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author | 2022-04-29 11:12:16 -0400 | |
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committer | 2022-05-09 16:21:45 -0400 | |
commit | 5aab331ad68f7cad432f350c6b28f0b5a9c777fc (patch) | |
tree | 8c0854c2733a4b6ef160d0b1f02d42b3f9f99686 /fs/cramfs/README | |
parent | coda: Convert coda to read_folio (diff) | |
download | linux-5aab331ad68f7cad432f350c6b28f0b5a9c777fc.tar.gz linux-5aab331ad68f7cad432f350c6b28f0b5a9c777fc.tar.bz2 linux-5aab331ad68f7cad432f350c6b28f0b5a9c777fc.zip |
cramfs: Convert cramfs to read_folio
This is a "weak" conversion which converts straight back to using pages.
A full conversion should be performed at some point, hopefully by
someone familiar with the filesystem.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Diffstat (limited to 'fs/cramfs/README')
-rw-r--r-- | fs/cramfs/README | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/cramfs/README b/fs/cramfs/README index d71b27e0ff15..778df5c4d70b 100644 --- a/fs/cramfs/README +++ b/fs/cramfs/README @@ -115,7 +115,7 @@ Block Size (Block size in cramfs refers to the size of input data that is compressed at a time. It's intended to be somewhere around -PAGE_SIZE for cramfs_readpage's convenience.) +PAGE_SIZE for cramfs_read_folio's convenience.) The superblock ought to indicate the block size that the fs was written for, since comments in <linux/pagemap.h> indicate that @@ -161,7 +161,7 @@ size. The options are: PAGE_SIZE. It's easy enough to change the kernel to use a smaller value than -PAGE_SIZE: just make cramfs_readpage read multiple blocks. +PAGE_SIZE: just make cramfs_read_folio read multiple blocks. The cost of option 1 is that kernels with a larger PAGE_SIZE value don't get as good compression as they can. @@ -173,9 +173,9 @@ they don't mind their cramfs being inaccessible to kernels with smaller PAGE_SIZE values. Option 3 is easy to implement if we don't mind being CPU-inefficient: -e.g. get readpage to decompress to a buffer of size MAX_BLKSIZE (which +e.g. get read_folio to decompress to a buffer of size MAX_BLKSIZE (which must be no larger than 32KB) and discard what it doesn't need. -Getting readpage to read into all the covered pages is harder. +Getting read_folio to read into all the covered pages is harder. The main advantage of option 3 over 1, 2, is better compression. The cost is greater complexity. Probably not worth it, but I hope someone |