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TOMOYO Linux Cross Reference
Linux/fs/ext4/fsmap.c

Version: ~ [ linux-6.12-rc7 ] ~ [ linux-6.11.7 ] ~ [ linux-6.10.14 ] ~ [ linux-6.9.12 ] ~ [ linux-6.8.12 ] ~ [ linux-6.7.12 ] ~ [ linux-6.6.60 ] ~ [ linux-6.5.13 ] ~ [ linux-6.4.16 ] ~ [ linux-6.3.13 ] ~ [ linux-6.2.16 ] ~ [ linux-6.1.116 ] ~ [ linux-6.0.19 ] ~ [ linux-5.19.17 ] ~ [ linux-5.18.19 ] ~ [ linux-5.17.15 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.171 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.229 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.285 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.323 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.336 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.337 ] ~ [ linux-4.4.302 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.12 ] ~ [ policy-sample ] ~
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Diff markup

Differences between /fs/ext4/fsmap.c (Version linux-6.12-rc7) and /fs/ext4/fsmap.c (Version linux-6.11.7)


  1 // SPDX-License-Identifier: GPL-2.0+                1 // SPDX-License-Identifier: GPL-2.0+
  2 /*                                                  2 /*
  3  * Copyright (C) 2017 Oracle.  All Rights Rese      3  * Copyright (C) 2017 Oracle.  All Rights Reserved.
  4  *                                                  4  *
  5  * Author: Darrick J. Wong <darrick.wong@oracl      5  * Author: Darrick J. Wong <darrick.wong@oracle.com>
  6  */                                                 6  */
  7 #include "ext4.h"                                   7 #include "ext4.h"
  8 #include <linux/fsmap.h>                            8 #include <linux/fsmap.h>
  9 #include "fsmap.h"                                  9 #include "fsmap.h"
 10 #include "mballoc.h"                               10 #include "mballoc.h"
 11 #include <linux/sort.h>                            11 #include <linux/sort.h>
 12 #include <linux/list_sort.h>                       12 #include <linux/list_sort.h>
 13 #include <trace/events/ext4.h>                     13 #include <trace/events/ext4.h>
 14                                                    14 
 15 /* Convert an ext4_fsmap to an fsmap. */           15 /* Convert an ext4_fsmap to an fsmap. */
 16 void ext4_fsmap_from_internal(struct super_blo     16 void ext4_fsmap_from_internal(struct super_block *sb, struct fsmap *dest,
 17                               struct ext4_fsma     17                               struct ext4_fsmap *src)
 18 {                                                  18 {
 19         dest->fmr_device = src->fmr_device;        19         dest->fmr_device = src->fmr_device;
 20         dest->fmr_flags = src->fmr_flags;          20         dest->fmr_flags = src->fmr_flags;
 21         dest->fmr_physical = src->fmr_physical     21         dest->fmr_physical = src->fmr_physical << sb->s_blocksize_bits;
 22         dest->fmr_owner = src->fmr_owner;          22         dest->fmr_owner = src->fmr_owner;
 23         dest->fmr_offset = 0;                      23         dest->fmr_offset = 0;
 24         dest->fmr_length = src->fmr_length <<      24         dest->fmr_length = src->fmr_length << sb->s_blocksize_bits;
 25         dest->fmr_reserved[0] = 0;                 25         dest->fmr_reserved[0] = 0;
 26         dest->fmr_reserved[1] = 0;                 26         dest->fmr_reserved[1] = 0;
 27         dest->fmr_reserved[2] = 0;                 27         dest->fmr_reserved[2] = 0;
 28 }                                                  28 }
 29                                                    29 
 30 /* Convert an fsmap to an ext4_fsmap. */           30 /* Convert an fsmap to an ext4_fsmap. */
 31 void ext4_fsmap_to_internal(struct super_block     31 void ext4_fsmap_to_internal(struct super_block *sb, struct ext4_fsmap *dest,
 32                             struct fsmap *src)     32                             struct fsmap *src)
 33 {                                                  33 {
 34         dest->fmr_device = src->fmr_device;        34         dest->fmr_device = src->fmr_device;
 35         dest->fmr_flags = src->fmr_flags;          35         dest->fmr_flags = src->fmr_flags;
 36         dest->fmr_physical = src->fmr_physical     36         dest->fmr_physical = src->fmr_physical >> sb->s_blocksize_bits;
 37         dest->fmr_owner = src->fmr_owner;          37         dest->fmr_owner = src->fmr_owner;
 38         dest->fmr_length = src->fmr_length >>      38         dest->fmr_length = src->fmr_length >> sb->s_blocksize_bits;
 39 }                                                  39 }
 40                                                    40 
 41 /* getfsmap query state */                         41 /* getfsmap query state */
 42 struct ext4_getfsmap_info {                        42 struct ext4_getfsmap_info {
 43         struct ext4_fsmap_head  *gfi_head;         43         struct ext4_fsmap_head  *gfi_head;
 44         ext4_fsmap_format_t     gfi_formatter;     44         ext4_fsmap_format_t     gfi_formatter;  /* formatting fn */
 45         void                    *gfi_format_ar     45         void                    *gfi_format_arg;/* format buffer */
 46         ext4_fsblk_t            gfi_next_fsblk     46         ext4_fsblk_t            gfi_next_fsblk; /* next fsblock we expect */
 47         u32                     gfi_dev;           47         u32                     gfi_dev;        /* device id */
 48         ext4_group_t            gfi_agno;          48         ext4_group_t            gfi_agno;       /* bg number, if applicable */
 49         struct ext4_fsmap       gfi_low;           49         struct ext4_fsmap       gfi_low;        /* low rmap key */
 50         struct ext4_fsmap       gfi_high;          50         struct ext4_fsmap       gfi_high;       /* high rmap key */
 51         struct ext4_fsmap       gfi_lastfree;      51         struct ext4_fsmap       gfi_lastfree;   /* free ext at end of last bg */
 52         struct list_head        gfi_meta_list;     52         struct list_head        gfi_meta_list;  /* fixed metadata list */
 53         bool                    gfi_last;          53         bool                    gfi_last;       /* last extent? */
 54 };                                                 54 };
 55                                                    55 
 56 /* Associate a device with a getfsmap handler.     56 /* Associate a device with a getfsmap handler. */
 57 struct ext4_getfsmap_dev {                         57 struct ext4_getfsmap_dev {
 58         int                     (*gfd_fn)(stru     58         int                     (*gfd_fn)(struct super_block *sb,
 59                                       struct e     59                                       struct ext4_fsmap *keys,
 60                                       struct e     60                                       struct ext4_getfsmap_info *info);
 61         u32                     gfd_dev;           61         u32                     gfd_dev;
 62 };                                                 62 };
 63                                                    63 
 64 /* Compare two getfsmap device handlers. */        64 /* Compare two getfsmap device handlers. */
 65 static int ext4_getfsmap_dev_compare(const voi     65 static int ext4_getfsmap_dev_compare(const void *p1, const void *p2)
 66 {                                                  66 {
 67         const struct ext4_getfsmap_dev *d1 = p     67         const struct ext4_getfsmap_dev *d1 = p1;
 68         const struct ext4_getfsmap_dev *d2 = p     68         const struct ext4_getfsmap_dev *d2 = p2;
 69                                                    69 
 70         return d1->gfd_dev - d2->gfd_dev;          70         return d1->gfd_dev - d2->gfd_dev;
 71 }                                                  71 }
 72                                                    72 
 73 /* Compare a record against our starting point     73 /* Compare a record against our starting point */
 74 static bool ext4_getfsmap_rec_before_low_key(s     74 static bool ext4_getfsmap_rec_before_low_key(struct ext4_getfsmap_info *info,
 75                                              s     75                                              struct ext4_fsmap *rec)
 76 {                                                  76 {
 77         return rec->fmr_physical < info->gfi_l     77         return rec->fmr_physical < info->gfi_low.fmr_physical;
 78 }                                                  78 }
 79                                                    79 
 80 /*                                                 80 /*
 81  * Format a reverse mapping for getfsmap, havi     81  * Format a reverse mapping for getfsmap, having translated rm_startblock
 82  * into the appropriate daddr units.               82  * into the appropriate daddr units.
