Root/fs/jfs/inode.c

1/*
2 * Copyright (C) International Business Machines Corp., 2000-2004
3 * Portions Copyright (C) Christoph Hellwig, 2001-2002
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20#include <linux/fs.h>
21#include <linux/mpage.h>
22#include <linux/buffer_head.h>
23#include <linux/pagemap.h>
24#include <linux/quotaops.h>
25#include <linux/writeback.h>
26#include "jfs_incore.h"
27#include "jfs_inode.h"
28#include "jfs_filsys.h"
29#include "jfs_imap.h"
30#include "jfs_extent.h"
31#include "jfs_unicode.h"
32#include "jfs_debug.h"
33
34
35struct inode *jfs_iget(struct super_block *sb, unsigned long ino)
36{
37    struct inode *inode;
38    int ret;
39
40    inode = iget_locked(sb, ino);
41    if (!inode)
42        return ERR_PTR(-ENOMEM);
43    if (!(inode->i_state & I_NEW))
44        return inode;
45
46    ret = diRead(inode);
47    if (ret < 0) {
48        iget_failed(inode);
49        return ERR_PTR(ret);
50    }
51
52    if (S_ISREG(inode->i_mode)) {
53        inode->i_op = &jfs_file_inode_operations;
54        inode->i_fop = &jfs_file_operations;
55        inode->i_mapping->a_ops = &jfs_aops;
56    } else if (S_ISDIR(inode->i_mode)) {
57        inode->i_op = &jfs_dir_inode_operations;
58        inode->i_fop = &jfs_dir_operations;
59    } else if (S_ISLNK(inode->i_mode)) {
60        if (inode->i_size >= IDATASIZE) {
61            inode->i_op = &page_symlink_inode_operations;
62            inode->i_mapping->a_ops = &jfs_aops;
63        } else {
64            inode->i_op = &jfs_fast_symlink_inode_operations;
65            /*
66             * The inline data should be null-terminated, but
67             * don't let on-disk corruption crash the kernel
68             */
69            JFS_IP(inode)->i_inline[inode->i_size] = '\0';
70        }
71    } else {
72        inode->i_op = &jfs_file_inode_operations;
73        init_special_inode(inode, inode->i_mode, inode->i_rdev);
74    }
75    unlock_new_inode(inode);
76    return inode;
77}
78
79/*
80 * Workhorse of both fsync & write_inode
81 */
82int jfs_commit_inode(struct inode *inode, int wait)
83{
84    int rc = 0;
85    tid_t tid;
86    static int noisy = 5;
87
88    jfs_info("In jfs_commit_inode, inode = 0x%p", inode);
89
90    /*
91     * Don't commit if inode has been committed since last being
92     * marked dirty, or if it has been deleted.
93     */
94    if (inode->i_nlink == 0 || !test_cflag(COMMIT_Dirty, inode))
95        return 0;
96
97    if (isReadOnly(inode)) {
98        /* kernel allows writes to devices on read-only
99         * partitions and may think inode is dirty
100         */
101        if (!special_file(inode->i_mode) && noisy) {
102            jfs_err("jfs_commit_inode(0x%p) called on "
103                   "read-only volume", inode);
104            jfs_err("Is remount racy?");
105            noisy--;
106        }
107        return 0;
108    }
109
110    tid = txBegin(inode->i_sb, COMMIT_INODE);
111    mutex_lock(&JFS_IP(inode)->commit_mutex);
112
113    /*
114     * Retest inode state after taking commit_mutex
115     */
116    if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
117        rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
118
119    txEnd(tid);
120    mutex_unlock(&JFS_IP(inode)->commit_mutex);
121    return rc;
122}
123
124int jfs_write_inode(struct inode *inode, struct writeback_control *wbc)
125{
126    int wait = wbc->sync_mode == WB_SYNC_ALL;
127
128    if (test_cflag(COMMIT_Nolink, inode))
129        return 0;
130    /*
131     * If COMMIT_DIRTY is not set, the inode isn't really dirty.
132     * It has been committed since the last change, but was still
133     * on the dirty inode list.
