summaryrefslogtreecommitdiff
path: root/fs/file.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/file.c')
-rw-r--r--fs/file.c208
1 files changed, 72 insertions, 136 deletions
diff --git a/fs/file.c b/fs/file.c
index 17e6a55521e2..857fa49e984c 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -32,46 +32,28 @@ struct fdtable_defer {
*/
static DEFINE_PER_CPU(struct fdtable_defer, fdtable_defer_list);
-
-/*
- * Allocate an fd array, using kmalloc or vmalloc.
- * Note: the array isn't cleared at allocation time.
- */
-struct file ** alloc_fd_array(int num)
+static inline void * alloc_fdmem(unsigned int size)
{
- struct file **new_fds;
- int size = num * sizeof(struct file *);
-
if (size <= PAGE_SIZE)
- new_fds = (struct file **) kmalloc(size, GFP_KERNEL);
- else
- new_fds = (struct file **) vmalloc(size);
- return new_fds;
+ return kmalloc(size, GFP_KERNEL);
+ else
+ return vmalloc(size);
}
-void free_fd_array(struct file **array, int num)
+static inline void free_fdarr(struct fdtable *fdt)
{
- int size = num * sizeof(struct file *);
-
- if (!array) {
- printk (KERN_ERR "free_fd_array: array = 0 (num = %d)\n", num);
- return;
- }
-
- if (num <= NR_OPEN_DEFAULT) /* Don't free the embedded fd array! */
- return;
- else if (size <= PAGE_SIZE)
- kfree(array);
+ if (fdt->max_fds <= (PAGE_SIZE / sizeof(struct file *)))
+ kfree(fdt->fd);
else
- vfree(array);
+ vfree(fdt->fd);
}
-static void __free_fdtable(struct fdtable *fdt)
+static inline void free_fdset(struct fdtable *fdt)
{
- free_fdset(fdt->open_fds, fdt->max_fds);
- free_fdset(fdt->close_on_exec, fdt->max_fds);
- free_fd_array(fdt->fd, fdt->max_fds);
- kfree(fdt);
+ if (fdt->max_fds <= (PAGE_SIZE * BITS_PER_BYTE / 2))
+ kfree(fdt->open_fds);
+ else
+ vfree(fdt->open_fds);
}
static void free_fdtable_work(struct work_struct *work)
@@ -86,7 +68,9 @@ static void free_fdtable_work(struct work_struct *work)
spin_unlock_bh(&f->lock);
while(fdt) {
struct fdtable *next = fdt->next;
- __free_fdtable(fdt);
+ vfree(fdt->fd);
+ free_fdset(fdt);
+ kfree(fdt);
fdt = next;
}
}
@@ -94,12 +78,9 @@ static void free_fdtable_work(struct work_struct *work)
void free_fdtable_rcu(struct rcu_head *rcu)
{
struct fdtable *fdt = container_of(rcu, struct fdtable, rcu);
- int fdset_size, fdarray_size;
struct fdtable_defer *fddef;
BUG_ON(!fdt);
- fdset_size = fdt->max_fds / 8;
- fdarray_size = fdt->max_fds * sizeof(struct file *);
if (fdt->max_fds <= NR_OPEN_DEFAULT) {
/*
@@ -110,10 +91,9 @@ void free_fdtable_rcu(struct rcu_head *rcu)
container_of(fdt, struct files_struct, fdtab));
return;
}
- if (fdset_size <= PAGE_SIZE && fdarray_size <= PAGE_SIZE) {
- kfree(fdt->open_fds);
- kfree(fdt->close_on_exec);
+ if (fdt->max_fds <= (PAGE_SIZE / sizeof(struct file *))) {
kfree(fdt->fd);
+ kfree(fdt->open_fds);
kfree(fdt);
} else {
fddef = &get_cpu_var(fdtable_defer_list);
@@ -131,116 +111,70 @@ void free_fdtable_rcu(struct rcu_head *rcu)
* Expand the fdset in the files_struct. Called with the files spinlock
* held for write.
*/
-static void copy_fdtable(struct fdtable *nfdt, struct fdtable *fdt)
+static void copy_fdtable(struct fdtable *nfdt, struct fdtable *ofdt)
{
- int i;
- int count;
-
- BUG_ON(nfdt->max_fds < fdt->max_fds);
- /* Copy the existing tables and install the new pointers */
-
- i = fdt->max_fds / (sizeof(unsigned long) * 8);
- count = (nfdt->max_fds - fdt->max_fds) / 8;
-
- /*
- * Don't copy the entire array if the current fdset is
- * not yet initialised.
- */
- if (i) {
- memcpy (nfdt->open_fds, fdt->open_fds,
- fdt->max_fds/8);
- memcpy (nfdt->close_on_exec, fdt->close_on_exec,
- fdt->max_fds/8);
- memset (&nfdt->open_fds->fds_bits[i], 0, count);
- memset (&nfdt->close_on_exec->fds_bits[i], 0, count);
- }
+ unsigned int cpy, set;
- /* Don't copy/clear the array if we are creating a new
- fd array for fork() */
- if (fdt->max_fds) {
- memcpy(nfdt->fd, fdt->fd,
- fdt->max_fds * sizeof(struct file *));
- /* clear the remainder of the array */
- memset(&nfdt->fd[fdt->max_fds], 0,
- (nfdt->max_fds - fdt->max_fds) *
- sizeof(struct file *));
- }
-}
-
-/*
- * Allocate an fdset array, using kmalloc or vmalloc.