 83  */                                                83  */
 84 static int ext4_getfsmap_helper(struct super_b     84 static int ext4_getfsmap_helper(struct super_block *sb,
 85                                 struct ext4_ge     85                                 struct ext4_getfsmap_info *info,
 86                                 struct ext4_fs     86                                 struct ext4_fsmap *rec)
 87 {                                                  87 {
 88         struct ext4_fsmap fmr;                     88         struct ext4_fsmap fmr;
 89         struct ext4_sb_info *sbi = EXT4_SB(sb)     89         struct ext4_sb_info *sbi = EXT4_SB(sb);
 90         ext4_fsblk_t rec_fsblk = rec->fmr_phys     90         ext4_fsblk_t rec_fsblk = rec->fmr_physical;
 91         ext4_group_t agno;                         91         ext4_group_t agno;
 92         ext4_grpblk_t cno;                         92         ext4_grpblk_t cno;
 93         int error;                                 93         int error;
 94                                                    94 
 95         if (fatal_signal_pending(current))         95         if (fatal_signal_pending(current))
 96                 return -EINTR;                     96                 return -EINTR;
 97                                                    97 
 98         /*                                         98         /*
 99          * Filter out records that start befor     99          * Filter out records that start before our startpoint, if the
100          * caller requested that.                 100          * caller requested that.
101          */                                       101          */
102         if (ext4_getfsmap_rec_before_low_key(i    102         if (ext4_getfsmap_rec_before_low_key(info, rec)) {
103                 rec_fsblk += rec->fmr_length;     103                 rec_fsblk += rec->fmr_length;
104                 if (info->gfi_next_fsblk < rec    104                 if (info->gfi_next_fsblk < rec_fsblk)
105                         info->gfi_next_fsblk =    105                         info->gfi_next_fsblk = rec_fsblk;
106                 return EXT4_QUERY_RANGE_CONTIN    106                 return EXT4_QUERY_RANGE_CONTINUE;
107         }                                         107         }
108                                                   108 
109         /* Are we just counting mappings? */      109         /* Are we just counting mappings? */
110         if (info->gfi_head->fmh_count == 0) {     110         if (info->gfi_head->fmh_count == 0) {
111                 if (info->gfi_head->fmh_entrie    111                 if (info->gfi_head->fmh_entries == UINT_MAX)
112                         return EXT4_QUERY_RANG    112                         return EXT4_QUERY_RANGE_ABORT;
113                                                   113 
114                 if (rec_fsblk > info->gfi_next    114                 if (rec_fsblk > info->gfi_next_fsblk)
115                         info->gfi_head->fmh_en    115                         info->gfi_head->fmh_entries++;
116                                                   116 
117                 if (info->gfi_last)               117                 if (info->gfi_last)
118                         return EXT4_QUERY_RANG    118                         return EXT4_QUERY_RANGE_CONTINUE;
119                                                   119 
120                 info->gfi_head->fmh_entries++;    120                 info->gfi_head->fmh_entries++;
121                                                   121 
122                 rec_fsblk += rec->fmr_length;     122                 rec_fsblk += rec->fmr_length;
123                 if (info->gfi_next_fsblk < rec    123                 if (info->gfi_next_fsblk < rec_fsblk)
124                         info->gfi_next_fsblk =    124                         info->gfi_next_fsblk = rec_fsblk;
125                 return EXT4_QUERY_RANGE_CONTIN    125                 return EXT4_QUERY_RANGE_CONTINUE;
126         }                                         126         }
127                                                   127 
128         /*                                        128         /*
129          * If the record starts past the last     129          * If the record starts past the last physical block we saw,
130          * then we've found a gap.  Report the    130          * then we've found a gap.  Report the gap as being owned by
131          * whatever the caller specified is th    131          * whatever the caller specified is the missing owner.
132          */                                       132          */
133         if (rec_fsblk > info->gfi_next_fsblk)     133         if (rec_fsblk > info->gfi_next_fsblk) {
134                 if (info->gfi_head->fmh_entrie    134                 if (info->gfi_head->fmh_entries >= info->gfi_head->fmh_count)
135                         return EXT4_QUERY_RANG    135                         return EXT4_QUERY_RANGE_ABORT;
136                                                   136 
137                 ext4_get_group_no_and_offset(s    137                 ext4_get_group_no_and_offset(sb, info->gfi_next_fsblk,
138                                 &agno, &cno);     138                                 &agno, &cno);
139                 trace_ext4_fsmap_mapping(sb, i    139                 trace_ext4_fsmap_mapping(sb, info->gfi_dev, agno,
140                                 EXT4_C2B(sbi,     140                                 EXT4_C2B(sbi, cno),
141                                 rec_fsblk - in    141                                 rec_fsblk - info->gfi_next_fsblk,
142                                 EXT4_FMR_OWN_U    142                                 EXT4_FMR_OWN_UNKNOWN);
143                                                   143 
144                 fmr.fmr_device = info->gfi_dev    144                 fmr.fmr_device = info->gfi_dev;
145                 fmr.fmr_physical = info->gfi_n    145                 fmr.fmr_physical = info->gfi_next_fsblk;
146                 fmr.fmr_owner = EXT4_FMR_OWN_U    146                 fmr.fmr_owner = EXT4_FMR_OWN_UNKNOWN;
147                 fmr.fmr_length = rec_fsblk - i    147                 fmr.fmr_length = rec_fsblk - info->gfi_next_fsblk;
148                 fmr.fmr_flags = FMR_OF_SPECIAL    148                 fmr.fmr_flags = FMR_OF_SPECIAL_OWNER;
149                 error = info->gfi_formatter(&f    149                 error = info->gfi_formatter(&fmr, info->gfi_format_arg);
150                 if (error)                        150                 if (error)
151                         return error;             151                         return error;
152                 info->gfi_head->fmh_entries++;    152                 info->gfi_head->fmh_entries++;
153         }                                         153         }
154                                                   154 
155         if (info->gfi_last)                       155         if (info->gfi_last)
156                 goto out;                         156                 goto out;
157                                                   157 
