1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
4  * Copyright (C) 2004-2011 Red Hat, Inc.  All rights reserved.
5  */
6 
7 #include <linux/slab.h>
8 #include <linux/spinlock.h>
9 #include <linux/completion.h>
10 #include <linux/buffer_head.h>
11 #include <linux/namei.h>
12 #include <linux/mm.h>
13 #include <linux/cred.h>
14 #include <linux/xattr.h>
15 #include <linux/posix_acl.h>
16 #include <linux/gfs2_ondisk.h>
17 #include <linux/crc32.h>
18 #include <linux/iomap.h>
19 #include <linux/security.h>
20 #include <linux/fiemap.h>
21 #include <linux/uaccess.h>
22 
23 #include "gfs2.h"
24 #include "incore.h"
25 #include "acl.h"
26 #include "bmap.h"
27 #include "dir.h"
28 #include "xattr.h"
29 #include "glock.h"
30 #include "inode.h"
31 #include "meta_io.h"
32 #include "quota.h"
33 #include "rgrp.h"
34 #include "trans.h"
35 #include "util.h"
36 #include "super.h"
37 #include "glops.h"
38 
39 static const struct inode_operations gfs2_file_iops;
40 static const struct inode_operations gfs2_dir_iops;
41 static const struct inode_operations gfs2_symlink_iops;
42 
43 /**
44  * gfs2_set_iop - Sets inode operations
45  * @inode: The inode with correct i_mode filled in
46  *
47  * GFS2 lookup code fills in vfs inode contents based on info obtained
48  * from directory entry inside gfs2_inode_lookup().
49  */
50 
gfs2_set_iop(struct inode * inode)51 static void gfs2_set_iop(struct inode *inode)
52 {
53 	struct gfs2_sbd *sdp = GFS2_SB(inode);
54 	umode_t mode = inode->i_mode;
55 
56 	if (S_ISREG(mode)) {
57 		inode->i_op = &gfs2_file_iops;
58 		if (gfs2_localflocks(sdp))
59 			inode->i_fop = &gfs2_file_fops_nolock;
60 		else
61 			inode->i_fop = &gfs2_file_fops;
62 	} else if (S_ISDIR(mode)) {
63 		inode->i_op = &gfs2_dir_iops;
64 		if (gfs2_localflocks(sdp))
65 			inode->i_fop = &gfs2_dir_fops_nolock;
66 		else
67 			inode->i_fop = &gfs2_dir_fops;
68 	} else if (S_ISLNK(mode)) {
69 		inode->i_op = &gfs2_symlink_iops;
70 	} else {
71 		inode->i_op = &gfs2_file_iops;
72 		init_special_inode(inode, inode->i_mode, inode->i_rdev);
73 	}
74 }
75 
iget_test(struct inode * inode,void * opaque)76 static int iget_test(struct inode *inode, void *opaque)
77 {
78 	u64 no_addr = *(u64 *)opaque;
79 
80 	return GFS2_I(inode)->i_no_addr == no_addr;
81 }
82 
iget_set(struct inode * inode,void * opaque)83 static int iget_set(struct inode *inode, void *opaque)
84 {
85 	u64 no_addr = *(u64 *)opaque;
86 
87 	GFS2_I(inode)->i_no_addr = no_addr;
88 	inode->i_ino = no_addr;
89 	return 0;
90 }
91 
92 /**
93  * gfs2_inode_lookup - Lookup an inode
94  * @sb: The super block
95  * @type: The type of the inode
96  * @no_addr: The inode number
97  * @no_formal_ino: The inode generation number
98  * @blktype: Requested block type (GFS2_BLKST_DINODE or GFS2_BLKST_UNLINKED;
99  *           GFS2_BLKST_FREE to indicate not to verify)
100  *
101  * If @type is DT_UNKNOWN, the inode type is fetched from disk.
102  *
103  * If @blktype is anything other than GFS2_BLKST_FREE (which is used as a
104  * placeholder because it doesn't otherwise make sense), the on-disk block type
105  * is verified to be @blktype.
106  *
107  * When @no_formal_ino is non-zero, this function will return ERR_PTR(-ESTALE)
108  * if it detects that @no_formal_ino doesn't match the actual inode generation
109  * number.  However, it doesn't always know unless @type is DT_UNKNOWN.
110  *
111  * Returns: A VFS inode, or an error
112  */
113 
gfs2_inode_lookup(struct super_block * sb,unsigned int type,u64 no_addr,u64 no_formal_ino,unsigned int blktype)114 struct inode *gfs2_inode_lookup(struct super_block *sb, unsigned int type,
115 				u64 no_addr, u64 no_formal_ino,
116 				unsigned int blktype)
117 {
118 	struct inode *inode;
119 	struct gfs2_inode *ip;
120 	struct gfs2_holder i_gh;
121 	int error;
122 
123 	gfs2_holder_mark_uninitialized(&i_gh);
124 	inode = iget5_locked(sb, no_addr, iget_test, iget_set, &no_addr);
125 	if (!inode)
126 		return ERR_PTR(-ENOMEM);
127 
128 	ip = GFS2_I(inode);
129 
130 	if (inode->i_state & I_NEW) {
131 		struct gfs2_sbd *sdp = GFS2_SB(inode);
132 		struct gfs2_glock *io_gl;
133 		int extra_flags = 0;
134 
135 		error = gfs2_glock_get(sdp, no_addr, &gfs2_inode_glops, CREATE,
136 				       &ip->i_gl);
137 		if (unlikely(error))
138 			goto fail;
139 
140 		error = gfs2_glock_get(sdp, no_addr, &gfs2_iopen_glops, CREATE,
141 				       &io_gl);
142 		if (unlikely(error))
143 			goto fail;
144 
145 		/*
146 		 * The only caller that sets @blktype to GFS2_BLKST_UNLINKED is
147 		 * delete_work_func().  Make sure not to cancel the delete work
148 		 * from within itself here.
149 		 */
150 		if (blktype == GFS2_BLKST_UNLINKED)
151 			extra_flags |= LM_FLAG_TRY;
152 		else
153 			gfs2_cancel_delete_work(io_gl);
154 		error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED,
155 					   GL_EXACT | GL_NOPID | extra_flags,
156 					   &ip->i_iopen_gh);
157 		gfs2_glock_put(io_gl);
158 		if (unlikely(error))
159 			goto fail;
160 
161 		if (type == DT_UNKNOWN || blktype != GFS2_BLKST_FREE) {
162 			/*
163 			 * The GL_SKIP flag indicates to skip reading the inode
164 			 * block.  We read the inode when instantiating it
165 			 * after possibly checking the block type.
166 			 */
167 			error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE,
168 						   GL_SKIP, &i_gh);
169 			if (error)
170 				goto fail;
171 
172 			error = -ESTALE;
173 			if (no_formal_ino &&
174 			    gfs2_inode_already_deleted(ip->i_gl, no_formal_ino))
175 				goto fail;
176 
177 			if (blktype != GFS2_BLKST_FREE) {
178 				error = gfs2_check_blk_type(sdp, no_addr,
179 							    blktype);
180 				if (error)
181 					goto fail;
182 			}
183 		}
184 
185 		set_bit(GLF_INSTANTIATE_NEEDED, &ip->i_gl->gl_flags);
186 
187 		/* Lowest possible timestamp; will be overwritten in gfs2_dinode_in. */
188 		inode_set_atime(inode,
189 				1LL << (8 * sizeof(inode_get_atime_sec(inode)) - 1),
190 				0);
191 
192 		glock_set_object(ip->i_gl, ip);
193 
194 		if (type == DT_UNKNOWN) {
195 			/* Inode glock must be locked already */
196 			error = gfs2_instantiate(&i_gh);
197 			if (error) {
198 				glock_clear_object(ip->i_gl, ip);
199 				goto fail;
200 			}
201 		} else {
202 			ip->i_no_formal_ino = no_formal_ino;
203 			inode->i_mode = DT2IF(type);
204 		}
205 
206 		if (gfs2_holder_initialized(&i_gh))
207 			gfs2_glock_dq_uninit(&i_gh);
208 		glock_set_object(ip->i_iopen_gh.gh_gl, ip);
209 
210 		gfs2_set_iop(inode);
211 		unlock_new_inode(inode);
212 	}
213 
214 	if (no_formal_ino && ip->i_no_formal_ino &&
215 	    no_formal_ino != ip->i_no_formal_ino) {
216 		iput(inode);
217 		return ERR_PTR(-ESTALE);
218 	}
219 
220 	return inode;
221 
222 fail:
223 	if (error == GLR_TRYFAILED)
224 		error = -EAGAIN;
225 	if (gfs2_holder_initialized(&ip->i_iopen_gh))
226 		gfs2_glock_dq_uninit(&ip->i_iopen_gh);
227 	if (gfs2_holder_initialized(&i_gh))
228 		gfs2_glock_dq_uninit(&i_gh);
229 	if (ip->i_gl) {
230 		gfs2_glock_put(ip->i_gl);
231 		ip->i_gl = NULL;
232 	}
233 	iget_failed(inode);
234 	return ERR_PTR(error);
235 }
236 
237 /**
238  * gfs2_lookup_by_inum - look up an inode by inode number
239  * @sdp: The super block
240  * @no_addr: The inode number
241  * @no_formal_ino: The inode generation number (0 for any)
242  * @blktype: Requested block type (see gfs2_inode_lookup)
243  */
gfs2_lookup_by_inum(struct gfs2_sbd * sdp,u64 no_addr,u64 no_formal_ino,unsigned int blktype)244 struct inode *gfs2_lookup_by_inum(struct gfs2_sbd *sdp, u64 no_addr,
245 				  u64 no_formal_ino, unsigned int blktype)
246 {
247 	struct super_block *sb = sdp->sd_vfs;
248 	struct inode *inode;
249 	int error;
250 
251 	inode = gfs2_inode_lookup(sb, DT_UNKNOWN, no_addr, no_formal_ino,
252 				  blktype);
253 	if (IS_ERR(inode))
254 		return inode;
255 
256 	if (no_formal_ino) {
257 		error = -EIO;
258 		if (GFS2_I(inode)->i_diskflags & GFS2_DIF_SYSTEM)
259 			goto fail_iput;
260 	}
261 	return inode;
262 
263 fail_iput:
264 	iput(inode);
265 	return ERR_PTR(error);
266 }
267 
268 
269 /**
270  * gfs2_lookup_meta - Look up an inode in a metadata directory
271  * @dip: The directory
272  * @name: The name of the inode
273  */
gfs2_lookup_meta(struct inode * dip,const char * name)274 struct inode *gfs2_lookup_meta(struct inode *dip, const char *name)
275 {
276 	struct qstr qstr;
277 	struct inode *inode;
278 
279 	gfs2_str2qstr(&qstr, name);
280 	inode = gfs2_lookupi(dip, &qstr, 1);
281 	if (IS_ERR_OR_NULL(inode))
282 		return inode ? inode : ERR_PTR(-ENOENT);
283 
284 	/*
285 	 * Must not call back into the filesystem when allocating
286 	 * pages in the metadata inode's address space.
