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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6.36/fs/xfs/
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 */
50int
51xfs_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	mode_t		mode,
57	xfs_nlink_t	nlink,
58	xfs_dev_t	rdev,
59	cred_t		*credp,
60	prid_t		prid,		/* project id */
61	int		okalloc,	/* ok to allocate new space */
62	xfs_inode_t	**ipp,		/* pointer to inode; it will be
63					   locked. */
64	int		*committed)
65
66{
67	xfs_trans_t	*tp;
68	xfs_trans_t	*ntp;
69	xfs_inode_t	*ip;
70	xfs_buf_t	*ialloc_context = NULL;
71	boolean_t	call_again = B_FALSE;
72	int		code;
73	uint		log_res;
74	uint		log_count;
75	void		*dqinfo;
76	uint		tflags;
77
78	tp = *tpp;
79	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
80
81	/*
82	 * xfs_ialloc will return a pointer to an incore inode if
83	 * the Space Manager has an available inode on the free
84	 * list. Otherwise, it will do an allocation and replenish
85	 * the freelist.  Since we can only do one allocation per
86	 * transaction without deadlocks, we will need to commit the
87	 * current transaction and start a new one.  We will then
88	 * need to call xfs_ialloc again to get the inode.
89	 *
90	 * If xfs_ialloc did an allocation to replenish the freelist,
91	 * it returns the bp containing the head of the freelist as
92	 * ialloc_context. We will hold a lock on it across the
93	 * transaction commit so that no other process can steal
94	 * the inode(s) that we've just allocated.
95	 */
96	code = xfs_ialloc(tp, dp, mode, nlink, rdev, credp, prid, okalloc,
97			  &ialloc_context, &call_again, &ip);
98
99	/*
100	 * Return an error if we were unable to allocate a new inode.
101	 * This should only happen if we run out of space on disk or
102	 * encounter a disk error.
103	 */
104	if (code) {
105		*ipp = NULL;
106		return code;
107	}
108	if (!call_again && (ip == NULL)) {
109		*ipp = NULL;
110		return XFS_ERROR(ENOSPC);
111	}
112
113	/*
114	 * If call_again is set, then we were unable to get an
115	 * inode in one operation.  We need to commit the current
116	 * transaction and call xfs_ialloc() again.  It is guaranteed
117	 * to succeed the second time.
118	 */
119	if (call_again) {
120
121		/*
122		 * Normally, xfs_trans_commit releases all the locks.
123		 * We call bhold to hang on to the ialloc_context across
124		 * the commit.  Holding this buffer prevents any other
125		 * processes from doing any allocations in this
126		 * allocation group.
127		 */
128		xfs_trans_bhold(tp, ialloc_context);
129		/*
130		 * Save the log reservation so we can use
131		 * them in the next transaction.
132		 */
133		log_res = xfs_trans_get_log_res(tp);
134		log_count = xfs_trans_get_log_count(tp);
135
136		/*
137		 * We want the quota changes to be associated with the next
138		 * transaction, NOT this one. So, detach the dqinfo from this
139		 * and attach it to the next transaction.
140		 */
141		dqinfo = NULL;
142		tflags = 0;
143		if (tp->t_dqinfo) {
144			dqinfo = (void *)tp->t_dqinfo;
145			tp->t_dqinfo = NULL;
146			tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY;
147			tp->t_flags &= ~(XFS_TRANS_DQ_DIRTY);
148		}
149
150		ntp = xfs_trans_dup(tp);
151		code = xfs_trans_commit(tp, 0);
152		tp = ntp;
153		if (committed != NULL) {
154			*committed = 1;
155		}
156		/*
157		 * If we get an error during the commit processing,
158		 * release the buffer that is still held and return
159		 * to the caller.
160		 */
161		if (code) {
162			xfs_buf_relse(ialloc_context);
163			if (dqinfo) {
164				tp->t_dqinfo = dqinfo;
165				xfs_trans_free_dqinfo(tp);
166			}
167			*tpp = ntp;
168			*ipp = NULL;
169			return code;
170		}
171
172		/*
173		 * transaction commit worked ok so we can drop the extra ticket
174		 * reference that we gained in xfs_trans_dup()
175		 */
176		xfs_log_ticket_put(tp->t_ticket);
177		code = xfs_trans_reserve(tp, 0, log_res, 0,
178					 XFS_TRANS_PERM_LOG_RES, log_count);
179		/*
180		 * Re-attach the quota info that we detached from prev trx.
