Mount the external journal device and write accessible extent metadata #59
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During fill super, call simplefs_parse_options to find the external device path and set it as the journal device. Additionally, add the `make journal` parameter in the Makefile to create an external journal device.
In the current design of simplefs, we can only access the extent metadata and perform the 'journal' action on it. To write inode and other metadata, we might need to emulate `ext4_dirty_inode`. This method primarily uses the content of struct ext4_iloc to find the correct location of the inode on disk and records it in the journal. However, in our current situation, simply using `mark_inode_dirty` to handle dirty inodes does not allow us to obtain the inode's location, thus preventing us from recording it in the journal. But currently, the idea is that we might create a new buffer head, use `jbd2_journal_get_create_access` to put the dirty inode in it, and then use `jbd2_journal_dirty_metadata` to write it to the journal.
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| @@ -196,6 +201,251 @@ static int simplefs_statfs(struct dentry *dentry, struct kstatfs *stat) | |||
| return 0; | |||
| } | |||
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| /* journal relation code */ | |||
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Drop unnecessary |
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Fix compatibility with Linux v6.5: |
jserv
changed the title
Based on feedback from previous pull requests, addressed the mentioned issues and ensured that the related external device journal loading function operates correctly in kernel version 6.5.
…o external-journal
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The latest commit has addressed the mentioned issues. |
| @@ -332,8 +401,7 @@ static int simplefs_load_journal(struct super_block *sb, | |||
| struct simplefs_sb_info *sbi = SIMPLEFS_SB(sb); | |||
| dev_t journal_dev; | |||
| int err = 0; | |||
| pr_info("simplefs_load_journal: loading journal from device number %lu\n", | |||
| journal_devnum); | |||
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Ensure that journal device can be mounted for Linux kernels prior to v6.5. At least, tweak for version 6.1, 5.15, and 5.10.
See https://kernel.org/ for LTS.
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@jserv Could you please clarify if you would like me to rebase all the commits into a single commit, or if there is a specific way you prefer me to rework them? Thank you! |
There should be only one commit rebasing the latest |
This pull request currently adds the parse_option in fill super to mount the external journal device to simplefs. It also writes the currently accessible extent metadata to the journal during write operations. The image below demonstrates that it is already possible to mount the external journal device in the v6.8 environment.