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-rw-r--r--fs/read_write.c37
-rw-r--r--include/linux/fs.h2
2 files changed, 30 insertions, 9 deletions
diff --git a/fs/read_write.c b/fs/read_write.c
index 672b187def62..dfd125798791 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -51,23 +51,23 @@ static loff_t lseek_execute(struct file *file, struct inode *inode,
}
/**
- * generic_file_llseek - generic llseek implementation for regular files
+ * generic_file_llseek_size - generic llseek implementation for regular files
* @file: file structure to seek on
* @offset: file offset to seek to
* @origin: type of seek
+ * @size: max size of file system
*
- * This is a generic implemenation of ->llseek usable for all normal local
- * filesystems. It just updates the file offset to the value specified by
- * @offset and @origin under i_mutex.
+ * This is a variant of generic_file_llseek that allows passing in a custom
+ * file size.
*
* Synchronization:
- * SEEK_SET is unsynchronized (but atomic on 64bit platforms)
+ * SEEK_SET and SEEK_END are unsynchronized (but atomic on 64bit platforms)
* SEEK_CUR is synchronized against other SEEK_CURs, but not read/writes.
* read/writes behave like SEEK_SET against seeks.
- * SEEK_END
*/
loff_t
-generic_file_llseek(struct file *file, loff_t offset, int origin)
+generic_file_llseek_size(struct file *file, loff_t offset, int origin,
+ loff_t maxsize)
{
struct inode *inode = file->f_mapping->host;
@@ -91,7 +91,7 @@ generic_file_llseek(struct file *file, loff_t offset, int origin)
*/
spin_lock(&file->f_lock);
offset = lseek_execute(file, inode, file->f_pos + offset,
- inode->i_sb->s_maxbytes);
+ maxsize);
spin_unlock(&file->f_lock);
return offset;
case SEEK_DATA:
@@ -113,7 +113,26 @@ generic_file_llseek(struct file *file, loff_t offset, int origin)
break;
}
- return lseek_execute(file, inode, offset, inode->i_sb->s_maxbytes);
+ return lseek_execute(file, inode, offset, maxsize);
+}
+EXPORT_SYMBOL(generic_file_llseek_size);
+
+/**
+ * generic_file_llseek - generic llseek implementation for regular files
+ * @file: file structure to seek on
+ * @offset: file offset to seek to
+ * @origin: type of seek
+ *
+ * This is a generic implemenation of ->llseek useable for all normal local
+ * filesystems. It just updates the file offset to the value specified by
+ * @offset and @origin under i_mutex.
+ */
+loff_t generic_file_llseek(struct file *file, loff_t offset, int origin)
+{
+ struct inode *inode = file->f_mapping->host;
+
+ return generic_file_llseek_size(file, offset, origin,
+ inode->i_sb->s_maxbytes);
}
EXPORT_SYMBOL(generic_file_llseek);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index db85196f6308..d055cc7d7240 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2403,6 +2403,8 @@ file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
extern loff_t noop_llseek(struct file *file, loff_t offset, int origin);
extern loff_t no_llseek(struct file *file, loff_t offset, int origin);
extern loff_t generic_file_llseek(struct file *file, loff_t offset, int origin);
+extern loff_t generic_file_llseek_size(struct file *file, loff_t offset,
+ int origin, loff_t maxsize);
extern int generic_file_open(struct inode * inode, struct file * filp);
extern int nonseekable_open(struct inode * inode, struct file * filp);