Root/fs/ext4/ext4.h

1/*
2 * ext4.h
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/include/linux/minix_fs.h
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 */
15
16#ifndef _EXT4_H
17#define _EXT4_H
18
19#include <linux/types.h>
20#include <linux/blkdev.h>
21#include <linux/magic.h>
22#include <linux/jbd2.h>
23#include <linux/quota.h>
24#include <linux/rwsem.h>
25#include <linux/rbtree.h>
26#include <linux/seqlock.h>
27#include <linux/mutex.h>
28#include <linux/timer.h>
29#include <linux/wait.h>
30#include <linux/blockgroup_lock.h>
31#include <linux/percpu_counter.h>
32
33/*
34 * The fourth extended filesystem constants/structures
35 */
36
37/*
38 * Define EXT4FS_DEBUG to produce debug messages
39 */
40#undef EXT4FS_DEBUG
41
42/*
43 * Debug code
44 */
45#ifdef EXT4FS_DEBUG
46#define ext4_debug(f, a...) \
47    do { \
48        printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:", \
49            __FILE__, __LINE__, __func__); \
50        printk(KERN_DEBUG f, ## a); \
51    } while (0)
52#else
53#define ext4_debug(f, a...) do {} while (0)
54#endif
55
56/* data type for block offset of block group */
57typedef int ext4_grpblk_t;
58
59/* data type for filesystem-wide blocks number */
60typedef unsigned long long ext4_fsblk_t;
61
62/* data type for file logical block number */
63typedef __u32 ext4_lblk_t;
64
65/* data type for block group number */
66typedef unsigned int ext4_group_t;
67
68
69/* prefer goal again. length */
70#define EXT4_MB_HINT_MERGE 1
71/* blocks already reserved */
72#define EXT4_MB_HINT_RESERVED 2
73/* metadata is being allocated */
74#define EXT4_MB_HINT_METADATA 4
75/* first blocks in the file */
76#define EXT4_MB_HINT_FIRST 8
77/* search for the best chunk */
78#define EXT4_MB_HINT_BEST 16
79/* data is being allocated */
80#define EXT4_MB_HINT_DATA 32
81/* don't preallocate (for tails) */
82#define EXT4_MB_HINT_NOPREALLOC 64
83/* allocate for locality group */
84#define EXT4_MB_HINT_GROUP_ALLOC 128
85/* allocate goal blocks or none */
86#define EXT4_MB_HINT_GOAL_ONLY 256
87/* goal is meaningful */
88#define EXT4_MB_HINT_TRY_GOAL 512
89/* blocks already pre-reserved by delayed allocation */
90#define EXT4_MB_DELALLOC_RESERVED 1024
91
92
93struct ext4_allocation_request {
94    /* target inode for block we're allocating */
95    struct inode *inode;
96    /* how many blocks we want to allocate */
97    unsigned int len;
98    /* logical block in target inode */
99    ext4_lblk_t logical;
100    /* the closest logical allocated block to the left */
101    ext4_lblk_t lleft;
102    /* the closest logical allocated block to the right */
103    ext4_lblk_t lright;
104    /* phys. target (a hint) */
105    ext4_fsblk_t goal;
106    /* phys. block for the closest logical allocated block to the left */
107    ext4_fsblk_t pleft;
108    /* phys. block for the closest logical allocated block to the right */
109    ext4_fsblk_t pright;
110    /* flags. see above EXT4_MB_HINT_* */
111    unsigned int flags;
112};
113
114/*
115 * Special inodes numbers
116 */
117#define EXT4_BAD_INO 1 /* Bad blocks inode */
118#define EXT4_ROOT_INO 2 /* Root inode */
119#define EXT4_BOOT_LOADER_INO 5 /* Boot loader inode */
120#define EXT4_UNDEL_DIR_INO 6 /* Undelete directory inode */
121#define EXT4_RESIZE_INO 7 /* Reserved group descriptors inode */
122#define EXT4_JOURNAL_INO 8 /* Journal inode */
123
124/* First non-reserved inode for old ext4 filesystems */
125#define EXT4_GOOD_OLD_FIRST_INO 11
