diff options
Diffstat (limited to 'fs/dcache.c')
-rw-r--r-- | fs/dcache.c | 117 |
1 files changed, 45 insertions, 72 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 89509b5..3c6d311 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -38,6 +38,7 @@ #include <linux/prefetch.h> #include <linux/ratelimit.h> #include "internal.h" +#include "mount.h" /* * Usage: @@ -275,15 +276,15 @@ static void dentry_lru_prune(struct dentry *dentry) } } -static void dentry_lru_move_tail(struct dentry *dentry) +static void dentry_lru_move_list(struct dentry *dentry, struct list_head *list) { spin_lock(&dcache_lru_lock); if (list_empty(&dentry->d_lru)) { - list_add_tail(&dentry->d_lru, &dentry->d_sb->s_dentry_lru); + list_add_tail(&dentry->d_lru, list); dentry->d_sb->s_nr_dentry_unused++; dentry_stat.nr_unused++; } else { - list_move_tail(&dentry->d_lru, &dentry->d_sb->s_dentry_lru); + list_move_tail(&dentry->d_lru, list); } spin_unlock(&dcache_lru_lock); } @@ -769,14 +770,18 @@ static void shrink_dentry_list(struct list_head *list) } /** - * __shrink_dcache_sb - shrink the dentry LRU on a given superblock - * @sb: superblock to shrink dentry LRU. - * @count: number of entries to prune - * @flags: flags to control the dentry processing + * prune_dcache_sb - shrink the dcache + * @sb: superblock + * @count: number of entries to try to free * - * If flags contains DCACHE_REFERENCED reference dentries will not be pruned. + * Attempt to shrink the superblock dcache LRU by @count entries. This is + * done when we need more memory an called from the superblock shrinker + * function. + * + * This function may fail to free any resources if all the dentries are in + * use. */ -static void __shrink_dcache_sb(struct super_block *sb, int count, int flags) +void prune_dcache_sb(struct super_block *sb, int count) { struct dentry *dentry; LIST_HEAD(referenced); @@ -795,13 +800,7 @@ relock: goto relock; } - /* - * If we are honouring the DCACHE_REFERENCED flag and the - * dentry has this flag set, don't free it. Clear the flag - * and put it back on the LRU. - */ - if (flags & DCACHE_REFERENCED && - dentry->d_flags & DCACHE_REFERENCED) { + if (dentry->d_flags & DCACHE_REFERENCED) { dentry->d_flags &= ~DCACHE_REFERENCED; list_move(&dentry->d_lru, &referenced); spin_unlock(&dentry->d_lock); @@ -821,23 +820,6 @@ relock: } /** - * prune_dcache_sb - shrink the dcache - * @sb: superblock - * @nr_to_scan: number of entries to try to free - * - * Attempt to shrink the superblock dcache LRU by @nr_to_scan entries. This is - * done when we need more memory an called from the superblock shrinker - * function. - * - * This function may fail to free any resources if all the dentries are in - * use. - */ -void prune_dcache_sb(struct super_block *sb, int nr_to_scan) -{ - __shrink_dcache_sb(sb, nr_to_scan, DCACHE_REFERENCED); -} - -/** * shrink_dcache_sb - shrink dcache for a superblock * @sb: superblock * @@ -1091,7 +1073,7 @@ EXPORT_SYMBOL(have_submounts); * drop the lock and return early due to latency * constraints. */ -static int select_parent(struct dentry * parent) +static int select_parent(struct dentry *parent, struct list_head *dispose) { struct dentry *this_parent; struct list_head *next; @@ -1113,12 +1095,11 @@ resume: spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); - /* - * move only zero ref count dentries to the end - * of the unused list for prune_dcache + /* + * move only zero ref count dentries to the dispose list. */ if (!dentry->d_count) { - dentry_lru_move_tail(dentry); + dentry_lru_move_list(dentry, dispose); found++; } else { dentry_lru_del(dentry); @@ -1180,14 +1161,13 @@ rename_retry: * * Prune the dcache to remove unused children of the parent dentry. */ - void shrink_dcache_parent(struct dentry * parent) { - struct super_block *sb = parent->d_sb; + LIST_HEAD(dispose); int found; - while ((found = select_parent(parent)) != 0) - __shrink_dcache_sb(sb, found, 0); + while ((found = select_parent(parent, &dispose)) != 0) + shrink_dentry_list(&dispose); } EXPORT_SYMBOL(shrink_dcache_parent); @@ -1460,6 +1440,23 @@ struct dentry * d_alloc_root(struct inode * root_inode) } EXPORT_SYMBOL(d_alloc_root); +struct dentry *d_make_root(struct inode *root_inode) +{ + struct dentry *res = NULL; + + if (root_inode) { + static const struct qstr name = { .name = "/", .len = 1 }; + + res = __d_alloc(root_inode->i_sb, &name); + if (res) + d_instantiate(res, root_inode); + else + iput(root_inode); + } + return res; +} +EXPORT_SYMBOL(d_make_root); + static struct dentry * __d_find_any_alias(struct inode *inode) { struct dentry *alias; @@ -2451,6 +2448,7 @@ static int prepend_path(const struct path *path, { struct dentry *dentry = path->dentry; struct vfsmount *vfsmnt = path->mnt; + struct mount *mnt = real_mount(vfsmnt); bool slash = false; int error = 0; @@ -2460,11 +2458,11 @@ static int prepend_path(const struct path *path, if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) { /* Global root? */ - if (vfsmnt->mnt_parent == vfsmnt) { + if (!mnt_has_parent(mnt)) goto global_root; - } - dentry = vfsmnt->mnt_mountpoint; - vfsmnt = vfsmnt->mnt_parent; + dentry = mnt->mnt_mountpoint; + mnt = mnt->mnt_parent; + vfsmnt = &mnt->mnt; continue; } parent = dentry->d_parent; @@ -2501,7 +2499,7 @@ global_root: if (!slash) error = prepend(buffer, buflen, "/", 1); if (!error) - error = vfsmnt->mnt_ns ? 1 : 2; + error = real_mount(vfsmnt)->mnt_ns ? 1 : 2; goto out; } @@ -2853,31 +2851,6 @@ int is_subdir(struct dentry *new_dentry, struct dentry *old_dentry) return result; } -int path_is_under(struct path *path1, struct path *path2) -{ - struct vfsmount *mnt = path1->mnt; - struct dentry *dentry = path1->dentry; - int res; - - br_read_lock(vfsmount_lock); - if (mnt != path2->mnt) { - for (;;) { - if (mnt->mnt_parent == mnt) { - br_read_unlock(vfsmount_lock); - return 0; - } - if (mnt->mnt_parent == path2->mnt) - break; - mnt = mnt->mnt_parent; - } - dentry = mnt->mnt_mountpoint; - } - res = is_subdir(dentry, path2->dentry); - br_read_unlock(vfsmount_lock); - return res; -} -EXPORT_SYMBOL(path_is_under); - void d_genocide(struct dentry *root) { struct dentry *this_parent; |