287 	 */
288 	mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
289 
290 	return inode;
291 }
292 
293 
294 /**
295  * gfs2_lookupi - Look up a filename in a directory and return its inode
296  * @dir: The inode of the directory containing the inode to look-up
297  * @name: The name of the inode to look for
298  * @is_root: If 1, ignore the caller's permissions
299  *
300  * This can be called via the VFS filldir function when NFS is doing
301  * a readdirplus and the inode which its intending to stat isn't
302  * already in cache. In this case we must not take the directory glock
303  * again, since the readdir call will have already taken that lock.
304  *
305  * Returns: errno
306  */
307 
gfs2_lookupi(struct inode * dir,const struct qstr * name,int is_root)308 struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name,
309 			   int is_root)
310 {
311 	struct super_block *sb = dir->i_sb;
312 	struct gfs2_inode *dip = GFS2_I(dir);
313 	struct gfs2_holder d_gh;
314 	int error = 0;
315 	struct inode *inode = NULL;
316 
317 	gfs2_holder_mark_uninitialized(&d_gh);
318 	if (!name->len || name->len > GFS2_FNAMESIZE)
319 		return ERR_PTR(-ENAMETOOLONG);
320 
321 	if ((name->len == 1 && memcmp(name->name, ".", 1) == 0) ||
322 	    (name->len == 2 && memcmp(name->name, "..", 2) == 0 &&
323 	     dir == d_inode(sb->s_root))) {
324 		igrab(dir);
325 		return dir;
326 	}
327 
328 	if (gfs2_glock_is_locked_by_me(dip->i_gl) == NULL) {
329 		error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
330 		if (error)
331 			return ERR_PTR(error);
332 	}
333 
334 	if (!is_root) {
335 		error = gfs2_permission(&nop_mnt_idmap, dir, MAY_EXEC);
336 		if (error)
337 			goto out;
338 	}
339 
340 	inode = gfs2_dir_search(dir, name, false);
341 	if (IS_ERR(inode))
342 		error = PTR_ERR(inode);
343 out:
344 	if (gfs2_holder_initialized(&d_gh))
345 		gfs2_glock_dq_uninit(&d_gh);
346 	if (error == -ENOENT)
347 		return NULL;
348 	return inode ? inode : ERR_PTR(error);
349 }
350 
351 /**
352  * create_ok - OK to create a new on-disk inode here?
353  * @dip:  Directory in which dinode is to be created
354  * @name:  Name of new dinode
355  * @mode:
356  *
357  * Returns: errno
358  */
359 
create_ok(struct gfs2_inode * dip,const struct qstr * name,umode_t mode)360 static int create_ok(struct gfs2_inode *dip, const struct qstr *name,
361 		     umode_t mode)
362 {
363 	int error;
364 
365 	error = gfs2_permission(&nop_mnt_idmap, &dip->i_inode,
366 				MAY_WRITE | MAY_EXEC);
367 	if (error)
368 		return error;
369 
370 	/*  Don't create entries in an unlinked directory  */
371 	if (!dip->i_inode.i_nlink)
372 		return -ENOENT;
373 
374 	if (dip->i_entries == (u32)-1)
375 		return -EFBIG;
376 	if (S_ISDIR(mode) && dip->i_inode.i_nlink == (u32)-1)
377 		return -EMLINK;
378 
379 	return 0;
380 }
381 
munge_mode_uid_gid(const struct gfs2_inode * dip,struct inode * inode)382 static void munge_mode_uid_gid(const struct gfs2_inode *dip,
383 			       struct inode *inode)
384 {
385 	if (GFS2_SB(&dip->i_inode)->sd_args.ar_suiddir &&
386 	    (dip->i_inode.i_mode & S_ISUID) &&
387 	    !uid_eq(dip->i_inode.i_uid, GLOBAL_ROOT_UID)) {
388 		if (S_ISDIR(inode->i_mode))
389 			inode->i_mode |= S_ISUID;
390 		else if (!uid_eq(dip->i_inode.i_uid, current_fsuid()))
391 			inode->i_mode &= ~07111;
392 		inode->i_uid = dip->i_inode.i_uid;
393 	} else
394 		inode->i_uid = current_fsuid();
395 
396 	if (dip->i_inode.i_mode & S_ISGID) {
397 		if (S_ISDIR(inode->i_mode))
398 			inode->i_mode |= S_ISGID;
399 		inode->i_gid = dip->i_inode.i_gid;
400 	} else
401 		inode->i_gid = current_fsgid();
402 }
403 
alloc_dinode(struct gfs2_inode * ip,u32 flags,unsigned * dblocks)404 static int alloc_dinode(struct gfs2_inode *ip, u32 flags, unsigned *dblocks)
405 {
406 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
407 	struct gfs2_alloc_parms ap = { .target = *dblocks, .aflags = flags, };
408 	int error;
409 
410 	error = gfs2_quota_lock_check(ip, &ap);
411 	if (error)
412 		goto out;
413 
414 	error = gfs2_inplace_reserve(ip, &ap);
415 	if (error)
416 		goto out_quota;
417 
418 	error = gfs2_trans_begin(sdp, (*dblocks * RES_RG_BIT) + RES_STATFS + RES_QUOTA, 0);
419 	if (error)
420 		goto out_ipreserv;
421 
422 	error = gfs2_alloc_blocks(ip, &ip->i_no_addr, dblocks, 1);
423 	if (error)
424 		goto out_trans_end;
425 
426 	ip->i_no_formal_ino = ip->i_generation;
427 	ip->i_inode.i_ino = ip->i_no_addr;
428 	ip->i_goal = ip->i_no_addr;
429 	if (*dblocks > 1)
430 		ip->i_eattr = ip->i_no_addr + 1;
431 
432 out_trans_end:
433 	gfs2_trans_end(sdp);
434 out_ipreserv:
435 	gfs2_inplace_release(ip);
436 out_quota:
437 	gfs2_quota_unlock(ip);
438 out:
439 	return error;
440 }
441 
gfs2_init_dir(struct buffer_head * dibh,const struct gfs2_inode * parent)442 static void gfs2_init_dir(struct buffer_head *dibh,
443 			  const struct gfs2_inode *parent)
444 {
445 	struct gfs2_dinode *di = (struct gfs2_dinode *)dibh->b_data;
446 	struct gfs2_dirent *dent = (struct gfs2_dirent *)(di+1);
447 
448 	gfs2_qstr2dirent(&gfs2_qdot, GFS2_DIRENT_SIZE(gfs2_qdot.len), dent);
449 	dent->de_inum = di->di_num; /* already GFS2 endian */
450 	dent->de_type = cpu_to_be16(DT_DIR);
451 
452 	dent = (struct gfs2_dirent *)((char*)dent + GFS2_DIRENT_SIZE(1));
453 	gfs2_qstr2dirent(&gfs2_qdotdot, dibh->b_size - GFS2_DIRENT_SIZE(1) - sizeof(struct gfs2_dinode), dent);
454 	gfs2_inum_out(parent, dent);
455 	dent->de_type = cpu_to_be16(DT_DIR);
456 
457 }
458 
459 /**
460  * gfs2_init_xattr - Initialise an xattr block for a new inode
461  * @ip: The inode in question
462  *
463  * This sets up an empty xattr block for a new inode, ready to
464  * take any ACLs, LSM xattrs, etc.
465  */
466 
gfs2_init_xattr(struct gfs2_inode * ip)467 static void gfs2_init_xattr(struct gfs2_inode *ip)
468 {
469 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
470 	struct buffer_head *bh;
471 	struct gfs2_ea_header *ea;
472 
473 	bh = gfs2_meta_new(ip->i_gl, ip->i_eattr);
474 	gfs2_trans_add_meta(ip->i_gl, bh);
475 	gfs2_metatype_set(bh, GFS2_METATYPE_EA, GFS2_FORMAT_EA);
476 	gfs2_buffer_clear_tail(bh, sizeof(struct gfs2_meta_header));
477 
478 	ea = GFS2_EA_BH2FIRST(bh);
479 	ea->ea_rec_len = cpu_to_be32(sdp->sd_jbsize);
480 	ea->ea_type = GFS2_EATYPE_UNUSED;
481 	ea->ea_flags = GFS2_EAFLAG_LAST;
482 
483 	brelse(bh);
484 }
485 
486 /**
487  * init_dinode - Fill in a new dinode structure
488  * @dip: The directory this inode is being created in
489  * @ip: The inode
490  * @symname: The symlink destination (if a symlink)
491  *
492  */
493 
init_dinode(struct gfs2_inode * dip,struct gfs2_inode * ip,const char * symname)494 static void init_dinode(struct gfs2_inode *dip, struct gfs2_inode *ip,
495 			const char *symname)
496 {
497 	struct gfs2_dinode *di;
498 	struct buffer_head *dibh;
499 
500 	dibh = gfs2_meta_new(ip->i_gl, ip->i_no_addr);
501 	gfs2_trans_add_meta(ip->i_gl, dibh);
502 	di = (struct gfs2_dinode *)dibh->b_data;
503 	gfs2_dinode_out(ip, di);
504 
505 	di->di_major = cpu_to_be32(imajor(&ip->i_inode));
506 	di->di_minor = cpu_to_be32(iminor(&ip->i_inode));
507 	di->__pad1 = 0;
508 	di->__pad2 = 0;
509 	di->__pad3 = 0;
510 	memset(&di->__pad4, 0, sizeof(di->__pad4));
511 	memset(&di->di_reserved, 0, sizeof(di->di_reserved));
512 	gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
513 
514 	switch(ip->i_inode.i_mode & S_IFMT) {
515 	case S_IFDIR:
516 		gfs2_init_dir(dibh, dip);
517 		break;
518 	case S_IFLNK:
519 		memcpy(dibh->b_data + sizeof(struct gfs2_dinode), symname, ip->i_inode.i_size);
520 		break;
521 	}
522 
523 	set_buffer_uptodate(dibh);
524 	brelse(dibh);
525 }
526 
527 /**
528  * gfs2_trans_da_blks - Calculate number of blocks to link inode
529  * @dip: The directory we are linking into
530  * @da: The dir add information
531  * @nr_inodes: The number of inodes involved
532  *
533  * This calculate the number of blocks we need to reserve in a
534  * transaction to link @nr_inodes into a directory. In most cases
535  * @nr_inodes will be 2 (the directory plus the inode being linked in)
536  * but in case of rename, 4 may be required.
