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authorAkira Fujita <a-fujita@rs.jp.nec.com>2009-06-17 19:24:03 -0400
committerTheodore Ts'o <tytso@mit.edu>2009-06-17 19:24:03 -0400
commit748de6736c1e482e111f9d1b5a5d5b1787600cad (patch)
tree9e5bd6085cd0eea0453c2a8bbce1422f291f059f
parent8b0f9e8f78bd0a65fa001bf18f2c47eef2893a10 (diff)
ext4: online defrag -- Add EXT4_IOC_MOVE_EXT ioctl
The EXT4_IOC_MOVE_EXT exchanges the blocks between orig_fd and donor_fd, and then write the file data of orig_fd to donor_fd. ext4_mext_move_extent() is the main fucntion of ext4 online defrag, and this patch includes all functions related to ext4 online defrag. Signed-off-by: Akira Fujita <a-fujita@rs.jp.nec.com> Signed-off-by: Takashi Sato <t-sato@yk.jp.nec.com> Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat
-rw-r--r--fs/ext4/Makefile2
-rw-r--r--fs/ext4/ext4.h15
-rw-r--r--fs/ext4/ext4_extents.h4
-rw-r--r--fs/ext4/extents.c4
-rw-r--r--fs/ext4/ioctl.c36
-rw-r--r--fs/ext4/move_extent.c1320
6 files changed, 1378 insertions, 3 deletions
diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile
index 8a34710ecf40..8867b2a1e5fe 100644
--- a/fs/ext4/Makefile
+++ b/fs/ext4/Makefile
@@ -6,7 +6,7 @@ obj-$(CONFIG_EXT4_FS) += ext4.o
6 6
7ext4-y := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o \ 7ext4-y := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o \
8 ioctl.o namei.o super.o symlink.o hash.o resize.o extents.o \ 8 ioctl.o namei.o super.o symlink.o hash.o resize.o extents.o \
9 ext4_jbd2.o migrate.o mballoc.o block_validity.o 9 ext4_jbd2.o migrate.o mballoc.o block_validity.o move_extent.o
10 10
11ext4-$(CONFIG_EXT4_FS_XATTR) += xattr.o xattr_user.o xattr_trusted.o 11ext4-$(CONFIG_EXT4_FS_XATTR) += xattr.o xattr_user.o xattr_trusted.o
12ext4-$(CONFIG_EXT4_FS_POSIX_ACL) += acl.o 12ext4-$(CONFIG_EXT4_FS_POSIX_ACL) += acl.o
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index cc7d5edc38c9..276a26f117e6 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -352,6 +352,7 @@ struct ext4_new_group_data {
352 /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */ 352 /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
353 /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */ 353 /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
354#define EXT4_IOC_ALLOC_DA_BLKS _IO('f', 12) 354#define EXT4_IOC_ALLOC_DA_BLKS _IO('f', 12)
355#define EXT4_IOC_MOVE_EXT _IOWR('f', 15, struct move_extent)
355 356
356/* 357/*
357 * ioctl commands in 32 bit emulation 358 * ioctl commands in 32 bit emulation
@@ -447,6 +448,15 @@ struct ext4_inode {
447 __le32 i_version_hi; /* high 32 bits for 64-bit version */ 448 __le32 i_version_hi; /* high 32 bits for 64-bit version */
448}; 449};
449 450
451struct move_extent {
452 __u32 reserved; /* should be zero */
453 __u32 donor_fd; /* donor file descriptor */
454 __u64 orig_start; /* logical start offset in block for orig */
455 __u64 donor_start; /* logical start offset in block for donor */
456 __u64 len; /* block length to be moved */
457 __u64 moved_len; /* moved block length */
458};
459#define MAX_DEFRAG_SIZE ((1UL<<31) - 1)
450 460
451#define EXT4_EPOCH_BITS 2 461#define EXT4_EPOCH_BITS 2
452#define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1) 462#define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
@@ -1647,6 +1657,11 @@ extern int ext4_get_blocks(handle_t *handle, struct inode *inode,
1647 struct buffer_head *bh, int flags); 1657 struct buffer_head *bh, int flags);
1648extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 1658extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1649 __u64 start, __u64 len); 1659 __u64 start, __u64 len);
1660/* move_extent.c */
1661extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
1662 __u64 start_orig, __u64 start_donor,
1663 __u64 len, __u64 *moved_len);
1664
1650 1665
1651/* 1666/*
1652 * Add new method to test wether block and inode bitmaps are properly 1667 * Add new method to test wether block and inode bitmaps are properly
diff --git a/fs/ext4/ext4_extents.h b/fs/ext4/ext4_extents.h
index f0c3ec85bd48..20a84105a10b 100644
--- a/fs/ext4/ext4_extents.h
+++ b/fs/ext4/ext4_extents.h
@@ -221,12 +221,16 @@ static inline int ext4_ext_get_actual_len(struct ext4_extent *ext)
221} 221}
222 222
223extern int ext4_ext_calc_metadata_amount(struct inode *inode, int blocks); 223extern int ext4_ext_calc_metadata_amount(struct inode *inode, int blocks);
224extern ext4_fsblk_t ext_pblock(struct ext4_extent *ex);
224extern ext4_fsblk_t idx_pblock(struct ext4_extent_idx *); 225extern ext4_fsblk_t idx_pblock(struct ext4_extent_idx *);
225extern void ext4_ext_store_pblock(struct ext4_extent *, ext4_fsblk_t); 226extern void ext4_ext_store_pblock(struct ext4_extent *, ext4_fsblk_t);
226extern int ext4_extent_tree_init(handle_t *, struct inode *); 227extern int ext4_extent_tree_init(handle_t *, struct inode *);
227extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode, 228extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
228 int num, 229 int num,
229 struct ext4_ext_path *path); 230 struct ext4_ext_path *path);
231extern int ext4_can_extents_be_merged(struct inode *inode,
232 struct ext4_extent *ex1,
233 struct ext4_extent *ex2);
230extern int ext4_ext_try_to_merge(struct inode *inode, 234extern int ext4_ext_try_to_merge(struct inode *inode,
231 struct ext4_ext_path *path, 235 struct ext4_ext_path *path,
232 struct ext4_extent *); 236 struct ext4_extent *);
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 2593f748c3a4..50322a09bd01 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -49,7 +49,7 @@
49 * ext_pblock: 49 * ext_pblock:
50 * combine low and high parts of physical block number into ext4_fsblk_t 50 * combine low and high parts of physical block number into ext4_fsblk_t
51 */ 51 */
52static ext4_fsblk_t ext_pblock(struct ext4_extent *ex) 52ext4_fsblk_t ext_pblock(struct ext4_extent *ex)
53{ 53{
54 ext4_fsblk_t block; 54 ext4_fsblk_t block;
55 55
@@ -1417,7 +1417,7 @@ static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1417 return err; 1417 return err;
1418} 1418}
1419 1419
1420static int 1420int
1421ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, 1421ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1422 struct ext4_extent *ex2) 1422 struct ext4_extent *ex2)
1423{ 1423{
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 91e75f7a9e73..bb415408fdb6 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -14,6 +14,7 @@
14#include <linux/compat.h> 14#include <linux/compat.h>
15#include <linux/smp_lock.h> 15#include <linux/smp_lock.h>
16#include <linux/mount.h> 16#include <linux/mount.h>
17#include <linux/file.h>
17#include <asm/uaccess.h> 18#include <asm/uaccess.h>
18#include "ext4_jbd2.h" 19#include "ext4_jbd2.h"
19#include "ext4.h" 20#include "ext4.h"
@@ -213,6 +214,41 @@ setversion_out:
213 214
214 return err; 215 return err;
215 } 216 }
217
218 case EXT4_IOC_MOVE_EXT: {
219 struct move_extent me;
220 struct file *donor_filp;
221 int err;
222
223 if (copy_from_user(&me,
224 (struct move_extent __user *)arg, sizeof(me)))
225 return -EFAULT;
226
227 donor_filp = fget(me.donor_fd);
228 if (!donor_filp)
229 return -EBADF;
230
231 if (!capable(CAP_DAC_OVERRIDE)) {
232 if ((current->real_cred->fsuid != inode->i_uid) ||
233 !(inode->i_mode & S_IRUSR) ||
234 !(donor_filp->f_dentry->d_inode->i_mode &
235 S_IRUSR)) {
236 fput(donor_filp);
237 return -EACCES;
238 }
239 }
240
241 err = ext4_move_extents(filp, donor_filp, me.orig_start,
242 me.donor_start, me.len, &me.moved_len);
243 fput(donor_filp);
244
245 if (!err)
246 if (copy_to_user((struct move_extent *)arg,
247 &me, sizeof(me)))
248 return -EFAULT;
249 return err;
250 }
251
216 case EXT4_IOC_GROUP_ADD: { 252 case EXT4_IOC_GROUP_ADD: {
217 struct ext4_new_group_data input; 253 struct ext4_new_group_data input;
218 struct super_block *sb = inode->i_sb; 254 struct super_block *sb = inode->i_sb;
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
new file mode 100644
index 000000000000..bbf2dd9404dc
--- /dev/null
+++ b/fs/ext4/move_extent.c
@@ -0,0 +1,1320 @@
1/*
2 * Copyright (c) 2008,2009 NEC Software Tohoku, Ltd.
