From: Arnd Bergmann on
There are currently 191 users of default_llseek.
Nine of these are in device drivers that use the
big kernel lock. None of these ever touch
file->f_pos outside of llseek or file_pos_write.

Consequently, we never rely on the BKL
in the default_llseek function and can
replace that with i_mutex, which is also
used in generic_file_llseek.

Signed-off-by: Arnd Bergmann <arnd(a)>
fs/read_write.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index 9c04852..31c0be7 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -124,7 +124,7 @@ loff_t default_llseek(struct file *file, loff_t offset, int origin)
loff_t retval;

- lock_kernel();
+ mutex_lock(&file->f_dentry->d_inode->i_mutex);
switch (origin) {
case SEEK_END:
offset += i_size_read(file->f_path.dentry->d_inode);
@@ -145,7 +145,7 @@ loff_t default_llseek(struct file *file, loff_t offset, int origin)
retval = offset;
- unlock_kernel();
+ mutex_unlock(&file->f_dentry->d_inode->i_mutex);
return retval;

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