126
127/*
128 * Maximal count of links to a file
129 */
130#define EXT4_LINK_MAX 65000
131
132/*
133 * Macro-instructions used to manage several block sizes
134 */
135#define EXT4_MIN_BLOCK_SIZE 1024
136#define EXT4_MAX_BLOCK_SIZE 65536
137#define EXT4_MIN_BLOCK_LOG_SIZE 10
138#ifdef __KERNEL__
139# define EXT4_BLOCK_SIZE(s) ((s)->s_blocksize)
140#else
141# define EXT4_BLOCK_SIZE(s) (EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
142#endif
143#define EXT4_ADDR_PER_BLOCK(s) (EXT4_BLOCK_SIZE(s) / sizeof(__u32))
144#ifdef __KERNEL__
145# define EXT4_BLOCK_SIZE_BITS(s) ((s)->s_blocksize_bits)
146#else
147# define EXT4_BLOCK_SIZE_BITS(s) ((s)->s_log_block_size + 10)
148#endif
149#ifdef __KERNEL__
150#define EXT4_ADDR_PER_BLOCK_BITS(s) (EXT4_SB(s)->s_addr_per_block_bits)
151#define EXT4_INODE_SIZE(s) (EXT4_SB(s)->s_inode_size)
152#define EXT4_FIRST_INO(s) (EXT4_SB(s)->s_first_ino)
153#else
154#define EXT4_INODE_SIZE(s) (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
155                 EXT4_GOOD_OLD_INODE_SIZE : \
156                 (s)->s_inode_size)
157#define EXT4_FIRST_INO(s) (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
158                 EXT4_GOOD_OLD_FIRST_INO : \
159                 (s)->s_first_ino)
160#endif
161#define EXT4_BLOCK_ALIGN(size, blkbits) ALIGN((size), (1 << (blkbits)))
162
163/*
164 * Structure of a blocks group descriptor
165 */
166struct ext4_group_desc
167{
168    __le32 bg_block_bitmap_lo; /* Blocks bitmap block */
169    __le32 bg_inode_bitmap_lo; /* Inodes bitmap block */
170    __le32 bg_inode_table_lo; /* Inodes table block */
171    __le16 bg_free_blocks_count_lo;/* Free blocks count */
172    __le16 bg_free_inodes_count_lo;/* Free inodes count */
173    __le16 bg_used_dirs_count_lo; /* Directories count */
174    __le16 bg_flags; /* EXT4_BG_flags (INODE_UNINIT, etc) */
175    __u32 bg_reserved[2]; /* Likely block/inode bitmap checksum */
176    __le16 bg_itable_unused_lo; /* Unused inodes count */
177    __le16 bg_checksum; /* crc16(sb_uuid+group+desc) */
178    __le32 bg_block_bitmap_hi; /* Blocks bitmap block MSB */
179    __le32 bg_inode_bitmap_hi; /* Inodes bitmap block MSB */
180    __le32 bg_inode_table_hi; /* Inodes table block MSB */
181    __le16 bg_free_blocks_count_hi;/* Free blocks count MSB */
182    __le16 bg_free_inodes_count_hi;/* Free inodes count MSB */
183    __le16 bg_used_dirs_count_hi; /* Directories count MSB */
184    __le16 bg_itable_unused_hi; /* Unused inodes count MSB */
185    __u32 bg_reserved2[3];
186};
187
188/*
189 * Structure of a flex block group info
190 */
191
192struct flex_groups {
193    atomic_t free_inodes;
194    atomic_t free_blocks;
195    atomic_t used_dirs;
196};
197
198#define EXT4_BG_INODE_UNINIT 0x0001 /* Inode table/bitmap not in use */
199#define EXT4_BG_BLOCK_UNINIT 0x0002 /* Block bitmap not in use */
200#define EXT4_BG_INODE_ZEROED 0x0004 /* On-disk itable initialized to zero */
201
202/*
203 * Macro-instructions used to manage group descriptors
204 */
205#define EXT4_MIN_DESC_SIZE 32
206#define EXT4_MIN_DESC_SIZE_64BIT 64
207#define EXT4_MAX_DESC_SIZE EXT4_MIN_BLOCK_SIZE
208#define EXT4_DESC_SIZE(s) (EXT4_SB(s)->s_desc_size)
209#ifdef __KERNEL__
210# define EXT4_BLOCKS_PER_GROUP(s) (EXT4_SB(s)->s_blocks_per_group)
211# define EXT4_DESC_PER_BLOCK(s) (EXT4_SB(s)->s_desc_per_block)
212# define EXT4_INODES_PER_GROUP(s) (EXT4_SB(s)->s_inodes_per_group)
213# define EXT4_DESC_PER_BLOCK_BITS(s) (EXT4_SB(s)->s_desc_per_block_bits)