158         /* Fill out the extent we found */        158         /* Fill out the extent we found */
159         if (info->gfi_head->fmh_entries >= inf    159         if (info->gfi_head->fmh_entries >= info->gfi_head->fmh_count)
160                 return EXT4_QUERY_RANGE_ABORT;    160                 return EXT4_QUERY_RANGE_ABORT;
161                                                   161 
162         ext4_get_group_no_and_offset(sb, rec_f    162         ext4_get_group_no_and_offset(sb, rec_fsblk, &agno, &cno);
163         trace_ext4_fsmap_mapping(sb, info->gfi    163         trace_ext4_fsmap_mapping(sb, info->gfi_dev, agno, EXT4_C2B(sbi, cno),
164                         rec->fmr_length, rec->    164                         rec->fmr_length, rec->fmr_owner);
165                                                   165 
166         fmr.fmr_device = info->gfi_dev;           166         fmr.fmr_device = info->gfi_dev;
167         fmr.fmr_physical = rec_fsblk;             167         fmr.fmr_physical = rec_fsblk;
168         fmr.fmr_owner = rec->fmr_owner;           168         fmr.fmr_owner = rec->fmr_owner;
169         fmr.fmr_flags = FMR_OF_SPECIAL_OWNER;     169         fmr.fmr_flags = FMR_OF_SPECIAL_OWNER;
170         fmr.fmr_length = rec->fmr_length;         170         fmr.fmr_length = rec->fmr_length;
171         error = info->gfi_formatter(&fmr, info    171         error = info->gfi_formatter(&fmr, info->gfi_format_arg);
172         if (error)                                172         if (error)
173                 return error;                     173                 return error;
174         info->gfi_head->fmh_entries++;            174         info->gfi_head->fmh_entries++;
175                                                   175 
176 out:                                              176 out:
177         rec_fsblk += rec->fmr_length;             177         rec_fsblk += rec->fmr_length;
178         if (info->gfi_next_fsblk < rec_fsblk)     178         if (info->gfi_next_fsblk < rec_fsblk)
179                 info->gfi_next_fsblk = rec_fsb    179                 info->gfi_next_fsblk = rec_fsblk;
180         return EXT4_QUERY_RANGE_CONTINUE;         180         return EXT4_QUERY_RANGE_CONTINUE;
181 }                                                 181 }
182                                                   182 
183 static inline ext4_fsblk_t ext4_fsmap_next_pbl    183 static inline ext4_fsblk_t ext4_fsmap_next_pblk(struct ext4_fsmap *fmr)
184 {                                                 184 {
185         return fmr->fmr_physical + fmr->fmr_le    185         return fmr->fmr_physical + fmr->fmr_length;
186 }                                                 186 }
187                                                   187 
188 /* Transform a blockgroup's free record into a    188 /* Transform a blockgroup's free record into a fsmap */
189 static int ext4_getfsmap_datadev_helper(struct    189 static int ext4_getfsmap_datadev_helper(struct super_block *sb,
190                                         ext4_g    190                                         ext4_group_t agno, ext4_grpblk_t start,
191                                         ext4_g    191                                         ext4_grpblk_t len, void *priv)
192 {                                                 192 {
193         struct ext4_fsmap irec;                   193         struct ext4_fsmap irec;
194         struct ext4_getfsmap_info *info = priv    194         struct ext4_getfsmap_info *info = priv;
195         struct ext4_fsmap *p;                     195         struct ext4_fsmap *p;
196         struct ext4_fsmap *tmp;                   196         struct ext4_fsmap *tmp;
197         struct ext4_sb_info *sbi = EXT4_SB(sb)    197         struct ext4_sb_info *sbi = EXT4_SB(sb);
198         ext4_fsblk_t fsb;                         198         ext4_fsblk_t fsb;
199         ext4_fsblk_t fslen;                       199         ext4_fsblk_t fslen;
200         int error;                                200         int error;
201                                                   201 
202         fsb = (EXT4_C2B(sbi, start) + ext4_gro    202         fsb = (EXT4_C2B(sbi, start) + ext4_group_first_block_no(sb, agno));
203         fslen = EXT4_C2B(sbi, len);               203         fslen = EXT4_C2B(sbi, len);
204                                                   204 
205         /* If the retained free extent record     205         /* If the retained free extent record is set... */
206         if (info->gfi_lastfree.fmr_owner) {       206         if (info->gfi_lastfree.fmr_owner) {
207                 /* ...and abuts this one, leng    207                 /* ...and abuts this one, lengthen it and return. */
208                 if (ext4_fsmap_next_pblk(&info    208                 if (ext4_fsmap_next_pblk(&info->gfi_lastfree) == fsb) {
209                         info->gfi_lastfree.fmr    209                         info->gfi_lastfree.fmr_length += fslen;
210                         return 0;                 210                         return 0;
211                 }                                 211                 }
212                                                   212 
213                 /*                                213                 /*
214                  * There's a gap between the t    214                  * There's a gap between the two free extents; emit the
215                  * retained extent prior to me    215                  * retained extent prior to merging the meta_list.
216                  */                               216                  */
217                 error = ext4_getfsmap_helper(s    217                 error = ext4_getfsmap_helper(sb, info, &info->gfi_lastfree);
218                 if (error)                        218                 if (error)
219                         return error;             219                         return error;
220                 info->gfi_lastfree.fmr_owner =    220                 info->gfi_lastfree.fmr_owner = 0;
221         }                                         221         }
222                                                   222 
223         /* Merge in any relevant extents from     223         /* Merge in any relevant extents from the meta_list */
224         list_for_each_entry_safe(p, tmp, &info    224         list_for_each_entry_safe(p, tmp, &info->gfi_meta_list, fmr_list) {
225                 if (p->fmr_physical + p->fmr_l    225                 if (p->fmr_physical + p->fmr_length <= info->gfi_next_fsblk) {
226                         list_del(&p->fmr_list)    226                         list_del(&p->fmr_list);
227                         kfree(p);                 227                         kfree(p);
228                 } else if (p->fmr_physical < f    228                 } else if (p->fmr_physical < fsb) {
229                         error = ext4_getfsmap_    229                         error = ext4_getfsmap_helper(sb, info, p);
230                         if (error)                230                         if (error)
231                                 return error;     231                                 return error;
232                                                   232 
