fs/reiserfs/ioctl.c

0001 /*
0002  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
0003  */
0004
0005 #include <linux/capability.h>
0006 #include <linux/fs.h>
0007 #include <linux/mount.h>
0008 #include "reiserfs.h"
0009 #include <linux/time.h>
0010 #include <linux/uaccess.h>
0011 #include <linux/pagemap.h>
0012 #include <linux/compat.h>
0013 #include <linux/fileattr.h>
0014
0015 int reiserfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
0016 {
0017     struct inode *inode = d_inode(dentry);
0018
0019     if (!reiserfs_attrs(inode->i_sb))
0020         return -ENOTTY;
0021
0022     fileattr_fill_flags(fa, REISERFS_I(inode)->i_attrs);
0023
0024     return 0;
0025 }
0026
0027 int reiserfs_fileattr_set(struct user_namespace *mnt_userns,
0028               struct dentry *dentry, struct fileattr *fa)
0029 {
0030     struct inode *inode = d_inode(dentry);
0031     unsigned int flags = fa->flags;
0032     int err;
0033
0034     reiserfs_write_lock(inode->i_sb);
0035
0036     err = -ENOTTY;
0037     if (!reiserfs_attrs(inode->i_sb))
0038         goto unlock;
0039
0040     err = -EOPNOTSUPP;
0041     if (fileattr_has_fsx(fa))
0042         goto unlock;
0043
0044     /*
0045      * Is it quota file? Do not allow user to mess with it
0046      */
0047     err = -EPERM;
0048     if (IS_NOQUOTA(inode))
0049         goto unlock;
0050
0051     if ((flags & REISERFS_NOTAIL_FL) && S_ISREG(inode->i_mode)) {
0052         err = reiserfs_unpack(inode);
0053         if (err)
0054             goto unlock;
0055     }
0056     sd_attrs_to_i_attrs(flags, inode);
0057     REISERFS_I(inode)->i_attrs = flags;
0058     inode->i_ctime = current_time(inode);
0059     mark_inode_dirty(inode);
0060     err = 0;
0061 unlock:
0062     reiserfs_write_unlock(inode->i_sb);
0063
0064     return err;
0065 }
0066
0067 /*
0068  * reiserfs_ioctl - handler for ioctl for inode
0069  * supported commands:
0070  *  1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
0071  *                           and prevent packing file (argument arg has t
0072  *                be non-zero)
0073  *  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
0074  *  3) That's all for a while ...
0075  */
0076 long reiserfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
0077 {
0078     struct inode *inode = file_inode(filp);
0079     int err = 0;
0080
0081     reiserfs_write_lock(inode->i_sb);
0082
0083     switch (cmd) {
0084     case REISERFS_IOC_UNPACK:
0085         if (S_ISREG(inode->i_mode)) {
0086             if (arg)
0087                 err = reiserfs_unpack(inode);
0088         } else
0089             err = -ENOTTY;
0090         break;
0091         /*
0092          * following two cases are taken from fs/ext2/ioctl.c by Remy
0093          * Card (card@masi.ibp.fr)
0094          */
0095     case REISERFS_IOC_GETVERSION:
0096         err = put_user(inode->i_generation, (int __user *)arg);
0097         break;
0098     case REISERFS_IOC_SETVERSION:
0099         if (!inode_owner_or_capable(&init_user_ns, inode)) {
0100             err = -EPERM;
0101             break;
0102         }
0103         err = mnt_want_write_file(filp);
0104         if (err)
0105             break;
0106         if (get_user(inode->i_generation, (int __user *)arg)) {
0107             err = -EFAULT;
0108             goto setversion_out;
0109         }
0110         inode->i_ctime = current_time(inode);
0111         mark_inode_dirty(inode);
0112 setversion_out:
0113         mnt_drop_write_file(filp);
0114         break;
0115     default:
0116         err = -ENOTTY;
0117     }
0118
0119     reiserfs_write_unlock(inode->i_sb);
0120
0121     return err;
0122 }
0123
0124 #ifdef CONFIG_COMPAT
0125 long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
0126                 unsigned long arg)
0127 {
0128     /*
0129      * These are just misnamed, they actually
0130      * get/put from/to user an int
0131      */
0132     switch (cmd) {
0133     case REISERFS_IOC32_UNPACK:
0134         cmd = REISERFS_IOC_UNPACK;
0135         break;
0136     case REISERFS_IOC32_GETVERSION:
0137         cmd = REISERFS_IOC_GETVERSION;
0138         break;
0139     case REISERFS_IOC32_SETVERSION:
0140         cmd = REISERFS_IOC_SETVERSION;
0141         break;
0142     default:
0143         return -ENOIOCTLCMD;
0144     }
0145
0146     return reiserfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
0147 }
0148 #endif
0149
0150 int reiserfs_commit_write(struct file *f, struct page *page,
0151               unsigned from, unsigned to);
0152 /*
0153  * reiserfs_unpack
0154  * Function try to convert tail from direct item into indirect.
0155  * It set up nopack attribute in the REISERFS_I(inode)->nopack
0156  */
0157 int reiserfs_unpack(struct inode *inode)
0158 {
0159     int retval = 0;
0160     int index;
0161     struct page *page;
0162     struct address_space *mapping;
0163     unsigned long write_from;
0164     unsigned long blocksize = inode->i_sb->s_blocksize;
0165
0166     if (inode->i_size == 0) {
0167         REISERFS_I(inode)->i_flags |= i_nopack_mask;
0168         return 0;
0169     }
0170     /* ioctl already done */
0171     if (REISERFS_I(inode)->i_flags & i_nopack_mask) {
0172         return 0;
0173     }
0174
0175     /* we need to make sure nobody is changing the file size beneath us */
0176     {
0177         int depth = reiserfs_write_unlock_nested(inode->i_sb);
0178
0179         inode_lock(inode);
0180         reiserfs_write_lock_nested(inode->i_sb, depth);
0181     }
0182
0183     reiserfs_write_lock(inode->i_sb);
0184
0185     write_from = inode->i_size & (blocksize - 1);
0186     /* if we are on a block boundary, we are already unpacked.  */
0187     if (write_from == 0) {
0188         REISERFS_I(inode)->i_flags |= i_nopack_mask;
0189         goto out;
0190     }
0191
0192     /*
0193      * we unpack by finding the page with the tail, and calling
0194      * __reiserfs_write_begin on that page.  This will force a
0195      * reiserfs_get_block to unpack the tail for us.
0196      */
0197     index = inode->i_size >> PAGE_SHIFT;
0198     mapping = inode->i_mapping;
0199     page = grab_cache_page(mapping, index);
0200     retval = -ENOMEM;
0201     if (!page) {
0202         goto out;
0203     }
0204     retval = __reiserfs_write_begin(page, write_from, 0);
0205     if (retval)
0206         goto out_unlock;
0207
0208     /* conversion can change page contents, must flush */
0209     flush_dcache_page(page);
0210     retval = reiserfs_commit_write(NULL, page, write_from, write_from);
0211     REISERFS_I(inode)->i_flags |= i_nopack_mask;
0212
0213 out_unlock:
0214     unlock_page(page);
0215     put_page(page);
0216
0217 out:
0218     inode_unlock(inode);
0219     reiserfs_write_unlock(inode->i_sb);
0220     return retval;
0221 }