#define SHMEM_PAGEIN VM_READ
#define SHMEM_TRUNCATE VM_WRITE
-/* Definition to limit shmem_truncate's steps between cond_rescheds */
-#define LATENCY_LIMIT 64
-
/* Pretend that each entry is of this size in directory's i_size */
#define BOGO_DIRENT_SIZE 20
static LIST_HEAD(shmem_swaplist);
static spinlock_t shmem_swaplist_lock = SPIN_LOCK_UNLOCKED;
-static void shmem_free_blocks(struct inode *inode, long pages)
+static void shmem_free_block(struct inode *inode)
{
struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
if (sbinfo) {
spin_lock(&sbinfo->stat_lock);
- sbinfo->free_blocks += pages;
- inode->i_blocks -= pages*BLOCKS_PER_PAGE;
+ sbinfo->free_blocks++;
+ inode->i_blocks -= BLOCKS_PER_PAGE;
spin_unlock(&sbinfo->stat_lock);
}
}
freed = info->alloced - info->swapped - inode->i_mapping->nrpages;
if (freed > 0) {
+ struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
info->alloced -= freed;
shmem_unacct_blocks(info->flags, freed);
- shmem_free_blocks(inode, freed);
+ if (sbinfo) {
+ spin_lock(&sbinfo->stat_lock);
+ sbinfo->free_blocks += freed;
+ inode->i_blocks -= freed*BLOCKS_PER_PAGE;
+ spin_unlock(&sbinfo->stat_lock);
+ }
}
}
spin_lock(&info->lock);
if (!page) {
- shmem_free_blocks(inode, 1);
+ shmem_free_block(inode);
return ERR_PTR(-ENOMEM);
}
if (sgp != SGP_WRITE &&
}
if (page) {
/* another task gave its page, or truncated the file */
- shmem_free_blocks(inode, 1);
+ shmem_free_block(inode);
shmem_dir_free(page);
}
if (info->next_index <= index && !IS_ERR(entry))
return freed;
}
-static int shmem_map_and_free_swp(struct page *subdir,
- int offset, int limit, struct page ***dir)
-{
- swp_entry_t *ptr;
- int freed = 0;
-
- ptr = shmem_swp_map(subdir);
- for (; offset < limit; offset += LATENCY_LIMIT) {
- int size = limit - offset;
- if (size > LATENCY_LIMIT)
- size = LATENCY_LIMIT;
- freed += shmem_free_swp(ptr+offset, ptr+offset+size);
- if (need_resched()) {
- shmem_swp_unmap(ptr);
- if (*dir) {
- shmem_dir_unmap(*dir);
- *dir = NULL;
- }
- cond_resched();
- ptr = shmem_swp_map(subdir);
- }
- }
- shmem_swp_unmap(ptr);
- return freed;
-}
-
-static void shmem_free_pages(struct list_head *next)
-{
- struct page *page;
- int freed = 0;
-
- do {
- page = container_of(next, struct page, lru);
- next = next->next;
- shmem_dir_free(page);
- freed++;
- if (freed >= LATENCY_LIMIT) {
- cond_resched();
- freed = 0;
- }
- } while (next);
-}
-
static void shmem_truncate(struct inode *inode)
{
struct shmem_inode_info *info = SHMEM_I(inode);
unsigned long size;
unsigned long limit;
unsigned long stage;
- unsigned long diroff;
struct page **dir;
- struct page *topdir;
- struct page *middir;
struct page *subdir;
+ struct page *empty;
swp_entry_t *ptr;
- LIST_HEAD(pages_to_free);
- long nr_pages_to_free = 0;
- long nr_swaps_freed = 0;
int offset;
int freed;
info->flags |= SHMEM_TRUNCATE;
limit = info->next_index;
info->next_index = idx;
- topdir = info->i_indirect;
- if (topdir && idx <= SHMEM_NR_DIRECT) {
- info->i_indirect = NULL;
- nr_pages_to_free++;
- list_add(&topdir->lru, &pages_to_free);
- }
- spin_unlock(&info->lock);
-
if (info->swapped && idx < SHMEM_NR_DIRECT) {
ptr = info->i_direct;
size = limit;
if (size > SHMEM_NR_DIRECT)
size = SHMEM_NR_DIRECT;