233                         list_del(&p->fmr_list)    233                         list_del(&p->fmr_list);
234                         kfree(p);                 234                         kfree(p);
235                 }                                 235                 }
236         }                                         236         }
237                                                   237 
238         irec.fmr_device = 0;                      238         irec.fmr_device = 0;
239         irec.fmr_physical = fsb;                  239         irec.fmr_physical = fsb;
240         irec.fmr_length = fslen;                  240         irec.fmr_length = fslen;
241         irec.fmr_owner = EXT4_FMR_OWN_FREE;       241         irec.fmr_owner = EXT4_FMR_OWN_FREE;
242         irec.fmr_flags = 0;                       242         irec.fmr_flags = 0;
243                                                   243 
244         /* If this is a free extent at the end    244         /* If this is a free extent at the end of a bg, buffer it. */
245         if (ext4_fsmap_next_pblk(&irec) ==        245         if (ext4_fsmap_next_pblk(&irec) ==
246                         ext4_group_first_block    246                         ext4_group_first_block_no(sb, agno + 1)) {
247                 info->gfi_lastfree = irec;        247                 info->gfi_lastfree = irec;
248                 return 0;                         248                 return 0;
249         }                                         249         }
250                                                   250 
251         /* Otherwise, emit it */                  251         /* Otherwise, emit it */
252         return ext4_getfsmap_helper(sb, info,     252         return ext4_getfsmap_helper(sb, info, &irec);
253 }                                                 253 }
254                                                   254 
255 /* Execute a getfsmap query against the log de    255 /* Execute a getfsmap query against the log device. */
256 static int ext4_getfsmap_logdev(struct super_b    256 static int ext4_getfsmap_logdev(struct super_block *sb, struct ext4_fsmap *keys,
257                                 struct ext4_ge    257                                 struct ext4_getfsmap_info *info)
258 {                                                 258 {
259         journal_t *journal = EXT4_SB(sb)->s_jo    259         journal_t *journal = EXT4_SB(sb)->s_journal;
260         struct ext4_fsmap irec;                   260         struct ext4_fsmap irec;
261                                                   261 
262         /* Set up search keys */                  262         /* Set up search keys */
263         info->gfi_low = keys[0];                  263         info->gfi_low = keys[0];
264         info->gfi_low.fmr_length = 0;             264         info->gfi_low.fmr_length = 0;
265                                                   265 
266         memset(&info->gfi_high, 0xFF, sizeof(i    266         memset(&info->gfi_high, 0xFF, sizeof(info->gfi_high));
267                                                   267 
268         trace_ext4_fsmap_low_key(sb, info->gfi    268         trace_ext4_fsmap_low_key(sb, info->gfi_dev, 0,
269                         info->gfi_low.fmr_phys    269                         info->gfi_low.fmr_physical,
270                         info->gfi_low.fmr_leng    270                         info->gfi_low.fmr_length,
271                         info->gfi_low.fmr_owne    271                         info->gfi_low.fmr_owner);
272                                                   272 
273         trace_ext4_fsmap_high_key(sb, info->gf    273         trace_ext4_fsmap_high_key(sb, info->gfi_dev, 0,
274                         info->gfi_high.fmr_phy    274                         info->gfi_high.fmr_physical,
275                         info->gfi_high.fmr_len    275                         info->gfi_high.fmr_length,
276                         info->gfi_high.fmr_own    276                         info->gfi_high.fmr_owner);
277                                                   277 
278         if (keys[0].fmr_physical > 0)             278         if (keys[0].fmr_physical > 0)
279                 return 0;                         279                 return 0;
280                                                   280 
281         /* Fabricate an rmap entry for the ext    281         /* Fabricate an rmap entry for the external log device. */
282         irec.fmr_physical = journal->j_blk_off    282         irec.fmr_physical = journal->j_blk_offset;
283         irec.fmr_length = journal->j_total_len    283         irec.fmr_length = journal->j_total_len;
284         irec.fmr_owner = EXT4_FMR_OWN_LOG;        284         irec.fmr_owner = EXT4_FMR_OWN_LOG;
285         irec.fmr_flags = 0;                       285         irec.fmr_flags = 0;
286                                                   286 
287         return ext4_getfsmap_helper(sb, info,     287         return ext4_getfsmap_helper(sb, info, &irec);
288 }                                                 288 }
289                                                   289 
290 /* Helper to fill out an ext4_fsmap. */           290 /* Helper to fill out an ext4_fsmap. */
291 static inline int ext4_getfsmap_fill(struct li    291 static inline int ext4_getfsmap_fill(struct list_head *meta_list,
292                                      ext4_fsbl    292                                      ext4_fsblk_t fsb, ext4_fsblk_t len,
293                                      uint64_t     293                                      uint64_t owner)
294 {                                                 294 {
295         struct ext4_fsmap *fsm;                   295         struct ext4_fsmap *fsm;
296                                                   296 
297         fsm = kmalloc(sizeof(*fsm), GFP_NOFS);    297         fsm = kmalloc(sizeof(*fsm), GFP_NOFS);
298         if (!fsm)                                 298         if (!fsm)
299                 return -ENOMEM;                   299                 return -ENOMEM;
300         fsm->fmr_device = 0;                      300         fsm->fmr_device = 0;
301         fsm->fmr_flags = 0;                       301         fsm->fmr_flags = 0;
302         fsm->fmr_physical = fsb;                  302         fsm->fmr_physical = fsb;
303         fsm->fmr_owner = owner;                   303         fsm->fmr_owner = owner;
304         fsm->fmr_length = len;                    304         fsm->fmr_length = len;
305         list_add_tail(&fsm->fmr_list, meta_lis    305         list_add_tail(&fsm->fmr_list, meta_list);
306                                                   306 
307         return 0;                                 307         return 0;
308 }                                                 308 }
309                                                   309 
310 /*                                                310 /*
311  * This function returns the number of file sy    311  * This function returns the number of file system metadata blocks at
312  * the beginning of a block group, including t    312  * the beginning of a block group, including the reserved gdt blocks.
