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Diffstat (limited to 'fs/buffer.c')
-rw-r--r--fs/buffer.c101
1 files changed, 84 insertions, 17 deletions
diff --git a/fs/buffer.c b/fs/buffer.c
index 6569fda5cfe..b58208f1640 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -99,10 +99,18 @@ __clear_page_buffers(struct page *page)
page_cache_release(page);
}
+
+static int quiet_error(struct buffer_head *bh)
+{
+ if (!test_bit(BH_Quiet, &bh->b_state) && printk_ratelimit())
+ return 0;
+ return 1;
+}
+
+
static void buffer_io_error(struct buffer_head *bh)
{
char b[BDEVNAME_SIZE];
-
printk(KERN_ERR "Buffer I/O error on device %s, logical block %Lu\n",
bdevname(bh->b_bdev, b),
(unsigned long long)bh->b_blocknr);
@@ -144,7 +152,7 @@ void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
if (uptodate) {
set_buffer_uptodate(bh);
} else {
- if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
+ if (!buffer_eopnotsupp(bh) && !quiet_error(bh)) {
buffer_io_error(bh);
printk(KERN_WARNING "lost page write due to "
"I/O error on %s\n",
@@ -195,10 +203,25 @@ int fsync_bdev(struct block_device *bdev)
* happen on bdev until thaw_bdev() is called.
* If a superblock is found on this device, we take the s_umount semaphore
* on it to make sure nobody unmounts until the snapshot creation is done.
+ * The reference counter (bd_fsfreeze_count) guarantees that only the last
+ * unfreeze process can unfreeze the frozen filesystem actually when multiple
+ * freeze requests arrive simultaneously. It counts up in freeze_bdev() and
+ * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
+ * actually.
*/
struct super_block *freeze_bdev(struct block_device *bdev)
{
struct super_block *sb;
+ int error = 0;
+
+ mutex_lock(&bdev->bd_fsfreeze_mutex);
+ if (bdev->bd_fsfreeze_count > 0) {
+ bdev->bd_fsfreeze_count++;
+ sb = get_super(bdev);
+ mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ return sb;
+ }
+ bdev->bd_fsfreeze_count++;
down(&bdev->bd_mount_sem);
sb = get_super(bdev);
@@ -213,11 +236,24 @@ struct super_block *freeze_bdev(struct block_device *bdev)
sync_blockdev(sb->s_bdev);
- if (sb->s_op->write_super_lockfs)
- sb->s_op->write_super_lockfs(sb);
+ if (sb->s_op->freeze_fs) {
+ error = sb->s_op->freeze_fs(sb);
+ if (error) {
+ printk(KERN_ERR
+ "VFS:Filesystem freeze failed\n");
+ sb->s_frozen = SB_UNFROZEN;
+ drop_super(sb);
+ up(&bdev->bd_mount_sem);
+ bdev->bd_fsfreeze_count--;
+ mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ return ERR_PTR(error);
+ }
+ }
}
sync_blockdev(bdev);
+ mutex_unlock(&bdev->bd_fsfreeze_mutex);
+
return sb; /* thaw_bdev releases s->s_umount and bd_mount_sem */
}
EXPORT_SYMBOL(freeze_bdev);
@@ -229,20 +265,48 @@ EXPORT_SYMBOL(freeze_bdev);
*
* Unlocks the filesystem and marks it writeable again after freeze_bdev().
