summaryrefslogtreecommitdiff
path: root/fs/direct-io.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/direct-io.c')
-rw-r--r--fs/direct-io.c30
1 files changed, 20 insertions, 10 deletions
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 30dbbd1df511..27f3e787faca 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -857,6 +857,7 @@ do_holes:
/* Handle holes */
if (!buffer_mapped(map_bh)) {
char *kaddr;
+ loff_t i_size_aligned;
/* AKPM: eargh, -ENOTBLK is a hack */
if (dio->rw == WRITE) {
@@ -864,8 +865,14 @@ do_holes:
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;
@@ -1148,15 +1155,16 @@ direct_io_worker(int rw, struct kiocb *iocb, struct inode *inode,
* 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_mutex and return with i_mutex held, even though
- * it is internally dropped.
+ * 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_mutex, return without it, never touch it.
- * For reads, i_mutex is held on entry and will be released before returning.
+ * 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.
*/
@@ -1175,7 +1183,8 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
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;
@@ -1218,7 +1227,6 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
* 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_mutex is already held and release for writers here)
*/
dio->lock_type = dio_lock_type;
if (dio_lock_type != DIO_NO_LOCKING) {
@@ -1229,7 +1237,7 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
mapping = iocb->ki_filp->f_mapping;
if (dio_lock_type != DIO_OWN_LOCKING) {
mutex_lock(&inode->i_mutex);
- reader_with_isem = 1;
+ release_i_mutex = 1;
}
retval = filemap_write_and_wait_range(mapping, offset,
@@ -1241,7 +1249,7 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
if (dio_lock_type == DIO_OWN_LOCKING) {
mutex_unlock(&inode->i_mutex);
- reader_with_isem = 0;
+ acquire_i_mutex = 1;
}
}
@@ -1262,11 +1270,13 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
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)
+ 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;