313  */                                               313  */
314 static unsigned int ext4_getfsmap_find_sb(stru    314 static unsigned int ext4_getfsmap_find_sb(struct super_block *sb,
315                                           ext4    315                                           ext4_group_t agno,
316                                           stru    316                                           struct list_head *meta_list)
317 {                                                 317 {
318         struct ext4_sb_info *sbi = EXT4_SB(sb)    318         struct ext4_sb_info *sbi = EXT4_SB(sb);
319         ext4_fsblk_t fsb = ext4_group_first_bl    319         ext4_fsblk_t fsb = ext4_group_first_block_no(sb, agno);
320         ext4_fsblk_t len;                         320         ext4_fsblk_t len;
321         unsigned long first_meta_bg = le32_to_    321         unsigned long first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
322         unsigned long metagroup = agno / EXT4_    322         unsigned long metagroup = agno / EXT4_DESC_PER_BLOCK(sb);
323         int error;                                323         int error;
324                                                   324 
325         /* Record the superblock. */              325         /* Record the superblock. */
326         if (ext4_bg_has_super(sb, agno)) {        326         if (ext4_bg_has_super(sb, agno)) {
327                 error = ext4_getfsmap_fill(met    327                 error = ext4_getfsmap_fill(meta_list, fsb, 1, EXT4_FMR_OWN_FS);
328                 if (error)                        328                 if (error)
329                         return error;             329                         return error;
330                 fsb++;                            330                 fsb++;
331         }                                         331         }
332                                                   332 
333         /* Record the group descriptors. */       333         /* Record the group descriptors. */
334         len = ext4_bg_num_gdb(sb, agno);          334         len = ext4_bg_num_gdb(sb, agno);
335         if (!len)                                 335         if (!len)
336                 return 0;                         336                 return 0;
337         error = ext4_getfsmap_fill(meta_list,     337         error = ext4_getfsmap_fill(meta_list, fsb, len,
338                                    EXT4_FMR_OW    338                                    EXT4_FMR_OWN_GDT);
339         if (error)                                339         if (error)
340                 return error;                     340                 return error;
341         fsb += len;                               341         fsb += len;
342                                                   342 
343         /* Reserved GDT blocks */                 343         /* Reserved GDT blocks */
344         if (!ext4_has_feature_meta_bg(sb) || m    344         if (!ext4_has_feature_meta_bg(sb) || metagroup < first_meta_bg) {
345                 len = le16_to_cpu(sbi->s_es->s    345                 len = le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks);
346                 error = ext4_getfsmap_fill(met    346                 error = ext4_getfsmap_fill(meta_list, fsb, len,
347                                            EXT    347                                            EXT4_FMR_OWN_RESV_GDT);
348                 if (error)                        348                 if (error)
349                         return error;             349                         return error;
350         }                                         350         }
351                                                   351 
352         return 0;                                 352         return 0;
353 }                                                 353 }
354                                                   354 
355 /* Compare two fsmap items. */                    355 /* Compare two fsmap items. */
356 static int ext4_getfsmap_compare(void *priv,      356 static int ext4_getfsmap_compare(void *priv,
357                                  const struct     357                                  const struct list_head *a,
358                                  const struct     358                                  const struct list_head *b)
359 {                                                 359 {
360         struct ext4_fsmap *fa;                    360         struct ext4_fsmap *fa;
361         struct ext4_fsmap *fb;                    361         struct ext4_fsmap *fb;
362                                                   362 
363         fa = container_of(a, struct ext4_fsmap    363         fa = container_of(a, struct ext4_fsmap, fmr_list);
364         fb = container_of(b, struct ext4_fsmap    364         fb = container_of(b, struct ext4_fsmap, fmr_list);
365         if (fa->fmr_physical < fb->fmr_physica    365         if (fa->fmr_physical < fb->fmr_physical)
366                 return -1;                        366                 return -1;
367         else if (fa->fmr_physical > fb->fmr_ph    367         else if (fa->fmr_physical > fb->fmr_physical)
368                 return 1;                         368                 return 1;
369         return 0;                                 369         return 0;
370 }                                                 370 }
371                                                   371 
372 /* Merge adjacent extents of fixed metadata. *    372 /* Merge adjacent extents of fixed metadata. */
373 static void ext4_getfsmap_merge_fixed_metadata    373 static void ext4_getfsmap_merge_fixed_metadata(struct list_head *meta_list)
374 {                                                 374 {
375         struct ext4_fsmap *p;                     375         struct ext4_fsmap *p;
376         struct ext4_fsmap *prev = NULL;           376         struct ext4_fsmap *prev = NULL;
377         struct ext4_fsmap *tmp;                   377         struct ext4_fsmap *tmp;
378                                                   378 
379         list_for_each_entry_safe(p, tmp, meta_    379         list_for_each_entry_safe(p, tmp, meta_list, fmr_list) {
380                 if (!prev) {                      380                 if (!prev) {
381                         prev = p;                 381                         prev = p;
382                         continue;                 382                         continue;
383                 }                                 383                 }
384                                                   384 
385                 if (prev->fmr_owner == p->fmr_    385                 if (prev->fmr_owner == p->fmr_owner &&
386                     prev->fmr_physical + prev-    386                     prev->fmr_physical + prev->fmr_length == p->fmr_physical) {
387                         prev->fmr_length += p-    387                         prev->fmr_length += p->fmr_length;
388                         list_del(&p->fmr_list)    388                         list_del(&p->fmr_list);
389                         kfree(p);                 389                         kfree(p);
390                 } else                            390                 } else
391                         prev = p;                 391                         prev = p;
392         }                                         392         }
393 }                                                 393 }
394                                                   394 
395 /* Free a list of fixed metadata. */              395 /* Free a list of fixed metadata. */
396 static void ext4_getfsmap_free_fixed_metadata(    396 static void ext4_getfsmap_free_fixed_metadata(struct list_head *meta_list)
397 {                                                 397 {
398         struct ext4_fsmap *p;                     398         struct ext4_fsmap *p;
399         struct ext4_fsmap *tmp;                   399         struct ext4_fsmap *tmp;
400                                                   400 
401         list_for_each_entry_safe(p, tmp, meta_    401         list_for_each_entry_safe(p, tmp, meta_list, fmr_list) {
402                 list_del(&p->fmr_list);           402                 list_del(&p->fmr_list);
403                 kfree(p);                         403                 kfree(p);
404         }                                         404         }
405 }                                                 405 }
406                                                   406 
407 /* Find all the fixed metadata in the filesyst    407 /* Find all the fixed metadata in the filesystem. */
408 static int ext4_getfsmap_find_fixed_metadata(s    408 static int ext4_getfsmap_find_fixed_metadata(struct super_block *sb,
409                                              s    409                                              struct list_head *meta_list)
410 {                                                 410 {
411         struct ext4_group_desc *gdp;              411         struct ext4_group_desc *gdp;
412         ext4_group_t agno;                        412         ext4_group_t agno;
413         int error;                                413         int error;
414                                                   414 
415         INIT_LIST_HEAD(meta_list);                415         INIT_LIST_HEAD(meta_list);
416                                                   416 
417         /* Collect everything. */                 417         /* Collect everything. */
418         for (agno = 0; agno < EXT4_SB(sb)->s_g    418         for (agno = 0; agno < EXT4_SB(sb)->s_groups_count; agno++) {
419                 gdp = ext4_get_group_desc(sb,     419                 gdp = ext4_get_group_desc(sb, agno, NULL);
420                 if (!gdp) {                       420                 if (!gdp) {
421                         error = -EFSCORRUPTED;    421                         error = -EFSCORRUPTED;
422                         goto err;                 422                         goto err;
423                 }                                 423                 }
424                                                   424 
425                 /* Superblock & GDT */            425                 /* Superblock & GDT */
426                 error = ext4_getfsmap_find_sb(    426                 error = ext4_getfsmap_find_sb(sb, agno, meta_list);
427                 if (error)                        427                 if (error)
428                         goto err;                 428                         goto err;
429                                                   429 
430                 /* Block bitmap */                430                 /* Block bitmap */
431                 error = ext4_getfsmap_fill(met    431                 error = ext4_getfsmap_fill(meta_list,
432                                            ext    432                                            ext4_block_bitmap(sb, gdp), 1,
433                                            EXT    433                                            EXT4_FMR_OWN_BLKBM);
