From 1f5ce9e93aa96a867f195ed45f6f77935175f12e Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 9 Jun 2006 09:34:16 -0400 Subject: VFS: Unexport do_kern_mount() and clean up simple_pin_fs() Replace all module uses with the new vfs_kern_mount() interface, and fix up simple_pin_fs(). Signed-off-by: Trond Myklebust --- mm/shmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index 4c5e68e4e9ae..8184342440f0 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2261,7 +2261,7 @@ static int __init init_tmpfs(void) #ifdef CONFIG_TMPFS devfs_mk_dir("shm"); #endif - shm_mnt = do_kern_mount(tmpfs_fs_type.name, MS_NOUSER, + shm_mnt = vfs_kern_mount(&tmpfs_fs_type, MS_NOUSER, tmpfs_fs_type.name, NULL); if (IS_ERR(shm_mnt)) { error = PTR_ERR(shm_mnt); -- cgit v1.2.2 From 454e2398be9b9fa30433fccc548db34d19aa9958 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 23 Jun 2006 02:02:57 -0700 Subject: [PATCH] VFS: Permit filesystem to override root dentry on mount Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells Acked-by: Al Viro Cc: Nathan Scott Cc: Roland Dreier Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/shmem.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index 1e43c8a865ba..7617bb1c6bf7 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2233,10 +2233,10 @@ static struct vm_operations_struct shmem_vm_ops = { }; -static struct super_block *shmem_get_sb(struct file_system_type *fs_type, - int flags, const char *dev_name, void *data) +static int shmem_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data, struct vfsmount *mnt) { - return get_sb_nodev(fs_type, flags, data, shmem_fill_super); + return get_sb_nodev(fs_type, flags, data, shmem_fill_super, mnt); } static struct file_system_type tmpfs_fs_type = { -- cgit v1.2.2 From 726c334223180e3c0197cc980a432681370d4baf Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 23 Jun 2006 02:02:58 -0700 Subject: [PATCH] VFS: Permit filesystem to perform statfs with a known root dentry Give the statfs superblock operation a dentry pointer rather than a superblock pointer. This complements the get_sb() patch. That reduced the significance of sb->s_root, allowing NFS to place a fake root there. However, NFS does require a dentry to use as a target for the statfs operation. This permits the root in the vfsmount to be used instead. linux/mount.h has been added where necessary to make allyesconfig build successfully. Interest has also been expressed for use with the FUSE and XFS filesystems. Signed-off-by: David Howells Acked-by: Al Viro Cc: Nathan Scott Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/shmem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index 7617bb1c6bf7..10020d8b4073 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1654,9 +1654,9 @@ static ssize_t shmem_file_sendfile(struct file *in_file, loff_t *ppos, return desc.error; } -static int shmem_statfs(struct super_block *sb, struct kstatfs *buf) +static int shmem_statfs(struct dentry *dentry, struct kstatfs *buf) { - struct shmem_sb_info *sbinfo = SHMEM_SB(sb); + struct shmem_sb_info *sbinfo = SHMEM_SB(dentry->d_sb); buf->f_type = TMPFS_MAGIC; buf->f_bsize = PAGE_CACHE_SIZE; -- cgit v1.2.2 From 3c5a87f476bed45616e7e543dcaea4440c77bf93 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Fri, 23 Jun 2006 02:03:08 -0700 Subject: [PATCH] migration: remove unnecessary PageSwapCache checks Remove two unnecessary PageSwapCache checks. The page refcount is raised and therefore page migration cannot occur in both functions. Signed-off-by: Christoph Lameter Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/shmem.c | 8 -------- 1 file changed, 8 deletions(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index 10020d8b4073..84b5cf9b63c5 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1081,14 +1081,6 @@ repeat: page_cache_release(swappage); goto repeat; } - if (!PageSwapCache(swappage)) { - /* Page migration has occured */ - shmem_swp_unmap(entry); - spin_unlock(&info->lock); - unlock_page(swappage); - page_cache_release(swappage); - goto repeat; - } if (PageWriteback(swappage)) { shmem_swp_unmap(entry); spin_unlock(&info->lock); -- cgit v1.2.2 From 95dc112a5770dc670a1b45a3d9ee346fdd2b2697 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 20 Jun 2005 21:15:16 -0700 Subject: [PATCH] devfs: Remove devfs_mk_dir() function from the kernel tree Removes the devfs_mk_dir() function and all callers of it. Signed-off-by: Greg Kroah-Hartman --- mm/shmem.