214#else
215# define EXT4_BLOCKS_PER_GROUP(s) ((s)->s_blocks_per_group)
216# define EXT4_DESC_PER_BLOCK(s) (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
217# define EXT4_INODES_PER_GROUP(s) ((s)->s_inodes_per_group)
218#endif
219
220/*
221 * Constants relative to the data blocks
222 */
223#define EXT4_NDIR_BLOCKS 12
224#define EXT4_IND_BLOCK EXT4_NDIR_BLOCKS
225#define EXT4_DIND_BLOCK (EXT4_IND_BLOCK + 1)
226#define EXT4_TIND_BLOCK (EXT4_DIND_BLOCK + 1)
227#define EXT4_N_BLOCKS (EXT4_TIND_BLOCK + 1)
228
229/*
230 * Inode flags
231 */
232#define EXT4_SECRM_FL 0x00000001 /* Secure deletion */
233#define EXT4_UNRM_FL 0x00000002 /* Undelete */
234#define EXT4_COMPR_FL 0x00000004 /* Compress file */
235#define EXT4_SYNC_FL 0x00000008 /* Synchronous updates */
236#define EXT4_IMMUTABLE_FL 0x00000010 /* Immutable file */
237#define EXT4_APPEND_FL 0x00000020 /* writes to file may only append */
238#define EXT4_NODUMP_FL 0x00000040 /* do not dump file */
239#define EXT4_NOATIME_FL 0x00000080 /* do not update atime */
240/* Reserved for compression usage... */
241#define EXT4_DIRTY_FL 0x00000100
242#define EXT4_COMPRBLK_FL 0x00000200 /* One or more compressed clusters */
243#define EXT4_NOCOMPR_FL 0x00000400 /* Don't compress */
244#define EXT4_ECOMPR_FL 0x00000800 /* Compression error */
245/* End compression flags --- maybe not all used */
246#define EXT4_INDEX_FL 0x00001000 /* hash-indexed directory */
247#define EXT4_IMAGIC_FL 0x00002000 /* AFS directory */
248#define EXT4_JOURNAL_DATA_FL 0x00004000 /* file data should be journaled */
249#define EXT4_NOTAIL_FL 0x00008000 /* file tail should not be merged */
250#define EXT4_DIRSYNC_FL 0x00010000 /* dirsync behaviour (directories only) */
251#define EXT4_TOPDIR_FL 0x00020000 /* Top of directory hierarchies*/
252#define EXT4_HUGE_FILE_FL 0x00040000 /* Set to each huge file */
253#define EXT4_EXTENTS_FL 0x00080000 /* Inode uses extents */
254#define EXT4_EXT_MIGRATE 0x00100000 /* Inode is migrating */
255#define EXT4_RESERVED_FL 0x80000000 /* reserved for ext4 lib */
256
257#define EXT4_FL_USER_VISIBLE 0x000BDFFF /* User visible flags */
258#define EXT4_FL_USER_MODIFIABLE 0x000B80FF /* User modifiable flags */
259
260/* Flags that should be inherited by new inodes from their parent. */
261#define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
262               EXT4_SYNC_FL | EXT4_IMMUTABLE_FL | EXT4_APPEND_FL |\
263               EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
264               EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
265               EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
266
267/* Flags that are appropriate for regular files (all but dir-specific ones). */
268#define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
269
270/* Flags that are appropriate for non-directories/regular files. */
271#define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
272
273/* Mask out flags that are inappropriate for the given type of inode. */
274static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
275{
276    if (S_ISDIR(mode))
277        return flags;
278    else if (S_ISREG(mode))
279        return flags & EXT4_REG_FLMASK;
280    else
281        return flags & EXT4_OTHER_FLMASK;
282}
283
284/*
285 * Inode dynamic state flags
286 */
287#define EXT4_STATE_JDATA 0x00000001 /* journaled data exists */
288#define EXT4_STATE_NEW 0x00000002 /* inode is newly created */
