From 38c31464089f639630b7c28ce933a4d60e135a02 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Tue, 14 Feb 2017 19:04:07 +0100 Subject: btrfs: merge length input and output parameter in compress_pages The length parameter is basically duplicated for input and output in the top level caller of the compress_pages chain. We can simply use one variable for that and reduce stack consumption. The compression implementation will sink the parameter to a local variable so everything works as before. Signed-off-by: David Sterba --- fs/btrfs/zlib.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs/btrfs/zlib.c') diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c index da497f184ff4..42d76b7824c3 100644 --- a/fs/btrfs/zlib.c +++ b/fs/btrfs/zlib.c @@ -73,7 +73,7 @@ fail: static int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, - u64 start, unsigned long len, + u64 start, struct page **pages, unsigned long nr_dest_pages, unsigned long *out_pages, @@ -89,6 +89,7 @@ static int zlib_compress_pages(struct list_head *ws, struct page *in_page = NULL; struct page *out_page = NULL; unsigned long bytes_left; + unsigned long len = *total_out; *out_pages = 0; *total_out = 0; -- cgit v1.2.3 From 4d3a800ebb1299944408f3b40b5b6b996477fba2 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Tue, 14 Feb 2017 19:04:07 +0100 Subject: btrfs: merge nr_pages input and output parameter in compress_pages The parameter saying how many pages can be allocated at maximum can be merged with the output page counter, to save some stack space. The compression implementation will sink the parameter to a local variable so everything works as before. The nr_pages variables can also be simply merged in compress_file_range into one. Signed-off-by: David Sterba --- fs/btrfs/compression.c | 7 +++---- fs/btrfs/compression.h | 2 -- fs/btrfs/inode.c | 13 ++++++------- fs/btrfs/lzo.c | 2 +- fs/btrfs/zlib.c | 2 +- 5 files changed, 11 insertions(+), 15 deletions(-) (limited to 'fs/btrfs/zlib.c') diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 7e214fd254e4..11dcda57e15c 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -914,8 +914,8 @@ static void free_workspaces(void) * Given an address space and start and length, compress the bytes into @pages * that are allocated on demand. * - * @out_pages is used to return the number of pages allocated. There - * may be pages allocated even if we return an error. + * @out_pages is an in/out parameter, holds maximum number of pages to allocate + * and returns number of actually allocated pages * * @total_in is used to return the number of bytes actually read. It * may be smaller than the input length if we had to exit early because we @@ -930,7 +930,6 @@ static void free_workspaces(void) */ int btrfs_compress_pages(int type, struct address_space *mapping, u64 start, struct page **pages, - unsigned long nr_dest_pages, unsigned long *out_pages, unsigned long *total_in, unsigned long *total_out, @@ -943,7 +942,7 @@ int btrfs_compress_pages(int type, struct address_space *mapping, ret = btrfs_compress_op[type-1]->compress_pages(workspace, mapping, start, pages, - nr_dest_pages, out_pages, + out_pages, total_in, total_out, max_out); free_workspace(type, workspace); diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h index 725d1e0bd25d..cfcec709c61b 100644 --- a/fs/btrfs/compression.h +++ b/fs/btrfs/compression.h @@ -24,7 +24,6 @@ void btrfs_exit_compress(void); int btrfs_compress_pages(int type, struct address_space *mapping, u64 start, struct page **pages, - unsigned long nr_dest_pages, unsigned long *out_pages, unsigned long *total_in, unsigned long *total_out, @@ -60,7 +59,6 @@ struct btrfs_compress_op { struct address_space *mapping, u64 start, struct page **pages, - unsigned long nr_dest_pages, unsigned long *out_pages, unsigned long *total_in, unsigned long *total_out, diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 8b9eac33d431..83bbe1e31869 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -430,7 +430,6 @@ static noinline void compress_file_range(struct inode *inode, int ret = 0; struct page **pages = NULL; unsigned long nr_pages; - unsigned long nr_pages_ret = 0; unsigned long total_compressed = 0; unsigned long total_in = 0; unsigned long max_compressed = SZ_128K; @@ -518,7 +517,7 @@ again: ret = btrfs_compress_pages(compress_type, inode->i_mapping, start, pages, - nr_pages, &nr_pages_ret, + &nr_pages, &total_in, &total_compressed, max_compressed); @@ -526,7 +525,7 @@ again: if (!ret) { unsigned long offset = total_compressed & (PAGE_SIZE - 1); - struct page *page = pages[nr_pages_ret - 1]; + struct page *page = pages[nr_pages - 1]; char *kaddr; /* zero the tail end of the last page, we might be @@ -607,7 +606,7 @@ cont: * will submit them to the elevator. */ add_async_extent(async_cow, start, num_bytes, - total_compressed, pages, nr_pages_ret, + total_compressed, pages, nr_pages, compress_type); if (start + num_bytes < end) { @@ -624,14 +623,14 @@ cont: * the compression code ran but failed to make things smaller, * free any pages it allocated and our page pointer array */ - for (i = 0; i < nr_pages_ret; i++) { + for (i = 0; i < nr_pages; i++) { WARN_ON(pages[i]->mapping); put_page(pages[i]); } kfree(pages); pages = NULL; total_compressed = 0; - nr_pages_ret = 0; + nr_pages = 0; /* flag the file so we don't compress in the future */ if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) && @@ -660,7 +659,7 @@ cleanup_and_bail_uncompressed: return; free_pages_out: - for (i = 0; i < nr_pages_ret; i++) { + for (i = 0; i < nr_pages; i++) { WARN_ON(pages[i]->mapping); put_page(pages[i]); } diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c index 489f78c4e5ec..0baf978fbcaf 100644 --- a/fs/btrfs/lzo.c +++ b/fs/btrfs/lzo.c @@ -88,7 +88,6 @@ static int lzo_compress_pages(struct list_head *ws, struct address_space *mapping, u64 start, struct page **pages, - unsigned long nr_dest_pages, unsigned long *out_pages, unsigned long *total_in, unsigned long *total_out, @@ -103,6 +102,7 @@ static int lzo_compress_pages(struct list_head *ws, struct page *out_page = NULL; unsigned long bytes_left; unsigned long len = *total_out; + unsigned long nr_dest_pages = *out_pages; size_t in_len; size_t out_len; char *buf; diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c index 42d76b7824c3..e7f2020f8ee7 100644 --- a/fs/btrfs/zlib.c +++ b/fs/btrfs/zlib.c @@ -75,7 +75,6 @@ static int zlib_compress_pages(struct list_head *ws, struct address_space *mapping, u64 start, struct page **pages, - unsigned long nr_dest_pages, unsigned long *out_pages, unsigned long *total_in, unsigned long *total_out, @@ -90,6 +89,7 @@ static int zlib_compress_pages(struct list_head *ws, struct page *out_page = NULL; unsigned long bytes_left; unsigned long len = *total_out; + unsigned long nr_dest_pages = *out_pages; *out_pages = 0; *total_out = 0; -- cgit v1.2.3 From e5d74902362f1a06ea3674042d09f1af178c0a20 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Tue, 14 Feb 2017 19:45:05 +0100 Subject: btrfs: derive maximum output size in the compression implementation The value of max_out can be calculated from the parameters passed to the compressors, which is number of pages and the page size, and we don't have to needlessly pass it around. Signed-off-by: David Sterba --- fs/btrfs/compression.c | 6 ++---- fs/btrfs/compression.h | 6 ++---- fs/btrfs/inode.c | 3 +-- fs/btrfs/lzo.c | 4 ++-- fs/btrfs/zlib.c | 4 ++-- 5 files changed, 9 insertions(+), 14 deletions(-) (limited to 'fs/btrfs/zlib.c') diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 11dcda57e15c..c7721a6aa3bb 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -932,8 +932,7 @@ int btrfs_compress_pages(int type, struct address_space *mapping, u64 start, struct page **pages, unsigned long *out_pages, unsigned long *total_in, - unsigned long *total_out, - unsigned long max_out) + unsigned long *total_out) { struct list_head *workspace; int ret; @@ -943,8 +942,7 @@ int btrfs_compress_pages(int type, struct address_space *mapping, ret = btrfs_compress_op[type-1]->compress_pages(workspace, mapping, start, pages, out_pages, - total_in, total_out, - max_out); + total_in, total_out); free_workspace(type, workspace); return ret; } diff --git a/fs/btrfs/compression.h b/fs/btrfs/compression.h index 619e64c27444..39ec43ab8df1 100644 --- a/fs/btrfs/compression.h +++ b/fs/btrfs/compression.h @@ -41,8 +41,7 @@ int btrfs_compress_pages(int type, struct address_space *mapping, u64 start, struct page **pages, unsigned long *out_pages, unsigned long *total_in, - unsigned long *total_out, - unsigned long max_out); + unsigned long *total_out); int btrfs_decompress(int type, unsigned char *data_in, struct page *dest_page, unsigned long start_byte, size_t srclen, size_t destlen); int btrfs_decompress_buf2page(const char *buf, unsigned long buf_start, @@ -76,8 +75,7 @@ struct btrfs_compress_op { struct page **pages, unsigned long *out_pages, unsigned long *total_in, - unsigned long *total_out, - unsigned long max_out); + unsigned long *total_out); int (*decompress_bio)(struct list_head *workspace, struct page **pages_in, diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 11a4eeadf662..0d932b9594de 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -510,8 +510,7 @@ again: pages, &nr_pages, &total_in, - &total_compressed, - BTRFS_MAX_COMPRESSED); + &total_compressed); if (!ret) { unsigned long offset = total_compressed & diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c index 0baf978fbcaf..f48c8c14dc14 100644 --- a/fs/btrfs/lzo.c +++ b/fs/btrfs/lzo.c @@ -90,8 +90,7 @@ static int lzo_compress_pages(struct list_head *ws, struct page **pages, unsigned long *out_pages, unsigned long *total_in, - unsigned long *total_out, - unsigned long max_out) + unsigned long *total_out) { struct workspace *workspace = list_entry(ws, struct workspace, list); int ret = 0; @@ -103,6 +102,7 @@ static int lzo_compress_pages(struct list_head *ws, unsigned long bytes_left; unsigned long len = *total_out; unsigned long nr_dest_pages = *out_pages; + const unsigned long max_out = nr_dest_pages * PAGE_SIZE; size_t in_len; size_t out_len; char *buf; diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c index e7f2020f8ee7..135b10823c6d 100644 --- a/fs/btrfs/zlib.c +++ b/fs/btrfs/zlib.c @@ -77,8 +77,7 @@ static int zlib_compress_pages(struct list_head *ws, struct page **pages, unsigned long *out_pages, unsigned long *total_in, - unsigned long *total_out, - unsigned long max_out) + unsigned long *total_out) { struct workspace *workspace = list_entry(ws, struct workspace, list); int ret; @@ -90,6 +89,7 @@ static int zlib_compress_pages(struct list_head *ws, unsigned long bytes_left; unsigned long len = *total_out; unsigned long nr_dest_pages = *out_pages; + const unsigned long max_out = nr_dest_pages * PAGE_SIZE; *out_pages = 0; *total_out = 0; -- cgit v1.2.3