[PATCH] mutex subsystem, semaphore to mutex: VFS, ->i_sem
This patch converts the inode semaphore to a mutex. I have tested it on
XFS and compiled as much as one can consider on an ia64. Anyway your
luck with it might be different.
Modified-by: Ingo Molnar <mingo@elte.hu>
(finished the conversion)
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/mm/filemap.c b/mm/filemap.c
index 478f4c7..5fca273 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -61,7 +61,7 @@
* ->swap_lock (exclusive_swap_page, others)
* ->mapping->tree_lock
*
- * ->i_sem
+ * ->i_mutex
* ->i_mmap_lock (truncate->unmap_mapping_range)
*
* ->mmap_sem
@@ -73,9 +73,9 @@
* ->lock_page (access_process_vm)
*
* ->mmap_sem
- * ->i_sem (msync)
+ * ->i_mutex (msync)
*
- * ->i_sem
+ * ->i_mutex
* ->i_alloc_sem (various)
*
* ->inode_lock
@@ -276,7 +276,7 @@
* integrity" operation. It waits upon in-flight writeout before starting and
* waiting upon new writeout. If there was an IO error, return it.
*
- * We need to re-take i_sem during the generic_osync_inode list walk because
+ * We need to re-take i_mutex during the generic_osync_inode list walk because
* it is otherwise livelockable.
*/
int sync_page_range(struct inode *inode, struct address_space *mapping,
@@ -290,9 +290,9 @@
return 0;
ret = filemap_fdatawrite_range(mapping, pos, pos + count - 1);
if (ret == 0) {
- down(&inode->i_sem);
+ mutex_lock(&inode->i_mutex);
ret = generic_osync_inode(inode, mapping, OSYNC_METADATA);
- up(&inode->i_sem);
+ mutex_unlock(&inode->i_mutex);
}
if (ret == 0)
ret = wait_on_page_writeback_range(mapping, start, end);
@@ -301,7 +301,7 @@
EXPORT_SYMBOL(sync_page_range);
/*
- * Note: Holding i_sem across sync_page_range_nolock is not a good idea
+ * Note: Holding i_mutex across sync_page_range_nolock is not a good idea
* as it forces O_SYNC writers to different parts of the same file
* to be serialised right until io completion.
*/
@@ -1892,7 +1892,7 @@
/*
* Sync the fs metadata but not the minor inode changes and
* of course not the data as we did direct DMA for the IO.
- * i_sem is held, which protects generic_osync_inode() from
+ * i_mutex is held, which protects generic_osync_inode() from
* livelocking.
*/
if (written >= 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
@@ -2195,10 +2195,10 @@
BUG_ON(iocb->ki_pos != pos);
- down(&inode->i_sem);
+ mutex_lock(&inode->i_mutex);
ret = __generic_file_aio_write_nolock(iocb, &local_iov, 1,
&iocb->ki_pos);
- up(&inode->i_sem);
+ mutex_unlock(&inode->i_mutex);
if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
ssize_t err;
@@ -2220,9 +2220,9 @@
struct iovec local_iov = { .iov_base = (void __user *)buf,
.iov_len = count };
- down(&inode->i_sem);
+ mutex_lock(&inode->i_mutex);
ret = __generic_file_write_nolock(file, &local_iov, 1, ppos);
- up(&inode->i_sem);
+ mutex_unlock(&inode->i_mutex);
if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
ssize_t err;
@@ -2256,9 +2256,9 @@
struct inode *inode = mapping->host;
ssize_t ret;
- down(&inode->i_sem);
+ mutex_lock(&inode->i_mutex);
ret = __generic_file_write_nolock(file, iov, nr_segs, ppos);
- up(&inode->i_sem);
+ mutex_unlock(&inode->i_mutex);
if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
int err;
@@ -2272,7 +2272,7 @@
EXPORT_SYMBOL(generic_file_writev);
/*
- * Called under i_sem for writes to S_ISREG files. Returns -EIO if something
+ * Called under i_mutex for writes to S_ISREG files. Returns -EIO if something
* went wrong during pagecache shootdown.
*/
static ssize_t
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index 9cf687e..e2b34e9 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -338,7 +338,7 @@
*ppos = pos;
/*
* No need to use i_size_read() here, the i_size
- * cannot change under us because we hold i_sem.
+ * cannot change under us because we hold i_mutex.