289#define EXT4_STATE_XATTR 0x00000004 /* has in-inode xattrs */
290#define EXT4_STATE_NO_EXPAND 0x00000008 /* No space for expansion */
291#define EXT4_STATE_DA_ALLOC_CLOSE 0x00000010 /* Alloc DA blks on close */
292
293/* Used to pass group descriptor data when online resize is done */
294struct ext4_new_group_input {
295    __u32 group; /* Group number for this data */
296    __u64 block_bitmap; /* Absolute block number of block bitmap */
297    __u64 inode_bitmap; /* Absolute block number of inode bitmap */
298    __u64 inode_table; /* Absolute block number of inode table start */
299    __u32 blocks_count; /* Total number of blocks in this group */
300    __u16 reserved_blocks; /* Number of reserved blocks in this group */
301    __u16 unused;
302};
303
304/* The struct ext4_new_group_input in kernel space, with free_blocks_count */
305struct ext4_new_group_data {
306    __u32 group;
307    __u64 block_bitmap;
308    __u64 inode_bitmap;
309    __u64 inode_table;
310    __u32 blocks_count;
311    __u16 reserved_blocks;
312    __u16 unused;
313    __u32 free_blocks_count;
314};
315
316/*
317 * Flags used by ext4_get_blocks()
318 */
319    /* Allocate any needed blocks and/or convert an unitialized
320       extent to be an initialized ext4 */
321#define EXT4_GET_BLOCKS_CREATE 0x0001
322    /* Request the creation of an unitialized extent */
323#define EXT4_GET_BLOCKS_UNINIT_EXT 0x0002
324#define EXT4_GET_BLOCKS_CREATE_UNINIT_EXT (EXT4_GET_BLOCKS_UNINIT_EXT|\
325                         EXT4_GET_BLOCKS_CREATE)
326    /* Caller is from the delayed allocation writeout path,
327       so set the magic i_delalloc_reserve_flag after taking the
328       inode allocation semaphore for */
329#define EXT4_GET_BLOCKS_DELALLOC_RESERVE 0x0004
330    /* Call ext4_da_update_reserve_space() after successfully
331       allocating the blocks */
332#define EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE 0x0008
333
334
335/*
336 * ioctl commands
337 */
338#define EXT4_IOC_GETFLAGS FS_IOC_GETFLAGS
339#define EXT4_IOC_SETFLAGS FS_IOC_SETFLAGS
340#define EXT4_IOC_GETVERSION _IOR('f', 3, long)
341#define EXT4_IOC_SETVERSION _IOW('f', 4, long)
342#define EXT4_IOC_GETVERSION_OLD FS_IOC_GETVERSION
343#define EXT4_IOC_SETVERSION_OLD FS_IOC_SETVERSION
344#ifdef CONFIG_JBD2_DEBUG
345#define EXT4_IOC_WAIT_FOR_READONLY _IOR('f', 99, long)
346#endif
347#define EXT4_IOC_GETRSVSZ _IOR('f', 5, long)
348#define EXT4_IOC_SETRSVSZ _IOW('f', 6, long)
349#define EXT4_IOC_GROUP_EXTEND _IOW('f', 7, unsigned long)
350#define EXT4_IOC_GROUP_ADD _IOW('f', 8, struct ext4_new_group_input)
351#define EXT4_IOC_MIGRATE _IO('f', 9)
352 /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
353 /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
354#define EXT4_IOC_ALLOC_DA_BLKS _IO('f', 12)
355#define EXT4_IOC_MOVE_EXT _IOWR('f', 15, struct move_extent)
356
357/*
358 * ioctl commands in 32 bit emulation
359 */
360#define EXT4_IOC32_GETFLAGS FS_IOC32_GETFLAGS
361#define EXT4_IOC32_SETFLAGS FS_IOC32_SETFLAGS
362#define EXT4_IOC32_GETVERSION _IOR('f', 3, int)
363#define EXT4_IOC32_SETVERSION _IOW('f', 4, int)
364#define EXT4_IOC32_GETRSVSZ _IOR('f', 5, int)
365#define EXT4_IOC32_SETRSVSZ _IOW('f', 6, int)
366#define EXT4_IOC32_GROUP_EXTEND _IOW('f', 7, unsigned int)
367#ifdef CONFIG_JBD2_DEBUG
368#define EXT4_IOC32_WAIT_FOR_READONLY _IOR('f', 99, int)
369#endif
370#define EXT4_IOC32_GETVERSION_OLD FS_IOC32_GETVERSION
