Commit acc55e22 authored by NeilBrown's avatar NeilBrown Committed by Linus Torvalds
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[PATCH] md/bitmap: tidy up i_writecount handling in md/bitmap



md/bitmap modifies i_writecount of a bitmap file to make sure that no-one else
writes to it.  The reverting of the change is sometimes done twice, and there
is one error path where it is omitted.

This patch tidies that up.
Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 0cdd02ca
......@@ -625,7 +625,6 @@ static void drain_write_queues(struct bitmap *bitmap)
static void bitmap_file_put(struct bitmap *bitmap)
{
struct file *file;
struct inode *inode;
unsigned long flags;
spin_lock_irqsave(&bitmap->lock, flags);
......@@ -637,13 +636,8 @@ static void bitmap_file_put(struct bitmap *bitmap)
bitmap_file_unmap(bitmap);
if (file) {
inode = file->f_mapping->host;
spin_lock(&inode->i_lock);
atomic_set(&inode->i_writecount, 1); /* allow writes again */
spin_unlock(&inode->i_lock);
if (file)
fput(file);
}
}
......
......@@ -2877,6 +2877,32 @@ out:
return err;
}
/* similar to deny_write_access, but accounts for our holding a reference
* to the file ourselves */
static int deny_bitmap_write_access(struct file * file)
{
struct inode *inode = file->f_mapping->host;
spin_lock(&inode->i_lock);
if (atomic_read(&inode->i_writecount) > 1) {
spin_unlock(&inode->i_lock);
return -ETXTBSY;
}
atomic_set(&inode->i_writecount, -1);
spin_unlock(&inode->i_lock);
return 0;
}
static void restore_bitmap_write_access(struct file *file)
{
struct inode *inode = file->f_mapping->host;
spin_lock(&inode->i_lock);
atomic_set(&inode->i_writecount, 1);
spin_unlock(&inode->i_lock);
}
static int do_md_stop(mddev_t * mddev, int ro)
{
int err = 0;
......@@ -2940,7 +2966,7 @@ static int do_md_stop(mddev_t * mddev, int ro)
bitmap_destroy(mddev);
if (mddev->bitmap_file) {
atomic_set(&mddev->bitmap_file->f_dentry->d_inode->i_writecount, 1);
restore_bitmap_write_access(mddev->bitmap_file);
fput(mddev->bitmap_file);
mddev->bitmap_file = NULL;
}
......@@ -3544,23 +3570,6 @@ abort_export:
return err;
}
/* similar to deny_write_access, but accounts for our holding a reference
* to the file ourselves */
static int deny_bitmap_write_access(struct file * file)
{
struct inode *inode = file->f_mapping->host;
spin_lock(&inode->i_lock);
if (atomic_read(&inode->i_writecount) > 1) {
spin_unlock(&inode->i_lock);
return -ETXTBSY;
}
atomic_set(&inode->i_writecount, -1);
spin_unlock(&inode->i_lock);
return 0;
}
static int set_bitmap_file(mddev_t *mddev, int fd)
{
int err;
......@@ -3608,8 +3617,10 @@ static int set_bitmap_file(mddev_t *mddev, int fd)
mddev->pers->quiesce(mddev, 0);
}
if (fd < 0) {
if (mddev->bitmap_file)
if (mddev->bitmap_file) {
restore_bitmap_write_access(mddev->bitmap_file);
fput(mddev->bitmap_file);
}
mddev->bitmap_file = NULL;
}
......
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