434                 if (error)                        434                 if (error)
435                         goto err;                 435                         goto err;
436                                                   436 
437                 /* Inode bitmap */                437                 /* Inode bitmap */
438                 error = ext4_getfsmap_fill(met    438                 error = ext4_getfsmap_fill(meta_list,
439                                            ext    439                                            ext4_inode_bitmap(sb, gdp), 1,
440                                            EXT    440                                            EXT4_FMR_OWN_INOBM);
441                 if (error)                        441                 if (error)
442                         goto err;                 442                         goto err;
443                                                   443 
444                 /* Inodes */                      444                 /* Inodes */
445                 error = ext4_getfsmap_fill(met    445                 error = ext4_getfsmap_fill(meta_list,
446                                            ext    446                                            ext4_inode_table(sb, gdp),
447                                            EXT    447                                            EXT4_SB(sb)->s_itb_per_group,
448                                            EXT    448                                            EXT4_FMR_OWN_INODES);
449                 if (error)                        449                 if (error)
450                         goto err;                 450                         goto err;
451         }                                         451         }
452                                                   452 
453         /* Sort the list */                       453         /* Sort the list */
454         list_sort(NULL, meta_list, ext4_getfsm    454         list_sort(NULL, meta_list, ext4_getfsmap_compare);
455                                                   455 
456         /* Merge adjacent extents */              456         /* Merge adjacent extents */
457         ext4_getfsmap_merge_fixed_metadata(met    457         ext4_getfsmap_merge_fixed_metadata(meta_list);
458                                                   458 
459         return 0;                                 459         return 0;
460 err:                                              460 err:
461         ext4_getfsmap_free_fixed_metadata(meta    461         ext4_getfsmap_free_fixed_metadata(meta_list);
462         return error;                             462         return error;
463 }                                                 463 }
464                                                   464 
465 /* Execute a getfsmap query against the buddy     465 /* Execute a getfsmap query against the buddy bitmaps */
466 static int ext4_getfsmap_datadev(struct super_    466 static int ext4_getfsmap_datadev(struct super_block *sb,
467                                  struct ext4_f    467                                  struct ext4_fsmap *keys,
468                                  struct ext4_g    468                                  struct ext4_getfsmap_info *info)
469 {                                                 469 {
470         struct ext4_sb_info *sbi = EXT4_SB(sb)    470         struct ext4_sb_info *sbi = EXT4_SB(sb);
471         ext4_fsblk_t start_fsb;                   471         ext4_fsblk_t start_fsb;
472         ext4_fsblk_t end_fsb;                     472         ext4_fsblk_t end_fsb;
473         ext4_fsblk_t bofs;                        473         ext4_fsblk_t bofs;
474         ext4_fsblk_t eofs;                        474         ext4_fsblk_t eofs;
475         ext4_group_t start_ag;                    475         ext4_group_t start_ag;
476         ext4_group_t end_ag;                      476         ext4_group_t end_ag;
477         ext4_grpblk_t first_cluster;              477         ext4_grpblk_t first_cluster;
478         ext4_grpblk_t last_cluster;               478         ext4_grpblk_t last_cluster;
479         int error = 0;                            479         int error = 0;
480                                                   480 
481         bofs = le32_to_cpu(sbi->s_es->s_first_    481         bofs = le32_to_cpu(sbi->s_es->s_first_data_block);
482         eofs = ext4_blocks_count(sbi->s_es);      482         eofs = ext4_blocks_count(sbi->s_es);
483         if (keys[0].fmr_physical >= eofs)         483         if (keys[0].fmr_physical >= eofs)
484                 return 0;                         484                 return 0;
485         else if (keys[0].fmr_physical < bofs)     485         else if (keys[0].fmr_physical < bofs)
486                 keys[0].fmr_physical = bofs;      486                 keys[0].fmr_physical = bofs;
487         if (keys[1].fmr_physical >= eofs)         487         if (keys[1].fmr_physical >= eofs)
488                 keys[1].fmr_physical = eofs -     488                 keys[1].fmr_physical = eofs - 1;
489         if (keys[1].fmr_physical < keys[0].fmr    489         if (keys[1].fmr_physical < keys[0].fmr_physical)
490                 return 0;                         490                 return 0;
491         start_fsb = keys[0].fmr_physical;         491         start_fsb = keys[0].fmr_physical;
492         end_fsb = keys[1].fmr_physical;           492         end_fsb = keys[1].fmr_physical;
493                                                   493 
494         /* Determine first and last group to e    494         /* Determine first and last group to examine based on start and end */
495         ext4_get_group_no_and_offset(sb, start    495         ext4_get_group_no_and_offset(sb, start_fsb, &start_ag, &first_cluster);
496         ext4_get_group_no_and_offset(sb, end_f    496         ext4_get_group_no_and_offset(sb, end_fsb, &end_ag, &last_cluster);
497                                                   497 
498         /*                                        498         /*
499          * Convert the fsmap low/high keys to     499          * Convert the fsmap low/high keys to bg based keys.  Initialize
500          * low to the fsmap low key and max ou    500          * low to the fsmap low key and max out the high key to the end
501          * of the bg.                             501          * of the bg.
502          */                                       502          */
503         info->gfi_low = keys[0];                  503         info->gfi_low = keys[0];
504         info->gfi_low.fmr_physical = EXT4_C2B(    504         info->gfi_low.fmr_physical = EXT4_C2B(sbi, first_cluster);
505         info->gfi_low.fmr_length = 0;             505         info->gfi_low.fmr_length = 0;
506                                                   506 
507         memset(&info->gfi_high, 0xFF, sizeof(i    507         memset(&info->gfi_high, 0xFF, sizeof(info->gfi_high));
508                                                   508 
509         /* Assemble a list of all the fixed-lo    509         /* Assemble a list of all the fixed-location metadata. */
510         error = ext4_getfsmap_find_fixed_metad    510         error = ext4_getfsmap_find_fixed_metadata(sb, &info->gfi_meta_list);
511         if (error)                                511         if (error)
512                 goto err;                         512                 goto err;
513                                                   513 
514         /* Query each bg */                       514         /* Query each bg */
515         for (info->gfi_agno = start_ag;           515         for (info->gfi_agno = start_ag;
516              info->gfi_agno <= end_ag;            516              info->gfi_agno <= end_ag;
517              info->gfi_agno++) {                  517              info->gfi_agno++) {
518                 /*                                518                 /*
519                  * Set the bg high key from th    519                  * Set the bg high key from the fsmap high key if this
520                  * is the last bg that we're q    520                  * is the last bg that we're querying.
521                  */                               521                  */
522                 if (info->gfi_agno == end_ag)     522                 if (info->gfi_agno == end_ag) {
523                         info->gfi_high = keys[    523                         info->gfi_high = keys[1];
524                         info->gfi_high.fmr_phy    524                         info->gfi_high.fmr_physical = EXT4_C2B(sbi,
525                                         last_c    525                                         last_cluster);
526                         info->gfi_high.fmr_len    526                         info->gfi_high.fmr_length = 0;
527                 }                                 527                 }
528                                                   528 
529                 trace_ext4_fsmap_low_key(sb, i    529                 trace_ext4_fsmap_low_key(sb, info->gfi_dev, info->gfi_agno,
530                                 info->gfi_low.    530                                 info->gfi_low.fmr_physical,
531                                 info->gfi_low.    531                                 info->gfi_low.fmr_length,
532                                 info->gfi_low.    532                                 info->gfi_low.fmr_owner);
533                                                   533 
534                 trace_ext4_fsmap_high_key(sb,     534                 trace_ext4_fsmap_high_key(sb, info->gfi_dev, info->gfi_agno,
535                                 info->gfi_high    535                                 info->gfi_high.fmr_physical,
536                                 info->gfi_high    536                                 info->gfi_high.fmr_length,
537                                 info->gfi_high    537                                 info->gfi_high.fmr_owner);
538                                                   538 
539                 error = ext4_mballoc_query_ran    539                 error = ext4_mballoc_query_range(sb, info->gfi_agno,
540                                 EXT4_B2C(sbi,     540                                 EXT4_B2C(sbi, info->gfi_low.fmr_physical),
541                                 EXT4_B2C(sbi,     541                                 EXT4_B2C(sbi, info->gfi_high.fmr_physical),
542                                 ext4_getfsmap_    542                                 ext4_getfsmap_datadev_helper, info);
543                 if (error)                        543                 if (error)
544                         goto err;                 544                         goto err;
545                                                   545 
546                 /*                                546                 /*
547                  * Set the bg low key to the s    547                  * Set the bg low key to the start of the bg prior to
548                  * moving on to the next bg.      548                  * moving on to the next bg.