3 * Written by Takashi Sato <t-sato@yk.jp.nec.com>
4 * Akira Fujita <a-fujita@rs.jp.nec.com>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of version 2.1 of the GNU Lesser General Public License
8 * as published by the Free Software Foundation.
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 the
13 * GNU General Public License for more details.
14 */
15
16#include <linux/fs.h>
17#include <linux/quotaops.h>
18#include "ext4_jbd2.h"
19#include "ext4_extents.h"
20#include "ext4.h"
21
22#define get_ext_path(path, inode, block, ret) \
23 do { \
24 path = ext4_ext_find_extent(inode, block, path); \
25 if (IS_ERR(path)) { \
26 ret = PTR_ERR(path); \
27 path = NULL; \
28 } \
29 } while (0)
30
31/**
32 * copy_extent_status - Copy the extent's initialization status
33 *
34 * @src: an extent for getting initialize status
35 * @dest: an extent to be set the status
36 */
37static void
38copy_extent_status(struct ext4_extent *src, struct ext4_extent *dest)
39{
40 if (ext4_ext_is_uninitialized(src))
41 ext4_ext_mark_uninitialized(dest);
42 else
43 dest->ee_len = cpu_to_le16(ext4_ext_get_actual_len(dest));
44}
45
46/**
47 * mext_next_extent - Search for the next extent and set it to "extent"
48 *
49 * @inode: inode which is searched
50 * @path: this will obtain data for the next extent
51 * @extent: pointer to the next extent we have just gotten
52 *
53 * Search the next extent in the array of ext4_ext_path structure (@path)
54 * and set it to ext4_extent structure (@extent). In addition, the member of
55 * @path (->p_ext) also points the next extent. Return 0 on success, 1 if
56 * ext4_ext_path structure refers to the last extent, or a negative error
57 * value on failure.
58 */
59static int
60mext_next_extent(struct inode *inode, struct ext4_ext_path *path,
61 struct ext4_extent **extent)
62{
63 int ppos, leaf_ppos = path->p_depth;
64
65 ppos = leaf_ppos;
66 if (EXT_LAST_EXTENT(path[ppos].p_hdr) > path[ppos].p_ext) {
67 /* leaf block */
68 *extent = ++path[ppos].p_ext;
69 return 0;
70 }
71
72 while (--ppos >= 0) {
73 if (EXT_LAST_INDEX(path[ppos].p_hdr) >
74 path[ppos].p_idx) {
75 int cur_ppos = ppos;
76
77 /* index block */
78 path[ppos].p_idx++;
79 path[ppos].p_block = idx_pblock(path[ppos].p_idx);
80 if (path[ppos+1].p_bh)
81 brelse(path[ppos+1].p_bh);
82 path[ppos+1].p_bh =
83 sb_bread(inode->i_sb, path[ppos].p_block);
84 if (!path[ppos+1].p_bh)
85 return -EIO;
86 path[ppos+1].p_hdr =
87 ext_block_hdr(path[ppos+1].p_bh);
88
89 /* Halfway index block */
90 while (++cur_ppos < leaf_ppos) {
91 path[cur_ppos].p_idx =
92 EXT_FIRST_INDEX(path[cur_ppos].p_hdr);
93 path[cur_ppos].p_block =
94 idx_pblock(path[cur_ppos].p_idx);
95 if (path[cur_ppos+1].p_bh)
96 brelse(path[cur_ppos+1].p_bh);
97 path[cur_ppos+1].p_bh = sb_bread(inode->i_sb,
98 path[cur_ppos].p_block);
99 if (!path[cur_ppos+1].p_bh)
100 return -EIO;
101 path[cur_ppos+1].p_hdr =
102 ext_block_hdr(path[cur_ppos+1].p_bh);
103 }
104
105 /* leaf block */
106 path[leaf_ppos].p_ext = *extent =
107 EXT_FIRST_EXTENT(path[leaf_ppos].p_hdr);
108 return 0;
109 }
110 }
111 /* We found the last extent */
112 return 1;
113}
114
115/**
116 * mext_double_down_read - Acquire two inodes' read semaphore
117 *
118 * @orig_inode: original inode structure
119 * @donor_inode: donor inode structure
120 * Acquire read semaphore of the two inodes (orig and donor) by i_ino order.
121 */
122static void
123mext_double_down_read(struct inode *orig_inode, struct inode *donor_inode)
124{
125 struct inode *first = orig_inode, *second = donor_inode;
126
127 BUG_ON(orig_inode == NULL || donor_inode == NULL);
128
129 /*
130 * Use the inode number to provide the stable locking order instead
131 * of its address, because the C language doesn't guarantee you can
132 * compare pointers that don't come from the same array.
133 */
134 if (donor_inode->i_ino < orig_inode->i_ino) {
135 first = donor_inode;
136 second = orig_inode;
137 }
138
139 down_read(&EXT4_I(first)->i_data_sem);
140 down_read(&EXT4_I(second)->i_data_sem);
141}
142
143/**
144 * mext_double_down_write - Acquire two inodes' write semaphore
145 *
146 * @orig_inode: original inode structure
147 * @donor_inode: donor inode structure
148 * Acquire write semaphore of the two inodes (orig and donor) by i_ino order.
149 */
150static void
151mext_double_down_write(struct inode *orig_inode, struct inode *donor_inode)
152{
153 struct inode *first = orig_inode, *second = donor_inode;
154
155 BUG_ON(orig_inode == NULL || donor_inode == NULL);
156
157 /*
158 * Use the inode number to provide the stable locking order instead
159 * of its address, because the C language doesn't guarantee you can
160 * compare pointers that don't come from the same array.
