diff options
Diffstat (limited to 'fs')
53 files changed, 813 insertions, 604 deletions
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c index 9e60fd20171..a7528b91393 100644 --- a/fs/binfmt_misc.c +++ b/fs/binfmt_misc.c @@ -108,7 +108,7 @@ static int load_misc_binary(struct linux_binprm *bprm, struct pt_regs *regs) Node *fmt; struct file * interp_file = NULL; char iname[BINPRM_BUF_SIZE]; - char *iname_addr = iname; + const char *iname_addr = iname; int retval; int fd_binary = -1; diff --git a/fs/binfmt_script.c b/fs/binfmt_script.c index aca9d55afb2..396a9884591 100644 --- a/fs/binfmt_script.c +++ b/fs/binfmt_script.c @@ -16,7 +16,8 @@ static int load_script(struct linux_binprm *bprm,struct pt_regs *regs) { - char *cp, *i_name, *i_arg; + const char *i_arg, *i_name; + char *cp; struct file *file; char interp[BINPRM_BUF_SIZE]; int retval; diff --git a/fs/buffer.c b/fs/buffer.c index 50efa339e05..3e7dca279d1 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -770,11 +770,12 @@ static int fsync_buffers_list(spinlock_t *lock, struct list_head *list) spin_unlock(lock); /* * Ensure any pending I/O completes so that - * ll_rw_block() actually writes the current - * contents - it is a noop if I/O is still in - * flight on potentially older contents. + * write_dirty_buffer() actually writes the + * current contents - it is a noop if I/O is + * still in flight on potentially older + * contents. */ - ll_rw_block(SWRITE_SYNC_PLUG, 1, &bh); + write_dirty_buffer(bh, WRITE_SYNC_PLUG); /* * Kick off IO for the previous mapping. Note @@ -2912,13 +2913,6 @@ int submit_bh(int rw, struct buffer_head * bh) BUG_ON(buffer_unwritten(bh)); /* - * Mask in barrier bit for a write (could be either a WRITE or a - * WRITE_SYNC - */ - if (buffer_ordered(bh) && (rw & WRITE)) - rw |= WRITE_BARRIER; - - /* * Only clear out a write error when rewriting */ if (test_set_buffer_req(bh) && (rw & WRITE)) @@ -2956,22 +2950,21 @@ EXPORT_SYMBOL(submit_bh); /** * ll_rw_block: low-level access to block devices (DEPRECATED) - * @rw: whether to %READ or %WRITE or %SWRITE or maybe %READA (readahead) + * @rw: whether to %READ or %WRITE or maybe %READA (readahead) * @nr: number of &struct buffer_heads in the array * @bhs: array of pointers to &struct buffer_head * * ll_rw_block() takes an array of pointers to &struct buffer_heads, and * requests an I/O operation on them, either a %READ or a %WRITE. The third - * %SWRITE is like %WRITE only we make sure that the *current* data in buffers - * are sent to disk. The fourth %READA option is described in the documentation - * for generic_make_request() which ll_rw_block() calls. + * %READA option is described in the documentation for generic_make_request() + * which ll_rw_block() calls. * * This function drops any buffer that it cannot get a lock on (with the - * BH_Lock state bit) unless SWRITE is required, any buffer that appears to be - * clean when doing a write request, and any buffer that appears to be - * up-to-date when doing read request. Further it marks as clean buffers that - * are processed for writing (the buffer cache won't assume that they are - * actually clean until the buffer gets unlocked). + * BH_Lock state bit), any buffer that appears to be clean when doing a write + * request, and any buffer that appears to be up-to-date when doing read + * request. Further it marks as clean buffers that are processed for + * writing (the buffer cache won't assume that they are actually clean + * until the buffer gets unlocked). * * ll_rw_block sets b_end_io to simple completion handler that marks * the buffer up-to-date (if approriate), unlocks the buffer and wakes @@ -2987,20 +2980,13 @@ void ll_rw_block(int rw, int nr, struct buffer_head *bhs[]) for (i = 0; i < nr; i++) { struct buffer_head *bh = bhs[i]; - if (rw == SWRITE || rw == SWRITE_SYNC || rw == SWRITE_SYNC_PLUG) - lock_buffer(bh); - else if (!trylock_buffer(bh)) + if (!trylock_buffer(bh)) continue; - - if (rw == WRITE || rw == SWRITE || rw == SWRITE_SYNC || - rw == SWRITE_SYNC_PLUG) { + if (rw == WRITE) { if (test_clear_buffer_dirty(bh)) { bh->b_end_io = end_buffer_write_sync; get_bh(bh); - if (rw == SWRITE_SYNC) - submit_bh(WRITE_SYNC, bh); - else - submit_bh(WRITE, bh); + submit_bh(WRITE, bh); continue; } } else { @@ -3016,12 +3002,25 @@ void ll_rw_block(int rw, int nr, struct buffer_head *bhs[]) } EXPORT_SYMBOL(ll_rw_block); +void write_dirty_buffer(struct buffer_head *bh, int rw) +{ + lock_buffer(bh); + if (!test_clear_buffer_dirty(bh)) { + unlock_buffer(bh); + return; + } + bh->b_end_io = end_buffer_write_sync; + get_bh(bh); + submit_bh(rw, bh); +} +EXPORT_SYMBOL(write_dirty_buffer); + /* * For a data-integrity writeout, we need to wait upon any in-progress I/O * and then start new I/O and then wait upon it. The caller must have a ref on * the buffer_head. */ -int sync_dirty_buffer(struct buffer_head *bh) +int __sync_dirty_buffer(struct buffer_head *bh, int rw) { int ret = 0; @@ -3030,7 +3029,7 @@ int sync_dirty_buffer(struct buffer_head *bh) if (test_clear_buffer_dirty(bh)) { get_bh(bh); bh->b_end_io = end_buffer_write_sync; - ret = submit_bh(WRITE_SYNC, bh); + ret = submit_bh(rw, bh); wait_on_buffer(bh); if (buffer_eopnotsupp(bh)) { clear_buffer_eopnotsupp(bh); @@ -3043,6 +3042,12 @@ int sync_dirty_buffer(struct buffer_head *bh) } return ret; } +EXPORT_SYMBOL(__sync_dirty_buffer); + +int sync_dirty_buffer(struct buffer_head *bh) +{ + return __sync_dirty_buffer(bh, WRITE_SYNC); +} EXPORT_SYMBOL(sync_dirty_buffer); /* diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c index a53b130b366..1e7a33028d3 100644 --- a/fs/cramfs/inode.c +++ b/fs/cramfs/inode.c @@ -80,7 +80,7 @@ static struct inode *get_cramfs_inode(struct super_block *sb, } } else { inode = iget_locked(sb, CRAMINO(cramfs_inode)); - if (inode) { + if (inode && (inode->i_state & I_NEW)) { setup_inode(inode, cramfs_inode); unlock_new_inode(inode); } diff --git a/fs/dcache.c b/fs/dcache.c index 4d13bf50b7b..83293be4814 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1332,31 +1332,13 @@ EXPORT_SYMBOL(d_add_ci); * d_lookup - search for a dentry * @parent: parent dentry * @name: qstr of name we wish to find + * Returns: dentry, or NULL * - * Searches the children of the parent dentry for the name in question. If - * the dentry is found its reference count is incremented and the dentry - * is returned. The caller must use dput to free the entry when it has - * finished using it. %NULL is returned on failure. - * - * __d_lookup is dcache_lock free. The hash list is protected using RCU. - * Memory barriers are used while updating and doing lockless traversal. - * To avoid races with d_move while rename is happening, d_lock is used. - * - * Overflows in memcmp(), while d_move, are avoided by keeping the length - * and name pointer in one structure pointed by d_qstr. - * - * rcu_read_lock() and rcu_read_unlock() are used to disable preemption while - * lookup is going on. - * - * The dentry unused LRU is not updated even if lookup finds the required dentry - * in there. It is updated in places such as prune_dcache, shrink_dcache_sb, - * select_parent and __dget_locked. This laziness saves lookup from dcache_lock - * acquisition. - * - * d_lookup() is protected against the concurrent renames in some unrelated - * directory using the seqlockt_t rename_lock. + * d_lookup searches the children of the parent dentry for the name in + * question. If the dentry is found its reference count is incremented and the + * dentry is returned. The caller must use dput to free the entry when it has + * finished using it. %NULL is returned if the dentry does not exist. */ - struct dentry * d_lookup(struct dentry * parent, struct qstr * name) { struct dentry * dentry = NULL; @@ -1372,6 +1354,21 @@ struct dentry * d_lookup(struct dentry * parent, struct