537  *
538  * Returns: Number of blocks
539  */
540 
gfs2_trans_da_blks(const struct gfs2_inode * dip,const struct gfs2_diradd * da,unsigned nr_inodes)541 static unsigned gfs2_trans_da_blks(const struct gfs2_inode *dip,
542 				   const struct gfs2_diradd *da,
543 				   unsigned nr_inodes)
544 {
545 	return da->nr_blocks + gfs2_rg_blocks(dip, da->nr_blocks) +
546 	       (nr_inodes * RES_DINODE) + RES_QUOTA + RES_STATFS;
547 }
548 
link_dinode(struct gfs2_inode * dip,const struct qstr * name,struct gfs2_inode * ip,struct gfs2_diradd * da)549 static int link_dinode(struct gfs2_inode *dip, const struct qstr *name,
550 		       struct gfs2_inode *ip, struct gfs2_diradd *da)
551 {
552 	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
553 	struct gfs2_alloc_parms ap = { .target = da->nr_blocks, };
554 	int error;
555 
556 	if (da->nr_blocks) {
557 		error = gfs2_quota_lock_check(dip, &ap);
558 		if (error)
559 			goto fail_quota_locks;
560 
561 		error = gfs2_inplace_reserve(dip, &ap);
562 		if (error)
563 			goto fail_quota_locks;
564 
565 		error = gfs2_trans_begin(sdp, gfs2_trans_da_blks(dip, da, 2), 0);
566 		if (error)
567 			goto fail_ipreserv;
568 	} else {
569 		error = gfs2_trans_begin(sdp, RES_LEAF + 2 * RES_DINODE, 0);
570 		if (error)
571 			goto fail_quota_locks;
572 	}
573 
574 	error = gfs2_dir_add(&dip->i_inode, name, ip, da);
575 
576 	gfs2_trans_end(sdp);
577 fail_ipreserv:
578 	gfs2_inplace_release(dip);
579 fail_quota_locks:
580 	gfs2_quota_unlock(dip);
581 	return error;
582 }
583 
gfs2_initxattrs(struct inode * inode,const struct xattr * xattr_array,void * fs_info)584 static int gfs2_initxattrs(struct inode *inode, const struct xattr *xattr_array,
585 		    void *fs_info)
586 {
587 	const struct xattr *xattr;
588 	int err = 0;
589 
590 	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
591 		err = __gfs2_xattr_set(inode, xattr->name, xattr->value,
592 				       xattr->value_len, 0,
593 				       GFS2_EATYPE_SECURITY);
594 		if (err < 0)
595 			break;
596 	}
597 	return err;
598 }
599 
600 /**
601  * gfs2_create_inode - Create a new inode
602  * @dir: The parent directory
603  * @dentry: The new dentry
604  * @file: If non-NULL, the file which is being opened
605  * @mode: The permissions on the new inode
606  * @dev: For device nodes, this is the device number
607  * @symname: For symlinks, this is the link destination
608  * @size: The initial size of the inode (ignored for directories)
609  * @excl: Force fail if inode exists
610  *
611  * FIXME: Change to allocate the disk blocks and write them out in the same
612  * transaction.  That way, we can no longer end up in a situation in which an
613  * inode is allocated, the node crashes, and the block looks like a valid
614  * inode.  (With atomic creates in place, we will also no longer need to zero
615  * the link count and dirty the inode here on failure.)
616  *
617  * Returns: 0 on success, or error code
618  */
619 
gfs2_create_inode(struct inode * dir,struct dentry * dentry,struct file * file,umode_t mode,dev_t dev,const char * symname,unsigned int size,int excl)620 static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
621 			     struct file *file,
622 			     umode_t mode, dev_t dev, const char *symname,
623 			     unsigned int size, int excl)
624 {
625 	const struct qstr *name = &dentry->d_name;
626 	struct posix_acl *default_acl, *acl;
627 	struct gfs2_holder d_gh, gh;
628 	struct inode *inode = NULL;
629 	struct gfs2_inode *dip = GFS2_I(dir), *ip;
630 	struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
631 	struct gfs2_glock *io_gl;
632 	int error;
633 	u32 aflags = 0;
634 	unsigned blocks = 1;
635 	struct gfs2_diradd da = { .bh = NULL, .save_loc = 1, };
636 
637 	if (!name->len || name->len > GFS2_FNAMESIZE)
638 		return -ENAMETOOLONG;
639 
640 	error = gfs2_qa_get(dip);
641 	if (error)
642 		return error;
643 
644 	error = gfs2_rindex_update(sdp);
645 	if (error)
646 		goto fail;
647 
648 	error = gfs2_glock_nq_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, &d_gh);
649 	if (error)
650 		goto fail;
651 	gfs2_holder_mark_uninitialized(&gh);
652 
653 	error = create_ok(dip, name, mode);
654 	if (error)
655 		goto fail_gunlock;
656 
657 	inode = gfs2_dir_search(dir, &dentry->d_name, !S_ISREG(mode) || excl);
658 	error = PTR_ERR(inode);
659 	if (!IS_ERR(inode)) {
660 		if (S_ISDIR(inode->i_mode)) {
661 			iput(inode);
662 			inode = ERR_PTR(-EISDIR);
663 			goto fail_gunlock;
664 		}
665 		d_instantiate(dentry, inode);
666 		error = 0;
667 		if (file) {
668 			if (S_ISREG(inode->i_mode))
669 				error = finish_open(file, dentry, gfs2_open_common);
670 			else
671 				error = finish_no_open(file, NULL);
672 		}
673 		gfs2_glock_dq_uninit(&d_gh);
674 		goto fail;
675 	} else if (error != -ENOENT) {
676 		goto fail_gunlock;
677 	}
678 
679 	error = gfs2_diradd_alloc_required(dir, name, &da);
680 	if (error < 0)
681 		goto fail_gunlock;
682 
683 	inode = new_inode(sdp->sd_vfs);
684 	error = -ENOMEM;
685 	if (!inode)
686 		goto fail_gunlock;
687 	ip = GFS2_I(inode);
688 
689 	error = posix_acl_create(dir, &mode, &default_acl, &acl);
690 	if (error)
691 		goto fail_gunlock;
692 
693 	error = gfs2_qa_get(ip);
694 	if (error)
695 		goto fail_free_acls;
696 
697 	inode->i_mode = mode;
698 	set_nlink(inode, S_ISDIR(mode) ? 2 : 1);
699 	inode->i_rdev = dev;
700 	inode->i_size = size;
701 	simple_inode_init_ts(inode);
702 	munge_mode_uid_gid(dip, inode);
703 	check_and_update_goal(dip);
704 	ip->i_goal = dip->i_goal;
705 	ip->i_diskflags = 0;
706 	ip->i_eattr = 0;
707 	ip->i_height = 0;
708 	ip->i_depth = 0;
709 	ip->i_entries = 0;
710 	ip->i_no_addr = 0; /* Temporarily zero until real addr is assigned */
711 
712 	switch(mode & S_IFMT) {
713 	case S_IFREG:
714 		if ((dip->i_diskflags & GFS2_DIF_INHERIT_JDATA) ||
715 		    gfs2_tune_get(sdp, gt_new_files_jdata))
716 			ip->i_diskflags |= GFS2_DIF_JDATA;
717 		gfs2_set_aops(inode);
718 		break;
719 	case S_IFDIR:
720 		ip->i_diskflags |= (dip->i_diskflags & GFS2_DIF_INHERIT_JDATA);
721 		ip->i_diskflags |= GFS2_DIF_JDATA;
722 		ip->i_entries = 2;
723 		break;
724 	}
725 
726 	/* Force SYSTEM flag on all files and subdirs of a SYSTEM directory */
727 	if (dip->i_diskflags & GFS2_DIF_SYSTEM)
728 		ip->i_diskflags |= GFS2_DIF_SYSTEM;
729 
730 	gfs2_set_inode_flags(inode);
731 
732 	if ((GFS2_I(d_inode(sdp->sd_root_dir)) == dip) ||
733 	    (dip->i_diskflags & GFS2_DIF_TOPDIR))
734 		aflags |= GFS2_AF_ORLOV;
735 
736 	if (default_acl || acl)
737 		blocks++;
738 
739 	error = alloc_dinode(ip, aflags, &blocks);
740 	if (error)
741 		goto fail_free_inode;
742 
743 	gfs2_set_inode_blocks(inode, blocks);
744 
745 	error = gfs2_glock_get(sdp, ip->i_no_addr, &gfs2_inode_glops, CREATE, &ip->i_gl);
746 	if (error)
747 		goto fail_free_inode;
748 
749 	error = gfs2_glock_get(sdp, ip->i_no_addr, &gfs2_iopen_glops, CREATE, &io_gl);
750 	if (error)
751 		goto fail_free_inode;
752 	gfs2_cancel_delete_work(io_gl);
753 	io_gl->gl_no_formal_ino = ip->i_no_formal_ino;
754 
755 retry:
756 	error = insert_inode_locked4(inode, ip->i_no_addr, iget_test, &ip->i_no_addr);
757 	if (error == -EBUSY)
758 		goto retry;
759 	if (error)
760 		goto fail_gunlock2;
761 
762 	error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT | GL_NOPID,
763 				   &ip->i_iopen_gh);
764 	if (error)
765 		goto fail_gunlock2;
766 
767 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_SKIP, &gh);
768 	if (error)
769 		goto fail_gunlock3;
770 
771 	error = gfs2_trans_begin(sdp, blocks, 0);
772 	if (error)
773 		goto fail_gunlock3;
774 
775 	if (blocks > 1)
776 		gfs2_init_xattr(ip);
777 	init_dinode(dip, ip, symname);
778 	gfs2_trans_end(sdp);
779 
780 	glock_set_object(ip->i_gl, ip);
781 	glock_set_object(io_gl, ip);
782 	gfs2_set_iop(inode);
783 
784 	if (default_acl) {
785 		error = __gfs2_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
786 		if (error)
787 			goto fail_gunlock4;
788 		posix_acl_release(default_acl);
789 		default_acl = NULL;
790 	}
791 	if (acl) {
792 		error = __gfs2_set_acl(inode, acl, ACL_TYPE_ACCESS);
793 		if (error)
794 			goto fail_gunlock4;
795 		posix_acl_release(acl);
796 		acl = NULL;
797 	}
798 
799 	error = security_inode_init_security(&ip->i_inode, &dip->i_inode, name,
800 					     &gfs2_initxattrs, NULL);
801 	if (error)
802 		goto fail_gunlock4;
803 
804 	error = link_dinode(dip, name, ip, &da);
805 	if (error)
806 		goto fail_gunlock4;
807 
808 	mark_inode_dirty(inode);
809 	d_instantiate(dentry, inode);