549                  */                               549                  */
550                 if (info->gfi_agno == start_ag    550                 if (info->gfi_agno == start_ag)
551                         memset(&info->gfi_low,    551                         memset(&info->gfi_low, 0, sizeof(info->gfi_low));
552         }                                         552         }
553                                                   553 
554         /* Do we have a retained free extent?     554         /* Do we have a retained free extent? */
555         if (info->gfi_lastfree.fmr_owner) {       555         if (info->gfi_lastfree.fmr_owner) {
556                 error = ext4_getfsmap_helper(s    556                 error = ext4_getfsmap_helper(sb, info, &info->gfi_lastfree);
557                 if (error)                        557                 if (error)
558                         goto err;                 558                         goto err;
559         }                                         559         }
560                                                   560 
561         /* Report any gaps at the end of the b    561         /* Report any gaps at the end of the bg */
562         info->gfi_last = true;                    562         info->gfi_last = true;
563         error = ext4_getfsmap_datadev_helper(s    563         error = ext4_getfsmap_datadev_helper(sb, end_ag, last_cluster, 0, info);
564         if (error)                                564         if (error)
565                 goto err;                         565                 goto err;
566                                                   566 
567 err:                                              567 err:
568         ext4_getfsmap_free_fixed_metadata(&inf    568         ext4_getfsmap_free_fixed_metadata(&info->gfi_meta_list);
569         return error;                             569         return error;
570 }                                                 570 }
571                                                   571 
572 /* Do we recognize the device? */                 572 /* Do we recognize the device? */
573 static bool ext4_getfsmap_is_valid_device(stru    573 static bool ext4_getfsmap_is_valid_device(struct super_block *sb,
574                                           stru    574                                           struct ext4_fsmap *fm)
575 {                                                 575 {
576         if (fm->fmr_device == 0 || fm->fmr_dev    576         if (fm->fmr_device == 0 || fm->fmr_device == UINT_MAX ||
577             fm->fmr_device == new_encode_dev(s    577             fm->fmr_device == new_encode_dev(sb->s_bdev->bd_dev))
578                 return true;                      578                 return true;
579         if (EXT4_SB(sb)->s_journal_bdev_file &    579         if (EXT4_SB(sb)->s_journal_bdev_file &&
580             fm->fmr_device ==                     580             fm->fmr_device ==
581             new_encode_dev(file_bdev(EXT4_SB(s    581             new_encode_dev(file_bdev(EXT4_SB(sb)->s_journal_bdev_file)->bd_dev))
582                 return true;                      582                 return true;
583         return false;                             583         return false;
584 }                                                 584 }
585                                                   585 
586 /* Ensure that the low key is less than the hi    586 /* Ensure that the low key is less than the high key. */
587 static bool ext4_getfsmap_check_keys(struct ex    587 static bool ext4_getfsmap_check_keys(struct ext4_fsmap *low_key,
588                                      struct ex    588                                      struct ext4_fsmap *high_key)
589 {                                                 589 {
590         if (low_key->fmr_device > high_key->fm    590         if (low_key->fmr_device > high_key->fmr_device)
591                 return false;                     591                 return false;
592         if (low_key->fmr_device < high_key->fm    592         if (low_key->fmr_device < high_key->fmr_device)
593                 return true;                      593                 return true;
594                                                   594 
595         if (low_key->fmr_physical > high_key->    595         if (low_key->fmr_physical > high_key->fmr_physical)
596                 return false;                     596                 return false;
597         if (low_key->fmr_physical < high_key->    597         if (low_key->fmr_physical < high_key->fmr_physical)
598                 return true;                      598                 return true;
599                                                   599 
600         if (low_key->fmr_owner > high_key->fmr    600         if (low_key->fmr_owner > high_key->fmr_owner)
601                 return false;                     601                 return false;
602         if (low_key->fmr_owner < high_key->fmr    602         if (low_key->fmr_owner < high_key->fmr_owner)
603                 return true;                      603                 return true;
604                                                   604 
605         return false;                             605         return false;
606 }                                                 606 }
607                                                   607 
608 #define EXT4_GETFSMAP_DEVS      2                 608 #define EXT4_GETFSMAP_DEVS      2
609 /*                                                609 /*
610  * Get filesystem's extents as described in he    610  * Get filesystem's extents as described in head, and format for
611  * output.  Calls formatter to fill the user's    611  * output.  Calls formatter to fill the user's buffer until all
612  * extents are mapped, until the passed-in hea    612  * extents are mapped, until the passed-in head->fmh_count slots have
613  * been filled, or until the formatter short-c    613  * been filled, or until the formatter short-circuits the loop, if it
614  * is tracking filled-in extents on its own.      614  * is tracking filled-in extents on its own.
615  *                                                615  *
616  * Key to Confusion                               616  * Key to Confusion
617  * ----------------                               617  * ----------------
618  * There are multiple levels of keys and count    618  * There are multiple levels of keys and counters at work here:
619  * _fsmap_head.fmh_keys         -- low and hig    619  * _fsmap_head.fmh_keys         -- low and high fsmap keys passed in;
620  *                                 these refle    620  *                                 these reflect fs-wide block addrs.
621  * dkeys                        -- fmh_keys us    621  * dkeys                        -- fmh_keys used to query each device;
622  *                                 these are f    622  *                                 these are fmh_keys but w/ the low key
623  *                                 bumped up b    623  *                                 bumped up by fmr_length.
624  * _getfsmap_info.gfi_next_fsblk-- next fs blo    624  * _getfsmap_info.gfi_next_fsblk-- next fs block we expect to see; this
625  *                                 is how we d    625  *                                 is how we detect gaps in the fsmap
626  *                                 records and    626  *                                 records and report them.
627  * _getfsmap_info.gfi_low/high  -- per-bg low/    627  * _getfsmap_info.gfi_low/high  -- per-bg low/high keys computed from
628  *                                 dkeys; used    628  *                                 dkeys; used to query the free space.