*/
if (pos > inode->i_size) {
i_size_write(inode, pos);
@@ -358,7 +358,7 @@
loff_t pos;
ssize_t ret;
- down(&inode->i_sem);
+ mutex_lock(&inode->i_mutex);
if (!access_ok(VERIFY_READ, buf, len)) {
ret=-EFAULT;
@@ -390,7 +390,7 @@
out_backing:
current->backing_dev_info = NULL;
out_up:
- up(&inode->i_sem);
+ mutex_unlock(&inode->i_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(xip_file_write);
diff --git a/mm/memory.c b/mm/memory.c
index 3944fec..7a11ddd 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1784,13 +1784,13 @@
if (!inode->i_op || !inode->i_op->truncate_range)
return -ENOSYS;
- down(&inode->i_sem);
+ mutex_lock(&inode->i_mutex);
down_write(&inode->i_alloc_sem);
unmap_mapping_range(mapping, offset, (end - offset), 1);
truncate_inode_pages_range(mapping, offset, end);
inode->i_op->truncate_range(inode, offset, end);
up_write(&inode->i_alloc_sem);
- up(&inode->i_sem);
+ mutex_unlock(&inode->i_mutex);
return 0;
}
diff --git a/mm/msync.c b/mm/msync.c
index 1b5b6f6..3563a56 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -137,7 +137,7 @@
ret = filemap_fdatawrite(mapping);
if (file->f_op && file->f_op->fsync) {
/*
- * We don't take i_sem here because mmap_sem
+ * We don't take i_mutex here because mmap_sem
* is already held.
*/
err = file->f_op->fsync(file,file->f_dentry,1);
diff --git a/mm/rmap.c b/mm/rmap.c
index 66ec430..dfbb89f 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -20,13 +20,13 @@
/*
* Lock ordering in mm:
*
- * inode->i_sem (while writing or truncating, not reading or faulting)
+ * inode->i_mutex (while writing or truncating, not reading or faulting)
* inode->i_alloc_sem
*
* When a page fault occurs in writing from user to file, down_read
- * of mmap_sem nests within i_sem; in sys_msync, i_sem nests within
- * down_read of mmap_sem; i_sem and down_write of mmap_sem are never
- * taken together; in truncation, i_sem is taken outermost.
+ * of mmap_sem nests within i_mutex; in sys_msync, i_mutex nests within
+ * down_read of mmap_sem; i_mutex and down_write of mmap_sem are never
+ * taken together; in truncation, i_mutex is taken outermost.
*
* mm->mmap_sem
* page->flags PG_locked (lock_page)
diff --git a/mm/shmem.c b/mm/shmem.c
index a1f2f02..343b3c0 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1370,7 +1370,7 @@
if (!access_ok(VERIFY_READ, buf, count))
return -EFAULT;
- down(&inode->i_sem);
+ mutex_lock(&inode->i_mutex);
pos = *ppos;
written = 0;
@@ -1455,7 +1455,7 @@
if (written)
err = written;
out:
- up(&inode->i_sem);
+ mutex_unlock(&inode->i_mutex);
return err;
}
@@ -1491,7 +1491,7 @@
/*
* We must evaluate after, since reads (unlike writes)
- * are called without i_sem protection against truncate
+ * are called without i_mutex protection against truncate
*/
nr = PAGE_CACHE_SIZE;
i_size = i_size_read(inode);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 80f948a..6544565 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1187,9 +1187,9 @@
set_blocksize(bdev, p->old_block_size);
bd_release(bdev);
} else {
- down(&inode->i_sem);
+ mutex_lock(&inode->i_mutex);
inode->i_flags &= ~S_SWAPFILE;
- up(&inode->i_sem);
+ mutex_unlock(&inode->i_mutex);
}
filp_close(swap_file, NULL);
err = 0;
@@ -1406,7 +1406,7 @@
p->bdev = bdev;
} else if (S_ISREG(inode->i_mode)) {
p->bdev = inode->i_sb->s_bdev;
- down(&inode->i_sem);
+ mutex_lock(&inode->i_mutex);
did_down = 1;
if (IS_SWAPFILE(inode)) {
error = -EBUSY;
@@ -1596,7 +1596,7 @@
if (did_down) {
if (!error)
inode->i_flags |= S_SWAPFILE;
- up(&inode->i_sem);
+ mutex_unlock(&inode->i_mutex);
}
return error;
}
diff --git a/mm/truncate.c b/mm/truncate.c
index b1a463d..6cb3fff 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -196,7 +196,7 @@
* @mapping: mapping to truncate
* @lstart: offset from which to truncate
*
- * Called under (and serialised by) inode->i_sem.
+ * Called under (and serialised by) inode->i_mutex.
*/
void truncate_inode_pages(struct address_space *mapping, loff_t lstart)
{