134     */
135     if (!test_cflag(COMMIT_Dirty, inode)) {
136        /* Make sure committed changes hit the disk */
137        jfs_flush_journal(JFS_SBI(inode->i_sb)->log, wait);
138        return 0;
139     }
140
141    if (jfs_commit_inode(inode, wait)) {
142        jfs_err("jfs_write_inode: jfs_commit_inode failed!");
143        return -EIO;
144    } else
145        return 0;
146}
147
148void jfs_evict_inode(struct inode *inode)
149{
150    jfs_info("In jfs_evict_inode, inode = 0x%p", inode);
151
152    if (!inode->i_nlink && !is_bad_inode(inode)) {
153        dquot_initialize(inode);
154
155        if (JFS_IP(inode)->fileset == FILESYSTEM_I) {
156            truncate_inode_pages(&inode->i_data, 0);
157
158            if (test_cflag(COMMIT_Freewmap, inode))
159                jfs_free_zero_link(inode);
160
161            diFree(inode);
162
163            /*
164             * Free the inode from the quota allocation.
165             */
166            dquot_initialize(inode);
167            dquot_free_inode(inode);
168        }
169    } else {
170        truncate_inode_pages(&inode->i_data, 0);
171    }
172    end_writeback(inode);
173    dquot_drop(inode);
174}
175
176void jfs_dirty_inode(struct inode *inode, int flags)
177{
178    static int noisy = 5;
179
180    if (isReadOnly(inode)) {
181        if (!special_file(inode->i_mode) && noisy) {
182            /* kernel allows writes to devices on read-only
183             * partitions and may try to mark inode dirty
184             */
185            jfs_err("jfs_dirty_inode called on read-only volume");
186            jfs_err("Is remount racy?");
187            noisy--;
188        }
189        return;
190    }
191
192    set_cflag(COMMIT_Dirty, inode);
193}
194
195int jfs_get_block(struct inode *ip, sector_t lblock,
196          struct buffer_head *bh_result, int create)
197{
198    s64 lblock64 = lblock;
199    int rc = 0;
200    xad_t xad;
201    s64 xaddr;
202    int xflag;
203    s32 xlen = bh_result->b_size >> ip->i_blkbits;
204
205    /*
206     * Take appropriate lock on inode
207     */
208    if (create)
209        IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
210    else
211        IREAD_LOCK(ip, RDWRLOCK_NORMAL);
212
213    if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
214        (!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
215        xaddr) {
216        if (xflag & XAD_NOTRECORDED) {
217            if (!create)
218                /*
219                 * Allocated but not recorded, read treats
220                 * this as a hole
221                 */
222                goto unlock;
223#ifdef _JFS_4K
224            XADoffset(&xad, lblock64);
225            XADlength(&xad, xlen);
226            XADaddress(&xad, xaddr);
227#else /* _JFS_4K */
228            /*
229             * As long as block size = 4K, this isn't a problem.
230             * We should mark the whole page not ABNR, but how
231             * will we know to mark the other blocks BH_New?
232             */
233            BUG();
234#endif /* _JFS_4K */
235            rc = extRecord(ip, &xad);
236            if (rc)
237                goto unlock;
238            set_buffer_new(bh_result);
239        }
240
241        map_bh(bh_result, ip->i_sb, xaddr);
242        bh_result->b_size = xlen << ip->i_blkbits;
243        goto unlock;
244    }
245    if (!create)
246        goto unlock;
247
248    /*
249     * Allocate a new block
250     */
251#ifdef _JFS_4K
252    if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
253        goto unlock;
254    rc = extAlloc(ip, xlen, lblock64, &xad, false);
255    if (rc)
256        goto unlock;
257
258    set_buffer_new(bh_result);
259    map_bh(bh_result, ip->i_sb, addressXAD(&xad));
260    bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
261
262#else /* _JFS_4K */
263    /*
264     * We need to do whatever it takes to keep all but the last buffers
265     * in 4K pages - see jfs_write.c
266     */
267    BUG();
268#endif /* _JFS_4K */
269
270      unlock:
271    /*
272     * Release lock on inode
273     */
274    if (create)
275        IWRITE_UNLOCK(ip);
276    else
277        IREAD_UNLOCK(ip);