- * Note: the array isn't cleared at allocation time.
- */
-fd_set * alloc_fdset(int num)
-{
- fd_set *new_fdset;
- int size = num / 8;
-
- if (size <= PAGE_SIZE)
- new_fdset = (fd_set *) kmalloc(size, GFP_KERNEL);
- else
- new_fdset = (fd_set *) vmalloc(size);
- return new_fdset;
-}
-
-void free_fdset(fd_set *array, int num)
-{
- if (num <= NR_OPEN_DEFAULT) /* Don't free an embedded fdset */
+ BUG_ON(nfdt->max_fds < ofdt->max_fds);
+ if (ofdt->max_fds == 0)
return;
- else if (num <= 8 * PAGE_SIZE)
- kfree(array);
- else
- vfree(array);
+
+ cpy = ofdt->max_fds * sizeof(struct file *);
+ set = (nfdt->max_fds - ofdt->max_fds) * sizeof(struct file *);
+ memcpy(nfdt->fd, ofdt->fd, cpy);
+ memset((char *)(nfdt->fd) + cpy, 0, set);
+
+ cpy = ofdt->max_fds / BITS_PER_BYTE;
+ set = (nfdt->max_fds - ofdt->max_fds) / BITS_PER_BYTE;
+ memcpy(nfdt->open_fds, ofdt->open_fds, cpy);
+ memset((char *)(nfdt->open_fds) + cpy, 0, set);
+ memcpy(nfdt->close_on_exec, ofdt->close_on_exec, cpy);
+ memset((char *)(nfdt->close_on_exec) + cpy, 0, set);
}
-static struct fdtable *alloc_fdtable(int nr)
+static struct fdtable * alloc_fdtable(unsigned int nr)
{
- struct fdtable *fdt = NULL;
- int nfds = 0;
- fd_set *new_openset = NULL, *new_execset = NULL;
- struct file **new_fds;
-
- fdt = kzalloc(sizeof(*fdt), GFP_KERNEL);
- if (!fdt)
- goto out;
+ struct fdtable *fdt;
+ char *data;
- nfds = NR_OPEN_DEFAULT;
/*
- * Expand to the max in easy steps, and keep expanding it until
- * we have enough for the requested fd array size.
+ * Figure out how many fds we actually want to support in this fdtable.
+ * Allocation steps are keyed to the size of the fdarray, since it
+ * grows far faster than any of the other dynamic data. We try to fit
+ * the fdarray into comfortable page-tuned chunks: starting at 1024B
+ * and growing in powers of two from there on.
*/
- do {
-#if NR_OPEN_DEFAULT < 256
- if (nfds < 256)
- nfds = 256;
- else
-#endif
- if (nfds < (PAGE_SIZE / sizeof(struct file *)))
- nfds = PAGE_SIZE / sizeof(struct file *);
- else {
- nfds = nfds * 2;
- if (nfds > NR_OPEN)
- nfds = NR_OPEN;
- }
- } while (nfds <= nr);
-
- new_openset = alloc_fdset(nfds);
- new_execset = alloc_fdset(nfds);
- if (!new_openset || !new_execset)
- goto out;
- fdt->open_fds = new_openset;
- fdt->close_on_exec = new_execset;
+ nr /= (1024 / sizeof(struct file *));
+ nr = roundup_pow_of_two(nr + 1);
+ nr *= (1024 / sizeof(struct file *));
+ if (nr > NR_OPEN)
+ nr = NR_OPEN;
- new_fds = alloc_fd_array(nfds);
- if (!new_fds)
+ fdt = kmalloc(sizeof(struct fdtable), GFP_KERNEL);
+ if (!fdt)
goto out;
- fdt->fd = new_fds;
- fdt->max_fds = nfds;
+ fdt->max_fds = nr;
+ data = alloc_fdmem(nr * sizeof(struct file *));
+ if (!data)
+ goto out_fdt;
+ fdt->fd = (struct file **)data;
+ data = alloc_fdmem(max_t(unsigned int,
+ 2 * nr / BITS_PER_BYTE, L1_CACHE_BYTES));
+ if (!data)
+ goto out_arr;
+ fdt->open_fds = (fd_set *)data;
+ data += nr / BITS_PER_BYTE;
+ fdt->close_on_exec = (fd_set *)data;
+ INIT_RCU_HEAD(&fdt->rcu);
+ fdt->next = NULL;
+
return fdt;
-out:
- free_fdset(new_openset, nfds);
- free_fdset(new_execset, nfds);
+
+out_arr:
+ free_fdarr(fdt);
+out_fdt:
kfree(fdt);
+out:
return NULL;
}
@@ -275,7 +209,9 @@ static int expand_fdtable(struct files_struct *files, int nr)
call_rcu(&cur_fdt->rcu, free_fdtable_rcu);
} else {
/* Somebody else expanded, so undo our attempt */
- __free_fdtable(new_fdt);
+ free_fdarr(new_fdt);
+ free_fdset(new_fdt);
+ kfree(new_fdt);
}
return 1;
}