*/
-void thaw_bdev(struct block_device *bdev, struct super_block *sb)
+int thaw_bdev(struct block_device *bdev, struct super_block *sb)
{
+ int error = 0;
+
+ mutex_lock(&bdev->bd_fsfreeze_mutex);
+ if (!bdev->bd_fsfreeze_count) {
+ mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ return -EINVAL;
+ }
+
+ bdev->bd_fsfreeze_count--;
+ if (bdev->bd_fsfreeze_count > 0) {
+ if (sb)
+ drop_super(sb);
+ mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ return 0;
+ }
+
if (sb) {
BUG_ON(sb->s_bdev != bdev);
-
- if (sb->s_op->unlockfs)
- sb->s_op->unlockfs(sb);
- sb->s_frozen = SB_UNFROZEN;
- smp_wmb();
- wake_up(&sb->s_wait_unfrozen);
+ if (!(sb->s_flags & MS_RDONLY)) {
+ if (sb->s_op->unfreeze_fs) {
+ error = sb->s_op->unfreeze_fs(sb);
+ if (error) {
+ printk(KERN_ERR
+ "VFS:Filesystem thaw failed\n");
+ sb->s_frozen = SB_FREEZE_TRANS;
+ bdev->bd_fsfreeze_count++;
+ mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ return error;
+ }
+ }
+ sb->s_frozen = SB_UNFROZEN;
+ smp_wmb();
+ wake_up(&sb->s_wait_unfrozen);
+ }
drop_super(sb);
}
up(&bdev->bd_mount_sem);
+ mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ return 0;
}
EXPORT_SYMBOL(thaw_bdev);
@@ -394,7 +458,7 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate)
set_buffer_uptodate(bh);
} else {
clear_buffer_uptodate(bh);
- if (printk_ratelimit())
+ if (!quiet_error(bh))
buffer_io_error(bh);
SetPageError(page);
}
@@ -455,7 +519,7 @@ static void end_buffer_async_write(struct buffer_head *bh, int uptodate)
if (uptodate) {
set_buffer_uptodate(bh);
} else {
- if (printk_ratelimit()) {
+ if (!quiet_error(bh)) {
buffer_io_error(bh);
printk(KERN_WARNING "lost page write due to "
"I/O error on %s\n",
@@ -878,6 +942,7 @@ void invalidate_inode_buffers(struct inode *inode)
spin_unlock(&buffer_mapping->private_lock);
}
}
+EXPORT_SYMBOL(invalidate_inode_buffers);
/*
* Remove any clean buffers from the inode's buffer list. This is called
@@ -1987,7 +2052,7 @@ int block_write_begin(struct file *file, struct address_space *mapping,
page = *pagep;
if (page == NULL) {
ownpage = 1;
- page = __grab_cache_page(mapping, index);
+ page = grab_cache_page_write_begin(mapping, index, flags);
if (!page) {
status = -ENOMEM;
goto out;
@@ -2013,7 +2078,6 @@ int block_write_begin(struct file *file, struct address_space *mapping,
if (pos + len > inode->i_size)
vmtruncate(inode, inode->i_size);
}
- goto out;
}
out:
@@ -2493,7 +2557,7 @@ int nobh_write_begin(struct file *file, struct address_space *mapping,
from = pos & (PAGE_CACHE_SIZE - 1);
to = from + len;
- page = __grab_cache_page(mapping, index);
+ page = grab_cache_page_write_begin(mapping, index, flags);
if (!page)
return -ENOMEM;
*pagep = page;
@@ -2912,6 +2976,9 @@ static void end_bio_bh_io_sync(struct bio *bio, int err)
set_bit(BH_Eopnotsupp, &bh->b_state);
}
+ if (unlikely (test_bit(BIO_QUIET,&bio->bi_flags)))
+ set_bit(BH_Quiet, &bh->b_state);
+
bh->b_end_io(bh, test_bit(BIO_UPTODATE, &bio->bi_flags));
bio_put(bio);
}
@@ -3176,7 +3243,7 @@ void block_sync_page(struct page *page)
* Use of bdflush() is deprecated and will be removed in a future kernel.
* The `pdflush' kernel threads fully replace bdflush daemons and this call.
*/
-asmlinkage long sys_bdflush(int func, long data)
+SYSCALL_DEFINE2(bdflush, int, func, long, data)
{
static int msg_count;
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-03 02:10:43 +0000