From 99663be772c827b8f5f594fe87eb4807be1994e5 Mon Sep 17 00:00:00 2001 From: Vasiliy Kulikov Date: Thu, 5 Apr 2012 14:25:04 -0700 Subject: proc: fix mount -t proc -o AAA The proc_parse_options() call from proc_mount() runs only once at boot time. So on any later mount attempt, any mount options are ignored because ->s_root is already initialized. As a consequence, "mount -o " will ignore the options. The only way to change mount options is "mount -o remount,". To fix this, parse the mount options unconditionally. Signed-off-by: Vasiliy Kulikov Reported-by: Arkadiusz Miskiewicz Tested-by: Arkadiusz Miskiewicz Cc: Alexey Dobriyan Cc: Al Viro Cc: Valdis Kletnieks Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/root.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/proc/root.c b/fs/proc/root.c index 46a15d8..eed44bf 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -115,12 +115,13 @@ static struct dentry *proc_mount(struct file_system_type *fs_type, if (IS_ERR(sb)) return ERR_CAST(sb); + if (!proc_parse_options(options, ns)) { + deactivate_locked_super(sb); + return ERR_PTR(-EINVAL); + } + if (!sb->s_root) { sb->s_flags = flags; - if (!proc_parse_options(options, ns)) { - deactivate_locked_super(sb); - return ERR_PTR(-EINVAL); - } err = proc_fill_super(sb); if (err) { deactivate_locked_super(sb); -- cgit v1.1 From 703bf2d122c95412a30f72658c53ad6292867b0b Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Thu, 5 Apr 2012 14:25:06 -0700 Subject: fs/xattr.c: suppress page allocation failure warnings from sys_listxattr() This size is user controllable, up to a maximum of XATTR_LIST_MAX (64k). So it's trivial for someone to trigger a stream of order:4 page allocation errors. Signed-off-by: Dave Jones Cc: Al Viro Cc: Dave Chinner Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/xattr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/xattr.c b/fs/xattr.c index d6dfd24..a14d842 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -496,7 +496,7 @@ listxattr(struct dentry *d, char __user *list, size_t size) if (size) { if (size > XATTR_LIST_MAX) size = XATTR_LIST_MAX; - klist = kmalloc(size, GFP_KERNEL); + klist = kmalloc(size, __GFP_NOWARN | GFP_KERNEL); if (!klist) return -ENOMEM; } -- cgit v1.1 From 0d08d7b7e13b5060181b11ecdde82d8fda322123 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Thu, 5 Apr 2012 14:25:07 -0700 Subject: fs/xattr.c:listxattr(): fall back to vmalloc() if kmalloc() failed This allocation can be as large as 64k. As David points out, "falling back to vmalloc here is much better solution than failing to retreive the attribute - it will work no matter how fragmented memory gets. That means we don't get incomplete backups occurring after days or months of uptime and successful backups". Cc: Dave Chinner Cc: Dave Jones Cc: David Rientjes Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/xattr.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/xattr.c b/fs/xattr.c index a14d842..d14afba 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -19,8 +19,9 @@ #include #include #include -#include +#include +#include /* * Check permissions for extended attribute access. This is a bit complicated @@ -492,13 +493,18 @@ listxattr(struct dentry *d, char __user *list, size_t size) { ssize_t error; char *klist = NULL; + char *vlist = NULL; /* If non-NULL, we used vmalloc() */ if (size) { if (size > XATTR_LIST_MAX) size = XATTR_LIST_MAX; klist = kmalloc(size, __GFP_NOWARN | GFP_KERNEL); - if (!klist) - return -ENOMEM; + if (!klist) { + vlist = vmalloc(size); + if (!vlist) + return -ENOMEM; + klist = vlist; + } } error = vfs_listxattr(d, klist, size); @@ -510,7 +516,10 @@ listxattr(struct dentry *d, char __user *list, size_t size) than XATTR_LIST_MAX bytes. Not possible. */ error = -E2BIG; } - kfree(klist); + if (vlist) + vfree(vlist); + else + kfree(klist); return error; } -- cgit v1.1 From 44c824982fd37a578da23cc90885e9690a6a3f0e Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Thu, 5 Apr 2012 14:25:07 -0700 Subject: fs/xattr.c:setxattr(): improve handling of allocation failures This allocation can be as large as 64k. - Add __GFP_NOWARN so the a falied kmalloc() is silent - Fall back to vmalloc() if the kmalloc() failed Cc: Dave Chinner Cc: Dave Jones Cc: David Rientjes Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/xattr.