810 	/* After instantiate, errors should result in evict which will destroy
811 	 * both inode and iopen glocks properly. */
812 	if (file) {
813 		file->f_mode |= FMODE_CREATED;
814 		error = finish_open(file, dentry, gfs2_open_common);
815 	}
816 	gfs2_glock_dq_uninit(&d_gh);
817 	gfs2_qa_put(ip);
818 	gfs2_glock_dq_uninit(&gh);
819 	gfs2_glock_put(io_gl);
820 	gfs2_qa_put(dip);
821 	unlock_new_inode(inode);
822 	return error;
823 
824 fail_gunlock4:
825 	glock_clear_object(ip->i_gl, ip);
826 	glock_clear_object(io_gl, ip);
827 fail_gunlock3:
828 	gfs2_glock_dq_uninit(&ip->i_iopen_gh);
829 fail_gunlock2:
830 	gfs2_glock_put(io_gl);
831 fail_free_inode:
832 	if (ip->i_gl) {
833 		gfs2_glock_put(ip->i_gl);
834 		ip->i_gl = NULL;
835 	}
836 	gfs2_rs_deltree(&ip->i_res);
837 	gfs2_qa_put(ip);
838 fail_free_acls:
839 	posix_acl_release(default_acl);
840 	posix_acl_release(acl);
841 fail_gunlock:
842 	gfs2_dir_no_add(&da);
843 	gfs2_glock_dq_uninit(&d_gh);
844 	if (!IS_ERR_OR_NULL(inode)) {
845 		set_bit(GIF_ALLOC_FAILED, &ip->i_flags);
846 		clear_nlink(inode);
847 		if (ip->i_no_addr)
848 			mark_inode_dirty(inode);
849 		if (inode->i_state & I_NEW)
850 			iget_failed(inode);
851 		else
852 			iput(inode);
853 	}
854 	if (gfs2_holder_initialized(&gh))
855 		gfs2_glock_dq_uninit(&gh);
856 fail:
857 	gfs2_qa_put(dip);
858 	return error;
859 }
860 
861 /**
862  * gfs2_create - Create a file
863  * @idmap: idmap of the mount the inode was found from
864  * @dir: The directory in which to create the file
865  * @dentry: The dentry of the new file
866  * @mode: The mode of the new file
867  * @excl: Force fail if inode exists
868  *
869  * Returns: errno
870  */
871 
gfs2_create(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)872 static int gfs2_create(struct mnt_idmap *idmap, struct inode *dir,
873 		       struct dentry *dentry, umode_t mode, bool excl)
874 {
875 	return gfs2_create_inode(dir, dentry, NULL, S_IFREG | mode, 0, NULL, 0, excl);
876 }
877 
878 /**
879  * __gfs2_lookup - Look up a filename in a directory and return its inode
880  * @dir: The directory inode
881  * @dentry: The dentry of the new inode
882  * @file: File to be opened
883  *
884  *
885  * Returns: errno
886  */
887 
__gfs2_lookup(struct inode * dir,struct dentry * dentry,struct file * file)888 static struct dentry *__gfs2_lookup(struct inode *dir, struct dentry *dentry,
889 				    struct file *file)
890 {
891 	struct inode *inode;
892 	struct dentry *d;
893 	struct gfs2_holder gh;
894 	struct gfs2_glock *gl;
895 	int error;
896 
897 	inode = gfs2_lookupi(dir, &dentry->d_name, 0);
898 	if (inode == NULL) {
899 		d_add(dentry, NULL);
900 		return NULL;
901 	}
902 	if (IS_ERR(inode))
903 		return ERR_CAST(inode);
904 
905 	gl = GFS2_I(inode)->i_gl;
906 	error = gfs2_glock_nq_init(gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
907 	if (error) {
908 		iput(inode);
909 		return ERR_PTR(error);
910 	}
911 
912 	d = d_splice_alias(inode, dentry);
913 	if (IS_ERR(d)) {
914 		gfs2_glock_dq_uninit(&gh);
915 		return d;
916 	}
917 	if (file && S_ISREG(inode->i_mode))
918 		error = finish_open(file, dentry, gfs2_open_common);
919 
920 	gfs2_glock_dq_uninit(&gh);
921 	if (error) {
922 		dput(d);
923 		return ERR_PTR(error);
924 	}
925 	return d;
926 }
927 
gfs2_lookup(struct inode * dir,struct dentry * dentry,unsigned flags)928 static struct dentry *gfs2_lookup(struct inode *dir, struct dentry *dentry,
929 				  unsigned flags)
930 {
931 	return __gfs2_lookup(dir, dentry, NULL);
932 }
933 
934 /**
935  * gfs2_link - Link to a file
936  * @old_dentry: The inode to link
937  * @dir: Add link to this directory
938  * @dentry: The name of the link
939  *
940  * Link the inode in "old_dentry" into the directory "dir" with the
941  * name in "dentry".
942  *
943  * Returns: errno
944  */
945 
gfs2_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)946 static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
947 		     struct dentry *dentry)
948 {
949 	struct gfs2_inode *dip = GFS2_I(dir);
950 	struct gfs2_sbd *sdp = GFS2_SB(dir);
951 	struct inode *inode = d_inode(old_dentry);
952 	struct gfs2_inode *ip = GFS2_I(inode);
953 	struct gfs2_holder d_gh, gh;
954 	struct buffer_head *dibh;
955 	struct gfs2_diradd da = { .bh = NULL, .save_loc = 1, };
956 	int error;
957 
958 	if (S_ISDIR(inode->i_mode))
959 		return -EPERM;
960 
961 	error = gfs2_qa_get(dip);
962 	if (error)
963 		return error;
964 
965 	gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, &d_gh);
966 	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
967 
968 	error = gfs2_glock_nq(&d_gh);
969 	if (error)
970 		goto out_parent;
971 
972 	error = gfs2_glock_nq(&gh);
973 	if (error)
974 		goto out_child;
975 
976 	error = -ENOENT;
977 	if (inode->i_nlink == 0)
978 		goto out_gunlock;
979 
980 	error = gfs2_permission(&nop_mnt_idmap, dir, MAY_WRITE | MAY_EXEC);
981 	if (error)
982 		goto out_gunlock;
983 
984 	error = gfs2_dir_check(dir, &dentry->d_name, NULL);
985 	switch (error) {
986 	case -ENOENT:
987 		break;
988 	case 0:
989 		error = -EEXIST;
990 		goto out_gunlock;
991 	default:
992 		goto out_gunlock;
993 	}
994 
995 	error = -EINVAL;
996 	if (!dip->i_inode.i_nlink)
997 		goto out_gunlock;
998 	error = -EFBIG;
999 	if (dip->i_entries == (u32)-1)
1000 		goto out_gunlock;
1001 	error = -EPERM;
1002 	if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
1003 		goto out_gunlock;
1004 	error = -EMLINK;
1005 	if (ip->i_inode.i_nlink == (u32)-1)
1006 		goto out_gunlock;
1007 
1008 	error = gfs2_diradd_alloc_required(dir, &dentry->d_name, &da);
1009 	if (error < 0)
1010 		goto out_gunlock;
1011 
1012 	if (da.nr_blocks) {
1013 		struct gfs2_alloc_parms ap = { .target = da.nr_blocks, };
1014 		error = gfs2_quota_lock_check(dip, &ap);
1015 		if (error)
1016 			goto out_gunlock;
1017 
1018 		error = gfs2_inplace_reserve(dip, &ap);
1019 		if (error)
1020 			goto out_gunlock_q;
1021 
1022 		error = gfs2_trans_begin(sdp, gfs2_trans_da_blks(dip, &da, 2), 0);
1023 		if (error)
1024 			goto out_ipres;
1025 	} else {
1026 		error = gfs2_trans_begin(sdp, 2 * RES_DINODE + RES_LEAF, 0);
1027 		if (error)
1028 			goto out_ipres;
1029 	}
1030 
1031 	error = gfs2_meta_inode_buffer(ip, &dibh);
1032 	if (error)
1033 		goto out_end_trans;
1034 
1035 	error = gfs2_dir_add(dir, &dentry->d_name, ip, &da);
1036 	if (error)
1037 		goto out_brelse;
1038 
1039 	gfs2_trans_add_meta(ip->i_gl, dibh);
1040 	inc_nlink(&ip->i_inode);
1041 	inode_set_ctime_current(&ip->i_inode);
1042 	ihold(inode);
1043 	d_instantiate(dentry, inode);
1044 	mark_inode_dirty(inode);
1045 
1046 out_brelse:
1047 	brelse(dibh);
1048 out_end_trans:
1049 	gfs2_trans_end(sdp);
1050 out_ipres:
1051 	if (da.nr_blocks)
1052 		gfs2_inplace_release(dip);
1053 out_gunlock_q:
1054 	if (da.nr_blocks)
1055 		gfs2_quota_unlock(dip);
1056 out_gunlock:
1057 	gfs2_dir_no_add(&da);
1058 	gfs2_glock_dq(&gh);
1059 out_child:
1060 	gfs2_glock_dq(&d_gh);
1061 out_parent:
1062 	gfs2_qa_put(dip);
1063 	gfs2_holder_uninit(&d_gh);
1064 	gfs2_holder_uninit(&gh);
1065 	return error;
1066 }
1067 
1068 /*
1069  * gfs2_unlink_ok - check to see that a inode is still in a directory
1070  * @dip: the directory
1071  * @name: the name of the file
1072  * @ip: the inode
1073  *
1074  * Assumes that the lock on (at least) @dip is held.
1075  *
1076  * Returns: 0 if the parent/child relationship is correct, errno if it isn't
1077  */
1078 
gfs2_unlink_ok(struct gfs2_inode * dip,const struct qstr * name,const struct gfs2_inode * ip)1079 static int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name,
1080 			  const struct gfs2_inode *ip)
1081 {
1082 	int error;
1083 
1084 	if (IS_IMMUTABLE(&ip->i_inode) || IS_APPEND(&ip->i_inode))
1085 		return -EPERM;
1086 
1087 	if ((dip->i_inode.i_mode & S_ISVTX) &&
1088 	    !uid_eq(dip->i_inode.i_uid, current_fsuid()) &&
1089 	    !uid_eq(ip->i_inode.i_uid, current_fsuid()) && !capable(CAP_FOWNER))
1090 		return -EPERM;
1091 
1092 	if (IS_APPEND(&dip->i_inode))
1093 		return -EPERM;
1094 
1095 	error = gfs2_permission(&nop_mnt_idmap, &dip->i_inode,
1096 				MAY_WRITE | MAY_EXEC);
1097 	if (error)
1098 		return error;
1099 
1100 	return gfs2_dir_check(&dip->i_inode, name, ip);
1101 }
1102 
1103 /**
1104  * gfs2_unlink_inode - Removes an inode from its parent dir and unlinks it
1105  * @dip: The parent directory
1106  * @dentry: The dentry to unlink
1107  *
1108  * Called with all the locks and in a transaction. This will only be
1109  * called for a directory after it has been checked to ensure it is empty.