- nr_swaps_freed = shmem_free_swp(ptr+idx, ptr+size);
+ info->swapped -= shmem_free_swp(ptr+idx, ptr+size);
}
- if (!topdir)
+ if (!info->i_indirect)
goto done2;
BUG_ON(limit <= SHMEM_NR_DIRECT);
offset = idx % ENTRIES_PER_PAGE;
idx -= offset;
- dir = shmem_dir_map(topdir);
+ empty = NULL;
+ dir = shmem_dir_map(info->i_indirect);
stage = ENTRIES_PER_PAGEPAGE/2;
- if (idx < ENTRIES_PER_PAGEPAGE/2) {
- middir = topdir;
- diroff = idx/ENTRIES_PER_PAGE;
- } else {
+ if (idx < ENTRIES_PER_PAGEPAGE/2)
+ dir += idx/ENTRIES_PER_PAGE;
+ else {
dir += ENTRIES_PER_PAGE/2;
dir += (idx - ENTRIES_PER_PAGEPAGE/2)/ENTRIES_PER_PAGEPAGE;
while (stage <= idx)
stage += ENTRIES_PER_PAGEPAGE;
- middir = *dir;
if (*dir) {
- diroff = ((idx - ENTRIES_PER_PAGEPAGE/2) %
+ subdir = *dir;
+ size = ((idx - ENTRIES_PER_PAGEPAGE/2) %
ENTRIES_PER_PAGEPAGE) / ENTRIES_PER_PAGE;
- if (!diroff && !offset) {
+ if (!size && !offset) {
+ empty = subdir;
*dir = NULL;
- nr_pages_to_free++;
- list_add(&middir->lru, &pages_to_free);
}
shmem_dir_unmap(dir);
- dir = shmem_dir_map(middir);
+ dir = shmem_dir_map(subdir) + size;
} else {
- diroff = 0;
offset = 0;
idx = stage;
}
}
- for (; idx < limit; idx += ENTRIES_PER_PAGE, diroff++) {
+ for (; idx < limit; idx += ENTRIES_PER_PAGE, dir++) {
if (unlikely(idx == stage)) {
- shmem_dir_unmap(dir);
- dir = shmem_dir_map(topdir) +
+ shmem_dir_unmap(dir-1);
+ dir = shmem_dir_map(info->i_indirect) +
ENTRIES_PER_PAGE/2 + idx/ENTRIES_PER_PAGEPAGE;
while (!*dir) {
dir++;
goto done1;
}
stage = idx + ENTRIES_PER_PAGEPAGE;
- middir = *dir;
+ subdir = *dir;
*dir = NULL;
- nr_pages_to_free++;
- list_add(&middir->lru, &pages_to_free);
shmem_dir_unmap(dir);
- cond_resched();
- dir = shmem_dir_map(middir);
- diroff = 0;
+ if (empty) {
+ shmem_dir_free(empty);
+ shmem_free_block(inode);
+ }
+ empty = subdir;
+ cond_resched_lock(&info->lock);
+ dir = shmem_dir_map(subdir);
}
- subdir = dir[diroff];
+ subdir = *dir;
if (subdir && subdir->nr_swapped) {
+ ptr = shmem_swp_map(subdir);
size = limit - idx;
if (size > ENTRIES_PER_PAGE)
size = ENTRIES_PER_PAGE;
- freed = shmem_map_and_free_swp(subdir,
- offset, size, &dir);
- if (!dir)
- dir = shmem_dir_map(middir);
- nr_swaps_freed += freed;
- if (offset)
- spin_lock(&info->lock);
+ freed = shmem_free_swp(ptr+offset, ptr+size);
+ shmem_swp_unmap(ptr);
+ info->swapped -= freed;
subdir->nr_swapped -= freed;
- if (offset)
- spin_unlock(&info->lock);
BUG_ON(subdir->nr_swapped > offset);
}
if (offset)
offset = 0;
else if (subdir) {
- dir[diroff] = NULL;
- nr_pages_to_free++;
- list_add(&subdir->lru, &pages_to_free);
+ *dir = NULL;
+ shmem_dir_free(subdir);
+ shmem_free_block(inode);
}
}
done1:
- shmem_dir_unmap(dir);
+ shmem_dir_unmap(dir-1);
+ if (empty) {
+ shmem_dir_free(empty);
+ shmem_free_block(inode);
+ }
+ if (info->next_index <= SHMEM_NR_DIRECT) {
+ shmem_dir_free(info->i_indirect);
+ info->i_indirect = NULL;
+ shmem_free_block(inode);
+ }
done2:
+ BUG_ON(info->swapped > info->next_index);
if (inode->i_mapping->nrpages && (info->flags & SHMEM_PAGEIN)) {
/*
* Call truncate_inode_pages again: racing shmem_unuse_inode
* Also, though shmem_getpage checks i_size before adding to
* cache, no recheck after: so fix the narrow window there too.
