1 /*
2  * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
3  * All Rights Reserved.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it would be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write the Free Software Foundation,
16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  */
18 #include "xfs.h"
19 #include "xfs_fs.h"
20 #include "xfs_types.h"
21 #include "xfs_bit.h"
22 #include "xfs_log.h"
23 #include "xfs_inum.h"
24 #include "xfs_trans.h"
25 #include "xfs_sb.h"
26 #include "xfs_ag.h"
27 #include "xfs_dir2.h"
28 #include "xfs_mount.h"
29 #include "xfs_bmap_btree.h"
30 #include "xfs_dinode.h"
31 #include "xfs_inode.h"
32 #include "xfs_inode_item.h"
33 #include "xfs_bmap.h"
34 #include "xfs_error.h"
35 #include "xfs_quota.h"
36 #include "xfs_itable.h"
37 #include "xfs_utils.h"
38 
39 
40 /*
41  * Allocates a new inode from disk and return a pointer to the
42  * incore copy. This routine will internally commit the current
43  * transaction and allocate a new one if the Space Manager needed
44  * to do an allocation to replenish the inode free-list.
45  *
46  * This routine is designed to be called from xfs_create and
47  * xfs_create_dir.
48  *
49  */
50 int
xfs_dir_ialloc(xfs_trans_t ** tpp,xfs_inode_t * dp,umode_t mode,xfs_nlink_t nlink,xfs_dev_t rdev,prid_t prid,int okalloc,xfs_inode_t ** ipp,int * committed)51 xfs_dir_ialloc(
52 	xfs_trans_t	**tpp,		/* input: current transaction;
53 					   output: may be a new transaction. */
54 	xfs_inode_t	*dp,		/* directory within whose allocate
55 					   the inode. */
56 	umode_t		mode,
57 	xfs_nlink_t	nlink,
58 	xfs_dev_t	rdev,
59 	prid_t		prid,		/* project id */
60 	int		okalloc,	/* ok to allocate new space */
61 	xfs_inode_t	**ipp,		/* pointer to inode; it will be
62 					   locked. */
63 	int		*committed)
64 
65 {
66 	xfs_trans_t	*tp;
67 	xfs_trans_t	*ntp;
68 	xfs_inode_t	*ip;
69 	xfs_buf_t	*ialloc_context = NULL;
70 	boolean_t	call_again = B_FALSE;
71 	int		code;
72 	uint		log_res;
73 	uint		log_count;
74 	void		*dqinfo;
75 	uint		tflags;
76 
77 	tp = *tpp;
78 	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
79 
80 	/*
81 	 * xfs_ialloc will return a pointer to an incore inode if
82 	 * the Space Manager has an available inode on the free
83 	 * list. Otherwise, it will do an allocation and replenish
84 	 * the freelist.  Since we can only do one allocation per
85 	 * transaction without deadlocks, we will need to commit the
86 	 * current transaction and start a new one.  We will then
87 	 * need to call xfs_ialloc again to get the inode.
88 	 *
89 	 * If xfs_ialloc did an allocation to replenish the freelist,
90 	 * it returns the bp containing the head of the freelist as
91 	 * ialloc_context. We will hold a lock on it across the
92 	 * transaction commit so that no other process can steal
93 	 * the inode(s) that we've just allocated.
94 	 */
95 	code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid, okalloc,
96 			  &ialloc_context, &call_again, &ip);
97 
98 	/*
99 	 * Return an error if we were unable to allocate a new inode.
100 	 * This should only happen if we run out of space on disk or
101 	 * encounter a disk error.
102 	 */
103 	if (code) {
104 		*ipp = NULL;
105 		return code;
106 	}
107 	if (!call_again && (ip == NULL)) {
108 		*ipp = NULL;
109 		return XFS_ERROR(ENOSPC);
110 	}
111 
112 	/*
113 	 * If call_again is set, then we were unable to get an
114 	 * inode in one operation.  We need to commit the current
115 	 * transaction and call xfs_ialloc() again.  It is guaranteed
116 	 * to succeed the second time.
117 	 */
118 	if (call_again) {
119 
120 		/*
121 		 * Normally, xfs_trans_commit releases all the locks.
122 		 * We call bhold to hang on to the ialloc_context across
123 		 * the commit.  Holding this buffer prevents any other
124 		 * processes from doing any allocations in this
125 		 * allocation group.
126 		 */
127 		xfs_trans_bhold(tp, ialloc_context);
128 		/*
129 		 * Save the log reservation so we can use
130 		 * them in the next transaction.
131 		 */
132 		log_res = xfs_trans_get_log_res(tp);
133 		log_count = xfs_trans_get_log_count(tp);
134 
135 		/*
136 		 * We want the quota changes to be associated with the next
137 		 * transaction, NOT this one. So, detach the dqinfo from this
138 		 * and attach it to the next transaction.
139 		 */
140 		dqinfo = NULL;
141 		tflags = 0;
142 		if (tp->t_dqinfo) {
143 			dqinfo = (void *)tp->t_dqinfo;
144 			tp->t_dqinfo = NULL;
145 			tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY;
146 			tp->t_flags &= ~(XFS_TRANS_DQ_DIRTY);
147 		}
148 
149 		ntp = xfs_trans_dup(tp);
150 		code = xfs_trans_commit(tp, 0);
151 		tp = ntp;
152 		if (committed != NULL) {
153 			*committed = 1;
154 		}
155 		/*
156 		 * If we get an error during the commit processing,
157 		 * release the buffer that is still held and return
158 		 * to the caller.