1110  *
1111  * Returns: 0 on success, or an error
1112  */
1113 
gfs2_unlink_inode(struct gfs2_inode * dip,const struct dentry * dentry)1114 static int gfs2_unlink_inode(struct gfs2_inode *dip,
1115 			     const struct dentry *dentry)
1116 {
1117 	struct inode *inode = d_inode(dentry);
1118 	struct gfs2_inode *ip = GFS2_I(inode);
1119 	int error;
1120 
1121 	error = gfs2_dir_del(dip, dentry);
1122 	if (error)
1123 		return error;
1124 
1125 	ip->i_entries = 0;
1126 	inode_set_ctime_current(inode);
1127 	if (S_ISDIR(inode->i_mode))
1128 		clear_nlink(inode);
1129 	else
1130 		drop_nlink(inode);
1131 	mark_inode_dirty(inode);
1132 	if (inode->i_nlink == 0)
1133 		gfs2_unlink_di(inode);
1134 	return 0;
1135 }
1136 
1137 
1138 /**
1139  * gfs2_unlink - Unlink an inode (this does rmdir as well)
1140  * @dir: The inode of the directory containing the inode to unlink
1141  * @dentry: The file itself
1142  *
1143  * This routine uses the type of the inode as a flag to figure out
1144  * whether this is an unlink or an rmdir.
1145  *
1146  * Returns: errno
1147  */
1148 
gfs2_unlink(struct inode * dir,struct dentry * dentry)1149 static int gfs2_unlink(struct inode *dir, struct dentry *dentry)
1150 {
1151 	struct gfs2_inode *dip = GFS2_I(dir);
1152 	struct gfs2_sbd *sdp = GFS2_SB(dir);
1153 	struct inode *inode = d_inode(dentry);
1154 	struct gfs2_inode *ip = GFS2_I(inode);
1155 	struct gfs2_holder d_gh, r_gh, gh;
1156 	struct gfs2_rgrpd *rgd;
1157 	int error;
1158 
1159 	error = gfs2_rindex_update(sdp);
1160 	if (error)
1161 		return error;
1162 
1163 	error = -EROFS;
1164 
1165 	gfs2_holder_init(dip->i_gl, LM_ST_EXCLUSIVE, 0, &d_gh);
1166 	gfs2_holder_init(ip->i_gl,  LM_ST_EXCLUSIVE, 0, &gh);
1167 
1168 	rgd = gfs2_blk2rgrpd(sdp, ip->i_no_addr, 1);
1169 	if (!rgd)
1170 		goto out_inodes;
1171 
1172 	gfs2_holder_init(rgd->rd_gl, LM_ST_EXCLUSIVE, LM_FLAG_NODE_SCOPE, &r_gh);
1173 
1174 
1175 	error = gfs2_glock_nq(&d_gh);
1176 	if (error)
1177 		goto out_parent;
1178 
1179 	error = gfs2_glock_nq(&gh);
1180 	if (error)
1181 		goto out_child;
1182 
1183 	error = -ENOENT;
1184 	if (inode->i_nlink == 0)
1185 		goto out_rgrp;
1186 
1187 	if (S_ISDIR(inode->i_mode)) {
1188 		error = -ENOTEMPTY;
1189 		if (ip->i_entries > 2 || inode->i_nlink > 2)
1190 			goto out_rgrp;
1191 	}
1192 
1193 	error = gfs2_glock_nq(&r_gh); /* rgrp */
1194 	if (error)
1195 		goto out_rgrp;
1196 
1197 	error = gfs2_unlink_ok(dip, &dentry->d_name, ip);
1198 	if (error)
1199 		goto out_gunlock;
1200 
1201 	error = gfs2_trans_begin(sdp, 2*RES_DINODE + 3*RES_LEAF + RES_RG_BIT, 0);
1202 	if (error)
1203 		goto out_gunlock;
1204 
1205 	error = gfs2_unlink_inode(dip, dentry);
1206 	gfs2_trans_end(sdp);
1207 
1208 out_gunlock:
1209 	gfs2_glock_dq(&r_gh);
1210 out_rgrp:
1211 	gfs2_glock_dq(&gh);
1212 out_child:
1213 	gfs2_glock_dq(&d_gh);
1214 out_parent:
1215 	gfs2_holder_uninit(&r_gh);
1216 out_inodes:
1217 	gfs2_holder_uninit(&gh);
1218 	gfs2_holder_uninit(&d_gh);
1219 	return error;
1220 }
1221 
1222 /**
1223  * gfs2_symlink - Create a symlink
1224  * @idmap: idmap of the mount the inode was found from
1225  * @dir: The directory to create the symlink in
1226  * @dentry: The dentry to put the symlink in
1227  * @symname: The thing which the link points to
1228  *
1229  * Returns: errno
1230  */
1231 
gfs2_symlink(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,const char * symname)1232 static int gfs2_symlink(struct mnt_idmap *idmap, struct inode *dir,
1233 			struct dentry *dentry, const char *symname)
1234 {
1235 	unsigned int size;
1236 
1237 	size = strlen(symname);
1238 	if (size >= gfs2_max_stuffed_size(GFS2_I(dir)))
1239 		return -ENAMETOOLONG;
1240 
1241 	return gfs2_create_inode(dir, dentry, NULL, S_IFLNK | S_IRWXUGO, 0, symname, size, 0);
1242 }
1243 
1244 /**
1245  * gfs2_mkdir - Make a directory
1246  * @idmap: idmap of the mount the inode was found from
1247  * @dir: The parent directory of the new one
1248  * @dentry: The dentry of the new directory
1249  * @mode: The mode of the new directory
1250  *
1251  * Returns: the dentry, or ERR_PTR(errno)
1252  */
1253 
gfs2_mkdir(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode)1254 static struct dentry *gfs2_mkdir(struct mnt_idmap *idmap, struct inode *dir,
1255 				 struct dentry *dentry, umode_t mode)
1256 {
1257 	unsigned dsize = gfs2_max_stuffed_size(GFS2_I(dir));
1258 
1259 	return ERR_PTR(gfs2_create_inode(dir, dentry, NULL, S_IFDIR | mode, 0, NULL, dsize, 0));
1260 }
1261 
1262 /**
1263  * gfs2_mknod - Make a special file
1264  * @idmap: idmap of the mount the inode was found from
1265  * @dir: The directory in which the special file will reside
1266  * @dentry: The dentry of the special file
1267  * @mode: The mode of the special file
1268  * @dev: The device specification of the special file
1269  *
1270  */
1271 
gfs2_mknod(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t dev)1272 static int gfs2_mknod(struct mnt_idmap *idmap, struct inode *dir,
1273 		      struct dentry *dentry, umode_t mode, dev_t dev)
1274 {
1275 	return gfs2_create_inode(dir, dentry, NULL, mode, dev, NULL, 0, 0);
1276 }
1277 
1278 /**
1279  * gfs2_atomic_open - Atomically open a file
1280  * @dir: The directory
1281  * @dentry: The proposed new entry
1282  * @file: The proposed new struct file
1283  * @flags: open flags
1284  * @mode: File mode
1285  *
1286  * Returns: error code or 0 for success
1287  */
1288 
gfs2_atomic_open(struct inode * dir,struct dentry * dentry,struct file * file,unsigned flags,umode_t mode)1289 static int gfs2_atomic_open(struct inode *dir, struct dentry *dentry,
1290 			    struct file *file, unsigned flags,
1291 			    umode_t mode)
1292 {
1293 	struct dentry *d;
1294 	bool excl = !!(flags & O_EXCL);
1295 
1296 	if (!d_in_lookup(dentry))
1297 		goto skip_lookup;
1298 
1299 	d = __gfs2_lookup(dir, dentry, file);
1300 	if (IS_ERR(d))
1301 		return PTR_ERR(d);
1302 	if (d != NULL)
1303 		dentry = d;
1304 	if (d_really_is_positive(dentry)) {
1305 		if (!(file->f_mode & FMODE_OPENED))
1306 			return finish_no_open(file, d);
1307 		dput(d);
1308 		return excl && (flags & O_CREAT) ? -EEXIST : 0;
1309 	}
1310 
1311 	BUG_ON(d != NULL);
1312 
1313 skip_lookup:
1314 	if (!(flags & O_CREAT))
1315 		return -ENOENT;
1316 
1317 	return gfs2_create_inode(dir, dentry, file, S_IFREG | mode, 0, NULL, 0, excl);
1318 }
1319 
1320 /*
1321  * gfs2_ok_to_move - check if it's ok to move a directory to another directory
1322  * @this: move this
1323  * @to: to here
1324  *
1325  * Follow @to back to the root and make sure we don't encounter @this
1326  * Assumes we already hold the rename lock.
1327  *
1328  * Returns: errno
1329  */
1330 
gfs2_ok_to_move(struct gfs2_inode * this,struct gfs2_inode * to)1331 static int gfs2_ok_to_move(struct gfs2_inode *this, struct gfs2_inode *to)
1332 {
1333 	struct inode *dir = &to->i_inode;
1334 	struct super_block *sb = dir->i_sb;
1335 	struct inode *tmp;
1336 	int error = 0;
1337 
1338 	igrab(dir);
1339 
1340 	for (;;) {
1341 		if (dir == &this->i_inode) {
1342 			error = -EINVAL;
1343 			break;
1344 		}
1345 		if (dir == d_inode(sb->s_root)) {
1346 			error = 0;
1347 			break;
1348 		}
1349 
1350 		tmp = gfs2_lookupi(dir, &gfs2_qdotdot, 1);
1351 		if (!tmp) {
1352 			error = -ENOENT;
1353 			break;
1354 		}
1355 		if (IS_ERR(tmp)) {
1356 			error = PTR_ERR(tmp);
1357 			break;
1358 		}
1359 
1360 		iput(dir);
1361 		dir = tmp;
1362 	}
1363 
1364 	iput(dir);
1365 
1366 	return error;
1367 }
1368 
1369 /**
1370  * update_moved_ino - Update an inode that's being moved
1371  * @ip: The inode being moved
1372  * @ndip: The parent directory of the new filename
1373  * @dir_rename: True of ip is a directory
1374  *
1375  * Returns: errno
1376  */
1377 
update_moved_ino(struct gfs2_inode * ip,struct gfs2_inode * ndip,int dir_rename)1378 static int update_moved_ino(struct gfs2_inode *ip, struct gfs2_inode *ndip,
1379 			    int dir_rename)
1380 {
1381 	if (dir_rename)
1382 		return gfs2_dir_mvino(ip, &gfs2_qdotdot, ndip, DT_DIR);
1383 
1384 	inode_set_ctime_current(&ip->i_inode);
1385 	mark_inode_dirty_sync(&ip->i_inode);
1386 	return 0;
1387 }
1388 
1389 
1390 /**
1391  * gfs2_rename - Rename a file
1392  * @odir: Parent directory of old file name
1393  * @odentry: The old dentry of the file
1394  * @ndir: Parent directory of new file name
1395  * @ndentry: The new dentry of the file
1396  *
1397  * Returns: errno
1398  */
1399 
gfs2_rename(struct inode * odir,struct dentry * odentry,struct inode * ndir,struct dentry * ndentry)1400 static int gfs2_rename(struct inode *odir, struct dentry *odentry,
1401 		       struct inode *ndir, struct dentry *ndentry)
1402 {
1403 	struct gfs2_inode *odip = GFS2_I(odir);
1404 	struct gfs2_inode *ndip = GFS2_I(ndir);
1405 	struct gfs2_inode *ip = GFS2_I(d_inode(odentry));
1406 	struct gfs2_inode *nip = NULL;
1407 	struct gfs2_sbd *sdp = GFS2_SB(odir);
1408 	struct gfs2_holder ghs[4], r_gh, rd_gh;
1409 	struct gfs2_rgrpd *nrgd;
1410 	unsigned int num_gh;
1411 	int dir_rename = 0;
1412 	struct gfs2_diradd da = { .nr_blocks = 0, .save_loc = 0, };
1413 	unsigned int x;
1414 	int error;
1415 
1416 	gfs2_holder_mark_uninitialized(&r_gh);
1417 	gfs2_holder_mark_uninitialized(&rd_gh);
1418 	if (d_really_is_positive(ndentry)) {
1419 		nip = GFS2_I(d_inode(ndentry));
1420 		if (ip == nip)
1421 			return 0;
1422 	}
1423 
1424 	error = gfs2_rindex_update(sdp);
1425 	if (error)
1426 		return error;
1427 
1428 	error = gfs2_qa_get(ndip);
1429 	if (error)
1430 		return error;
1431 
1432 	if (odip != ndip) {
1433 		error = gfs2_glock_nq_init(sdp->sd_rename_gl, LM_ST_EXCLUSIVE,
1434 					   0, &r_gh);
1435 		if (error)
1436 			goto out;
1437 
1438 		if (S_ISDIR(ip->i_inode.i_mode)) {
1439 			dir_rename = 1;
1440 			/* don't move a directory into its subdir */
1441 			error = gfs2_ok_to_move(ip, ndip);
1442 			if (error)
1443 				goto out_gunlock_r;
1444 		}
1445 	}
1446 
1447 	num_gh = 1;
1448 	gfs2_holder_init(odip->i_gl, LM_ST_EXCLUSIVE, GL_ASYNC, ghs);
1449 	if (odip != ndip) {
1450 		gfs2_holder_init(ndip->i_gl, LM_ST_EXCLUSIVE,GL_ASYNC,
1451 				 ghs + num_gh);
1452 		num_gh++;
1453 	}
1454 	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ASYNC, ghs + num_gh);
1455 	num_gh++;
1456 
1457 	if (nip) {
1458 		gfs2_holder_init(nip->i_gl, LM_ST_EXCLUSIVE, GL_ASYNC,
1459 				 ghs + num_gh);
1460 		num_gh++;
1461 	}
1462 
1463 	for (x = 0; x < num_gh; x++) {
1464 		error = gfs2_glock_nq(ghs + x);
1465 		if (error)
1466 			goto out_gunlock;
1467 	}
1468 	error = gfs2_glock_async_wait(num_gh, ghs);
1469 	if (error)
1470 		goto out_gunlock;
1471 
1472 	if (nip) {
1473 		/* Grab the resource group glock for unlink flag twiddling.