qstr * name) } EXPORT_SYMBOL(d_lookup); +/* + * __d_lookup - search for a dentry (racy) + * @parent: parent dentry + * @name: qstr of name we wish to find + * Returns: dentry, or NULL + * + * __d_lookup is like d_lookup, however it may (rarely) return a + * false-negative result due to unrelated rename activity. + * + * __d_lookup is slightly faster by avoiding rename_lock read seqlock, + * however it must be used carefully, eg. with a following d_lookup in + * the case of failure. + * + * __d_lookup callers must be commented. + */ struct dentry * __d_lookup(struct dentry * parent, struct qstr * name) { unsigned int len = name->len; @@ -1382,6 +1379,19 @@ struct dentry * __d_lookup(struct dentry * parent, struct qstr * name) struct hlist_node *node; struct dentry *dentry; + /* + * The hash list is protected using RCU. + * + * Take d_lock when comparing a candidate dentry, to avoid races + * with d_move(). + * + * It is possible that concurrent renames can mess up our list + * walk here and result in missing our dentry, resulting in the + * false-negative result. d_lookup() protects against concurrent + * renames using rename_lock seqlock. + * + * See Documentation/vfs/dcache-locking.txt for more details. + */ rcu_read_lock(); hlist_for_each_entry_rcu(dentry, node, head, d_hash) { @@ -1396,8 +1406,8 @@ struct dentry * __d_lookup(struct dentry * parent, struct qstr * name) /* * Recheck the dentry after taking the lock - d_move may have - * changed things. Don't bother checking the hash because we're - * about to compare the whole name anyway. + * changed things. Don't bother checking the hash because + * we're about to compare the whole name anyway. */ if (dentry->d_parent != parent) goto next; @@ -1925,7 +1935,7 @@ static int prepend_path(const struct path *path, struct path *root, bool slash = false; int error = 0; - spin_lock(&vfsmount_lock); + br_read_lock(vfsmount_lock); while (dentry != root->dentry || vfsmnt != root->mnt) { struct dentry * parent; @@ -1954,7 +1964,7 @@ out: if (!error && !slash) error = prepend(buffer, buflen, "/", 1); - spin_unlock(&vfsmount_lock); + br_read_unlock(vfsmount_lock); return error; global_root: @@ -2292,11 +2302,12 @@ int path_is_under(struct path *path1, struct path *path2) struct vfsmount *mnt = path1->mnt; struct dentry *dentry = path1->dentry; int res; - spin_lock(&vfsmount_lock); + + br_read_lock(vfsmount_lock); if (mnt != path2->mnt) { for (;;) { if (mnt->mnt_parent == mnt) { - spin_unlock(&vfsmount_lock); + br_read_unlock(vfsmount_lock); return 0; } if (mnt->mnt_parent == path2->mnt) @@ -2306,7 +2317,7 @@ int path_is_under(struct path *path1, struct path *path2) dentry = mnt->mnt_mountpoint; } res = is_subdir(dentry, path2->dentry); - spin_unlock(&vfsmount_lock); + br_read_unlock(vfsmount_lock); return res; } EXPORT_SYMBOL(path_is_under); diff --git a/fs/exec.c b/fs/exec.c index 7761837e450..2d945528274 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -361,13 +361,13 @@ err: /* * count() counts the number of strings in array ARGV. */ -static int count(char __user * __user * argv, int max) +static int count(const char __user * const __user * argv, int max) { int i = 0; if (argv != NULL) { for (;;) { - char __user * p; + const char __user * p; if (get_user(p, argv)) return -EFAULT; @@ -387,7 +387,7 @@ static int count(char __user * __user * argv, int max) * processes's memory to the new process's stack. The call to get_user_pages() * ensures the destination page is created and not swapped out. */ -static int copy_strings(int argc, char __user * __user * argv, +static int copy_strings(int argc, const char __user *const __user *argv, struct linux_binprm *bprm) { struct page *kmapped_page = NULL; @@ -396,7 +396,7 @@ static int copy_strings(int argc, char __user * __user * argv, int ret; while (argc-- > 0) { - char __user *str; + const char __user *str; int len; unsigned long pos; @@ -470,12 +470,13 @@ out: /* * Like copy_strings, but get argv and its values from kernel memory. */ -int copy_strings_kernel(int argc,char ** argv, struct linux_binprm *bprm) +int copy_strings_kernel(int argc, const char *const *argv, + struct linux_binprm *bprm) { int r; mm_segment_t oldfs = get_fs(); set_fs(KERNEL_DS); - r = copy_strings(argc, (char __user * __user *)argv, bprm); + r = copy_strings(argc, (const char __user *const __user *)argv, bprm); set_fs(oldfs); return r; } @@ -997,7 +998,7 @@ EXPORT_SYMBOL(flush_old_exec); void setup_new_exec(struct linux_binprm * bprm) { int i, ch; - char * name; + const char *name; char tcomm[sizeof(current->comm)]; arch_pick_mmap_layout(current->mm); @@ -1117,7 +1118,7 @@ int check_unsafe_exec(struct linux_binprm *bprm) bprm->unsafe = tracehook_unsafe_exec(p); n_fs = 1; - write_lock(&p->fs->lock); + spin_lock(&p->fs->lock); rcu_read_lock(); for (t = next_thread(p); t != p; t = next_thread(t)) { if (t->fs == p->fs) @@ -1134,7 +1135,7 @@ int check_unsafe_exec(struct linux_binprm *bprm) res = 1; } } - write_unlock(&p->fs->lock); + spin_unlock(&p->fs->lock); return res; } @@ -1316,9 +1317,9 @@ EXPORT_SYMBOL(search_binary_handler); /* * sys_execve() executes a new program. */ -int do_execve(char * filename, - char __user *__user *argv, - char __user *__user *envp, +int do_execve(const char * filename, + const char __user *const __user *argv, + const char __user *const __user *envp, struct pt_regs * regs) { struct linux_binprm *bprm; diff --git a/fs/fat/misc.c b/fs/fat/misc.c index 1fa23f6ffba..1736f235638 100644 --- a/fs/fat/misc.c +++ b/fs/fat/misc.c @@ -250,7 +250,9 @@ int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs) { int i, err = 0; - ll_rw_block(SWRITE, nr_bhs, bhs); + for (i = 0; i < nr_bhs; i++) + write_dirty_buffer(bhs[i], WRITE); + for (i = 0; i < nr_bhs; i++) { wait_on_buffer(bhs[i]); if (buffer_eopnotsupp(bhs[i])) { diff --git a/fs/file_table.c b/fs/file_table.c index edecd36fed9..a04bdd81c11 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -20,7 +20,9 @@ #include <linux/cdev.h> #include <linux/fsnotify.h> #include <linux/sysctl.h> +#include <linux/lglock.h> #include <linux/percpu_counter.h> +#include <linux/percpu.h> #include <linux/ima.h> #include <asm/atomic.h> @@ -32,8 +34,8 @@ struct files_stat_struct files_stat = { .max_files = NR_FILE }; -/* public. Not pretty! */ -__cacheline_aligned_in_smp DEFINE_SPINLOCK(files_lock); +DECLARE_LGLOCK(files_lglock); +DEFINE_LGLOCK(files_lglock); /* SLAB cache for file structures */ static struct kmem_cache *filp_cachep __read_mostly; @@ -249,7 +251,7 @@ static void __fput(struct file *file) cdev_put(inode->i_cdev); fops_put(file->f_op); put_pid(file->f_owner.pid); - file_kill(file); + file_sb_list_del(file); if (file->f_mode & FMODE_WRITE) drop_file_write_access(file); file->f_path.dentry = NULL; @@ -328,41 +330,107 @@ struct file *fget_light(unsigned int fd, int *fput_needed) return file; } - void put_filp(struct file *file) { if (atomic_long_dec_and_test(&file->f_count)) { security_file_free(file); - file_kill(file); + file_sb_list_del(file); file_free(file); } } -void file_move(struct file *file, struct list_head *list) +static inline int file_list_cpu(struct file *file) { - if (!list) - return; - file_list_lock(); - list_move(&file->f_u.fu_list, list); - file_list_unlock(); +#ifdef CONFIG_SMP + return file->f_sb_list_cpu; +#else + return smp_processor_id(); +#endif +} + +/* helper for file_sb_list_add to reduce ifdefs */ +static inline void __file_sb_list_add(struct file *file, struct super_block *sb) +{ + struct list_head *list; +#ifdef CONFIG_SMP + int cpu; + cpu = smp_processor_id(); + file->f_sb_list_cpu = cpu; + list = per_cpu_ptr(sb->s_files, cpu); +#else + list = &sb->s_files; +#endif + list_add(&file->f_u.fu_list, list); } -void file_kill(struct file *file) +/** + * file_sb_list_add - add a file to the sb's file list + * @file: file to add + * @sb: sb to add it to + * + * Use this function to associate a file with the superblock of the inode it + * refers to. + */ +void file_sb_list_add(struct file *file, struct super_block *sb) +{ + lg_local_lock(files_lglock); + __file_sb_list_add(file, sb); + lg_local_unlock(files_lglock); +} + +/** + * file_sb_list_del - remove a file from the sb's file list + * @file: file to remove + * @sb: sb to remove it from + * + * Use this function to remove a file from its superblock. + */ +void file_sb_list_del(struct file *file) { if (!list_empty(&file->f_u.fu_list)) { - file_list_lock(); + lg_local_lock_cpu(files_lglock, file_list_cpu(file)); list_del_init(&file->f_u.fu_list); - file_list_unlock(); + lg_local_unlock_cpu(files_lglock, file_list_cpu(file)); } } +#ifdef CONFIG_SMP + +/* + * These macros iterate all files on all CPUs for a given superblock. + * files_lglock must be held globally. + */ +#define do_file_list_for_each_entry(__sb, __file) \ +{ \ + int i; \ + for_each_possible_cpu(i) { \ + struct list_head *list; \ + list = per_cpu_ptr((__sb)->s_files, i); \ + list_for_each_entry((__file), list, f_u.fu_list) + +#define while_file_list_for_each_entry \ + } \ +} + +#else + +#define do_file_list_for_each_entry(__sb, __file) \ +{ \ + struct list_head *list; \ + list = &(sb)->s_files; \ + list_for_each_entry((__file), list, f_u.fu_list) + +#define while_file_list_for_each_entry \ +} + +#endif + int fs_may_remount_ro(struct super_block *sb) { struct file *file; - /* Check that no files are currently opened for writing. */ - file_list_lock(); - list_for_each_entry(file, &sb->s_files, f_u.fu_list) { + lg_global_lock(files_lglock); + do_file_list_for_each_entry(sb, file) { struct inode *inode = file->f_path.dentry->d_inode; /* File with pending delete? */ @@ -372,11 +440,11 @@ int fs_may_remount_ro(struct super_block *sb) /* Writeable file? */ if (S_ISREG(inode->i_mode) && (file->f_mode & FMODE_WRITE)) goto too_bad; - } - file_list_unlock(); + } while_file_list_for_each_entry; + lg_global_unlock(files_lglock); return 1; /* Tis' cool bro. */ too_bad: - file_list_unlock(); + lg_global_unlock(files_lglock); return 0; } @@ -392,8 +460,8 @@ void mark_files_ro(struct super_block *sb) struct file *f; retry: - file_list_lock(); - list_for_each_entry(f, &sb->s_files, f_u.fu_list) { + lg_global_lock(files_lglock); + do_file_list_for_each_entry(sb, f) { struct vfsmount *mnt; if (!S_ISREG(f->f_path.dentry->d_inode->i_mode)) continue; @@ -408,16 +476,13 @@ retry: continue; file_release_write(f); mnt = mntget(f->f_path.mnt); - file_list_unlock(); - /* - * This can sleep, so we can't hold - * the file_list_lock() spinlock. - */ + /* This can sleep, so we can't hold the spinlock. */ + lg_global_unlock(files_lglock); mnt_drop_write(mnt); mntput(mnt); goto retry; - } - file_list_unlock(); + } while_file_list_for_each_entry; + lg_global_unlock(files_lglock); } void __init files_init(unsigned long mempages) @@ -437,5 +502,6 @@ void __init files_init(unsigned long mempages) if (files_stat.max_files < NR_FILE) files_stat.max_files = NR_FILE; files_defer_init(); + lg_lock_init(files_lglock); percpu_counter_init(&nr_files, 0); } diff --git a/fs/fs_struct.c b/fs/fs_struct.c index 1ee40eb9a2c..ed45a9cf5f3 100644 --- a/fs/fs_struct.c +++ b/fs/fs_struct.c @@ -13,11 +13,11 @@ void set_fs_root(struct fs_struct *fs, struct path *path) { struct path old_root; - write_lock(&fs->lock); + spin_lock(&fs->lock); old_root = fs->root; fs->root = *path; path_get(path); - write_unlock(&fs->lock); + spin_unlock(&fs->lock); if (old_root.dentry) path_put(&old_root); } @@ -30,11 +30,11 @@ void set_fs_pwd(struct fs_struct *fs, struct path *path) { struct path old_pwd; - write_lock(&fs->lock); + spin_lock(&fs->lock); old_pwd = fs->pwd; fs->pwd = *path; path_get(path); - write_unlock(&fs->lock); + spin_unlock(&fs->lock); if (old_pwd.dentry) path_put(&old_pwd); @@ -51,7 +51, |