161 */
162 if (donor_inode->i_ino < orig_inode->i_ino) {
163 first = donor_inode;
164 second = orig_inode;
165 }
166
167 down_write(&EXT4_I(first)->i_data_sem);
168 down_write(&EXT4_I(second)->i_data_sem);
169}
170
171/**
172 * mext_double_up_read - Release two inodes' read semaphore
173 *
174 * @orig_inode: original inode structure to be released its lock first
175 * @donor_inode: donor inode structure to be released its lock second
176 * Release read semaphore of two inodes (orig and donor).
177 */
178static void
179mext_double_up_read(struct inode *orig_inode, struct inode *donor_inode)
180{
181 BUG_ON(orig_inode == NULL || donor_inode == NULL);
182
183 up_read(&EXT4_I(orig_inode)->i_data_sem);
184 up_read(&EXT4_I(donor_inode)->i_data_sem);
185}
186
187/**
188 * mext_double_up_write - Release two inodes' write semaphore
189 *
190 * @orig_inode: original inode structure to be released its lock first
191 * @donor_inode: donor inode structure to be released its lock second
192 * Release write semaphore of two inodes (orig and donor).
193 */
194static void
195mext_double_up_write(struct inode *orig_inode, struct inode *donor_inode)
196{
197 BUG_ON(orig_inode == NULL || donor_inode == NULL);
198
199 up_write(&EXT4_I(orig_inode)->i_data_sem);
200 up_write(&EXT4_I(donor_inode)->i_data_sem);
201}
202
203/**
204 * mext_insert_across_blocks - Insert extents across leaf block
205 *
206 * @handle: journal handle
207 * @orig_inode: original inode
208 * @o_start: first original extent to be changed
209 * @o_end: last original extent to be changed
210 * @start_ext: first new extent to be inserted
211 * @new_ext: middle of new extent to be inserted
212 * @end_ext: last new extent to be inserted
213 *
214 * Allocate a new leaf block and insert extents into it. Return 0 on success,
215 * or a negative error value on failure.
216 */
217static int
218mext_insert_across_blocks(handle_t *handle, struct inode *orig_inode,
219 struct ext4_extent *o_start, struct ext4_extent *o_end,
220 struct ext4_extent *start_ext, struct ext4_extent *new_ext,
221 struct ext4_extent *end_ext)
222{
223 struct ext4_ext_path *orig_path = NULL;
224 ext4_lblk_t eblock = 0;
225 int new_flag = 0;
226 int end_flag = 0;
227 int err = 0;
228
229 if (start_ext->ee_len && new_ext->ee_len && end_ext->ee_len) {
230 if (o_start == o_end) {
231
232 /* start_ext new_ext end_ext
233 * donor |---------|-----------|--------|
234 * orig |------------------------------|
235 */
236 end_flag = 1;
237 } else {
238
239 /* start_ext new_ext end_ext
240 * donor |---------|----------|---------|
241 * orig |---------------|--------------|
242 */
243 o_end->ee_block = end_ext->ee_block;
244 o_end->ee_len = end_ext->ee_len;
245 ext4_ext_store_pblock(o_end, ext_pblock(end_ext));
246 }
247
248 o_start->ee_len = start_ext->ee_len;
249 new_flag = 1;
250
251 } else if (start_ext->ee_len && new_ext->ee_len &&
252 !end_ext->ee_len && o_start == o_end) {
253
254 /* start_ext new_ext
255 * donor |--------------|---------------|
256 * orig |------------------------------|
257 */
258 o_start->ee_len = start_ext->ee_len;
259 new_flag = 1;
260
261 } else if (!start_ext->ee_len && new_ext->ee_len &&
262 end_ext->ee_len && o_start == o_end) {
263
264 /* new_ext end_ext
265 * donor |--------------|---------------|
266 * orig |------------------------------|
267 */
268 o_end->ee_block = end_ext->ee_block;
269 o_end->ee_len = end_ext->ee_len;
270 ext4_ext_store_pblock(o_end, ext_pblock(end_ext));
271
272 /*
273 * Set 0 to the extent block if new_ext was
274 * the first block.
275 */
276 if (new_ext->ee_block)
277 eblock = le32_to_cpu(new_ext->ee_block);
278
279 new_flag = 1;
280 } else {
281 ext4_debug("ext4 move extent: Unexpected insert case\n");
282 return -EIO;
283 }
284
285 if (new_flag) {
286 get_ext_path(orig_path, orig_inode, eblock, err);
287 if (orig_path == NULL)
288 goto out;
289
290 if (ext4_ext_insert_extent(handle, orig_inode,
291 orig_path, new_ext))
292 goto out;
293 }
294
295 if (end_flag) {
296 get_ext_path(orig_path, orig_inode,
297 le32_to_cpu(end_ext->ee_block) - 1, err);
298 if (orig_path == NULL)
299 goto out;
300
301 if (ext4_ext_insert_extent(handle, orig_inode,
302 orig_path, end_ext))
303 goto out;
304 }
305out:
306 if (orig_path) {
307 ext4_ext_drop_refs(orig_path);
308 kfree(orig_path);
309 }
310
311 return err;
312
313}
314
315/**
316 * mext_insert_inside_block - Insert new extent to the extent block
317 *
318 * @o_start: first original extent to be moved
319 * @o_end: last original extent to be moved
320 * @start_ext: first new extent to be inserted
321 * @new_ext: middle of new extent to be inserted
322 * @end_ext: last new extent to be inserted
323 * @eh: extent header of target leaf block
324 * @range_to_move: used to decide how to insert extent
325 *
326 * Insert extents into the leaf block. The extent (@o_start) is overwritten
327 * by inserted extents.
328 */
329static void
330mext_insert_inside_block(struct ext4_extent *o_start,
331 struct ext4_extent *o_end,
332 struct ext4_extent *start_ext,
333 struct ext4_extent *new_ext,
334 struct ext4_extent *end_ext,
335 struct ext4_extent_header *eh,
336 int range_to_move)
337{
338 int i = 0;
339 unsigned long len;
340
341 /* Move the existing extents */
342 if (range_to_move && o_end < EXT_LAST_EXTENT(eh)) {
343 len = (unsigned long)(EXT_LAST_EXTENT(eh) + 1) -
344 (unsigned long)(o_end + 1);
345 memmove(o_end + 1 + range_to_move, o_end + 1, len);
346 }
347
348 /* Insert start entry */
349 if (start_ext->ee_len)
350 o_start[i++].ee_len = start_ext->ee_len;
351
352 /* Insert new entry */
353 if (new_ext->ee_len) {
354 o_start[i] = *new_ext;
355 ext4_ext_store_pblock(&o_start[i++], ext_pblock(new_ext));
356 }
357
358 /* Insert end entry */
359 if (end_ext->ee_len)
360 o_start[i] = *end_ext;
361
362 /* Increment the total entries counter on the extent block */
363 le16_add_cpu(&eh->eh_entries, range_to_move);
364}
365
366/**
367 * mext_insert_extents - Insert new extent
368 *
369 * @handle: journal handle
370 * @orig_inode: original inode
371 * @orig_path: path indicates first extent to be changed
372 * @o_start: first original extent to be changed
373 * @o_end: last original extent to be changed
374 * @start_ext: first new extent to be inserted
375 * @new_ext: middle of new extent to be inserted
376 * @end_ext: last new extent to be inserted
377 *
378 * Call the function to insert extents. If we cannot add more extents into
379 * the leaf block, we call mext_insert_across_blocks() to create a
380 * new leaf block. Otherwise call mext_insert_inside_block(). Return 0
381 * on success, or a negative error value on failure.