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/xattr.c b/fs/xattr.c index d14afba..3c8c1cc 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -321,6 +321,7 @@ setxattr(struct dentry *d, const char __user *name, const void __user *value, { int error; void *kvalue = NULL; + void *vvalue = NULL; /* If non-NULL, we used vmalloc() */ char kname[XATTR_NAME_MAX + 1]; if (flags & ~(XATTR_CREATE|XATTR_REPLACE)) @@ -335,13 +336,25 @@ setxattr(struct dentry *d, const char __user *name, const void __user *value, if (size) { if (size > XATTR_SIZE_MAX) return -E2BIG; - kvalue = memdup_user(value, size); - if (IS_ERR(kvalue)) - return PTR_ERR(kvalue); + kvalue = kmalloc(size, GFP_KERNEL | __GFP_NOWARN); + if (!kvalue) { + vvalue = vmalloc(size); + if (!vvalue) + return -ENOMEM; + kvalue = vvalue; + } + if (copy_from_user(kvalue, value, size)) { + error = -EFAULT; + goto out; + } } error = vfs_setxattr(d, kname, kvalue, size, flags); - kfree(kvalue); +out: + if (vvalue) + vfree(vvalue); + else + kfree(kvalue); return error; } -- cgit v1.1 From 7563ec4c211ba59c2331dc6b94a068250345c387 Mon Sep 17 00:00:00 2001 From: Hillf Danton Date: Thu, 5 Apr 2012 14:25:09 -0700 Subject: hugetlbfs: remove unregister_filesystem() when initializing module It was introduced by d1d5e05ffdc1 ("hugetlbfs: return error code when initializing module") but as Al pointed out, is a bad idea. Quoted comments from Al: "Note that unregister_filesystem() in module init is *always* wrong; it's not an issue here (it's done too early to care about and realistically the box is not going anywhere - it'll panic when attempt to exec /sbin/init fails, if not earlier), but it's a damn bad example. Consider a normal fs module. Somebody loads it and in parallel with that we get a mount attempt on that fs type. It comes between register and failure exits that causes unregister; at that point we are screwed since grabbing a reference to module as done by mount is enough to prevent exit, but not to prevent the failure of init. As the result, module will get freed when init fails, mounted fs of that type be damned." So remove it. Signed-off-by: Hillf Danton Cc: David Rientjes Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/hugetlbfs/inode.c | 1 - 1 file changed, 1 deletion(-) (limited to 'fs') diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index ea25174..28cf06e 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -1031,7 +1031,6 @@ static int __init init_hugetlbfs_fs(void) } error = PTR_ERR(vfsmount); - unregister_filesystem(&hugetlbfs_fs_type); out: kmem_cache_destroy(hugetlbfs_inode_cachep); -- cgit v1.1 From 20955e891d828b2027281fe3295dae6af8e0423b Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Thu, 5 Apr 2012 14:25:09 -0700 Subject: libfs: add simple_open() debugfs and a few other drivers use an open-coded version of simple_open() to pass a pointer from the file to the read/write file ops. Add support for this simple case to libfs so that we can remove the many duplicate copies of this simple function. Signed-off-by: Stephen Boyd Cc: Al Viro Cc: Julia Lawall Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/libfs.