From 9508c6b90b3f57ecea4e7a896cf8325400fc0c6e Mon Sep 17 00:00:00 2001 From: Phillip Lougher Date: Wed, 13 Nov 2013 02:56:26 +0000 Subject: Squashfs: Refactor decompressor interface and code The decompressor interface and code was written from the point of view of single-threaded operation. In doing so it mixed a lot of single-threaded implementation specific aspects into the decompressor code and elsewhere which makes it difficult to seamlessly support multiple different decompressor implementations. This patch does the following: 1. It removes compressor_options parsing from the decompressor init() function. This allows the decompressor init() function to be dynamically called to instantiate multiple decompressors, without the compressor options needing to be read and parsed each time. 2. It moves threading and all sleeping operations out of the decompressors. In doing so, it makes the decompressors non-blocking wrappers which only deal with interfacing with the decompressor implementation. 3. It splits decompressor.[ch] into decompressor generic functions in decompressor.[ch], and moves the single threaded decompressor implementation into decompressor_single.c. The result of this patch is Squashfs should now be able to support multiple decompressors by adding new decompressor_xxx.c files with specialised implementations of the functions in decompressor_single.c Signed-off-by: Phillip Lougher Reviewed-by: Minchan Kim --- fs/squashfs/block.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'fs/squashfs/block.c') diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c index 41d108ecc9be..4dd402597f22 100644 --- a/fs/squashfs/block.c +++ b/fs/squashfs/block.c @@ -93,7 +93,7 @@ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index, struct buffer_head **bh; int offset = index & ((1 << msblk->devblksize_log2) - 1); u64 cur_index = index >> msblk->devblksize_log2; - int bytes, compressed, b = 0, k = 0, page = 0, avail; + int bytes, compressed, b = 0, k = 0, page = 0, avail, i; bh = kcalloc(((srclength + msblk->devblksize - 1) >> msblk->devblksize_log2) + 1, sizeof(*bh), GFP_KERNEL); @@ -158,6 +158,12 @@ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index, ll_rw_block(READ, b - 1, bh + 1); } + for (i = 0; i < b; i++) { + wait_on_buffer(bh[i]); + if (!buffer_uptodate(bh[i])) + goto block_release; + } + if (compressed) { length = squashfs_decompress(msblk, buffer, bh, b, offset, length, srclength, pages); @@ -172,9 +178,6 @@ int squashfs_read_data(struct super_block *sb, void **buffer, u64 index, for (bytes = length; k < b; k++) { in = min(bytes, msblk->devblksize - offset); bytes -= in; - wait_on_buffer(bh[k]); - if (!buffer_uptodate(bh[k])) - goto block_release; while (in) { if (pg_offset == PAGE_CACHE_SIZE) { page++; -- cgit v1.2.3-58-ga151