382 */
383static int
384mext_insert_extents(handle_t *handle, struct inode *orig_inode,
385 struct ext4_ext_path *orig_path,
386 struct ext4_extent *o_start,
387 struct ext4_extent *o_end,
388 struct ext4_extent *start_ext,
389 struct ext4_extent *new_ext,
390 struct ext4_extent *end_ext)
391{
392 struct ext4_extent_header *eh;
393 unsigned long need_slots, slots_range;
394 int range_to_move, depth, ret;
395
396 /*
397 * The extents need to be inserted
398 * start_extent + new_extent + end_extent.
399 */
400 need_slots = (start_ext->ee_len ? 1 : 0) + (end_ext->ee_len ? 1 : 0) +
401 (new_ext->ee_len ? 1 : 0);
402
403 /* The number of slots between start and end */
404 slots_range = ((unsigned long)(o_end + 1) - (unsigned long)o_start + 1)
405 / sizeof(struct ext4_extent);
406
407 /* Range to move the end of extent */
408 range_to_move = need_slots - slots_range;
409 depth = orig_path->p_depth;
410 orig_path += depth;
411 eh = orig_path->p_hdr;
412
413 if (depth) {
414 /* Register to journal */
415 ret = ext4_journal_get_write_access(handle, orig_path->p_bh);
416 if (ret)
417 return ret;
418 }
419
420 /* Expansion */
421 if (range_to_move > 0 &&
422 (range_to_move > le16_to_cpu(eh->eh_max)
423 - le16_to_cpu(eh->eh_entries))) {
424
425 ret = mext_insert_across_blocks(handle, orig_inode, o_start,
426 o_end, start_ext, new_ext, end_ext);
427 if (ret < 0)
428 return ret;
429 } else
430 mext_insert_inside_block(o_start, o_end, start_ext, new_ext,
431 end_ext, eh, range_to_move);
432
433 if (depth) {
434 ret = ext4_handle_dirty_metadata(handle, orig_inode,
435 orig_path->p_bh);
436 if (ret)
437 return ret;
438 } else {
439 ret = ext4_mark_inode_dirty(handle, orig_inode);
440 if (ret < 0)
441 return ret;
442 }
443
444 return 0;
445}
446
447/**
448 * mext_leaf_block - Move one leaf extent block into the inode.
449 *
450 * @handle: journal handle
451 * @orig_inode: original inode
452 * @orig_path: path indicates first extent to be changed
453 * @dext: donor extent
454 * @from: start offset on the target file
455 *
456 * In order to insert extents into the leaf block, we must divide the extent
457 * in the leaf block into three extents. The one is located to be inserted
458 * extents, and the others are located around it.
459 *
460 * Therefore, this function creates structures to save extents of the leaf
461 * block, and inserts extents by calling mext_insert_extents() with
462 * created extents. Return 0 on success, or a negative error value on failure.
463 */
464static int
465mext_leaf_block(handle_t *handle, struct inode *orig_inode,
466 struct ext4_ext_path *orig_path, struct ext4_extent *dext,
467 ext4_lblk_t *from)
468{
469 struct ext4_extent *oext, *o_start, *o_end, *prev_ext;
470 struct ext4_extent new_ext, start_ext, end_ext;
471 ext4_lblk_t new_ext_end;
472 ext4_fsblk_t new_phys_end;
473 int oext_alen, new_ext_alen, end_ext_alen;
474 int depth = ext_depth(orig_inode);
475 int ret;
476
477 o_start = o_end = oext = orig_path[depth].p_ext;
478 oext_alen = ext4_ext_get_actual_len(oext);
479 start_ext.ee_len = end_ext.ee_len = 0;
480
481 new_ext.ee_block = cpu_to_le32(*from);
482 ext4_ext_store_pblock(&new_ext, ext_pblock(dext));
483 new_ext.ee_len = dext->ee_len;
484 new_ext_alen = ext4_ext_get_actual_len(&new_ext);
485 new_ext_end = le32_to_cpu(new_ext.ee_block) + new_ext_alen - 1;
486 new_phys_end = ext_pblock(&new_ext) + new_ext_alen - 1;
487
488 /*
489 * Case: original extent is first
490 * oext |--------|
491 * new_ext |--|
492 * start_ext |--|
493 */
494 if (le32_to_cpu(oext->ee_block) < le32_to_cpu(new_ext.ee_block) &&
495 le32_to_cpu(new_ext.ee_block) <
496 le32_to_cpu(oext->ee_block) + oext_alen) {
497 start_ext.ee_len = cpu_to_le16(le32_to_cpu(new_ext.ee_block) -
498 le32_to_cpu(oext->ee_block));
499 copy_extent_status(oext, &start_ext);
500 } else if (oext > EXT_FIRST_EXTENT(orig_path[depth].p_hdr)) {
501 prev_ext = oext - 1;
502 /*
503 * We can merge new_ext into previous extent,
504 * if these are contiguous and same extent type.
505 */
506 if (ext4_can_extents_be_merged(orig_inode, prev_ext,
507 &new_ext)) {
508 o_start = prev_ext;
509 start_ext.ee_len = cpu_to_le16(
510 ext4_ext_get_actual_len(prev_ext) +
511 new_ext_alen);
512 copy_extent_status(prev_ext, &start_ext);
513 new_ext.ee_len = 0;
514 }
515 }
516
517 /*
518 * Case: new_ext_end must be less than oext
519 * oext |-----------|
520 * new_ext |-------|
521 */
522 BUG_ON(le32_to_cpu(oext->ee_block) + oext_alen - 1 < new_ext_end);
523
524 /*
525 * Case: new_ext is smaller than original extent
526 * oext |---------------|
527 * new_ext |-----------|
528 * end_ext |---|
529 */
530 if (le32_to_cpu(oext->ee_block) <= new_ext_end &&
531 new_ext_end < le32_to_cpu(oext->ee_block) + oext_alen - 1) {
532 end_ext.ee_len =
533 cpu_to_le16(le32_to_cpu(oext->ee_block) +
534 oext_alen - 1 - new_ext_end);
535 copy_extent_status(oext, &end_ext);
536 end_ext_alen = ext4_ext_get_actual_len(&end_ext);
537 ext4_ext_store_pblock(&end_ext,
538 (ext_pblock(o_end) + oext_alen - end_ext_alen));
539 end_ext.ee_block =
540 cpu_to_le32(le32_to_cpu(o_end->ee_block) +
541 oext_alen - end_ext_alen);
542 }
543
544 ret = mext_insert_extents(handle, orig_inode, orig_path, o_start,
545 o_end, &start_ext, &new_ext, &end_ext);
546 return ret;
547}
548
549/**
550 * mext_calc_swap_extents - Calculate extents for extent swapping.