1474 		 * This is the case where the target dinode already exists
1475 		 * so we unlink before doing the rename.
1476 		 */
1477 		nrgd = gfs2_blk2rgrpd(sdp, nip->i_no_addr, 1);
1478 		if (!nrgd) {
1479 			error = -ENOENT;
1480 			goto out_gunlock;
1481 		}
1482 		error = gfs2_glock_nq_init(nrgd->rd_gl, LM_ST_EXCLUSIVE,
1483 					   LM_FLAG_NODE_SCOPE, &rd_gh);
1484 		if (error)
1485 			goto out_gunlock;
1486 	}
1487 
1488 	error = -ENOENT;
1489 	if (ip->i_inode.i_nlink == 0)
1490 		goto out_gunlock;
1491 
1492 	/* Check out the old directory */
1493 
1494 	error = gfs2_unlink_ok(odip, &odentry->d_name, ip);
1495 	if (error)
1496 		goto out_gunlock;
1497 
1498 	/* Check out the new directory */
1499 
1500 	if (nip) {
1501 		error = gfs2_unlink_ok(ndip, &ndentry->d_name, nip);
1502 		if (error)
1503 			goto out_gunlock;
1504 
1505 		if (nip->i_inode.i_nlink == 0) {
1506 			error = -EAGAIN;
1507 			goto out_gunlock;
1508 		}
1509 
1510 		if (S_ISDIR(nip->i_inode.i_mode)) {
1511 			if (nip->i_entries < 2) {
1512 				gfs2_consist_inode(nip);
1513 				error = -EIO;
1514 				goto out_gunlock;
1515 			}
1516 			if (nip->i_entries > 2) {
1517 				error = -ENOTEMPTY;
1518 				goto out_gunlock;
1519 			}
1520 		}
1521 	} else {
1522 		error = gfs2_permission(&nop_mnt_idmap, ndir,
1523 					MAY_WRITE | MAY_EXEC);
1524 		if (error)
1525 			goto out_gunlock;
1526 
1527 		error = gfs2_dir_check(ndir, &ndentry->d_name, NULL);
1528 		switch (error) {
1529 		case -ENOENT:
1530 			error = 0;
1531 			break;
1532 		case 0:
1533 			error = -EEXIST;
1534 			goto out_gunlock;
1535 		default:
1536 			goto out_gunlock;
1537 		}
1538 
1539 		if (odip != ndip) {
1540 			if (!ndip->i_inode.i_nlink) {
1541 				error = -ENOENT;
1542 				goto out_gunlock;
1543 			}
1544 			if (ndip->i_entries == (u32)-1) {
1545 				error = -EFBIG;
1546 				goto out_gunlock;
1547 			}
1548 			if (S_ISDIR(ip->i_inode.i_mode) &&
1549 			    ndip->i_inode.i_nlink == (u32)-1) {
1550 				error = -EMLINK;
1551 				goto out_gunlock;
1552 			}
1553 		}
1554 	}
1555 
1556 	/* Check out the dir to be renamed */
1557 
1558 	if (dir_rename) {
1559 		error = gfs2_permission(&nop_mnt_idmap, d_inode(odentry),
1560 					MAY_WRITE);
1561 		if (error)
1562 			goto out_gunlock;
1563 	}
1564 
1565 	if (nip == NULL) {
1566 		error = gfs2_diradd_alloc_required(ndir, &ndentry->d_name, &da);
1567 		if (error)
1568 			goto out_gunlock;
1569 	}
1570 
1571 	if (da.nr_blocks) {
1572 		struct gfs2_alloc_parms ap = { .target = da.nr_blocks, };
1573 		error = gfs2_quota_lock_check(ndip, &ap);
1574 		if (error)
1575 			goto out_gunlock;
1576 
1577 		error = gfs2_inplace_reserve(ndip, &ap);
1578 		if (error)
1579 			goto out_gunlock_q;
1580 
1581 		error = gfs2_trans_begin(sdp, gfs2_trans_da_blks(ndip, &da, 4) +
1582 					 4 * RES_LEAF + 4, 0);
1583 		if (error)
1584 			goto out_ipreserv;
1585 	} else {
1586 		error = gfs2_trans_begin(sdp, 4 * RES_DINODE +
1587 					 5 * RES_LEAF + 4, 0);
1588 		if (error)
1589 			goto out_gunlock;
1590 	}
1591 
1592 	/* Remove the target file, if it exists */
1593 
1594 	if (nip)
1595 		error = gfs2_unlink_inode(ndip, ndentry);
1596 
1597 	error = update_moved_ino(ip, ndip, dir_rename);
1598 	if (error)
1599 		goto out_end_trans;
1600 
1601 	error = gfs2_dir_del(odip, odentry);
1602 	if (error)
1603 		goto out_end_trans;
1604 
1605 	error = gfs2_dir_add(ndir, &ndentry->d_name, ip, &da);
1606 	if (error)
1607 		goto out_end_trans;
1608 
1609 out_end_trans:
1610 	gfs2_trans_end(sdp);
1611 out_ipreserv:
1612 	if (da.nr_blocks)
1613 		gfs2_inplace_release(ndip);
1614 out_gunlock_q:
1615 	if (da.nr_blocks)
1616 		gfs2_quota_unlock(ndip);
1617 out_gunlock:
1618 	gfs2_dir_no_add(&da);
1619 	if (gfs2_holder_initialized(&rd_gh))
1620 		gfs2_glock_dq_uninit(&rd_gh);
1621 
1622 	while (x--) {
1623 		if (gfs2_holder_queued(ghs + x))
1624 			gfs2_glock_dq(ghs + x);
1625 		gfs2_holder_uninit(ghs + x);
1626 	}
1627 out_gunlock_r:
1628 	if (gfs2_holder_initialized(&r_gh))
1629 		gfs2_glock_dq_uninit(&r_gh);
1630 out:
1631 	gfs2_qa_put(ndip);
1632 	return error;
1633 }
1634 
1635 /**
1636  * gfs2_exchange - exchange two files
1637  * @odir: Parent directory of old file name
1638  * @odentry: The old dentry of the file
1639  * @ndir: Parent directory of new file name
1640  * @ndentry: The new dentry of the file
1641  * @flags: The rename flags
1642  *
1643  * Returns: errno
1644  */
1645 
gfs2_exchange(struct inode * odir,struct dentry * odentry,struct inode * ndir,struct dentry * ndentry,unsigned int flags)1646 static int gfs2_exchange(struct inode *odir, struct dentry *odentry,
1647 			 struct inode *ndir, struct dentry *ndentry,
1648 			 unsigned int flags)
1649 {
1650 	struct gfs2_inode *odip = GFS2_I(odir);
1651 	struct gfs2_inode *ndip = GFS2_I(ndir);
1652 	struct gfs2_inode *oip = GFS2_I(odentry->d_inode);
1653 	struct gfs2_inode *nip = GFS2_I(ndentry->d_inode);
1654 	struct gfs2_sbd *sdp = GFS2_SB(odir);
1655 	struct gfs2_holder ghs[4], r_gh;
1656 	unsigned int num_gh;
1657 	unsigned int x;
1658 	umode_t old_mode = oip->i_inode.i_mode;
1659 	umode_t new_mode = nip->i_inode.i_mode;
1660 	int error;
1661 
1662 	gfs2_holder_mark_uninitialized(&r_gh);
1663 	error = gfs2_rindex_update(sdp);
1664 	if (error)
1665 		return error;
1666 
1667 	if (odip != ndip) {
1668 		error = gfs2_glock_nq_init(sdp->sd_rename_gl, LM_ST_EXCLUSIVE,
1669 					   0, &r_gh);
1670 		if (error)
1671 			goto out;
1672 
1673 		if (S_ISDIR(old_mode)) {
1674 			/* don't move a directory into its subdir */
1675 			error = gfs2_ok_to_move(oip, ndip);
1676 			if (error)
1677 				goto out_gunlock_r;
1678 		}
1679 
1680 		if (S_ISDIR(new_mode)) {
1681 			/* don't move a directory into its subdir */
1682 			error = gfs2_ok_to_move(nip, odip);
1683 			if (error)
1684 				goto out_gunlock_r;
1685 		}
1686 	}
1687 
1688 	num_gh = 1;
1689 	gfs2_holder_init(odip->i_gl, LM_ST_EXCLUSIVE, GL_ASYNC, ghs);
1690 	if (odip != ndip) {
1691 		gfs2_holder_init(ndip->i_gl, LM_ST_EXCLUSIVE, GL_ASYNC,
1692 				 ghs + num_gh);
1693 		num_gh++;
1694 	}
1695 	gfs2_holder_init(oip->i_gl, LM_ST_EXCLUSIVE, GL_ASYNC, ghs + num_gh);
1696 	num_gh++;
1697 
1698 	gfs2_holder_init(nip->i_gl, LM_ST_EXCLUSIVE, GL_ASYNC, ghs + num_gh);
1699 	num_gh++;
1700 
1701 	for (x = 0; x < num_gh; x++) {
1702 		error = gfs2_glock_nq(ghs + x);
1703 		if (error)
1704 			goto out_gunlock;
1705 	}
1706 
1707 	error = gfs2_glock_async_wait(num_gh, ghs);
1708 	if (error)
1709 		goto out_gunlock;
1710 
1711 	error = -ENOENT;
1712 	if (oip->i_inode.i_nlink == 0 || nip->i_inode.i_nlink == 0)
1713 		goto out_gunlock;
1714 
1715 	error = gfs2_unlink_ok(odip, &odentry->d_name, oip);
1716 	if (error)
1717 		goto out_gunlock;
1718 	error = gfs2_unlink_ok(ndip, &ndentry->d_name, nip);
1719 	if (error)
1720 		goto out_gunlock;
1721 
1722 	if (S_ISDIR(old_mode)) {
1723 		error = gfs2_permission(&nop_mnt_idmap, odentry->d_inode,
1724 					MAY_WRITE);
1725 		if (error)
1726 			goto out_gunlock;
1727 	}
1728 	if (S_ISDIR(new_mode)) {
1729 		error = gfs2_permission(&nop_mnt_idmap, ndentry->d_inode,
1730 					MAY_WRITE);
1731 		if (error)
1732 			goto out_gunlock;
1733 	}
1734 	error = gfs2_trans_begin(sdp, 4 * RES_DINODE + 4 * RES_LEAF, 0);
1735 	if (error)
1736 		goto out_gunlock;
1737 
1738 	error = update_moved_ino(oip, ndip, S_ISDIR(old_mode));
1739 	if (error)
1740 		goto out_end_trans;
1741 
1742 	error = update_moved_ino(nip, odip, S_ISDIR(new_mode));
1743 	if (error)
1744 		goto out_end_trans;
1745 
1746 	error = gfs2_dir_mvino(ndip, &ndentry->d_name, oip,
