* lock_type is DIO_LOCKING for regular files on direct-IO-naive filesystems.
* This determines whether we need to do the fancy locking which prevents
* direct-IO from being able to read uninitialised disk blocks. If its zero
- * (blockdev) this locking is not done, and if it is DIO_OWN_LOCKING i_sem is
+ * (blockdev) this locking is not done, and if it is DIO_OWN_LOCKING i_mutex is
* not held for the entire direct write (taken briefly, initially, during a
* direct read though, but its never held for the duration of a direct-IO).
*/
/* Handle holes */
if (!buffer_mapped(map_bh)) {
char *kaddr;
+ loff_t i_size_aligned;
/* AKPM: eargh, -ENOTBLK is a hack */
if (dio->rw == WRITE) {
return -ENOTBLK;
}
+ /*
+ * Be sure to account for a partial block as the
+ * last block in the file
+ */
+ i_size_aligned = ALIGN(i_size_read(dio->inode),
+ 1 << blkbits);
if (dio->block_in_file >=
- i_size_read(dio->inode)>>blkbits) {
+ i_size_aligned >> blkbits) {
/* We hit eof */
page_cache_release(page);
goto out;
}
/*
- * Releases both i_sem and i_alloc_sem
+ * Releases both i_mutex and i_alloc_sem
*/
static ssize_t
direct_io_worker(int rw, struct kiocb *iocb, struct inode *inode,
/*
* All block lookups have been performed. For READ requests
- * we can let i_sem go now that its achieved its purpose
+ * we can let i_mutex go now that its achieved its purpose
* of protecting us from looking up uninitialized blocks.
*/
if ((rw == READ) && (dio->lock_type == DIO_LOCKING))
- up(&dio->inode->i_sem);
+ mutex_unlock(&dio->inode->i_mutex);
/*
* OK, all BIOs are submitted, so we can decrement bio_count to truly
* The locking rules are governed by the dio_lock_type parameter.
*
* DIO_NO_LOCKING (no locking, for raw block device access)
- * For writes, i_sem is not held on entry; it is never taken.
+ * For writes, i_mutex is not held on entry; it is never taken.
*
* DIO_LOCKING (simple locking for regular files)
- * For writes we are called under i_sem and return with i_sem held, even though
- * it is internally dropped.
- * For reads, i_sem is not held on entry, but it is taken and dropped before
+ * For writes we are called under i_mutex and return with i_mutex held, even
+ * though it is internally dropped.
+ * For reads, i_mutex is not held on entry, but it is taken and dropped before
* returning.
*
* DIO_OWN_LOCKING (filesystem provides synchronisation and handling of
* uninitialised data, allowing parallel direct readers and writers)
- * For writes we are called without i_sem, return without it, never touch it.
- * For reads, i_sem is held on entry and will be released before returning.
+ * For writes we are called without i_mutex, return without it, never touch it.
+ * For reads we are called under i_mutex and return with i_mutex held, even
+ * though it may be internally dropped.
*
* Additional i_alloc_sem locking requirements described inline below.
*/
ssize_t retval = -EINVAL;
loff_t end = offset;
struct dio *dio;
- int reader_with_isem = (rw == READ && dio_lock_type == DIO_OWN_LOCKING);
+ int release_i_mutex = 0;
+ int acquire_i_mutex = 0;
if (rw & WRITE)
current->flags |= PF_SYNCWRITE;
* For block device access DIO_NO_LOCKING is used,
* neither readers nor writers do any locking at all
* For regular files using DIO_LOCKING,
- * readers need to grab i_sem and i_alloc_sem
- * writers need to grab i_alloc_sem only (i_sem is already held)
+ * readers need to grab i_mutex and i_alloc_sem
+ * writers need to grab i_alloc_sem only (i_mutex is already held)
* For regular files using DIO_OWN_LOCKING,
* neither readers nor writers take any locks here
- * (i_sem is already held and release for writers here)
*/
dio->lock_type = dio_lock_type;
if (dio_lock_type != DIO_NO_LOCKING) {
mapping = iocb->ki_filp->f_mapping;
if (dio_lock_type != DIO_OWN_LOCKING) {
- down(&inode->i_sem);
- reader_with_isem = 1;
+ mutex_lock(&inode->i_mutex);
+ release_i_mutex = 1;
}
retval = filemap_write_and_wait_range(mapping, offset,
}
if (dio_lock_type == DIO_OWN_LOCKING) {
- up(&inode->i_sem);
- reader_with_isem = 0;
+ mutex_unlock(&inode->i_mutex);
+ acquire_i_mutex = 1;
}
}
nr_segs, blkbits, get_blocks, end_io, dio);
if (rw == READ && dio_lock_type == DIO_LOCKING)
- reader_with_isem = 0;
+ release_i_mutex = 0;
out:
- if (reader_with_isem)
- up(&inode->i_sem);
+ if (release_i_mutex)
+ mutex_unlock(&inode->i_mutex);
+ else if (acquire_i_mutex)
+ mutex_lock(&inode->i_mutex);
if (rw & WRITE)
current->flags &= ~PF_SYNCWRITE;
return retval;
projects / linux-2.6-omap-h63xx.git / blobdiff