551 *
552 * @tmp_dext: the extent that will belong to the original inode
553 * @tmp_oext: the extent that will belong to the donor inode
554 * @orig_off: block offset of original inode
555 * @donor_off: block offset of donor inode
556 * @max_count: the maximun length of extents
557 */
558static void
559mext_calc_swap_extents(struct ext4_extent *tmp_dext,
560 struct ext4_extent *tmp_oext,
561 ext4_lblk_t orig_off, ext4_lblk_t donor_off,
562 ext4_lblk_t max_count)
563{
564 ext4_lblk_t diff, orig_diff;
565 struct ext4_extent dext_old, oext_old;
566
567 dext_old = *tmp_dext;
568 oext_old = *tmp_oext;
569
570 /* When tmp_dext is too large, pick up the target range. */
571 diff = donor_off - le32_to_cpu(tmp_dext->ee_block);
572
573 ext4_ext_store_pblock(tmp_dext, ext_pblock(tmp_dext) + diff);
574 tmp_dext->ee_block =
575 cpu_to_le32(le32_to_cpu(tmp_dext->ee_block) + diff);
576 tmp_dext->ee_len = cpu_to_le16(le16_to_cpu(tmp_dext->ee_len) - diff);
577
578 if (max_count < ext4_ext_get_actual_len(tmp_dext))
579 tmp_dext->ee_len = cpu_to_le16(max_count);
580
581 orig_diff = orig_off - le32_to_cpu(tmp_oext->ee_block);
582 ext4_ext_store_pblock(tmp_oext, ext_pblock(tmp_oext) + orig_diff);
583
584 /* Adjust extent length if donor extent is larger than orig */
585 if (ext4_ext_get_actual_len(tmp_dext) >
586 ext4_ext_get_actual_len(tmp_oext) - orig_diff)
587 tmp_dext->ee_len = cpu_to_le16(le16_to_cpu(tmp_oext->ee_len) -
588 orig_diff);
589
590 tmp_oext->ee_len = cpu_to_le16(ext4_ext_get_actual_len(tmp_dext));
591
592 copy_extent_status(&oext_old, tmp_dext);
593 copy_extent_status(&dext_old, tmp_oext);
594}
595
596/**
597 * mext_replace_branches - Replace original extents with new extents
598 *
599 * @handle: journal handle
600 * @orig_inode: original inode
601 * @donor_inode: donor inode
602 * @from: block offset of orig_inode
603 * @count: block count to be replaced
604 *
605 * Replace original inode extents and donor inode extents page by page.
606 * We implement this replacement in the following three steps:
607 * 1. Save the block information of original and donor inodes into
608 * dummy extents.
609 * 2. Change the block information of original inode to point at the
610 * donor inode blocks.
611 * 3. Change the block information of donor inode to point at the saved
612 * original inode blocks in the dummy extents.
613 *
614 * Return 0 on success, or a negative error value on failure.
615 */
616static int
617mext_replace_branches(handle_t *handle, struct inode *orig_inode,
618 struct inode *donor_inode, ext4_lblk_t from,
619 ext4_lblk_t count)
620{
621 struct ext4_ext_path *orig_path = NULL;
622 struct ext4_ext_path *donor_path = NULL;
623 struct ext4_extent *oext, *dext;
624 struct ext4_extent tmp_dext, tmp_oext;
625 ext4_lblk_t orig_off = from, donor_off = from;
626 int err = 0;
627 int depth;
628 int replaced_count = 0;
629 int dext_alen;
630
631 mext_double_down_write(orig_inode, donor_inode);
632
633 /* Get the original extent for the block "orig_off" */
634 get_ext_path(orig_path, orig_inode, orig_off, err);
635 if (orig_path == NULL)
636 goto out;
637
638 /* Get the donor extent for the head */
639 get_ext_path(donor_path, donor_inode, donor_off, err);
640 if (donor_path == NULL)
641 goto out;
642 depth = ext_depth(orig_inode);
643 oext = orig_path[depth].p_ext;
644 tmp_oext = *oext;
645
646 depth = ext_depth(donor_inode);
647 dext = donor_path[depth].p_ext;
648 tmp_dext = *dext;
649
650 mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
651 donor_off, count);
652
653 /* Loop for the donor extents */
654 while (1) {
655 /* The extent for donor must be found. */
656 BUG_ON(!dext || donor_off != le32_to_cpu(tmp_dext.ee_block));
657
658 /* Set donor extent to orig extent */
659 err = mext_leaf_block(handle, orig_inode,
660 orig_path, &tmp_dext, &orig_off);
661 if (err < 0)
662 goto out;
663
664 /* Set orig extent to donor extent */
665 err = mext_leaf_block(handle, donor_inode,
666 donor_path, &tmp_oext, &donor_off);
667 if (err < 0)
668 goto out;
669
670 dext_alen = ext4_ext_get_actual_len(&tmp_dext);
671 replaced_count += dext_alen;
672 donor_off += dext_alen;
673 orig_off += dext_alen;
674
675 /* Already moved the expected blocks */
676 if (replaced_count >= count)
677 break;
678
679 if (orig_path)
680 ext4_ext_drop_refs(orig_path);
681 get_ext_path(orig_path, orig_inode, orig_off, err);
682 if (orig_path == NULL)
683 goto out;
684 depth = ext_depth(orig_inode);
685 oext = orig_path[depth].p_ext;
686 if (le32_to_cpu(oext->ee_block) +
687 ext4_ext_get_actual_len(oext) <= orig_off) {
688 err = 0;
689 goto out;
690 }
691 tmp_oext = *oext;
692
693 if (donor_path)
694 ext4_ext_drop_refs(donor_path);
695 get_ext_path(donor_path, donor_inode,
696 donor_off, err);
697 if (donor_path == NULL)
698 goto out;
699 depth = ext_depth(donor_inode);
700 dext = donor_path[depth].p_ext;
701 if (le32_to_cpu(dext->ee_block) +
702 ext4_ext_get_actual_len(dext) <= donor_off) {
703 err = 0;
704 goto out;
705 }
706 tmp_dext = *dext;
707
708 mext_calc_swap_extents(&tmp_dext, &tmp_oext, orig_off,
709 donor_off,
710 count - replaced_count);
711 }
712
713out:
714 if (orig_path) {
715 ext4_ext_drop_refs(orig_path);
716 kfree(orig_path);
717 }
718 if (donor_path) {
719 ext4_ext_drop_refs(donor_path);
720 kfree(donor_path);
721 }
722
723 mext_double_up_write(orig_inode, donor_inode);
724 return err;
725}
726
727/**
728 * move_extent_per_page - Move extent data per page
729 *
730 * @o_filp: file structure of original file
731 * @donor_inode: donor inode
732 * @orig_page_offset: page index on original file
733 * @data_offset_in_page: block index where data swapping starts
734 * @block_len_in_page: the number of blocks to be swapped
735 * @uninit: orig extent is uninitialized or not
736 *
737 * Save the data in original inode blocks and replace original inode extents
738 * with donor inode extents by calling mext_replace_branches().
739 * Finally, write out the saved data in new original inode blocks. Return 0
740 * on success, or a negative error value on failure.
741 */
742static int
743move_extent_par_page(struct file *o_filp, struct inode *donor_inode,
744 pgoff_t orig_page_offset, int data_offset_in_page,
745 int block_len_in_page, int uninit)
746{
747 struct inode *orig_inode = o_filp->f_dentry->d_inode;
748 struct address_space *mapping = orig_inode->i_mapping;
749 struct buffer_head *bh;
750 struct page *page = NULL;
751 const struct address_space_operations *a_ops = mapping->a_ops;
752 handle_t *handle;
753 ext4_lblk_t orig_blk_offset;
754 long long offs = orig_page_offset << PAGE_CACHE_SHIFT;
755 unsigned long blocksize = orig_inode->i_sb->s_blocksize;
756 unsigned int w_flags = 0;
757 unsigned int tmp_data_len, data_len;
758 void *fsdata;
759 int ret, i, jblocks;
760 int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits;
761
762 /*
763 * It needs twice the amount of ordinary journal buffers because
764 * inode and donor_inode may change each different metadata blocks.