629  */                                               629  */
630 int ext4_getfsmap(struct super_block *sb, stru    630 int ext4_getfsmap(struct super_block *sb, struct ext4_fsmap_head *head,
631                   ext4_fsmap_format_t formatte    631                   ext4_fsmap_format_t formatter, void *arg)
632 {                                                 632 {
633         struct ext4_fsmap dkeys[2];     /* per    633         struct ext4_fsmap dkeys[2];     /* per-dev keys */
634         struct ext4_getfsmap_dev handlers[EXT4    634         struct ext4_getfsmap_dev handlers[EXT4_GETFSMAP_DEVS];
635         struct ext4_getfsmap_info info = { NUL    635         struct ext4_getfsmap_info info = { NULL };
636         int i;                                    636         int i;
637         int error = 0;                            637         int error = 0;
638                                                   638 
639         if (head->fmh_iflags & ~FMH_IF_VALID)     639         if (head->fmh_iflags & ~FMH_IF_VALID)
640                 return -EINVAL;                   640                 return -EINVAL;
641         if (!ext4_getfsmap_is_valid_device(sb,    641         if (!ext4_getfsmap_is_valid_device(sb, &head->fmh_keys[0]) ||
642             !ext4_getfsmap_is_valid_device(sb,    642             !ext4_getfsmap_is_valid_device(sb, &head->fmh_keys[1]))
643                 return -EINVAL;                   643                 return -EINVAL;
644                                                   644 
645         head->fmh_entries = 0;                    645         head->fmh_entries = 0;
646                                                   646 
647         /* Set up our device handlers. */         647         /* Set up our device handlers. */
648         memset(handlers, 0, sizeof(handlers));    648         memset(handlers, 0, sizeof(handlers));
649         handlers[0].gfd_dev = new_encode_dev(s    649         handlers[0].gfd_dev = new_encode_dev(sb->s_bdev->bd_dev);
650         handlers[0].gfd_fn = ext4_getfsmap_dat    650         handlers[0].gfd_fn = ext4_getfsmap_datadev;
651         if (EXT4_SB(sb)->s_journal_bdev_file)     651         if (EXT4_SB(sb)->s_journal_bdev_file) {
652                 handlers[1].gfd_dev = new_enco    652                 handlers[1].gfd_dev = new_encode_dev(
653                         file_bdev(EXT4_SB(sb)-    653                         file_bdev(EXT4_SB(sb)->s_journal_bdev_file)->bd_dev);
654                 handlers[1].gfd_fn = ext4_getf    654                 handlers[1].gfd_fn = ext4_getfsmap_logdev;
655         }                                         655         }
656                                                   656 
657         sort(handlers, EXT4_GETFSMAP_DEVS, siz    657         sort(handlers, EXT4_GETFSMAP_DEVS, sizeof(struct ext4_getfsmap_dev),
658                         ext4_getfsmap_dev_comp    658                         ext4_getfsmap_dev_compare, NULL);
659                                                   659 
660         /*                                        660         /*
661          * To continue where we left off, we a    661          * To continue where we left off, we allow userspace to use the
662          * last mapping from a previous call a    662          * last mapping from a previous call as the low key of the next.
663          * This is identified by a non-zero le    663          * This is identified by a non-zero length in the low key. We
664          * have to increment the low key in th    664          * have to increment the low key in this scenario to ensure we
665          * don't return the same mapping again    665          * don't return the same mapping again, and instead return the
666          * very next mapping.                     666          * very next mapping.
667          *                                        667          *
668          * Bump the physical offset as there c    668          * Bump the physical offset as there can be no other mapping for
669          * the same physical block range.         669          * the same physical block range.
670          */                                       670          */
671         dkeys[0] = head->fmh_keys[0];             671         dkeys[0] = head->fmh_keys[0];
672         dkeys[0].fmr_physical += dkeys[0].fmr_    672         dkeys[0].fmr_physical += dkeys[0].fmr_length;
673         dkeys[0].fmr_owner = 0;                   673         dkeys[0].fmr_owner = 0;
674         dkeys[0].fmr_length = 0;                  674         dkeys[0].fmr_length = 0;
675         memset(&dkeys[1], 0xFF, sizeof(struct     675         memset(&dkeys[1], 0xFF, sizeof(struct ext4_fsmap));
676                                                   676 
677         if (!ext4_getfsmap_check_keys(dkeys, &    677         if (!ext4_getfsmap_check_keys(dkeys, &head->fmh_keys[1]))
678                 return -EINVAL;                   678                 return -EINVAL;
679                                                   679 
680         info.gfi_next_fsblk = head->fmh_keys[0    680         info.gfi_next_fsblk = head->fmh_keys[0].fmr_physical +
681                           head->fmh_keys[0].fm    681                           head->fmh_keys[0].fmr_length;
682         info.gfi_formatter = formatter;           682         info.gfi_formatter = formatter;
683         info.gfi_format_arg = arg;                683         info.gfi_format_arg = arg;
684         info.gfi_head = head;                     684         info.gfi_head = head;
685                                                   685 
686         /* For each device we support... */       686         /* For each device we support... */
687         for (i = 0; i < EXT4_GETFSMAP_DEVS; i+    687         for (i = 0; i < EXT4_GETFSMAP_DEVS; i++) {
688                 /* Is this device within the r    688                 /* Is this device within the range the user asked for? */
689                 if (!handlers[i].gfd_fn)          689                 if (!handlers[i].gfd_fn)
690                         continue;                 690                         continue;
691                 if (head->fmh_keys[0].fmr_devi    691                 if (head->fmh_keys[0].fmr_device > handlers[i].gfd_dev)
692                         continue;                 692                         continue;
693                 if (head->fmh_keys[1].fmr_devi    693                 if (head->fmh_keys[1].fmr_device < handlers[i].gfd_dev)
694                         break;                    694                         break;
695                                                   695 
696                 /*                                696                 /*
697                  * If this device number match    697                  * If this device number matches the high key, we have
698                  * to pass the high key to the    698                  * to pass the high key to the handler to limit the
699                  * query results.  If the devi    699                  * query results.  If the device number exceeds the
700                  * low key, zero out the low k    700                  * low key, zero out the low key so that we get
701                  * everything from the beginni    701                  * everything from the beginning.
702                  */                               702                  */
703                 if (handlers[i].gfd_dev == hea    703                 if (handlers[i].gfd_dev == head->fmh_keys[1].fmr_device)
704                         dkeys[1] = head->fmh_k    704                         dkeys[1] = head->fmh_keys[1];
705                 if (handlers[i].gfd_dev > head    705                 if (handlers[i].gfd_dev > head->fmh_keys[0].fmr_device)
706                         memset(&dkeys[0], 0, s    706                         memset(&dkeys[0], 0, sizeof(struct ext4_fsmap));
707                                                   707 
708                 info.gfi_dev = handlers[i].gfd    708                 info.gfi_dev = handlers[i].gfd_dev;
709                 info.gfi_last = false;            709                 info.gfi_last = false;
710                 info.gfi_agno = -1;               710                 info.gfi_agno = -1;
711                 error = handlers[i].gfd_fn(sb,    711                 error = handlers[i].gfd_fn(sb, dkeys, &info);
712                 if (error)                        712                 if (error)
713                         break;                    713                         break;
714                 info.gfi_next_fsblk = 0;          714                 info.gfi_next_fsblk = 0;
715         }                                         715         }
716                                                   716 
717         head->fmh_oflags = FMH_OF_DEV_T;          717         head->fmh_oflags = FMH_OF_DEV_T;
718         return error;                             718         return error;
719 }                                                 719 }
720                                                   720 

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