diff options
| author | Christoph Hellwig <hch@lst.de> | 2023-06-15 08:48:39 +0200 |
|---|---|---|
| committer | Song Liu <song@kernel.org> | 2023-07-27 00:13:29 -0700 |
| commit | a34d4ef82c3c4bd8bda817e9fb53ef37c5595ddd (patch) | |
| tree | 19f0e7a3a90aadd603d603382a0a6fdb8a5cadd7 | |
| parent | d7038f951828da19fa9aafddfa087b69032c9687 (diff) | |
md: make bitmap file support optional
The support for write intent bitmaps in files on an external files in md
is a hot mess that abuses ->bmap to map file offsets into physical device
objects, and also abuses buffer_heads in a creative way.
Make this code optional so that MD can be built into future kernels
without buffer_head support, and so that we can eventually deprecate it.
Note this does not affect the internal bitmap support, which has none of
the problems.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230615064840.629492-11-hch@lst.de
| -rw-r--r-- | drivers/md/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/md/md-bitmap.c | 15 | ||||
| -rw-r--r-- | drivers/md/md.c | 7 |
3 files changed, 32 insertions, 0 deletions
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig index b0a22e99bade..9712ab9bcba5 100644 --- a/drivers/md/Kconfig +++ b/drivers/md/Kconfig @@ -50,6 +50,16 @@ config MD_AUTODETECT If unsure, say Y. +config MD_BITMAP_FILE + bool "MD bitmap file support" + default y + help + If you say Y here, support for write intent bitmaps in files on an + external file system is enabled. This is an alternative to the internal + bitmaps near the MD superblock, and very problematic code that abuses + various kernel APIs and can only work with files on a file system not + actually sitting on the MD device. + config MD_LINEAR tristate "Linear (append) mode (deprecated)" depends on BLK_DEV_MD diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c index a280bfd29f65..a58a4c30265e 100644 --- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -295,6 +295,7 @@ static void write_sb_page(struct bitmap *bitmap, unsigned long pg_index, static void md_bitmap_file_kick(struct bitmap *bitmap); +#ifdef CONFIG_MD_BITMAP_FILE static void write_file_page(struct bitmap *bitmap, struct page *page, int wait) { struct buffer_head *bh = page_buffers(page); @@ -408,6 +409,20 @@ out: ret); return ret; } +#else /* CONFIG_MD_BITMAP_FILE */ +static void write_file_page(struct bitmap *bitmap, struct page *page, int wait) +{ +} +static int read_file_page(struct file *file, unsigned long index, + struct bitmap *bitmap, unsigned long count, struct page *page) +{ + return -EIO; +} +static void free_buffers(struct page *page) +{ + put_page(page); +} +#endif /* CONFIG_MD_BITMAP_FILE */ /* * bitmap file superblock operations diff --git a/drivers/md/md.c b/drivers/md/md.c index 320d71537359..f46996a95b0c 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -7043,6 +7043,13 @@ static int set_bitmap_file(struct mddev *mddev, int fd) if (mddev->bitmap || mddev->bitmap_info.file) return -EEXIST; /* cannot add when bitmap is present */ + + if (!IS_ENABLED(CONFIG_MD_BITMAP_FILE)) { + pr_warn("%s: bitmap files not supported by this kernel\n", + mdname(mddev)); + return -EINVAL; + } + f = fget(fd); if (f == NULL) { |