765 */
766 jblocks = ext4_writepage_trans_blocks(orig_inode) * 2;
767 handle = ext4_journal_start(orig_inode, jblocks);
768 if (IS_ERR(handle)) {
769 ret = PTR_ERR(handle);
770 return ret;
771 }
772
773 if (segment_eq(get_fs(), KERNEL_DS))
774 w_flags |= AOP_FLAG_UNINTERRUPTIBLE;
775
776 orig_blk_offset = orig_page_offset * blocks_per_page +
777 data_offset_in_page;
778
779 /*
780 * If orig extent is uninitialized one,
781 * it's not necessary force the page into memory
782 * and then force it to be written out again.
783 * Just swap data blocks between orig and donor.
784 */
785 if (uninit) {
786 ret = mext_replace_branches(handle, orig_inode,
787 donor_inode, orig_blk_offset,
788 block_len_in_page);
789
790 /* Clear the inode cache not to refer to the old data */
791 ext4_ext_invalidate_cache(orig_inode);
792 ext4_ext_invalidate_cache(donor_inode);
793 goto out2;
794 }
795
796 offs = (long long)orig_blk_offset << orig_inode->i_blkbits;
797
798 /* Calculate data_len */
799 if ((orig_blk_offset + block_len_in_page - 1) ==
800 ((orig_inode->i_size - 1) >> orig_inode->i_blkbits)) {
801 /* Replace the last block */
802 tmp_data_len = orig_inode->i_size & (blocksize - 1);
803 /*
804 * If data_len equal zero, it shows data_len is multiples of
805 * blocksize. So we set appropriate value.
806 */
807 if (tmp_data_len == 0)
808 tmp_data_len = blocksize;
809
810 data_len = tmp_data_len +
811 ((block_len_in_page - 1) << orig_inode->i_blkbits);
812 } else {
813 data_len = block_len_in_page << orig_inode->i_blkbits;
814 }
815
816 ret = a_ops->write_begin(o_filp, mapping, offs, data_len, w_flags,
817 &page, &fsdata);
818 if (unlikely(ret < 0))
819 goto out;
820
821 if (!PageUptodate(page)) {
822 mapping->a_ops->readpage(o_filp, page);
823 lock_page(page);
824 }
825
826 /*
827 * try_to_release_page() doesn't call releasepage in writeback mode.
828 * We should care about the order of writing to the same file
829 * by multiple move extent processes.
830 * It needs to call wait_on_page_writeback() to wait for the
831 * writeback of the page.
832 */
833 if (PageWriteback(page))
834 wait_on_page_writeback(page);
835
836 /* Release old bh and drop refs */
837 try_to_release_page(page, 0);
838
839 ret = mext_replace_branches(handle, orig_inode, donor_inode,
840 orig_blk_offset, block_len_in_page);
841 if (ret < 0)
842 goto out;
843
844 /* Clear the inode cache not to refer to the old data */
845 ext4_ext_invalidate_cache(orig_inode);
846 ext4_ext_invalidate_cache(donor_inode);
847
848 if (!page_has_buffers(page))
849 create_empty_buffers(page, 1 << orig_inode->i_blkbits, 0);
850
851 bh = page_buffers(page);
852 for (i = 0; i < data_offset_in_page; i++)
853 bh = bh->b_this_page;
854
855 for (i = 0; i < block_len_in_page; i++) {
856 ret = ext4_get_block(orig_inode,
857 (sector_t)(orig_blk_offset + i), bh, 0);
858 if (ret < 0)
859 goto out;
860
861 if (bh->b_this_page != NULL)
862 bh = bh->b_this_page;
863 }
864
865 ret = a_ops->write_end(o_filp, mapping, offs, data_len, data_len,
866 page, fsdata);
867 page = NULL;
868
869out:
870 if (unlikely(page)) {
871 if (PageLocked(page))
872 unlock_page(page);
873 page_cache_release(page);
874 }
875out2:
876 ext4_journal_stop(handle);
877
878 return ret < 0 ? ret : 0;
879}
880
881/**
882 * mext_check_argumants - Check whether move extent can be done
883 *
884 * @orig_inode: original inode
885 * @donor_inode: donor inode
886 * @orig_start: logical start offset in block for orig
887 * @donor_start: logical start offset in block for donor
888 * @len: the number of blocks to be moved
889 * @moved_len: moved block length
890 *
891 * Check the arguments of ext4_move_extents() whether the files can be
892 * exchanged with each other.
893 * Return 0 on success, or a negative error value on failure.
894 */
895static int
896mext_check_arguments(struct inode *orig_inode,
897 struct inode *donor_inode, __u64 orig_start,
898 __u64 donor_start, __u64 *len, __u64 moved_len)
899{
900 /* Regular file check */
901 if (!S_ISREG(orig_inode->i_mode) || !S_ISREG(donor_inode->i_mode)) {
902 ext4_debug("ext4 move extent: The argument files should be "
903 "regular file [ino:orig %lu, donor %lu]\n",
904 orig_inode->i_ino, donor_inode->i_ino);
905 return -EINVAL;
906 }
907
908 /* Ext4 move extent does not support swapfile */
909 if (IS_SWAPFILE(orig_inode) || IS_SWAPFILE(donor_inode)) {
910 ext4_debug("ext4 move extent: The argument files should "
911 "not be swapfile [ino:orig %lu, donor %lu]\n",
912 orig_inode->i_ino, donor_inode->i_ino);
913 return -EINVAL;
914 }
915
916 /* Files should be in the same ext4 FS */
917 if (orig_inode->i_sb != donor_inode->i_sb) {
918 ext4_debug("ext4 move extent: The argument files "
919 "should be in same FS [ino:orig %lu, donor %lu]\n",
920 orig_inode->i_ino, donor_inode->i_ino);
921 return -EINVAL;
922 }
923
924 /* orig and donor should be different file */
925 if (orig_inode->i_ino == donor_inode->i_ino) {
926 ext4_debug("ext4 move extent: The argument files should not "
927 "be same file [ino:orig %lu, donor %lu]\n",
928 orig_inode->i_ino, donor_inode->i_ino);
929 return -EINVAL;
930 }
931
932 /* Ext4 move extent supports only extent based file */
933 if (!(EXT4_I(orig_inode)->i_flags & EXT4_EXTENTS_FL)) {
934 ext4_debug("ext4 move extent: orig file is not extents "
935 "based file [ino:orig %lu]\n", orig_inode->i_ino);
936 return -EOPNOTSUPP;
937 } else if (!(EXT4_I(donor_inode)->i_flags & EXT4_EXTENTS_FL)) {
938 ext4_debug("ext4 move extent: donor file is not extents "
939 "based file [ino:donor %lu]\n", donor_inode->i_ino);
940 return -EOPNOTSUPP;
941 }
942
943 if ((!orig_inode->i_size) || (!donor_inode->i_size)) {
944 ext4_debug("ext4 move extent: File size is 0 byte\n");
945 return -EINVAL;
946 }
947
948 /* Start offset should be same */
949 if (orig_start != donor_start) {
950 ext4_debug("ext4 move extent: orig and donor's start "
951 "offset are not same [ino:orig %lu, donor %lu]\n",
952 orig_inode->i_ino, donor_inode->i_ino);
953 return -EINVAL;
954 }
955
956 if (moved_len) {
957 ext4_debug("ext4 move extent: moved_len should be 0 "
958 "[ino:orig %lu, donor %lu]\n", orig_inode->i_ino,
959 donor_inode->i_ino);
960 return -EINVAL;
961 }
962
963 if ((orig_start > MAX_DEFRAG_SIZE) ||
964 (donor_start > MAX_DEFRAG_SIZE) ||
965 (*len > MAX_DEFRAG_SIZE) ||
966 (orig_start + *len > MAX_DEFRAG_SIZE)) {
967 ext4_debug("ext4 move extent: Can't handle over [%lu] blocks "
968 "[ino:orig %lu, donor %lu]\n", MAX_DEFRAG_SIZE,
969 orig_inode->i_ino, donor_inode->i_ino);
970 return -EINVAL;
971 }
972
973 if (orig_inode->i_size > donor_inode->i_size) {
974 if (orig_start >= donor_inode->i_size) {
975 ext4_debug("ext4 move extent: orig start offset "
976 "[%llu] should be less than donor file size "
977 "[%lld] [ino:orig %lu, donor_inode %lu]\n",
978 orig_start, donor_inode->i_size,
979 orig_inode->i_ino, donor_inode->i_ino);
980 return -EINVAL;
981 }
982
983 if (orig_start + *len > donor_inode->i_size) {
984 ext4_debug("ext4 move extent: End offset [%llu] should "
985 "be less than donor file size [%lld]."