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index 38bc3334f263..a4161abb9e76 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2252,9 +2252,7 @@ static int __init init_tmpfs(void) printk(KERN_ERR "Could not register tmpfs\n"); goto out2; } -#ifdef CONFIG_TMPFS - devfs_mk_dir("shm"); -#endif + shm_mnt = vfs_kern_mount(&tmpfs_fs_type, MS_NOUSER, tmpfs_fs_type.name, NULL); if (IS_ERR(shm_mnt)) { -- cgit v1.2.2 From ff23eca3e8f613034e0d20ff86f6a89b62f5a14e Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 20 Jun 2005 21:15:16 -0700 Subject: [PATCH] devfs: Remove the devfs_fs_kernel.h file from the tree Also fixes up all files that #include it. Signed-off-by: Greg Kroah-Hartman --- mm/shmem.c | 1 - 1 file changed, 1 deletion(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index a4161abb9e76..355904712a8f 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -26,7 +26,6 @@ #include #include #include -#include #include #include #include -- cgit v1.2.2 From f5e54d6e53a20cef45af7499e86164f0e0d16bb2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 28 Jun 2006 04:26:44 -0700 Subject: [PATCH] mark address_space_operations const Same as with already do with the file operations: keep them in .rodata and prevents people from doing runtime patching. Signed-off-by: Christoph Hellwig Cc: Steven French Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/shmem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index 38bc3334f263..ea64c07cbe72 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -174,7 +174,7 @@ static inline void shmem_unacct_blocks(unsigned long flags, long pages) } static struct super_operations shmem_ops; -static struct address_space_operations shmem_aops; +static const struct address_space_operations shmem_aops; static struct file_operations shmem_file_operations; static struct inode_operations shmem_inode_operations; static struct inode_operations shmem_dir_inode_operations; @@ -2162,7 +2162,7 @@ static void destroy_inodecache(void) printk(KERN_INFO "shmem_inode_cache: not all structures were freed\n"); } -static struct address_space_operations shmem_aops = { +static const struct address_space_operations shmem_aops = { .writepage = shmem_writepage, .set_page_dirty = __set_page_dirty_nobuffers, #ifdef CONFIG_TMPFS -- cgit v1.2.2 From 6ab3d5624e172c553004ecc862bfeac16d9d68b7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=B6rn=20Engel?= Date: Fri, 30 Jun 2006 19:25:36 +0200 Subject: Remove obsolete #include MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Jörn Engel Signed-off-by: Adrian Bunk --- mm/shmem.c | 1 - 1 file changed, 1 deletion(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index b14ff817d162..83c9fea1e0e3 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -23,7 +23,6 @@ * which makes it a completely usable filesystem. */ -#include #include #include #include -- cgit v1.2.2 From f8891e5e1f93a128c3900f82035e8541357896a7 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Fri, 30 Jun 2006 01:55:45 -0700 Subject: [PATCH] Light weight event counters The remaining counters in page_state after the zoned VM counter patches have been applied are all just for show in /proc/vmstat. They have no essential function for the VM. We use a simple increment of per cpu variables. In order to avoid the most severe races we disable preempt. Preempt does not prevent the race between an increment and an interrupt handler incrementing the same statistics counter. However, that race is exceedingly rare, we may only loose one increment or so and there is no requirement (at least not in kernel) that the vm event counters have to be accurate. In the non preempt case this results in a simple increment for each counter. For many architectures this will be reduced by the compiler to a single instruction. This single instruction is atomic for i386 and x86_64. And therefore even the rare race condition in an interrupt is avoided for both architectures in most cases. The patchset also adds an off switch for embedded systems that allows a building of linux kernels without these counters. The implementation of these counters is through inline code that hopefully results in only a single instruction increment instruction being emitted (i386, x86_64) or in the increment being hidden though instruction concurrency (EPIC architectures such as ia64 can get that done). Benefits: - VM event counter operations usually reduce to a single inline instruction on i386 and x86_64. - No interrupt disable, only preempt disable for the preempt case. Preempt disable can also be avoided by moving the counter into a spinlock. - Handling is similar to zoned VM counters. - Simple and easily extendable. - Can be omitted to reduce memory use for embedded use. References: RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=113512330605497&w=2 RFC http://marc.theaimsgroup.com/?l=linux-kernel&m=114988082814934&w=2 local_t http://marc.theaimsgroup.com/?l=linux-kernel&m=114991748606690&w=2 V2 http://marc.theaimsgroup.com/?t=115014808400007&r=1&w=2 V3 http://marc.theaimsgroup.com/?l=linux-kernel&m=115024767022346&w=2 V4 http://marc.theaimsgroup.com/?l=linux-kernel&m=115047968808926&w=2 Signed-off-by: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/shmem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index b14ff817d162..a9c09e0ba709 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1045,12 +1045,12 @@ repeat: swappage = lookup_swap_cache(swap); if (!swappage) { shmem_swp_unmap(entry); - spin_unlock(&info->lock); /* here we actually do the io */ if (type && *type == VM_FAULT_MINOR) { - inc_page_state(pgmajfault); + __count_vm_event(PGMAJFAULT); *type = VM_FAULT_MAJOR; } + spin_unlock(&info->lock); swappage = shmem_swapin(info, swap, idx); if (!swappage) { spin_lock(&info->lock); -- cgit v1.2.2