1747 			       IF2DT(old_mode));
1748 	if (error)
1749 		goto out_end_trans;
1750 
1751 	error = gfs2_dir_mvino(odip, &odentry->d_name, nip,
1752 			       IF2DT(new_mode));
1753 	if (error)
1754 		goto out_end_trans;
1755 
1756 	if (odip != ndip) {
1757 		if (S_ISDIR(new_mode) && !S_ISDIR(old_mode)) {
1758 			inc_nlink(&odip->i_inode);
1759 			drop_nlink(&ndip->i_inode);
1760 		} else if (S_ISDIR(old_mode) && !S_ISDIR(new_mode)) {
1761 			inc_nlink(&ndip->i_inode);
1762 			drop_nlink(&odip->i_inode);
1763 		}
1764 	}
1765 	mark_inode_dirty(&ndip->i_inode);
1766 	if (odip != ndip)
1767 		mark_inode_dirty(&odip->i_inode);
1768 
1769 out_end_trans:
1770 	gfs2_trans_end(sdp);
1771 out_gunlock:
1772 	while (x--) {
1773 		if (gfs2_holder_queued(ghs + x))
1774 			gfs2_glock_dq(ghs + x);
1775 		gfs2_holder_uninit(ghs + x);
1776 	}
1777 out_gunlock_r:
1778 	if (gfs2_holder_initialized(&r_gh))
1779 		gfs2_glock_dq_uninit(&r_gh);
1780 out:
1781 	return error;
1782 }
1783 
gfs2_rename2(struct mnt_idmap * idmap,struct inode * odir,struct dentry * odentry,struct inode * ndir,struct dentry * ndentry,unsigned int flags)1784 static int gfs2_rename2(struct mnt_idmap *idmap, struct inode *odir,
1785 			struct dentry *odentry, struct inode *ndir,
1786 			struct dentry *ndentry, unsigned int flags)
1787 {
1788 	flags &= ~RENAME_NOREPLACE;
1789 
1790 	if (flags & ~RENAME_EXCHANGE)
1791 		return -EINVAL;
1792 
1793 	if (flags & RENAME_EXCHANGE)
1794 		return gfs2_exchange(odir, odentry, ndir, ndentry, flags);
1795 
1796 	return gfs2_rename(odir, odentry, ndir, ndentry);
1797 }
1798 
1799 /**
1800  * gfs2_get_link - Follow a symbolic link
1801  * @dentry: The dentry of the link
1802  * @inode: The inode of the link
1803  * @done: destructor for return value
1804  *
1805  * This can handle symlinks of any size.
1806  *
1807  * Returns: 0 on success or error code
1808  */
1809 
gfs2_get_link(struct dentry * dentry,struct inode * inode,struct delayed_call * done)1810 static const char *gfs2_get_link(struct dentry *dentry,
1811 				 struct inode *inode,
1812 				 struct delayed_call *done)
1813 {
1814 	struct gfs2_inode *ip = GFS2_I(inode);
1815 	struct gfs2_holder i_gh;
1816 	struct buffer_head *dibh;
1817 	unsigned int size;
1818 	char *buf;
1819 	int error;
1820 
1821 	if (!dentry)
1822 		return ERR_PTR(-ECHILD);
1823 
1824 	gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
1825 	error = gfs2_glock_nq(&i_gh);
1826 	if (error) {
1827 		gfs2_holder_uninit(&i_gh);
1828 		return ERR_PTR(error);
1829 	}
1830 
1831 	size = (unsigned int)i_size_read(&ip->i_inode);
1832 	if (size == 0) {
1833 		gfs2_consist_inode(ip);
1834 		buf = ERR_PTR(-EIO);
1835 		goto out;
1836 	}
1837 
1838 	error = gfs2_meta_inode_buffer(ip, &dibh);
1839 	if (error) {
1840 		buf = ERR_PTR(error);
1841 		goto out;
1842 	}
1843 
1844 	buf = kzalloc(size + 1, GFP_NOFS);
1845 	if (!buf)
1846 		buf = ERR_PTR(-ENOMEM);
1847 	else
1848 		memcpy(buf, dibh->b_data + sizeof(struct gfs2_dinode), size);
1849 	brelse(dibh);
1850 out:
1851 	gfs2_glock_dq_uninit(&i_gh);
1852 	if (!IS_ERR(buf))
1853 		set_delayed_call(done, kfree_link, buf);
1854 	return buf;
1855 }
1856 
1857 /**
1858  * gfs2_permission
1859  * @idmap: idmap of the mount the inode was found from
1860  * @inode: The inode
1861  * @mask: The mask to be tested
1862  *
1863  * This may be called from the VFS directly, or from within GFS2 with the
1864  * inode locked, so we look to see if the glock is already locked and only
1865  * lock the glock if its not already been done.
1866  *
1867  * Returns: errno
1868  */
1869 
gfs2_permission(struct mnt_idmap * idmap,struct inode * inode,int mask)1870 int gfs2_permission(struct mnt_idmap *idmap, struct inode *inode,
1871 		    int mask)
1872 {
1873 	int may_not_block = mask & MAY_NOT_BLOCK;
1874 	struct gfs2_inode *ip;
1875 	struct gfs2_holder i_gh;
1876 	struct gfs2_glock *gl;
1877 	int error;
1878 
1879 	gfs2_holder_mark_uninitialized(&i_gh);
1880 	ip = GFS2_I(inode);
1881 	gl = rcu_dereference_check(ip->i_gl, !may_not_block);
1882 	if (unlikely(!gl)) {
1883 		/* inode is getting torn down, must be RCU mode */
1884 		WARN_ON_ONCE(!may_not_block);
1885 		return -ECHILD;
1886         }
1887 	if (gfs2_glock_is_locked_by_me(gl) == NULL) {
1888 		if (may_not_block)
1889 			return -ECHILD;
1890 		error = gfs2_glock_nq_init(gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
1891 		if (error)
1892 			return error;
1893 	}
1894 
1895 	if ((mask & MAY_WRITE) && IS_IMMUTABLE(inode))
1896 		error = -EPERM;
1897 	else
1898 		error = generic_permission(&nop_mnt_idmap, inode, mask);
1899 	if (gfs2_holder_initialized(&i_gh))
1900 		gfs2_glock_dq_uninit(&i_gh);
1901 
1902 	return error;
1903 }
1904 
__gfs2_setattr_simple(struct inode * inode,struct iattr * attr)1905 static int __gfs2_setattr_simple(struct inode *inode, struct iattr *attr)
1906 {
1907 	setattr_copy(&nop_mnt_idmap, inode, attr);
1908 	mark_inode_dirty(inode);
1909 	return 0;
1910 }
1911 
gfs2_setattr_simple(struct inode * inode,struct iattr * attr)1912 static int gfs2_setattr_simple(struct inode *inode, struct iattr *attr)
1913 {
1914 	int error;
1915 
1916 	if (current->journal_info)
1917 		return __gfs2_setattr_simple(inode, attr);
1918 
1919 	error = gfs2_trans_begin(GFS2_SB(inode), RES_DINODE, 0);
1920 	if (error)
1921 		return error;
1922 
1923 	error = __gfs2_setattr_simple(inode, attr);
1924 	gfs2_trans_end(GFS2_SB(inode));
1925 	return error;
1926 }
1927 
setattr_chown(struct inode * inode,struct iattr * attr)1928 static int setattr_chown(struct inode *inode, struct iattr *attr)
1929 {
1930 	struct gfs2_inode *ip = GFS2_I(inode);
1931 	struct gfs2_sbd *sdp = GFS2_SB(inode);
1932 	kuid_t ouid, nuid;
1933 	kgid_t ogid, ngid;
1934 	int error;
1935 	struct gfs2_alloc_parms ap = {};
1936 
1937 	ouid = inode->i_uid;
1938 	ogid = inode->i_gid;
1939 	nuid = attr->ia_uid;
1940 	ngid = attr->ia_gid;
1941 
1942 	if (!(attr->ia_valid & ATTR_UID) || uid_eq(ouid, nuid))
1943 		ouid = nuid = NO_UID_QUOTA_CHANGE;
1944 	if (!(attr->ia_valid & ATTR_GID) || gid_eq(ogid, ngid))
1945 		ogid = ngid = NO_GID_QUOTA_CHANGE;
1946 	error = gfs2_qa_get(ip);
1947 	if (error)
1948 		return error;
1949 
1950 	error = gfs2_rindex_update(sdp);
1951 	if (error)
1952 		goto out;
1953 
1954 	error = gfs2_quota_lock(ip, nuid, ngid);
1955 	if (error)
1956 		goto out;
1957 
1958 	ap.target = gfs2_get_inode_blocks(&ip->i_inode);
1959 
1960 	if (!uid_eq(ouid, NO_UID_QUOTA_CHANGE) ||
1961 	    !gid_eq(ogid, NO_GID_QUOTA_CHANGE)) {
1962 		error = gfs2_quota_check(ip, nuid, ngid, &ap);
1963 		if (error)
1964 			goto out_gunlock_q;
1965 	}
1966 
1967 	error = gfs2_trans_begin(sdp, RES_DINODE + 2 * RES_QUOTA, 0);
1968 	if (error)
1969 		goto out_gunlock_q;
1970 
1971 	error = gfs2_setattr_simple(inode, attr);
1972 	if (error)
1973 		goto out_end_trans;
1974 
1975 	if (!uid_eq(ouid, NO_UID_QUOTA_CHANGE) ||
1976 	    !gid_eq(ogid, NO_GID_QUOTA_CHANGE)) {
1977 		gfs2_quota_change(ip, -(s64)ap.target, ouid, ogid);
1978 		gfs2_quota_change(ip, ap.target, nuid, ngid);
1979 	}
1980 
1981 out_end_trans:
1982 	gfs2_trans_end(sdp);
1983 out_gunlock_q:
1984 	gfs2_quota_unlock(ip);
1985 out:
1986 	gfs2_qa_put(ip);
1987 	return error;
1988 }
1989 
1990 /**
1991  * gfs2_setattr - Change attributes on an inode
1992  * @idmap: idmap of the mount the inode was found from
1993  * @dentry: The dentry which is changing
1994  * @attr: The structure describing the change
1995  *
1996  * The VFS layer wants to change one or more of an inodes attributes.  Write
1997  * that change out to disk.
