diff options
| author | Maxim Patlasov <mpatlasov@parallels.com> | 2012-10-26 19:48:42 +0400 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@suse.cz> | 2013-01-24 16:21:26 +0100 |
| commit | 4d53dc99baf139e4fa0d395f7658032cc2eb3297 (patch) | |
| tree | 4709fcfd8631d744abc95195a257b67000e863fa /fs | |
| parent | b111c8c0e3e5e780ae0758fc4c1c376a7c9d5997 (diff) | |
fuse: rework fuse_retrieve()
The patch reworks fuse_retrieve() to allocate only so many page pointers
as needed. The core part of the patch is the following calculation:
num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
(thanks Miklos for formula). All other changes are mostly shuffling lines.
Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/fuse/dev.c | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index ff5e8bed5d8..28d9792de4a 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1577,13 +1577,24 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode, unsigned int num; unsigned int offset; size_t total_len = 0; + int num_pages; - req = fuse_get_req(fc, FUSE_MAX_PAGES_PER_REQ); + offset = outarg->offset & ~PAGE_CACHE_MASK; + file_size = i_size_read(inode); + + num = outarg->size; + if (outarg->offset > file_size) + num = 0; + else if (outarg->offset + num > file_size) + num = file_size - outarg->offset; + + num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; + num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ); + + req = fuse_get_req(fc, num_pages); if (IS_ERR(req)) return PTR_ERR(req); - offset = outarg->offset & ~PAGE_CACHE_MASK; - req->in.h.opcode = FUSE_NOTIFY_REPLY; req->in.h.nodeid = outarg->nodeid; req->in.numargs = 2; @@ -1592,14 +1603,8 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode, req->end = fuse_retrieve_end; index = outarg->offset >> PAGE_CACHE_SHIFT; - file_size = i_size_read(inode); - num = outarg->size; - if (outarg->offset > file_size) - num = 0; - else if (outarg->offset + num > file_size) - num = file_size - outarg->offset; - while (num && req->num_pages < FUSE_MAX_PAGES_PER_REQ) { + while (num && req->num_pages < num_pages) { struct page *page; unsigned int this_num; |