986 "So adjust length from %llu to %lld "
987 "[ino:orig %lu, donor %lu]\n",
988 orig_start + *len, donor_inode->i_size,
989 *len, donor_inode->i_size - orig_start,
990 orig_inode->i_ino, donor_inode->i_ino);
991 *len = donor_inode->i_size - orig_start;
992 }
993 } else {
994 if (orig_start >= orig_inode->i_size) {
995 ext4_debug("ext4 move extent: start offset [%llu] "
996 "should be less than original file size "
997 "[%lld] [inode:orig %lu, donor %lu]\n",
998 orig_start, orig_inode->i_size,
999 orig_inode->i_ino, donor_inode->i_ino);
1000 return -EINVAL;
1001 }
1002
1003 if (orig_start + *len > orig_inode->i_size) {
1004 ext4_debug("ext4 move extent: Adjust length "
1005 "from %llu to %lld. Because it should be "
1006 "less than original file size "
1007 "[ino:orig %lu, donor %lu]\n",
1008 *len, orig_inode->i_size - orig_start,
1009 orig_inode->i_ino, donor_inode->i_ino);
1010 *len = orig_inode->i_size - orig_start;
1011 }
1012 }
1013
1014 if (!*len) {
1015 ext4_debug("ext4 move extent: len shoudld not be 0 "
1016 "[ino:orig %lu, donor %lu]\n", orig_inode->i_ino,
1017 donor_inode->i_ino);
1018 return -EINVAL;
1019 }
1020
1021 return 0;
1022}
1023
1024/**
1025 * mext_inode_double_lock - Lock i_mutex on both @inode1 and @inode2
1026 *
1027 * @inode1: the inode structure
1028 * @inode2: the inode structure
1029 *
1030 * Lock two inodes' i_mutex by i_ino order. This function is moved from
1031 * fs/inode.c.
1032 */
1033static void
1034mext_inode_double_lock(struct inode *inode1, struct inode *inode2)
1035{
1036 if (inode1 == NULL || inode2 == NULL || inode1 == inode2) {
1037 if (inode1)
1038 mutex_lock(&inode1->i_mutex);
1039 else if (inode2)
1040 mutex_lock(&inode2->i_mutex);
1041 return;
1042 }
1043
1044 if (inode1->i_ino < inode2->i_ino) {
1045 mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT);
1046 mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD);
1047 } else {
1048 mutex_lock_nested(&inode2->i_mutex, I_MUTEX_PARENT);
1049 mutex_lock_nested(&inode1->i_mutex, I_MUTEX_CHILD);
1050 }
1051}
1052
1053/**
1054 * mext_inode_double_unlock - Release i_mutex on both @inode1 and @inode2
1055 *
1056 * @inode1: the inode that is released first
1057 * @inode2: the inode that is released second
1058 *
1059 * This function is moved from fs/inode.c.
1060 */
1061
1062static void
1063mext_inode_double_unlock(struct inode *inode1, struct inode *inode2)
1064{
1065 if (inode1)
1066 mutex_unlock(&inode1->i_mutex);
1067
1068 if (inode2 && inode2 != inode1)
1069 mutex_unlock(&inode2->i_mutex);
1070}
1071
1072/**
1073 * ext4_move_extents - Exchange the specified range of a file
1074 *
1075 * @o_filp: file structure of the original file
1076 * @d_filp: file structure of the donor file
1077 * @orig_start: start offset in block for orig
1078 * @donor_start: start offset in block for donor
1079 * @len: the number of blocks to be moved
1080 * @moved_len: moved block length
1081 *
1082 * This function returns 0 and moved block length is set in moved_len
1083 * if succeed, otherwise returns error value.
1084 *
1085 * Note: ext4_move_extents() proceeds the following order.
1086 * 1:ext4_move_extents() calculates the last block number of moving extent
1087 * function by the start block number (orig_start) and the number of blocks
1088 * to be moved (len) specified as arguments.
1089 * If the {orig, donor}_start points a hole, the extent's start offset
1090 * pointed by ext_cur (current extent), holecheck_path, orig_path are set
1091 * after hole behind.
1092 * 2:Continue step 3 to step 5, until the holecheck_path points to last_extent
1093 * or the ext_cur exceeds the block_end which is last logical block number.
1094 * 3:To get the length of continues area, call mext_next_extent()
1095 * specified with the ext_cur (initial value is holecheck_path) re-cursive,
1096 * until find un-continuous extent, the start logical block number exceeds
1097 * the block_end or the extent points to the last extent.
1098 * 4:Exchange the original inode data with donor inode data
1099 * from orig_page_offset to seq_end_page.
1100 * The start indexes of data are specified as arguments.
1101 * That of the original inode is orig_page_offset,
1102 * and the donor inode is also orig_page_offset
1103 * (To easily handle blocksize != pagesize case, the offset for the
1104 * donor inode is block unit).
1105 * 5:Update holecheck_path and orig_path to points a next proceeding extent,
1106 * then returns to step 2.
1107 * 6:Release holecheck_path, orig_path and set the len to moved_len
1108 * which shows the number of moved blocks.
1109 * The moved_len is useful for the command to calculate the file offset
1110 * for starting next move extent ioctl.
1111 * 7:Return 0 on success, or a negative error value on failure.