*/
+ spin_unlock(&info->lock);
truncate_inode_pages(inode->i_mapping, inode->i_size);
+ spin_lock(&info->lock);
}
-
- spin_lock(&info->lock);
info->flags &= ~SHMEM_TRUNCATE;
- info->swapped -= nr_swaps_freed;
- if (nr_pages_to_free)
- shmem_free_blocks(inode, nr_pages_to_free);
shmem_recalc_inode(inode);
spin_unlock(&info->lock);
-
- /*
- * Empty swap vector directory pages to be freed?
- */
- if (!list_empty(&pages_to_free)) {
- pages_to_free.prev->next = NULL;
- shmem_free_pages(pages_to_free.next);
- }
}
static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
}
if (!info->i_indirect)
goto lost2;
+ /* we might be racing with shmem_truncate */
+ if (limit <= SHMEM_NR_DIRECT)
+ goto lost2;
dir = shmem_dir_map(info->i_indirect);
stage = SHMEM_NR_DIRECT + ENTRIES_PER_PAGEPAGE/2;
idx);
if (!filepage) {
shmem_unacct_blocks(info->flags, 1);
- shmem_free_blocks(inode, 1);
+ shmem_free_block(inode);
error = -ENOMEM;
goto failed;
}
spin_unlock(&info->lock);
page_cache_release(filepage);
shmem_unacct_blocks(info->flags, 1);
- shmem_free_blocks(inode, 1);
+ shmem_free_block(inode);
filepage = NULL;
if (error)
goto failed;
info = SHMEM_I(inode);
memset(info, 0, (char *)inode - (char *)info);
spin_lock_init(&info->lock);
+ mpol_shared_policy_init(&info->policy);
INIT_LIST_HEAD(&info->swaplist);
switch (mode & S_IFMT) {
case S_IFREG:
inode->i_op = &shmem_inode_operations;
inode->i_fop = &shmem_file_operations;
- mpol_shared_policy_init(&info->policy);
break;
case S_IFDIR:
inode->i_nlink++;
inode->i_fop = &simple_dir_operations;
break;
case S_IFLNK:
- /*
- * Must not load anything in the rbtree,
- * mpol_free_shared_policy will not be called.
- */
- mpol_shared_policy_init(&info->policy);
break;
}
} else if (sbinfo) {
sbinfo->free_inodes = inodes;
}
sb->s_xattr = shmem_xattr_handlers;
-#else
- sb->s_flags |= MS_NOUSER;
#endif
sb->s_maxbytes = SHMEM_MAX_BYTES;
static void shmem_destroy_inode(struct inode *inode)
{
- if ((inode->i_mode & S_IFMT) == S_IFREG) {
- /* only struct inode is valid if it's an inline symlink */
- mpol_free_shared_policy(&SHMEM_I(inode)->policy);
- }
+ mpol_free_shared_policy(&SHMEM_I(inode)->policy);
kmem_cache_free(shmem_inode_cachep, SHMEM_I(inode));
}
git://git.onelab.eu / linux-2.6.git / blobdiff