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'fs') diff --git a/fs/libfs.c b/fs/libfs.c index 4a0d1f0..358094f 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -264,6 +264,13 @@ Enomem: return ERR_PTR(-ENOMEM); } +int simple_open(struct inode *inode, struct file *file) +{ + if (inode->i_private) + file->private_data = inode->i_private; + return 0; +} + int simple_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) { struct inode *inode = old_dentry->d_inode; @@ -984,6 +991,7 @@ EXPORT_SYMBOL(simple_dir_operations); EXPORT_SYMBOL(simple_empty); EXPORT_SYMBOL(simple_fill_super); EXPORT_SYMBOL(simple_getattr); +EXPORT_SYMBOL(simple_open); EXPORT_SYMBOL(simple_link); EXPORT_SYMBOL(simple_lookup); EXPORT_SYMBOL(simple_pin_fs); -- cgit v1.1 From 234e340582901211f40d8c732afc49f0630ecf05 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Thu, 5 Apr 2012 14:25:11 -0700 Subject: simple_open: automatically convert to simple_open() Many users of debugfs copy the implementation of default_open() when they want to support a custom read/write function op. This leads to a proliferation of the default_open() implementation across the entire tree. Now that the common implementation has been consolidated into libfs we can replace all the users of this function with simple_open(). This replacement was done with the following semantic patch: @ open @ identifier open_f != simple_open; identifier i, f; @@ -int open_f(struct inode *i, struct file *f) -{ ( -if (i->i_private) -f->private_data = i->i_private; | -f->private_data = i->i_private; ) -return 0; -} @ has_open depends on open @ identifier fops; identifier open.open_f; @@ struct file_operations fops = { ... -.open = open_f, +.open = simple_open, ... }; [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Stephen Boyd Cc: Greg Kroah-Hartman Cc: Al Viro Cc: Julia Lawall Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/debugfs/file.c | 14 +++----------- fs/dlm/debug_fs.c | 9 +-------- fs/pstore/inode.c | 8 +------- 3 files changed, 5 insertions(+), 26 deletions(-) (limited to 'fs') diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 21e93605..5dfafdd 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -33,18 +33,10 @@ static ssize_t default_write_file(struct file *file, const char __user *buf, return count; } -static int default_open(struct inode *inode, struct file *file) -{ - if (inode->i_private) - file->private_data = inode->i_private; - - return 0; -} - const struct file_operations debugfs_file_operations = { .read = default_read_file, .write = default_write_file, - .open = default_open, + .open = simple_open, .llseek = noop_llseek, }; @@ -447,7 +439,7 @@ static ssize_t write_file_bool(struct file *file, const char __user *user_buf, static const struct file_operations fops_bool = { .read = read_file_bool, .write = write_file_bool, - .open = default_open, + .open = simple_open, .llseek = default_llseek, }; @@ -492,7 +484,7 @@ static ssize_t read_file_blob(struct file *file, char __user *user_buf, static const struct file_operations fops_blob = { .read = read_file_blob, - .open = default_open, + .open = simple_open, .llseek = default_llseek, }; diff --git a/fs/dlm/debug_fs.c b/fs/dlm/debug_fs.c index 3dca2b3..1c9b0809 100644 --- a/fs/dlm/debug_fs.c +++ b/fs/dlm/debug_fs.c @@ -609,13 +609,6 @@ static const struct file_operations format3_fops = { /* * dump lkb's on the ls_waiters list */ - -static int waiters_open(struct inode *inode, struct file *file) -{ - file->private_data = inode->i_private; - return 0; -} - static ssize_t waiters_read(struct file *file, char __user *userbuf, size_t count, loff_t *ppos) { @@ -644,7 +637,7 @@ static ssize_t waiters_read(struct file *file, char __user *userbuf, static const struct file_operations waiters_fops = { .owner = THIS_MODULE, - .open = waiters_open, + .open = simple_open, .read = waiters_read, .llseek = default_llseek, }; diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index f37c32b..8ae5a03 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -52,12 +52,6 @@ struct pstore_private { char data[]; }; -static int pstore_file_open(struct inode *inode, struct file *file) -{ - file->private_data = inode->i_private; - return 0; -} - static ssize_t pstore_file_read(struct file *file, char __user *userbuf, size_t count, loff_t *ppos) { @@ -67,7 +61,7 @@ static ssize_t pstore_file_read(struct file *file, char __user *userbuf, } static const struct file_operations pstore_file_operations = { - .open = pstore_file_open, + .open = simple_open, .read = pstore_file_read, .llseek = default_llseek, }; -- cgit v1.1