371#define EXT4_IOC32_SETVERSION_OLD FS_IOC32_SETVERSION
372
373
374/*
375 * Mount options
376 */
377struct ext4_mount_options {
378    unsigned long s_mount_opt;
379    uid_t s_resuid;
380    gid_t s_resgid;
381    unsigned long s_commit_interval;
382    u32 s_min_batch_time, s_max_batch_time;
383#ifdef CONFIG_QUOTA
384    int s_jquota_fmt;
385    char *s_qf_names[MAXQUOTAS];
386#endif
387};
388
389/*
390 * Structure of an inode on the disk
391 */
392struct ext4_inode {
393    __le16 i_mode; /* File mode */
394    __le16 i_uid; /* Low 16 bits of Owner Uid */
395    __le32 i_size_lo; /* Size in bytes */
396    __le32 i_atime; /* Access time */
397    __le32 i_ctime; /* Inode Change time */
398    __le32 i_mtime; /* Modification time */
399    __le32 i_dtime; /* Deletion Time */
400    __le16 i_gid; /* Low 16 bits of Group Id */
401    __le16 i_links_count; /* Links count */
402    __le32 i_blocks_lo; /* Blocks count */
403    __le32 i_flags; /* File flags */
404    union {
405        struct {
406            __le32 l_i_version;
407        } linux1;
408        struct {
409            __u32 h_i_translator;
410        } hurd1;
411        struct {
412            __u32 m_i_reserved1;
413        } masix1;
414    } osd1; /* OS dependent 1 */
415    __le32 i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
416    __le32 i_generation; /* File version (for NFS) */
417    __le32 i_file_acl_lo; /* File ACL */
418    __le32 i_size_high;
419    __le32 i_obso_faddr; /* Obsoleted fragment address */
420    union {
421        struct {
422            __le16 l_i_blocks_high; /* were l_i_reserved1 */
423            __le16 l_i_file_acl_high;
424            __le16 l_i_uid_high; /* these 2 fields */
425            __le16 l_i_gid_high; /* were reserved2[0] */
426            __u32 l_i_reserved2;
427        } linux2;
428        struct {
429            __le16 h_i_reserved1; /* Obsoleted fragment number/size which are removed in ext4 */
430            __u16 h_i_mode_high;
431            __u16 h_i_uid_high;
432            __u16 h_i_gid_high;
433            __u32 h_i_author;
434        } hurd2;
435        struct {
436            __le16 h_i_reserved1; /* Obsoleted fragment number/size which are removed in ext4 */
437            __le16 m_i_file_acl_high;
438            __u32 m_i_reserved2[2];
439        } masix2;
440    } osd2; /* OS dependent 2 */
441    __le16 i_extra_isize;
442    __le16 i_pad1;
443    __le32 i_ctime_extra; /* extra Change time (nsec << 2 | epoch) */
444    __le32 i_mtime_extra; /* extra Modification time(nsec << 2 | epoch) */
445    __le32 i_atime_extra; /* extra Access time (nsec << 2 | epoch) */
446    __le32 i_crtime; /* File Creation time */
447    __le32 i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
448    __le32 i_version_hi; /* high 32 bits for 64-bit version */
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)
460
461#define EXT4_EPOCH_BITS 2
462#define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
463#define EXT4_NSEC_MASK (~0UL << EXT4_EPOCH_BITS)
464
465/*
466 * Extended fields will fit into an inode if the filesystem was formatted
467 * with large inodes (-I 256 or larger) and there are not currently any EAs
468 * consuming all of the available space. For new inodes we always reserve
469 * enough space for the kernel's known extended fields, but for inodes
470 * created with an old kernel this might not have been the case. None of
471 * the extended inode fields is critical for correct filesystem operation.
