Kernel/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2025-01-01 02:36:02 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

memcg_write_event_control(): switch to CLASS(fd)

Browse Source 
some reordering required - take both fdget() to the point before
the allocations, with matching move of fdput() to the very end
of failure exit(s); after that it converts trivially.

simplify the cleanups that involve css_put(), while we are at it...

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2024-07-22 20:18:10 -04:00
parent 66635b0776
commit 7133dd5ac6
1 changed files with 15 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

44
mm/memcontrol-v1.c
View File

@ -1911,8 +1911,6 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
struct mem_cgroup_event *event; struct mem_cgroup_event *event;
struct cgroup_subsys_state *cfile_css; struct cgroup_subsys_state *cfile_css;
unsigned int efd, cfd; unsigned int efd, cfd;
struct fd efile;
struct fd cfile;
struct dentry *cdentry; struct dentry *cdentry;
const char *name; const char *name;
char *endp; char *endp;
@ -1936,6 +1934,12 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
else else
return -EINVAL; return -EINVAL;
CLASS(fd, efile)(efd);
if (fd_empty(efile))
return -EBADF;
CLASS(fd, cfile)(cfd);
event = kzalloc(sizeof(*event), GFP_KERNEL); event = kzalloc(sizeof(*event), GFP_KERNEL);
if (!event) if (!event)
return -ENOMEM; return -ENOMEM;
@ -1946,20 +1950,13 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
init_waitqueue_func_entry(&event->wait, memcg_event_wake); init_waitqueue_func_entry(&event->wait, memcg_event_wake);
INIT_WORK(&event->remove, memcg_event_remove); INIT_WORK(&event->remove, memcg_event_remove);
efile = fdget(efd);
if (!fd_file(efile)) {
ret = -EBADF;
goto out_kfree;
}
event->eventfd = eventfd_ctx_fileget(fd_file(efile)); event->eventfd = eventfd_ctx_fileget(fd_file(efile));
if (IS_ERR(event->eventfd)) { if (IS_ERR(event->eventfd)) {
ret = PTR_ERR(event->eventfd); ret = PTR_ERR(event->eventfd);
goto out_put_efile; goto out_kfree;
} }
cfile = fdget(cfd); if (fd_empty(cfile)) {
if (!fd_file(cfile)) {
ret = -EBADF; ret = -EBADF;
goto out_put_eventfd; goto out_put_eventfd;
} }
@ -1968,7 +1965,7 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
/* AV: shouldn't we check that it's been opened for read instead? */ /* AV: shouldn't we check that it's been opened for read instead? */
ret = file_permission(fd_file(cfile), MAY_READ); ret = file_permission(fd_file(cfile), MAY_READ);
if (ret < 0) if (ret < 0)
goto out_put_cfile; goto out_put_eventfd;
/* /*
* The control file must be a regular cgroup1 file. As a regular cgroup * The control file must be a regular cgroup1 file. As a regular cgroup
@ -1977,7 +1974,7 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
cdentry = fd_file(cfile)->f_path.dentry; cdentry = fd_file(cfile)->f_path.dentry;
if (cdentry->d_sb->s_type != &cgroup_fs_type || !d_is_reg(cdentry)) { if (cdentry->d_sb->s_type != &cgroup_fs_type || !d_is_reg(cdentry)) {
ret = -EINVAL; ret = -EINVAL;
goto out_put_cfile; goto out_put_eventfd;
} }
/* /*
@ -2010,7 +2007,7 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
event->unregister_event = memsw_cgroup_usage_unregister_event; event->unregister_event = memsw_cgroup_usage_unregister_event;
} else { } else {
ret = -EINVAL; ret = -EINVAL;
goto out_put_cfile; goto out_put_eventfd;
} }
/* /*
@ -2022,11 +2019,9 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
&memory_cgrp_subsys); &memory_cgrp_subsys);
ret = -EINVAL; ret = -EINVAL;
if (IS_ERR(cfile_css)) if (IS_ERR(cfile_css))
goto out_put_cfile; goto out_put_eventfd;
if (cfile_css != css) { if (cfile_css != css)
css_put(cfile_css); goto out_put_css;
goto out_put_cfile;
}
ret = event->register_event(memcg, event->eventfd, buf); ret = event->register_event(memcg, event->eventfd, buf);
if (ret) if (ret)
@ -2037,23 +2032,14 @@ static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
spin_lock_irq(&memcg->event_list_lock); spin_lock_irq(&memcg->event_list_lock);
list_add(&event->list, &memcg->event_list); list_add(&event->list, &memcg->event_list);
spin_unlock_irq(&memcg->event_list_lock); spin_unlock_irq(&memcg->event_list_lock);
fdput(cfile);
fdput(efile);
return nbytes; return nbytes;
out_put_css: out_put_css:
css_put(css); css_put(cfile_css);
out_put_cfile:
fdput(cfile);
out_put_eventfd: out_put_eventfd:
eventfd_ctx_put(event->eventfd); eventfd_ctx_put(event->eventfd);
out_put_efile:
fdput(efile);
out_kfree: out_kfree:
kfree(event); kfree(event);
return ret; return ret;
} }