1112 */
1113int
1114ext4_move_extents(struct file *o_filp, struct file *d_filp,
1115 __u64 orig_start, __u64 donor_start, __u64 len,
1116 __u64 *moved_len)
1117{
1118 struct inode *orig_inode = o_filp->f_dentry->d_inode;
1119 struct inode *donor_inode = d_filp->f_dentry->d_inode;
1120 struct ext4_ext_path *orig_path = NULL, *holecheck_path = NULL;
1121 struct ext4_extent *ext_prev, *ext_cur, *ext_dummy;
1122 ext4_lblk_t block_start = orig_start;
1123 ext4_lblk_t block_end, seq_start, add_blocks, file_end, seq_blocks = 0;
1124 ext4_lblk_t rest_blocks;
1125 pgoff_t orig_page_offset = 0, seq_end_page;
1126 int ret, depth, last_extent = 0;
1127 int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits;
1128 int data_offset_in_page;
1129 int block_len_in_page;
1130 int uninit;
1131
1132 /* protect orig and donor against a truncate */
1133 mext_inode_double_lock(orig_inode, donor_inode);
1134
1135 mext_double_down_read(orig_inode, donor_inode);
1136 /* Check the filesystem environment whether move_extent can be done */
1137 ret = mext_check_arguments(orig_inode, donor_inode, orig_start,
1138 donor_start, &len, *moved_len);
1139 mext_double_up_read(orig_inode, donor_inode);
1140 if (ret)
1141 goto out2;
1142
1143 file_end = (i_size_read(orig_inode) - 1) >> orig_inode->i_blkbits;
1144 block_end = block_start + len - 1;
1145 if (file_end < block_end)
1146 len -= block_end - file_end;
1147
1148 get_ext_path(orig_path, orig_inode, block_start, ret);
1149 if (orig_path == NULL)
1150 goto out2;
1151
1152 /* Get path structure to check the hole */
1153 get_ext_path(holecheck_path, orig_inode, block_start, ret);
1154 if (holecheck_path == NULL)
1155 goto out;
1156
1157 depth = ext_depth(orig_inode);
1158 ext_cur = holecheck_path[depth].p_ext;
1159 if (ext_cur == NULL) {
1160 ret = -EINVAL;
1161 goto out;
1162 }
1163
1164 /*
1165 * Get proper extent whose ee_block is beyond block_start
1166 * if block_start was within the hole.
1167 */
1168 if (le32_to_cpu(ext_cur->ee_block) +
1169 ext4_ext_get_actual_len(ext_cur) - 1 < block_start) {
1170 last_extent = mext_next_extent(orig_inode,
1171 holecheck_path, &ext_cur);
1172 if (last_extent < 0) {
1173 ret = last_extent;
1174 goto out;
1175 }
1176 last_extent = mext_next_extent(orig_inode, orig_path,
1177 &ext_dummy);
1178 if (last_extent < 0) {
1179 ret = last_extent;
1180 goto out;
1181 }
1182 }
1183 seq_start = block_start;
1184
1185 /* No blocks within the specified range. */
1186 if (le32_to_cpu(ext_cur->ee_block) > block_end) {
1187 ext4_debug("ext4 move extent: The specified range of file "
1188 "may be the hole\n");
1189 ret = -EINVAL;
1190 goto out;
1191 }
1192
1193 /* Adjust start blocks */
1194 add_blocks = min(le32_to_cpu(ext_cur->ee_block) +
1195 ext4_ext_get_actual_len(ext_cur), block_end + 1) -
1196 max(le32_to_cpu(ext_cur->ee_block), block_start);
1197
1198 while (!last_extent && le32_to_cpu(ext_cur->ee_block) <= block_end) {
1199 seq_blocks += add_blocks;
1200
1201 /* Adjust tail blocks */
1202 if (seq_start + seq_blocks - 1 > block_end)
1203 seq_blocks = block_end - seq_start + 1;
1204
1205 ext_prev = ext_cur;
1206 last_extent = mext_next_extent(orig_inode, holecheck_path,
1207 &ext_cur);
1208 if (last_extent < 0) {
1209 ret = last_extent;
1210 break;
1211 }
1212 add_blocks = ext4_ext_get_actual_len(ext_cur);
1213
1214 /*
1215 * Extend the length of contiguous block (seq_blocks)
1216 * if extents are contiguous.
1217 */
1218 if (ext4_can_extents_be_merged(orig_inode,
1219 ext_prev, ext_cur) &&
1220 block_end >= le32_to_cpu(ext_cur->ee_block) &&
1221 !last_extent)
1222 continue;
1223
1224 /* Is original extent is uninitialized */
1225 uninit = ext4_ext_is_uninitialized(ext_prev);
1226
1227 data_offset_in_page = seq_start % blocks_per_page;
1228
1229 /*
1230 * Calculate data blocks count that should be swapped
1231 * at the first page.
1232 */
1233 if (data_offset_in_page + seq_blocks > blocks_per_page) {
1234 /* Swapped blocks are across pages */
1235 block_len_in_page =
1236 blocks_per_page - data_offset_in_page;
1237 } else {
1238 /* Swapped blocks are in a page */
1239 block_len_in_page = seq_blocks;
1240 }
1241
1242 orig_page_offset = seq_start >>
1243 (PAGE_CACHE_SHIFT - orig_inode->i_blkbits);
1244 seq_end_page = (seq_start + seq_blocks - 1) >>
1245 (PAGE_CACHE_SHIFT - orig_inode->i_blkbits);
1246 seq_start = le32_to_cpu(ext_cur->ee_block);
1247 rest_blocks = seq_blocks;
1248
1249 /* Discard preallocations of two inodes */
1250 down_write(&EXT4_I(orig_inode)->i_data_sem);
1251 ext4_discard_preallocations(orig_inode);
1252 up_write(&EXT4_I(orig_inode)->i_data_sem);
1253
1254 down_write(&EXT4_I(donor_inode)->i_data_sem);
1255 ext4_discard_preallocations(donor_inode);
1256 up_write(&EXT4_I(donor_inode)->i_data_sem);
1257
1258 while (orig_page_offset <= seq_end_page) {
1259
1260 /* Swap original branches with new branches */
1261 ret = move_extent_par_page(o_filp, donor_inode,
1262 orig_page_offset,
1263 data_offset_in_page,
1264 block_len_in_page, uninit);
1265 if (ret < 0)
1266 goto out;
1267 orig_page_offset++;
1268 /* Count how many blocks we have exchanged */
1269 *moved_len += block_len_in_page;
1270 BUG_ON(*moved_len > len);
1271
1272 data_offset_in_page = 0;
1273 rest_blocks -= block_len_in_page;
1274 if (rest_blocks > blocks_per_page)
1275 block_len_in_page = blocks_per_page;
1276 else
1277 block_len_in_page = rest_blocks;
1278 }
1279
1280 /* Decrease buffer counter */
1281 if (holecheck_path)
1282 ext4_ext_drop_refs(holecheck_path);
1283 get_ext_path(holecheck_path, orig_inode,
1284 seq_start, ret);
1285 if (holecheck_path == NULL)
1286 break;
1287 depth = holecheck_path->p_depth;
1288
1289 /* Decrease buffer counter */
1290 if (orig_path)
1291 ext4_ext_drop_refs(orig_path);
1292 get_ext_path(orig_path, orig_inode, seq_start, ret);
1293 if (orig_path == NULL)
1294 break;
1295
1296 ext_cur = holecheck_path[depth].p_ext;
1297 add_blocks = ext4_ext_get_actual_len(ext_cur);
1298 seq_blocks = 0;
1299
1300 }
1301out:
1302 if (orig_path) {
1303 ext4_ext_drop_refs(orig_path);
1304 kfree(orig_path);
1305 }
1306 if (holecheck_path) {
1307 ext4_ext_drop_refs(holecheck_path);
1308 kfree(holecheck_path);
1309 }
1310out2:
1311 mext_inode_double_unlock(orig_inode, donor_inode);
1312
1313 if (ret)
1314 return ret;
1315
1316 /* All of the specified blocks must be exchanged in succeed */
1317 BUG_ON(*moved_len != len);
1318
1319 return 0;
1320}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-02 00:39:35 -0400