From 9b65ef59d42a56fa1358958ede77aaa5bac385a8 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Wed, 22 Mar 2006 00:09:09 -0800 Subject: [PATCH] fix swap cluster offset When we've allocated SWAPFILE_CLUSTER pages, ->cluster_next should be the first index of swap cluster. But current code probably sets it wrong offset. Signed-off-by: Akinobu Mita Acked-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swapfile.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/swapfile.c') diff --git a/mm/swapfile.c b/mm/swapfile.c index 1f9cf0d073b8..365ed6ff182d 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -116,7 +116,7 @@ static inline unsigned long scan_swap_map(struct swap_info_struct *si) last_in_cluster = offset + SWAPFILE_CLUSTER; else if (offset == last_in_cluster) { spin_lock(&swap_lock); - si->cluster_next = offset-SWAPFILE_CLUSTER-1; + si->cluster_next = offset-SWAPFILE_CLUSTER+1; goto cluster; } if (unlikely(--latency_ration < 0)) { -- cgit v1.2.3 From f577eb30afdc68233f25d4d82b04102129262365 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 23 Mar 2006 02:59:59 -0800 Subject: [PATCH] swsusp: low level interface Introduce the low level interface that can be used for handling the snapshot of the system memory by the in-kernel swap-writing/reading code of swsusp and the userland interface code (to be introduced shortly). Also change the way in which swsusp records the allocated swap pages and, consequently, simplifies the in-kernel swap-writing/reading code (this is necessary for the userland interface too). To this end, it introduces two helper functions in mm/swapfile.c, so that the swsusp code does not refer directly to the swap internals. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek Signed-off-by: Adrian Bunk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swapfile.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 54 insertions(+), 1 deletion(-) (limited to 'mm/swapfile.c') diff --git a/mm/swapfile.c b/mm/swapfile.c index 365ed6ff182d..4d11f9d84666 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -45,7 +45,7 @@ static const char Unused_offset[] = "Unused swap offset entry "; struct swap_list_t swap_list = {-1, -1}; -struct swap_info_struct swap_info[MAX_SWAPFILES]; +static struct swap_info_struct swap_info[MAX_SWAPFILES]; static DEFINE_MUTEX(swapon_mutex); @@ -417,6 +417,59 @@ void free_swap_and_cache(swp_entry_t entry) } } +#ifdef CONFIG_SOFTWARE_SUSPEND +/* + * Find the swap type that corresponds to given device (if any) + * + * This is needed for software suspend and is done in such a way that inode + * aliasing is allowed. + */ +int swap_type_of(dev_t device) +{ + int i; + + if (!device) + return -EINVAL; + spin_lock(&swap_lock); + for (i = 0; i < nr_swapfiles; i++) { + struct inode *inode; + + if (!(swap_info[i].flags & SWP_WRITEOK)) + continue; + inode = swap_info->swap_file->f_dentry->d_inode; + if (S_ISBLK(inode->i_mode) && + device == MKDEV(imajor(inode), iminor(inode))) { + spin_unlock(&swap_lock); + return i; + } + } + spin_unlock(&swap_lock); + return -ENODEV; +} + +/* + * Return either the total number of swap pages of given type, or the number + * of free pages of that type (depending on @free) + * + * This is needed for software suspend + */ +unsigned int count_swap_pages(int type, int free) +{ + unsigned int n = 0; + + if (type < nr_swapfiles) { + spin_lock(&swap_lock); + if (swap_info[type].flags & SWP_WRITEOK) { + n = swap_info[type].pages; + if (free) + n -= swap_info[type].inuse_pages; + } + spin_unlock(&swap_lock); + } + return n; +} +#endif + /* * No need to decide whether this PTE shares the swap entry with others, * just let do_wp_page work it out if a write is requested later - to -- cgit v1.2.3 From 6e1819d615f24ce0726a7d0bd3dd0152d7b21654 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 23 Mar 2006 03:00:03 -0800 Subject: [PATCH] swsusp: userland interface MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch introduces a user space interface for swsusp. The interface is based on a special character device, called the snapshot device, that allows user space processes to perform suspend and resume-related operations with the help of some ioctls and the read()/write() functions.  Additionally it allows these processes to allocate free swap pages from a selected swap partition, called the resume partition, so that they know which sectors of the resume partition are available to them. The interface uses the same low-level system memory snapshot-handling functions that are used by the built-it swap-writing/reading code of swsusp. The interface documentation is included in the patch. The patch assumes that the major and minor numbers of the snapshot device will be 10 (ie. misc device) and 231, the registration of which has already been requested. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swapfile.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'mm/swapfile.c') diff --git a/mm/swapfile.c b/mm/swapfile.c index 4d11f9d84666..39aa9d129612 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -428,14 +428,16 @@ int swap_type_of(dev_t device) { int i; - if (!device) - return -EINVAL; spin_lock(&swap_lock); for (i = 0; i < nr_swapfiles; i++) { struct inode *inode; if (!(swap_info[i].flags & SWP_WRITEOK)) continue; + if (!device) { + spin_unlock(&swap_lock); + return i; + } inode = swap_info->swap_file->f_dentry->d_inode; if (S_ISBLK(inode->i_mode) && device == MKDEV(imajor(inode), iminor(inode))) { -- cgit v1.2.3