1998  *
1999  * Returns: errno
2000  */
2001 
gfs2_setattr(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * attr)2002 static int gfs2_setattr(struct mnt_idmap *idmap,
2003 			struct dentry *dentry, struct iattr *attr)
2004 {
2005 	struct inode *inode = d_inode(dentry);
2006 	struct gfs2_inode *ip = GFS2_I(inode);
2007 	struct gfs2_holder i_gh;
2008 	int error;
2009 
2010 	error = gfs2_qa_get(ip);
2011 	if (error)
2012 		return error;
2013 
2014 	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
2015 	if (error)
2016 		goto out;
2017 
2018 	error = may_setattr(&nop_mnt_idmap, inode, attr->ia_valid);
2019 	if (error)
2020 		goto error;
2021 
2022 	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
2023 	if (error)
2024 		goto error;
2025 
2026 	if (attr->ia_valid & ATTR_SIZE)
2027 		error = gfs2_setattr_size(inode, attr->ia_size);
2028 	else if (attr->ia_valid & (ATTR_UID | ATTR_GID))
2029 		error = setattr_chown(inode, attr);
2030 	else {
2031 		error = gfs2_setattr_simple(inode, attr);
2032 		if (!error && attr->ia_valid & ATTR_MODE)
2033 			error = posix_acl_chmod(&nop_mnt_idmap, dentry,
2034 						inode->i_mode);
2035 	}
2036 
2037 error:
2038 	if (!error)
2039 		mark_inode_dirty(inode);
2040 	gfs2_glock_dq_uninit(&i_gh);
2041 out:
2042 	gfs2_qa_put(ip);
2043 	return error;
2044 }
2045 
2046 /**
2047  * gfs2_getattr - Read out an inode's attributes
2048  * @idmap: idmap of the mount the inode was found from
2049  * @path: Object to query
2050  * @stat: The inode's stats
2051  * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
2052  * @flags: AT_STATX_xxx setting
2053  *
2054  * This may be called from the VFS directly, or from within GFS2 with the
2055  * inode locked, so we look to see if the glock is already locked and only
2056  * lock the glock if its not already been done. Note that its the NFS
2057  * readdirplus operation which causes this to be called (from filldir)
2058  * with the glock already held.
2059  *
2060  * Returns: errno
2061  */
2062 
gfs2_getattr(struct mnt_idmap * idmap,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int flags)2063 static int gfs2_getattr(struct mnt_idmap *idmap,
2064 			const struct path *path, struct kstat *stat,
2065 			u32 request_mask, unsigned int flags)
2066 {
2067 	struct inode *inode = d_inode(path->dentry);
2068 	struct gfs2_inode *ip = GFS2_I(inode);
2069 	struct gfs2_holder gh;
2070 	u32 gfsflags;
2071 	int error;
2072 
2073 	gfs2_holder_mark_uninitialized(&gh);
2074 	if (gfs2_glock_is_locked_by_me(ip->i_gl) == NULL) {
2075 		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
2076 		if (error)
2077 			return error;
2078 	}
2079 
2080 	gfsflags = ip->i_diskflags;
2081 	if (gfsflags & GFS2_DIF_APPENDONLY)
2082 		stat->attributes |= STATX_ATTR_APPEND;
2083 	if (gfsflags & GFS2_DIF_IMMUTABLE)
2084 		stat->attributes |= STATX_ATTR_IMMUTABLE;
2085 
2086 	stat->attributes_mask |= (STATX_ATTR_APPEND |
2087 				  STATX_ATTR_COMPRESSED |
2088 				  STATX_ATTR_ENCRYPTED |
2089 				  STATX_ATTR_IMMUTABLE |
2090 				  STATX_ATTR_NODUMP);
2091 
2092 	generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
2093 
2094 	if (gfs2_holder_initialized(&gh))
2095 		gfs2_glock_dq_uninit(&gh);
2096 
2097 	return 0;
2098 }
2099 
gfs2_fiemap(struct inode * inode,struct fiemap_extent_info * fieinfo,u64 start,u64 len)2100 static int gfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
2101 		       u64 start, u64 len)
2102 {
2103 	struct gfs2_inode *ip = GFS2_I(inode);
2104 	struct gfs2_holder gh;
2105 	int ret;
2106 
2107 	inode_lock_shared(inode);
2108 
2109 	ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
2110 	if (ret)
2111 		goto out;
2112 
2113 	ret = iomap_fiemap(inode, fieinfo, start, len, &gfs2_iomap_ops);
2114 
2115 	gfs2_glock_dq_uninit(&gh);
2116 
2117 out:
2118 	inode_unlock_shared(inode);
2119 	return ret;
2120 }
2121 
gfs2_seek_data(struct file * file,loff_t offset)2122 loff_t gfs2_seek_data(struct file *file, loff_t offset)
2123 {
2124 	struct inode *inode = file->f_mapping->host;
2125 	struct gfs2_inode *ip = GFS2_I(inode);
2126 	struct gfs2_holder gh;
2127 	loff_t ret;
2128 
2129 	inode_lock_shared(inode);
2130 	ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
2131 	if (!ret)
2132 		ret = iomap_seek_data(inode, offset, &gfs2_iomap_ops);
2133 	gfs2_glock_dq_uninit(&gh);
2134 	inode_unlock_shared(inode);
2135 
2136 	if (ret < 0)
2137 		return ret;
2138 	return vfs_setpos(file, ret, inode->i_sb->s_maxbytes);
2139 }
2140 
gfs2_seek_hole(struct file * file,loff_t offset)2141 loff_t gfs2_seek_hole(struct file *file, loff_t offset)
2142 {
2143 	struct inode *inode = file->f_mapping->host;
2144 	struct gfs2_inode *ip = GFS2_I(inode);
2145 	struct gfs2_holder gh;
2146 	loff_t ret;
2147 
2148 	inode_lock_shared(inode);
2149 	ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
2150 	if (!ret)
2151 		ret = iomap_seek_hole(inode, offset, &gfs2_iomap_ops);
2152 	gfs2_glock_dq_uninit(&gh);
2153 	inode_unlock_shared(inode);
2154 
2155 	if (ret < 0)
2156 		return ret;
2157 	return vfs_setpos(file, ret, inode->i_sb->s_maxbytes);
2158 }
2159 
gfs2_update_time(struct inode * inode,int flags)2160 static int gfs2_update_time(struct inode *inode, int flags)
2161 {
2162 	struct gfs2_inode *ip = GFS2_I(inode);
2163 	struct gfs2_glock *gl = ip->i_gl;
2164 	struct gfs2_holder *gh;
2165 	int error;
2166 
2167 	gh = gfs2_glock_is_locked_by_me(gl);
2168 	if (gh && gl->gl_state != LM_ST_EXCLUSIVE) {
2169 		gfs2_glock_dq(gh);
2170 		gfs2_holder_reinit(LM_ST_EXCLUSIVE, 0, gh);
2171 		error = gfs2_glock_nq(gh);
2172 		if (error)
2173 			return error;
2174 	}
2175 	generic_update_time(inode, flags);
2176 	return 0;
2177 }
2178 
2179 static const struct inode_operations gfs2_file_iops = {
2180 	.permission = gfs2_permission,
2181 	.setattr = gfs2_setattr,
2182 	.getattr = gfs2_getattr,
2183 	.listxattr = gfs2_listxattr,
2184 	.fiemap = gfs2_fiemap,
2185 	.get_inode_acl = gfs2_get_acl,
2186 	.set_acl = gfs2_set_acl,
2187 	.update_time = gfs2_update_time,
2188 	.fileattr_get = gfs2_fileattr_get,
2189 	.fileattr_set = gfs2_fileattr_set,
2190 };
2191 
2192 static const struct inode_operations gfs2_dir_iops = {
2193 	.create = gfs2_create,
2194 	.lookup = gfs2_lookup,
2195 	.link = gfs2_link,
2196 	.unlink = gfs2_unlink,
2197 	.symlink = gfs2_symlink,
2198 	.mkdir = gfs2_mkdir,
2199 	.rmdir = gfs2_unlink,
2200 	.mknod = gfs2_mknod,
2201 	.rename = gfs2_rename2,
2202 	.permission = gfs2_permission,
2203 	.setattr = gfs2_setattr,
2204 	.getattr = gfs2_getattr,
2205 	.listxattr = gfs2_listxattr,
2206 	.fiemap = gfs2_fiemap,
2207 	.get_inode_acl = gfs2_get_acl,
2208 	.set_acl = gfs2_set_acl,
2209 	.update_time = gfs2_update_time,
2210 	.atomic_open = gfs2_atomic_open,
2211 	.fileattr_get = gfs2_fileattr_get,
2212 	.fileattr_set = gfs2_fileattr_set,
2213 };
2214 
2215 static const struct inode_operations gfs2_symlink_iops = {
2216 	.get_link = gfs2_get_link,
2217 	.permission = gfs2_permission,
2218 	.setattr = gfs2_setattr,
2219 	.getattr = gfs2_getattr,
2220 	.listxattr = gfs2_listxattr,
2221 	.fiemap = gfs2_fiemap,
2222 };
2223 
2224