278    return rc;
279}
280
281static int jfs_writepage(struct page *page, struct writeback_control *wbc)
282{
283    return block_write_full_page(page, jfs_get_block, wbc);
284}
285
286static int jfs_writepages(struct address_space *mapping,
287            struct writeback_control *wbc)
288{
289    return mpage_writepages(mapping, wbc, jfs_get_block);
290}
291
292static int jfs_readpage(struct file *file, struct page *page)
293{
294    return mpage_readpage(page, jfs_get_block);
295}
296
297static int jfs_readpages(struct file *file, struct address_space *mapping,
298        struct list_head *pages, unsigned nr_pages)
299{
300    return mpage_readpages(mapping, pages, nr_pages, jfs_get_block);
301}
302
303static int jfs_write_begin(struct file *file, struct address_space *mapping,
304                loff_t pos, unsigned len, unsigned flags,
305                struct page **pagep, void **fsdata)
306{
307    int ret;
308
309    ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata,
310                jfs_get_block);
311    if (unlikely(ret)) {
312        loff_t isize = mapping->host->i_size;
313        if (pos + len > isize)
314            vmtruncate(mapping->host, isize);
315    }
316
317    return ret;
318}
319
320static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
321{
322    return generic_block_bmap(mapping, block, jfs_get_block);
323}
324
325static ssize_t jfs_direct_IO(int rw, struct kiocb *iocb,
326    const struct iovec *iov, loff_t offset, unsigned long nr_segs)
327{
328    struct file *file = iocb->ki_filp;
329    struct inode *inode = file->f_mapping->host;
330    ssize_t ret;
331
332    ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
333                offset, nr_segs, jfs_get_block, NULL);
334
335    /*
336     * In case of error extending write may have instantiated a few
337     * blocks outside i_size. Trim these off again.
338     */
339    if (unlikely((rw & WRITE) && ret < 0)) {
340        loff_t isize = i_size_read(inode);
341        loff_t end = offset + iov_length(iov, nr_segs);
342
343        if (end > isize)
344            vmtruncate(inode, isize);
345    }
346
347    return ret;
348}
349
350const struct address_space_operations jfs_aops = {
351    .readpage = jfs_readpage,
352    .readpages = jfs_readpages,
353    .writepage = jfs_writepage,
354    .writepages = jfs_writepages,
355    .write_begin = jfs_write_begin,
356    .write_end = nobh_write_end,
357    .bmap = jfs_bmap,
358    .direct_IO = jfs_direct_IO,
359};
360
361/*
362 * Guts of jfs_truncate. Called with locks already held. Can be called
363 * with directory for truncating directory index table.
364 */
365void jfs_truncate_nolock(struct inode *ip, loff_t length)
366{
367    loff_t newsize;
368    tid_t tid;
369
370    ASSERT(length >= 0);
371
372    if (test_cflag(COMMIT_Nolink, ip)) {
373        xtTruncate(0, ip, length, COMMIT_WMAP);
374        return;
375    }
376
377    do {
378        tid = txBegin(ip->i_sb, 0);
379
380        /*
381         * The commit_mutex cannot be taken before txBegin.
382         * txBegin may block and there is a chance the inode
383         * could be marked dirty and need to be committed
384         * before txBegin unblocks
385         */
386        mutex_lock(&JFS_IP(ip)->commit_mutex);
387
388        newsize = xtTruncate(tid, ip, length,
389                     COMMIT_TRUNCATE | COMMIT_PWMAP);
390        if (newsize < 0) {
391            txEnd(tid);
392            mutex_unlock(&JFS_IP(ip)->commit_mutex);
393            break;
394        }
395
396        ip->i_mtime = ip->i_ctime = CURRENT_TIME;
397        mark_inode_dirty(ip);
398
399        txCommit(tid, 1, &ip, 0);
400        txEnd(tid);
401        mutex_unlock(&JFS_IP(ip)->commit_mutex);
402    } while (newsize > length); /* Truncate isn't always atomic */
403}
404
405void jfs_truncate(struct inode *ip)
406{
407    jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
408
409    nobh_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);
410
411    IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
412    jfs_truncate_nolock(ip, ip->i_size);
413    IWRITE_UNLOCK(ip);
414}
415

Archive Download this file



interactive