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authorChristoph Hellwig <hch@lst.de>2010-06-04 11:29:53 +0200
committerAl Viro <viro@zeniv.linux.org.uk>2010-08-09 16:47:29 -0400
commiteafdc7d190a944c755a9fe68573c193e6e0217e7 (patch)
tree915c3cc8004706fabf88eae1ab123a3fa0147516 /fs/direct-io.c
parent256249584bda1a9357e2d29987a37f5b2df035f6 (diff)
downloadlwn-eafdc7d190a944c755a9fe68573c193e6e0217e7.tar.gz
lwn-eafdc7d190a944c755a9fe68573c193e6e0217e7.zip
sort out blockdev_direct_IO variants
Move the call to vmtruncate to get rid of accessive blocks to the callers in prepearation of the new truncate calling sequence. This was only done for DIO_LOCKING filesystems, so the __blockdev_direct_IO_newtrunc variant was not needed anyway. Get rid of blockdev_direct_IO_no_locking and its _newtrunc variant while at it as just opencoding the two additional paramters is shorted than the name suffix. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/direct-io.c')
-rw-r--r--fs/direct-io.c74
1 files changed, 20 insertions, 54 deletions
diff --git a/fs/direct-io.c b/fs/direct-io.c
index a10cb91cadea..51f270b479b6 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -1136,8 +1136,27 @@ direct_io_worker(int rw, struct kiocb *iocb, struct inode *inode,
return ret;
}
+/*
+ * This is a library function for use by filesystem drivers.
+ *
+ * The locking rules are governed by the flags parameter:
+ * - if the flags value contains DIO_LOCKING we use a fancy locking
+ * scheme for dumb filesystems.
+ * For writes this function is called under i_mutex and returns with
+ * i_mutex held, for reads, i_mutex is not held on entry, but it is
+ * taken and dropped again before returning.
+ * For reads and writes i_alloc_sem is taken in shared mode and released
+ * on I/O completion (which may happen asynchronously after returning to
+ * the caller).
+ *
+ * - if the flags value does NOT contain DIO_LOCKING we don't use any
+ * internal locking but rather rely on the filesystem to synchronize
+ * direct I/O reads/writes versus each other and truncate.
+ * For reads and writes both i_mutex and i_alloc_sem are not held on
+ * entry and are never taken.
+ */
ssize_t
-__blockdev_direct_IO_newtrunc(int rw, struct kiocb *iocb, struct inode *inode,
+__blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
struct block_device *bdev, const struct iovec *iov, loff_t offset,
unsigned long nr_segs, get_block_t get_block, dio_iodone_t end_io,
dio_submit_t submit_io, int flags)
@@ -1233,57 +1252,4 @@ __blockdev_direct_IO_newtrunc(int rw, struct kiocb *iocb, struct inode *inode,
out:
return retval;
}
-EXPORT_SYMBOL(__blockdev_direct_IO_newtrunc);
-
-/*
- * This is a library function for use by filesystem drivers.
- *
- * The locking rules are governed by the flags parameter:
- * - if the flags value contains DIO_LOCKING we use a fancy locking
- * scheme for dumb filesystems.
- * For writes this function is called under i_mutex and returns with
- * i_mutex held, for reads, i_mutex is not held on entry, but it is
- * taken and dropped again before returning.
- * For reads and writes i_alloc_sem is taken in shared mode and released
- * on I/O completion (which may happen asynchronously after returning to
- * the caller).
- *
- * - if the flags value does NOT contain DIO_LOCKING we don't use any
- * internal locking but rather rely on the filesystem to synchronize
- * direct I/O reads/writes versus each other and truncate.
- * For reads and writes both i_mutex and i_alloc_sem are not held on
- * entry and are never taken.
- */
-ssize_t
-__blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
- struct block_device *bdev, const struct iovec *iov, loff_t offset,
- unsigned long nr_segs, get_block_t get_block, dio_iodone_t end_io,
- dio_submit_t submit_io, int flags)
-{
- ssize_t retval;
-
- retval = __blockdev_direct_IO_newtrunc(rw, iocb, inode, bdev, iov,
- offset, nr_segs, get_block, end_io, submit_io, flags);
- /*
- * In case of error extending write may have instantiated a few
- * blocks outside i_size. Trim these off again for DIO_LOCKING.
- * NOTE: DIO_NO_LOCK/DIO_OWN_LOCK callers have to handle this in
- * their own manner. This is a further example of where the old
- * truncate sequence is inadequate.
- *
- * NOTE: filesystems with their own locking have to handle this
- * on their own.
- */
- if (flags & DIO_LOCKING) {
- if (unlikely((rw & WRITE) && retval < 0)) {
- loff_t isize = i_size_read(inode);
- loff_t end = offset + iov_length(iov, nr_segs);
-
- if (end > isize)
- vmtruncate(inode, isize);
- }
- }
-
- return retval;
-}
EXPORT_SYMBOL(__blockdev_direct_IO);