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[/] [test_project/] [trunk/] [linux_sd_driver/] [fs/] [attr.c] - Blame information for rev 79

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Line No. Rev Author Line
1 62 marcus.erl
/*
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 *  linux/fs/attr.c
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 *
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 *  Copyright (C) 1991, 1992  Linus Torvalds
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 *  changes by Thomas Schoebel-Theuer
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 */
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#include <linux/module.h>
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#include <linux/time.h>
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#include <linux/mm.h>
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#include <linux/string.h>
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#include <linux/capability.h>
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#include <linux/fsnotify.h>
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#include <linux/fcntl.h>
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#include <linux/quotaops.h>
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#include <linux/security.h>
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/* Taken over from the old code... */
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/* POSIX UID/GID verification for setting inode attributes. */
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int inode_change_ok(struct inode *inode, struct iattr *attr)
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{
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        int retval = -EPERM;
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        unsigned int ia_valid = attr->ia_valid;
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        /* If force is set do it anyway. */
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        if (ia_valid & ATTR_FORCE)
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                goto fine;
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        /* Make sure a caller can chown. */
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        if ((ia_valid & ATTR_UID) &&
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            (current->fsuid != inode->i_uid ||
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             attr->ia_uid != inode->i_uid) && !capable(CAP_CHOWN))
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                goto error;
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        /* Make sure caller can chgrp. */
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        if ((ia_valid & ATTR_GID) &&
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            (current->fsuid != inode->i_uid ||
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            (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) &&
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            !capable(CAP_CHOWN))
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                goto error;
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        /* Make sure a caller can chmod. */
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        if (ia_valid & ATTR_MODE) {
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                if (!is_owner_or_cap(inode))
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                        goto error;
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                /* Also check the setgid bit! */
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                if (!in_group_p((ia_valid & ATTR_GID) ? attr->ia_gid :
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                                inode->i_gid) && !capable(CAP_FSETID))
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                        attr->ia_mode &= ~S_ISGID;
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        }
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        /* Check for setting the inode time. */
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        if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET)) {
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                if (!is_owner_or_cap(inode))
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                        goto error;
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        }
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fine:
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        retval = 0;
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error:
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        return retval;
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}
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EXPORT_SYMBOL(inode_change_ok);
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int inode_setattr(struct inode * inode, struct iattr * attr)
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{
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        unsigned int ia_valid = attr->ia_valid;
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        if (ia_valid & ATTR_SIZE &&
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            attr->ia_size != i_size_read(inode)) {
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                int error = vmtruncate(inode, attr->ia_size);
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                if (error)
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                        return error;
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        }
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        if (ia_valid & ATTR_UID)
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                inode->i_uid = attr->ia_uid;
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        if (ia_valid & ATTR_GID)
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                inode->i_gid = attr->ia_gid;
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        if (ia_valid & ATTR_ATIME)
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                inode->i_atime = timespec_trunc(attr->ia_atime,
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                                                inode->i_sb->s_time_gran);
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        if (ia_valid & ATTR_MTIME)
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                inode->i_mtime = timespec_trunc(attr->ia_mtime,
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                                                inode->i_sb->s_time_gran);
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        if (ia_valid & ATTR_CTIME)
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                inode->i_ctime = timespec_trunc(attr->ia_ctime,
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                                                inode->i_sb->s_time_gran);
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        if (ia_valid & ATTR_MODE) {
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                umode_t mode = attr->ia_mode;
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                if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
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                        mode &= ~S_ISGID;
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                inode->i_mode = mode;
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        }
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        mark_inode_dirty(inode);
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        return 0;
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}
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EXPORT_SYMBOL(inode_setattr);
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int notify_change(struct dentry * dentry, struct iattr * attr)
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{
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        struct inode *inode = dentry->d_inode;
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        mode_t mode = inode->i_mode;
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        int error;
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        struct timespec now;
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        unsigned int ia_valid = attr->ia_valid;
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        now = current_fs_time(inode->i_sb);
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        attr->ia_ctime = now;
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        if (!(ia_valid & ATTR_ATIME_SET))
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                attr->ia_atime = now;
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        if (!(ia_valid & ATTR_MTIME_SET))
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                attr->ia_mtime = now;
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        if (ia_valid & ATTR_KILL_PRIV) {
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                attr->ia_valid &= ~ATTR_KILL_PRIV;
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                ia_valid &= ~ATTR_KILL_PRIV;
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                error = security_inode_need_killpriv(dentry);
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                if (error > 0)
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                        error = security_inode_killpriv(dentry);
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                if (error)
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                        return error;
126
        }
127
 
128
        /*
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         * We now pass ATTR_KILL_S*ID to the lower level setattr function so
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         * that the function has the ability to reinterpret a mode change
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         * that's due to these bits. This adds an implicit restriction that
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         * no function will ever call notify_change with both ATTR_MODE and
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         * ATTR_KILL_S*ID set.
134
         */
135
        if ((ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID)) &&
136
            (ia_valid & ATTR_MODE))
137
                BUG();
138
 
139
        if (ia_valid & ATTR_KILL_SUID) {
140
                if (mode & S_ISUID) {
141
                        ia_valid = attr->ia_valid |= ATTR_MODE;
142
                        attr->ia_mode = (inode->i_mode & ~S_ISUID);
143
                }
144
        }
145
        if (ia_valid & ATTR_KILL_SGID) {
146
                if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
147
                        if (!(ia_valid & ATTR_MODE)) {
148
                                ia_valid = attr->ia_valid |= ATTR_MODE;
149
                                attr->ia_mode = inode->i_mode;
150
                        }
151
                        attr->ia_mode &= ~S_ISGID;
152
                }
153
        }
154
        if (!(attr->ia_valid & ~(ATTR_KILL_SUID | ATTR_KILL_SGID)))
155
                return 0;
156
 
157
        if (ia_valid & ATTR_SIZE)
158
                down_write(&dentry->d_inode->i_alloc_sem);
159
 
160
        if (inode->i_op && inode->i_op->setattr) {
161
                error = security_inode_setattr(dentry, attr);
162
                if (!error)
163
                        error = inode->i_op->setattr(dentry, attr);
164
        } else {
165
                error = inode_change_ok(inode, attr);
166
                if (!error)
167
                        error = security_inode_setattr(dentry, attr);
168
                if (!error) {
169
                        if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
170
                            (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid))
171
                                error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0;
172
                        if (!error)
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                                error = inode_setattr(inode, attr);
174
                }
175
        }
176
 
177
        if (ia_valid & ATTR_SIZE)
178
                up_write(&dentry->d_inode->i_alloc_sem);
179
 
180
        if (!error)
181
                fsnotify_change(dentry, ia_valid);
182
 
183
        return error;
184
}
185
 
186
EXPORT_SYMBOL(notify_change);

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