181		 */
182		if (dqinfo) {
183			tp->t_dqinfo = dqinfo;
184			tp->t_flags |= tflags;
185		}
186
187		if (code) {
188			xfs_buf_relse(ialloc_context);
189			*tpp = ntp;
190			*ipp = NULL;
191			return code;
192		}
193		xfs_trans_bjoin(tp, ialloc_context);
194
195		/*
196		 * Call ialloc again. Since we've locked out all
197		 * other allocations in this allocation group,
198		 * this call should always succeed.
199		 */
200		code = xfs_ialloc(tp, dp, mode, nlink, rdev, credp, prid,
201				  okalloc, &ialloc_context, &call_again, &ip);
202
203		/*
204		 * If we get an error at this point, return to the caller
205		 * so that the current transaction can be aborted.
206		 */
207		if (code) {
208			*tpp = tp;
209			*ipp = NULL;
210			return code;
211		}
212		ASSERT ((!call_again) && (ip != NULL));
213
214	} else {
215		if (committed != NULL) {
216			*committed = 0;
217		}
218	}
219
220	*ipp = ip;
221	*tpp = tp;
222
223	return 0;
224}
225
226/*
227 * Decrement the link count on an inode & log the change.
228 * If this causes the link count to go to zero, initiate the
229 * logging activity required to truncate a file.
230 */
231int				/* error */
232xfs_droplink(
233	xfs_trans_t *tp,
234	xfs_inode_t *ip)
235{
236	int	error;
237
238	xfs_ichgtime(ip, XFS_ICHGTIME_CHG);
239
240	ASSERT (ip->i_d.di_nlink > 0);
241	ip->i_d.di_nlink--;
242	drop_nlink(VFS_I(ip));
243	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
244
245	error = 0;
246	if (ip->i_d.di_nlink == 0) {
247		/*
248		 * We're dropping the last link to this file.
249		 * Move the on-disk inode to the AGI unlinked list.
250		 * From xfs_inactive() we will pull the inode from
251		 * the list and free it.
252		 */
253		error = xfs_iunlink(tp, ip);
254	}
255	return error;
256}
257
258/*
259 * This gets called when the inode's version needs to be changed from 1 to 2.
260 * Currently this happens when the nlink field overflows the old 16-bit value
261 * or when chproj is called to change the project for the first time.
262 * As a side effect the superblock version will also get rev'd
263 * to contain the NLINK bit.
264 */
265void
266xfs_bump_ino_vers2(
267	xfs_trans_t	*tp,
268	xfs_inode_t	*ip)
269{
270	xfs_mount_t	*mp;
271
272	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
273	ASSERT(ip->i_d.di_version == 1);
274
275	ip->i_d.di_version = 2;
276	ip->i_d.di_onlink = 0;
277	memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad));
278	mp = tp->t_mountp;
279	if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
280		spin_lock(&mp->m_sb_lock);
281		if (!xfs_sb_version_hasnlink(&mp->m_sb)) {
282			xfs_sb_version_addnlink(&mp->m_sb);
283			spin_unlock(&mp->m_sb_lock);
284			xfs_mod_sb(tp, XFS_SB_VERSIONNUM);
285		} else {
286			spin_unlock(&mp->m_sb_lock);
287		}
288	}
289	/* Caller must log the inode */
290}
291
292/*
293 * Increment the link count on an inode & log the change.
294 */
295int
296xfs_bumplink(
297	xfs_trans_t *tp,
298	xfs_inode_t *ip)
299{
300	if (ip->i_d.di_nlink >= XFS_MAXLINK)
301		return XFS_ERROR(EMLINK);
302	xfs_ichgtime(ip, XFS_ICHGTIME_CHG);
303
304	ASSERT(ip->i_d.di_nlink > 0);
305	ip->i_d.di_nlink++;
306	inc_nlink(VFS_I(ip));
307	if ((ip->i_d.di_version == 1) &&
308	    (ip->i_d.di_nlink > XFS_MAXLINK_1)) {
309		/*
310		 * The inode has increased its number of links beyond
311		 * what can fit in an old format inode.  It now needs
312		 * to be converted to a version 2 inode with a 32 bit
313		 * link count.  If this is the first inode in the file
314		 * system to do this, then we need to bump the superblock
315		 * version number as well.
316		 */
317		xfs_bump_ino_vers2(tp, ip);
318	}
319
320	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
321	return 0;
322}
323