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vfs: use kmalloc() to allocate fdmem if possible

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Use kmalloc() to allocate fdmem if possible.

vmalloc() is used as a fallback solution for fdmem allocation.  A new
helper function __free_fdtable() is introduced to reduce the lines of
code.

A potential bug, vfree() a memory allocated by kmalloc(), is fixed.

[akpm@linux-foundation.org: use __GFP_NOWARN, uninline alloc_fdmem() and free_fdmem()]
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Changli Gao 2010-08-10 18:01:35 -07:00 committed by Linus Torvalds
parent 06b1e104b7
commit a892e2d7dc
1 changed files with 23 additions and 34 deletions
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55
fs/file.c
View file

@ -39,28 +39,27 @@ int sysctl_nr_open_max = 1024 * 1024; /* raised later */
*/ */
static DEFINE_PER_CPU(struct fdtable_defer, fdtable_defer_list); static DEFINE_PER_CPU(struct fdtable_defer, fdtable_defer_list);
static inline void * alloc_fdmem(unsigned int size) static inline void *alloc_fdmem(unsigned int size)
{ {
if (size <= PAGE_SIZE) void *data;
return kmalloc(size, GFP_KERNEL);
else data = kmalloc(size, GFP_KERNEL|__GFP_NOWARN);
if (data != NULL)
return data;
return vmalloc(size); return vmalloc(size);
} }
static inline void free_fdarr(struct fdtable *fdt) static void free_fdmem(void *ptr)
{ {
if (fdt->max_fds <= (PAGE_SIZE / sizeof(struct file *))) is_vmalloc_addr(ptr) ? vfree(ptr) : kfree(ptr);
kfree(fdt->fd);
else
vfree(fdt->fd);
} }
static inline void free_fdset(struct fdtable *fdt) static void __free_fdtable(struct fdtable *fdt)
{ {
if (fdt->max_fds <= (PAGE_SIZE * BITS_PER_BYTE / 2)) free_fdmem(fdt->fd);
kfree(fdt->open_fds); free_fdmem(fdt->open_fds);
else kfree(fdt);
vfree(fdt->open_fds);
} }
static void free_fdtable_work(struct work_struct *work) static void free_fdtable_work(struct work_struct *work)
@ -75,9 +74,8 @@ static void free_fdtable_work(struct work_struct *work)
spin_unlock_bh(&f->lock); spin_unlock_bh(&f->lock);
while(fdt) { while(fdt) {
struct fdtable *next = fdt->next; struct fdtable *next = fdt->next;
vfree(fdt->fd);
free_fdset(fdt); __free_fdtable(fdt);
kfree(fdt);
fdt = next; fdt = next;
} }
} }
@ -98,7 +96,7 @@ void free_fdtable_rcu(struct rcu_head *rcu)
container_of(fdt, struct files_struct, fdtab)); container_of(fdt, struct files_struct, fdtab));
return; return;
} }
if (fdt->max_fds <= (PAGE_SIZE / sizeof(struct file *))) { if (!is_vmalloc_addr(fdt->fd) && !is_vmalloc_addr(fdt->open_fds)) {
kfree(fdt->fd); kfree(fdt->fd);
kfree(fdt->open_fds); kfree(fdt->open_fds);
kfree(fdt); kfree(fdt);
@ -183,7 +181,7 @@ static struct fdtable * alloc_fdtable(unsigned int nr)
return fdt; return fdt;
out_arr: out_arr:
free_fdarr(fdt); free_fdmem(fdt->fd);
out_fdt: out_fdt:
kfree(fdt); kfree(fdt);
out: out:
@ -213,9 +211,7 @@ static int expand_fdtable(struct files_struct *files, int nr)
* caller and alloc_fdtable(). Cheaper to catch it here... * caller and alloc_fdtable(). Cheaper to catch it here...
*/ */
if (unlikely(new_fdt->max_fds <= nr)) { if (unlikely(new_fdt->max_fds <= nr)) {
free_fdarr(new_fdt); __free_fdtable(new_fdt);
free_fdset(new_fdt);
kfree(new_fdt);
return -EMFILE; return -EMFILE;
} }
/* /*
@ -231,9 +227,7 @@ static int expand_fdtable(struct files_struct *files, int nr)
free_fdtable(cur_fdt); free_fdtable(cur_fdt);
} else { } else {
/* Somebody else expanded, so undo our attempt */ /* Somebody else expanded, so undo our attempt */
free_fdarr(new_fdt); __free_fdtable(new_fdt);
free_fdset(new_fdt);
kfree(new_fdt);
} }
return 1; return 1;
} }
@ -323,11 +317,8 @@ struct files_struct *dup_fd(struct files_struct *oldf, int *errorp)
while (unlikely(open_files > new_fdt->max_fds)) { while (unlikely(open_files > new_fdt->max_fds)) {
spin_unlock(&oldf->file_lock); spin_unlock(&oldf->file_lock);
if (new_fdt != &newf->fdtab) { if (new_fdt != &newf->fdtab)
free_fdarr(new_fdt); __free_fdtable(new_fdt);
free_fdset(new_fdt);
kfree(new_fdt);
}
new_fdt = alloc_fdtable(open_files - 1); new_fdt = alloc_fdtable(open_files - 1);
if (!new_fdt) { if (!new_fdt) {
@ -337,9 +328,7 @@ struct files_struct *dup_fd(struct files_struct *oldf, int *errorp)
/* beyond sysctl_nr_open; nothing to do */ /* beyond sysctl_nr_open; nothing to do */
if (unlikely(new_fdt->max_fds < open_files)) { if (unlikely(new_fdt->max_fds < open_files)) {
free_fdarr(new_fdt); __free_fdtable(new_fdt);
free_fdset(new_fdt);
kfree(new_fdt);
*errorp = -EMFILE; *errorp = -EMFILE;
goto out_release; goto out_release;
} }