159 		 */
160 		if (code) {
161 			xfs_buf_relse(ialloc_context);
162 			if (dqinfo) {
163 				tp->t_dqinfo = dqinfo;
164 				xfs_trans_free_dqinfo(tp);
165 			}
166 			*tpp = ntp;
167 			*ipp = NULL;
168 			return code;
169 		}
170 
171 		/*
172 		 * transaction commit worked ok so we can drop the extra ticket
173 		 * reference that we gained in xfs_trans_dup()
174 		 */
175 		xfs_log_ticket_put(tp->t_ticket);
176 		code = xfs_trans_reserve(tp, 0, log_res, 0,
177 					 XFS_TRANS_PERM_LOG_RES, log_count);
178 		/*
179 		 * Re-attach the quota info that we detached from prev trx.
180 		 */
181 		if (dqinfo) {
182 			tp->t_dqinfo = dqinfo;
183 			tp->t_flags |= tflags;
184 		}
185 
186 		if (code) {
187 			xfs_buf_relse(ialloc_context);
188 			*tpp = ntp;
189 			*ipp = NULL;
190 			return code;
191 		}
192 		xfs_trans_bjoin(tp, ialloc_context);
193 
194 		/*
195 		 * Call ialloc again. Since we've locked out all
196 		 * other allocations in this allocation group,
197 		 * this call should always succeed.
198 		 */
199 		code = xfs_ialloc(tp, dp, mode, nlink, rdev, prid,
200 				  okalloc, &ialloc_context, &call_again, &ip);
201 
202 		/*
203 		 * If we get an error at this point, return to the caller
204 		 * so that the current transaction can be aborted.
205 		 */
206 		if (code) {
207 			*tpp = tp;
208 			*ipp = NULL;
209 			return code;
210 		}
211 		ASSERT ((!call_again) && (ip != NULL));
212 
213 	} else {
214 		if (committed != NULL) {
215 			*committed = 0;
216 		}
217 	}
218 
219 	*ipp = ip;
220 	*tpp = tp;
221 
222 	return 0;
223 }
224 
225 /*
226  * Decrement the link count on an inode & log the change.
227  * If this causes the link count to go to zero, initiate the
228  * logging activity required to truncate a file.
229  */
230 int				/* error */
xfs_droplink(xfs_trans_t * tp,xfs_inode_t * ip)231 xfs_droplink(
232 	xfs_trans_t *tp,
233 	xfs_inode_t *ip)
234 {
235 	int	error;
236 
237 	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
238 
239 	ASSERT (ip->i_d.di_nlink > 0);
240 	ip->i_d.di_nlink--;
241 	drop_nlink(VFS_I(ip));
242 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
243 
244 	error = 0;
245 	if (ip->i_d.di_nlink == 0) {
246 		/*
247 		 * We're dropping the last link to this file.
248 		 * Move the on-disk inode to the AGI unlinked list.
249 		 * From xfs_inactive() we will pull the inode from
250 		 * the list and free it.
251 		 */
252 		error = xfs_iunlink(tp, ip);
253 	}
254 	return error;
255 }
256 
257 /*
258  * This gets called when the inode's version needs to be changed from 1 to 2.
259  * Currently this happens when the nlink field overflows the old 16-bit value
260  * or when chproj is called to change the project for the first time.
261  * As a side effect the superblock version will also get rev'd
262  * to contain the NLINK bit.
263  */
264 void
xfs_bump_ino_vers2(xfs_trans_t * tp,xfs_inode_t * ip)265 xfs_bump_ino_vers2(
266 	xfs_trans_t	*tp,
267 	xfs_inode_t	*ip)
268 {
269 	xfs_mount_t	*mp;
270 
271 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
272 	ASSERT(ip->i_d.di_version == 1);
273 
274 	ip->i_d.di_version = 2;
275 	ip->i_d.di_onlink = 0;
276 	memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
277 	mp = tp->t_mountp;
278 	if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
279 		spin_lock(&mp->m_sb_lock);
280 		if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
281 			xfs_sb_version_addnlink(&mp->m_sb);
282 			spin_unlock(&mp->m_sb_lock);
283 			xfs_mod_sb(tp, XFS_SB_VERSIONNUM);
284 		} else {
285 			spin_unlock(&mp->m_sb_lock);
286 		}
287 	}
288 	/* Caller must log the inode */
289 }
290 
291 /*
292  * Increment the link count on an inode & log the change.
293  */
294 int
xfs_bumplink(xfs_trans_t * tp,xfs_inode_t * ip)295 xfs_bumplink(
296 	xfs_trans_t *tp,
297 	xfs_inode_t *ip)
298 {
299 	xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
300 
301 	ASSERT(ip->i_d.di_nlink > 0);
302 	ip->i_d.di_nlink++;
303 	inc_nlink(VFS_I(ip));
304 	if ((ip->i_d.di_version == 1) &&
305 	    (ip->i_d.di_nlink > XFS_MAXLINK_1)) {
306 		/*
307 		 * The inode has increased its number of links beyond
308 		 * what can fit in an old format inode.  It now needs
309 		 * to be converted to a version 2 inode with a 32 bit
310 		 * link count.  If this is the first inode in the file
311 		 * system to do this, then we need to bump the superblock
312 		 * version number as well.
313 		 */
314 		xfs_bump_ino_vers2(tp, ip);
315 	}
316 
317 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
318 	return 0;
319 }
320