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authorRitesh Harjani (IBM) <ritesh.list@gmail.com>2023-04-21 15:16:12 +0530
committerJan Kara <jack@suse.cz>2023-05-16 11:32:42 +0200
commit31b2ebc0929e964f4edfbfa7129d43f7e3c17165 (patch)
tree7dffe7cab84d3b01029d2e0a5c1ebd38b290e411 /fs/buffer.c
parentfcced95b6ba2a507a83b8b3e0358a8ac16b13e35 (diff)
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fs/buffer.c: Add generic_buffers_fsync*() implementation
Some of the higher layers like iomap takes inode_lock() when calling generic_write_sync(). Also writeback already happens from other paths without inode lock, so it's difficult to say that we really need sync_mapping_buffers() to take any inode locking here. Having said that, let's add generic_buffers_fsync/_noflush() implementation in buffer.c with no inode_lock/unlock() for now so that filesystems like ext2 and ext4's nojournal mode can use it. Ext4 when got converted to iomap for direct-io already copied it's own variant of __generic_file_fsync() without lock. This patch adds generic_buffers_fsync() & generic_buffers_fsync_noflush() implementations for use in filesystems like ext2 & ext4 respectively. Later we can review other filesystems as well to see if we can make generic_buffers_fsync/_noflush() which does not take any inode_lock() as the default path. Tested-by: Disha Goel <disgoel@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Message-Id: <d573408ac8408627d23a3d2d166e748c172c4c9e.1682069716.git.ritesh.list@gmail.com>
Diffstat (limited to 'fs/buffer.c')
-rw-r--r--fs/buffer.c70
1 files changed, 70 insertions, 0 deletions
diff --git a/fs/buffer.c b/fs/buffer.c
index a7fc561758b1..00cad2658a07 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -592,6 +592,76 @@ int sync_mapping_buffers(struct address_space *mapping)
}
EXPORT_SYMBOL(sync_mapping_buffers);
+/**
+ * generic_buffers_fsync_noflush - generic buffer fsync implementation
+ * for simple filesystems with no inode lock
+ *
+ * @file: file to synchronize
+ * @start: start offset in bytes
+ * @end: end offset in bytes (inclusive)
+ * @datasync: only synchronize essential metadata if true
+ *
+ * This is a generic implementation of the fsync method for simple
+ * filesystems which track all non-inode metadata in the buffers list
+ * hanging off the address_space structure.
+ */
+int generic_buffers_fsync_noflush(struct file *file, loff_t start, loff_t end,
+ bool datasync)
+{
+ struct inode *inode = file->f_mapping->host;
+ int err;
+ int ret;
+
+ err = file_write_and_wait_range(file, start, end);
+ if (err)
+ return err;
+
+ ret = sync_mapping_buffers(inode->i_mapping);
+ if (!(inode->i_state & I_DIRTY_ALL))
+ goto out;
+ if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
+ goto out;
+
+ err = sync_inode_metadata(inode, 1);
+ if (ret == 0)
+ ret = err;
+
+out:
+ /* check and advance again to catch errors after syncing out buffers */
+ err = file_check_and_advance_wb_err(file);
+ if (ret == 0)
+ ret = err;
+ return ret;
+}
+EXPORT_SYMBOL(generic_buffers_fsync_noflush);
+
+/**
+ * generic_buffers_fsync - generic buffer fsync implementation
+ * for simple filesystems with no inode lock
+ *
+ * @file: file to synchronize
+ * @start: start offset in bytes
+ * @end: end offset in bytes (inclusive)
+ * @datasync: only synchronize essential metadata if true
+ *
+ * This is a generic implementation of the fsync method for simple
+ * filesystems which track all non-inode metadata in the buffers list
+ * hanging off the address_space structure. This also makes sure that
+ * a device cache flush operation is called at the end.
+ */
+int generic_buffers_fsync(struct file *file, loff_t start, loff_t end,
+ bool datasync)
+{
+ struct inode *inode = file->f_mapping->host;
+ int ret;
+
+ ret = generic_buffers_fsync_noflush(file, start, end, datasync);
+ if (!ret)
+ ret = blkdev_issue_flush(inode->i_sb->s_bdev);
+ return ret;
+}
+EXPORT_SYMBOL(generic_buffers_fsync);
+
/*
* Called when we've recently written block `bblock', and it is known that
* `bblock' was for a buffer_boundary() buffer. This means that the block at