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nilfs2: use mnt_want_write in ioctls where write access is needed
A few nilfs2 ioctls need to ask for and then later release write access to the mount in order to avoid potential write to read-only mounts. This adds the missing mnt_want_write and mnt_drop_write in nilfs_ioctl_change_cpmode, nilfs_ioctl_delete_checkpoint, and nilfs_ioctl_clean_segments. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
This commit is contained in:
parent
e902ec9906
commit
7512487e6d
1 changed files with 44 additions and 18 deletions
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@ -26,6 +26,7 @@
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#include <linux/capability.h> /* capable() */
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#include <linux/capability.h> /* capable() */
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#include <linux/uaccess.h> /* copy_from_user(), copy_to_user() */
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#include <linux/uaccess.h> /* copy_from_user(), copy_to_user() */
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#include <linux/vmalloc.h>
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#include <linux/vmalloc.h>
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#include <linux/mount.h> /* mnt_want_write(), mnt_drop_write() */
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#include <linux/nilfs2_fs.h>
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#include <linux/nilfs2_fs.h>
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#include "nilfs.h"
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#include "nilfs.h"
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#include "segment.h"
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#include "segment.h"
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@ -107,20 +108,28 @@ static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
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if (!capable(CAP_SYS_ADMIN))
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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return -EPERM;
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ret = mnt_want_write(filp->f_path.mnt);
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if (ret)
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return ret;
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ret = -EFAULT;
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if (copy_from_user(&cpmode, argp, sizeof(cpmode)))
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if (copy_from_user(&cpmode, argp, sizeof(cpmode)))
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return -EFAULT;
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goto out;
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mutex_lock(&nilfs->ns_mount_mutex);
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mutex_lock(&nilfs->ns_mount_mutex);
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nilfs_transaction_begin(inode->i_sb, &ti, 0);
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nilfs_transaction_begin(inode->i_sb, &ti, 0);
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ret = nilfs_cpfile_change_cpmode(
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ret = nilfs_cpfile_change_cpmode(
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cpfile, cpmode.cm_cno, cpmode.cm_mode);
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cpfile, cpmode.cm_cno, cpmode.cm_mode);
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if (unlikely(ret < 0)) {
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if (unlikely(ret < 0))
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nilfs_transaction_abort(inode->i_sb);
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nilfs_transaction_abort(inode->i_sb);
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mutex_unlock(&nilfs->ns_mount_mutex);
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else
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return ret;
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nilfs_transaction_commit(inode->i_sb); /* never fails */
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}
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nilfs_transaction_commit(inode->i_sb); /* never fails */
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mutex_unlock(&nilfs->ns_mount_mutex);
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mutex_unlock(&nilfs->ns_mount_mutex);
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out:
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mnt_drop_write(filp->f_path.mnt);
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return ret;
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return ret;
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}
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}
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@ -135,16 +144,23 @@ nilfs_ioctl_delete_checkpoint(struct inode *inode, struct file *filp,
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if (!capable(CAP_SYS_ADMIN))
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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return -EPERM;
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ret = mnt_want_write(filp->f_path.mnt);
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if (ret)
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return ret;
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ret = -EFAULT;
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if (copy_from_user(&cno, argp, sizeof(cno)))
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if (copy_from_user(&cno, argp, sizeof(cno)))
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return -EFAULT;
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goto out;
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nilfs_transaction_begin(inode->i_sb, &ti, 0);
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nilfs_transaction_begin(inode->i_sb, &ti, 0);
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ret = nilfs_cpfile_delete_checkpoint(cpfile, cno);
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ret = nilfs_cpfile_delete_checkpoint(cpfile, cno);
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if (unlikely(ret < 0)) {
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if (unlikely(ret < 0))
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nilfs_transaction_abort(inode->i_sb);
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nilfs_transaction_abort(inode->i_sb);
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return ret;
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else
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}
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nilfs_transaction_commit(inode->i_sb); /* never fails */
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nilfs_transaction_commit(inode->i_sb); /* never fails */
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out:
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mnt_drop_write(filp->f_path.mnt);
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return ret;
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return ret;
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}
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}
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@ -496,12 +512,19 @@ static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
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if (!capable(CAP_SYS_ADMIN))
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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return -EPERM;
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if (copy_from_user(argv, argp, sizeof(argv)))
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ret = mnt_want_write(filp->f_path.mnt);
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return -EFAULT;
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if (ret)
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return ret;
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ret = -EFAULT;
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if (copy_from_user(argv, argp, sizeof(argv)))
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goto out;
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ret = -EINVAL;
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nsegs = argv[4].v_nmembs;
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nsegs = argv[4].v_nmembs;
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if (argv[4].v_size != argsz[4])
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if (argv[4].v_size != argsz[4])
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return -EINVAL;
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goto out;
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/*
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/*
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* argv[4] points to segment numbers this ioctl cleans. We
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* argv[4] points to segment numbers this ioctl cleans. We
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* use kmalloc() for its buffer because memory used for the
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* use kmalloc() for its buffer because memory used for the
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@ -509,9 +532,10 @@ static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
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*/
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*/
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kbufs[4] = memdup_user((void __user *)(unsigned long)argv[4].v_base,
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kbufs[4] = memdup_user((void __user *)(unsigned long)argv[4].v_base,
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nsegs * sizeof(__u64));
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nsegs * sizeof(__u64));
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if (IS_ERR(kbufs[4]))
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if (IS_ERR(kbufs[4])) {
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return PTR_ERR(kbufs[4]);
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ret = PTR_ERR(kbufs[4]);
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goto out;
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}
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nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
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nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
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for (n = 0; n < 4; n++) {
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for (n = 0; n < 4; n++) {
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@ -563,10 +587,12 @@ static int nilfs_ioctl_clean_segments(struct inode *inode, struct file *filp,
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nilfs_remove_all_gcinode(nilfs);
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nilfs_remove_all_gcinode(nilfs);
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clear_nilfs_gc_running(nilfs);
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clear_nilfs_gc_running(nilfs);
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out_free:
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out_free:
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while (--n >= 0)
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while (--n >= 0)
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vfree(kbufs[n]);
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vfree(kbufs[n]);
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kfree(kbufs[4]);
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kfree(kbufs[4]);
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out:
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mnt_drop_write(filp->f_path.mnt);
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return ret;
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return ret;
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}
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}
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