472 * This macro checks if a certain field fits in the inode. Note that
473 * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
474 */
475#define EXT4_FITS_IN_INODE(ext4_inode, einode, field) \
476    ((offsetof(typeof(*ext4_inode), field) + \
477      sizeof((ext4_inode)->field)) \
478    <= (EXT4_GOOD_OLD_INODE_SIZE + \
479        (einode)->i_extra_isize)) \
480
481static inline __le32 ext4_encode_extra_time(struct timespec *time)
482{
483       return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
484               time->tv_sec >> 32 : 0) |
485               ((time->tv_nsec << 2) & EXT4_NSEC_MASK));
486}
487
488static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
489{
490       if (sizeof(time->tv_sec) > 4)
491           time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
492                   << 32;
493       time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> 2;
494}
495
496#define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode) \
497do { \
498    (raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec); \
499    if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra)) \
500        (raw_inode)->xtime ## _extra = \
501                ext4_encode_extra_time(&(inode)->xtime); \
502} while (0)
503
504#define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode) \
505do { \
506    if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime)) \
507        (raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec); \
508    if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra)) \
509        (raw_inode)->xtime ## _extra = \
510                ext4_encode_extra_time(&(einode)->xtime); \
511} while (0)
512
513#define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode) \
514do { \
515    (inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime); \
516    if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra)) \
517        ext4_decode_extra_time(&(inode)->xtime, \
518                       raw_inode->xtime ## _extra); \
519} while (0)
520
521#define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode) \
522do { \
523    if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime)) \
524        (einode)->xtime.tv_sec = \
525            (signed)le32_to_cpu((raw_inode)->xtime); \
526    if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra)) \
527        ext4_decode_extra_time(&(einode)->xtime, \
528                       raw_inode->xtime ## _extra); \
529} while (0)
530
531#define i_disk_version osd1.linux1.l_i_version
532
533#if defined(__KERNEL__) || defined(__linux__)
534#define i_reserved1 osd1.linux1.l_i_reserved1
535#define i_file_acl_high osd2.linux2.l_i_file_acl_high
536#define i_blocks_high osd2.linux2.l_i_blocks_high
537#define i_uid_low i_uid
538#define i_gid_low i_gid
539#define i_uid_high osd2.linux2.l_i_uid_high
540#define i_gid_high osd2.linux2.l_i_gid_high
541#define i_reserved2 osd2.linux2.l_i_reserved2
542
543#elif defined(__GNU__)
544
545#define i_translator osd1.hurd1.h_i_translator
546#define i_uid_high osd2.hurd2.h_i_uid_high
547#define i_gid_high osd2.hurd2.h_i_gid_high
548#define i_author osd2.hurd2.h_i_author
549
550#elif defined(__masix__)
551
552#define i_reserved1 osd1.masix1.m_i_reserved1
553#define i_file_acl_high osd2.masix2.m_i_file_acl_high
554#define i_reserved2 osd2.masix2.m_i_reserved2
555
556#endif /* defined(__KERNEL__) || defined(__linux__) */
557
558/*
559 * storage for cached extent
560 */
561struct ext4_ext_cache {
562    ext4_fsblk_t ec_start;
563    ext4_lblk_t ec_block;
564    __u32 ec_len; /* must be 32bit to return holes */
565    __u32 ec_type;
566};
567
568/*
569 * fourth extended file system inode data in memory
570 */
571struct ext4_inode_info {
572    __le32 i_data[15]; /* unconverted */
573    __u32 i_flags;
574    ext4_fsblk_t i_file_acl;
575    __u32 i_dtime;
576
577    /*
578     * i_block_group is the number of the block group which contains
579     * this file's inode. Constant across the lifetime of the inode,
580     * it is ued for making block allocation decisions - we try to
581     * place a file's data blocks near its inode block, and new inodes
582     * near to their parent directory's inode.
