sysfs.h: add ATTRIBUTE_GROUPS() macro

[pandora-kernel.git] / fs / read_write.c

diff --git a/fs/read_write.c b/fs/read_write.c
index 2cefa41..122a384 100644 (file)
--- 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);
 
@@ -144,6 +153,26 @@ 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
@@ -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;
 }
@@ -1129,7 +1164,9 @@ 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
+       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);