_execute(struct file *file, struct inode *inode, - loff_t offset, loff_t maxsize) +/** + * vfs_setpos - update the file offset for lseek + * @file: file structure in question + * @offset: file offset to seek to + * @maxsize: maximum file size + * + * This is a low-level filesystem helper for updating the file offset to + * the value specified by @offset if the given offset is valid and it is + * not equal to the current file offset. + * + * Return the specified offset on success and -EINVAL on invalid offset. + */ +loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize) { if (offset < 0 && !unsigned_offsets(file)) return -EINVAL; @@ -55,6 +66,7 @@ static loff_t lseek_execute(struct file *file, struct inode *inode, } return offset; } +EXPORT_SYMBOL(vfs_setpos); /** * generic_file_llseek_size - generic llseek implementation for regular files @@ -76,8 +88,6 @@ loff_t generic_file_llseek_size(struct file *file, loff_t offset, int whence, loff_t maxsize, loff_t eof) { - struct inode *inode = file->f_mapping->host; - switch (whence) { case SEEK_END: offset += eof; @@ -97,8 +107,7 @@ generic_file_llseek_size(struct file *file, loff_t offset, int whence, * like SEEK_SET. */ spin_lock(&file->f_lock); - offset = lseek_execute(file, inode, file->f_pos + offset, - maxsize); + offset = vfs_setpos(file, file->f_pos + offset, maxsize); spin_unlock(&file->f_lock); return offset; case SEEK_DATA: @@ -120,7 +129,7 @@ generic_file_llseek_size(struct file *file, loff_t offset, int whence, break; } - return lseek_execute(file, inode, offset, maxsize); + return vfs_setpos(file, offset, maxsize); } EXPORT_SYMBOL(generic_file_llseek_size); @@ -145,6 +154,26 @@ loff_t generic_file_llseek(struct file *file, loff_t offset, int whence) EXPORT_SYMBOL(generic_file_llseek); /** + * fixed_size_llseek - llseek implementation for fixed-sized devices + * @file: file structure to seek on + * @offset: file offset to seek to + * @whence: type of seek + * @size: size of the file + * + */ +loff_t fixed_size_llseek(struct file *file, loff_t offset, int whence, loff_t size) +{ + switch (whence) { + case SEEK_SET: case SEEK_CUR: case SEEK_END: + return generic_file_llseek_size(file, offset, whence, + size, size); + default: + return -EINVAL; + } +} +EXPORT_SYMBOL(fixed_size_llseek); + +/** * noop_llseek - No Operation Performed llseek implementation * @file: file structure to seek on * @offset: file offset to seek to @@ -296,7 +325,7 @@ out_putf: * them to something that fits in "int" so that others * won't have to do range checks all the time. */ -int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count) +int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count) { struct inode *inode; loff_t pos; @@ -477,7 +506,8 @@ SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count) if (f.file) { loff_t pos = file_pos_read(f.file); ret = vfs_read(f.file, buf, count, &pos); - file_pos_write(f.file, pos); + if (ret >= 0) + file_pos_write(f.file, pos); fdput(f); } return ret; @@ -492,7 +522,8 @@ SYSCALL_DEFINE3(write, unsigned int, fd, const char __user *, buf, if (f.file) { loff_t pos = file_pos_read(f.file); ret = vfs_write(f.file, buf, count, &pos); - file_pos_write(f.file, pos); + if (ret >= 0) + file_pos_write(f.file, pos); fdput(f); } @@ -780,7 +811,8 @@ SYSCALL_DEFINE3(readv, unsigned long, fd, const struct iovec __user *, vec, if (f.file) { loff_t pos = file_pos_read(f.file); ret = vfs_readv(f.file, vec, vlen, &pos); - file_pos_write(f.file, pos); + if (ret >= 0) + file_pos_write(f.file, pos); fdput(f); } @@ -799,7 +831,8 @@ SYSCALL_DEFINE3(writev, unsigned long, fd, const struct iovec __user *, vec, if (f.file) { loff_t pos = file_pos_read(f.file); ret = vfs_writev(f.file, vec, vlen, &pos); - file_pos_write(f.file, pos); + if (ret >= 0) + file_pos_write(f.file, pos); fdput(f); } @@ -959,7 +992,8 @@ COMPAT_SYSCALL_DEFINE3(readv, unsigned long, fd, return -EBADF; pos = f.file->f_pos; ret = compat_readv(f.file, vec, vlen, &pos); - f.file->f_pos = pos; + if (ret >= 0) + f.file->f_pos = pos; fdput(f); return ret; } @@ -1025,7 +1059,8 @@ COMPAT_SYSCALL_DEFINE3(writev, unsigned long, fd, return -EBADF; pos = f.file->f_pos; ret = compat_writev(f.file, vec, vlen, &pos); - f.file->f_pos = pos; + if (ret >= 0) + f.file->f_pos = pos; fdput(f); return ret; } @@ -1064,6 +1099,7 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, struct fd in, out; struct inode *in_inode, *out_inode; loff_t pos; + loff_t out_pos; ssize_t retval; int fl; @@ -1077,12 +1113,14 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, if (!(in.file->f_mode & FMODE_READ)) goto fput_in; retval = -ESPIPE; - if (!ppos) - ppos = &in.file->f_pos; - else + if (!ppos) { + pos = in.file->f_pos; + } else { + pos = *ppos; if (!(in.file->f_mode & FMODE_PREAD)) goto fput_in; - retval = rw_verify_area(READ, in.file, ppos, count); + } + retval = rw_verify_area(READ, in.file, &pos, count); if (retval < 0) goto fput_in; count = retval; @@ -1099,7 +1137,8 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, retval = -EINVAL; in_inode = file_inode(in.file); out_inode = file_inode(out.file); - retval = rw_verify_area(WRITE, out.file, &out.file->f_pos, count); + out_pos = out.file->f_pos; + retval = rw_verify_area(WRITE, out.file, &out_pos, count); if (retval < 0) goto fput_out; count = retval; @@ -1107,7 +1146,6 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, if (!max) max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); - pos = *ppos; if (unlikely(pos + count > max)) { retval = -EOVERFLOW; if (pos >= max) @@ -1126,18 +1164,25 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, if (in.file->f_flags & O_NONBLOCK) fl = SPLICE_F_NONBLOCK; #endif - retval = do_splice_direct(in.file, ppos, out.file, count, fl); + file_start_write(out.file); + retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); + file_end_write(out.file); if (retval > 0) { add_rchar(current, retval); add_wchar(current, retval); fsnotify_access(in.file); fsnotify_modify(out.file); + out.file->f_pos = out_pos; + if (ppos) + *ppos = pos; + else + in.file->f_pos = pos; } inc_syscr(current); inc_syscw(current); - if (*ppos > max) + if (pos > max) retval = -EOVERFLOW; fput_out: |