583     */
584    ext4_group_t i_block_group;
585    __u32 i_state; /* Dynamic state flags for ext4 */
586
587    ext4_lblk_t i_dir_start_lookup;
588#ifdef CONFIG_EXT4_FS_XATTR
589    /*
590     * Extended attributes can be read independently of the main file
591     * data. Taking i_mutex even when reading would cause contention
592     * between readers of EAs and writers of regular file data, so
593     * instead we synchronize on xattr_sem when reading or changing
594     * EAs.
595     */
596    struct rw_semaphore xattr_sem;
597#endif
598
599    struct list_head i_orphan; /* unlinked but open inodes */
600
601    /*
602     * i_disksize keeps track of what the inode size is ON DISK, not
603     * in memory. During truncate, i_size is set to the new size by
604     * the VFS prior to calling ext4_truncate(), but the filesystem won't
605     * set i_disksize to 0 until the truncate is actually under way.
606     *
607     * The intent is that i_disksize always represents the blocks which
608     * are used by this file. This allows recovery to restart truncate
609     * on orphans if we crash during truncate. We actually write i_disksize
610     * into the on-disk inode when writing inodes out, instead of i_size.
611     *
612     * The only time when i_disksize and i_size may be different is when
613     * a truncate is in progress. The only things which change i_disksize
614     * are ext4_get_block (growth) and ext4_truncate (shrinkth).
615     */
616    loff_t i_disksize;
617
618    /*
619     * i_data_sem is for serialising ext4_truncate() against
620     * ext4_getblock(). In the 2.4 ext2 design, great chunks of inode's
621     * data tree are chopped off during truncate. We can't do that in
622     * ext4 because whenever we perform intermediate commits during
623     * truncate, the inode and all the metadata blocks *must* be in a
624     * consistent state which allows truncation of the orphans to restart
625     * during recovery. Hence we must fix the get_block-vs-truncate race
626     * by other means, so we have i_data_sem.
627     */
628    struct rw_semaphore i_data_sem;
629    struct inode vfs_inode;
630    struct jbd2_inode jinode;
631
632    struct ext4_ext_cache i_cached_extent;
633    /*
634     * File creation time. Its function is same as that of
635     * struct timespec i_{a,c,m}time in the generic inode.
636     */
637    struct timespec i_crtime;
638
639    /* mballoc */
640    struct list_head i_prealloc_list;
641    spinlock_t i_prealloc_lock;
642
643    /* ialloc */
644    ext4_group_t i_last_alloc_group;
645
646    /* allocation reservation info for delalloc */
647    unsigned int i_reserved_data_blocks;
648    unsigned int i_reserved_meta_blocks;
649    unsigned int i_allocated_meta_blocks;
650    unsigned short i_delalloc_reserved_flag;
651
652    /* on-disk additional length */
653    __u16 i_extra_isize;
654
655    spinlock_t i_block_reservation_lock;
656};
657
658/*
659 * File system states
660 */
661#define EXT4_VALID_FS 0x0001 /* Unmounted cleanly */
662#define EXT4_ERROR_FS 0x0002 /* Errors detected */
663#define EXT4_ORPHAN_FS 0x0004 /* Orphans being recovered */
664
665/*
666 * Misc. filesystem flags
667 */
668#define EXT2_FLAGS_SIGNED_HASH 0x0001 /* Signed dirhash in use */
669#define EXT2_FLAGS_UNSIGNED_HASH 0x0002 /* Unsigned dirhash in use */
670#define EXT2_FLAGS_TEST_FILESYS 0x0004 /* to test development code */
671
672/*
673 * Mount flags
674 */
675#define EXT4_MOUNT_OLDALLOC 0x00002 /* Don't use the new Orlov allocator */
676#define EXT4_MOUNT_GRPID 0x00004 /* Create files with directory's group */
677#define EXT4_MOUNT_DEBUG 0x00008 /* Some debugging messages */
678#define EXT4_MOUNT_ERRORS_CONT 0x00010 /* Continue on errors */
679#define EXT4_MOUNT_ERRORS_RO 0x00020 /* Remount fs ro on errors */
680#define EXT4_MOUNT_ERRORS_PANIC 0x00040 /* Panic on errors */
681#define EXT4_MOUNT_MINIX_DF 0x00080 /* Mimics the Minix statfs */
682#define EXT4_MOUNT_NOLOAD 0x00100 /* Don't use existing journal*/
683#define EXT4_MOUNT_DATA_FLAGS 0x00C00 /* Mode for data writes: */
684#define EXT4_MOUNT_JOURNAL_DATA 0x00400 /* Write data to journal */
685#define EXT4_MOUNT_ORDERED_DATA 0x00800 /* Flush data before commit */
686#define EXT4_MOUNT_WRITEBACK_DATA 0x00C00 /* No data ordering */
687#define EXT4_MOUNT_UPDATE_JOURNAL 0x01000 /* Update the journal format */
688#define EXT4_MOUNT_NO_UID32 0x02000 /* Disable 32-bit UIDs */
689#define EXT4_MOUNT_XATTR_USER 0x04000 /* Extended user attributes */
690#define EXT4_MOUNT_POSIX_ACL 0x08000 /* POSIX Access Control Lists */
691#define EXT4_MOUNT_NO_AUTO_DA_ALLOC 0x10000 /* No auto delalloc mapping */
692#define EXT4_MOUNT_BARRIER 0x20000 /* Use block barriers */
693#define EXT4_MOUNT_NOBH 0x40000 /* No bufferheads */
694#define EXT4_MOUNT_QUOTA 0x80000 /* Some quota option set */
695#define EXT4_MOUNT_USRQUOTA 0x100000 /* "old" user quota */
696#define EXT4_MOUNT_GRPQUOTA 0x200000 /* "old" group quota */
697#define EXT4_MOUNT_JOURNAL_CHECKSUM 0x800000 /* Journal checksums */
698#define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
699#define EXT4_MOUNT_I_VERSION 0x2000000 /* i_version support */
700#define EXT4_MOUNT_DELALLOC 0x8000000 /* Delalloc support */
701#define EXT4_MOUNT_DATA_ERR_ABORT 0x10000000 /* Abort on file data write */
702#define EXT4_MOUNT_BLOCK_VALIDITY 0x20000000 /* Block validity checking */
703
704#define clear_opt(o, opt) o &= ~EXT4_MOUNT_##opt
705#define set_opt(o, opt) o |= EXT4_MOUNT_##opt
706#define test_opt(sb, opt) (EXT4_SB(sb)->s_mount_opt & \
707                     EXT4_MOUNT_##opt)
708
709#define ext4_set_bit ext2_set_bit
710#define ext4_set_bit_atomic ext2_set_bit_atomic
711#define ext4_clear_bit ext2_clear_bit
712#define ext4_clear_bit_atomic ext2_clear_bit_atomic
713#define ext4_test_bit ext2_test_bit
714#define ext4_find_first_zero_bit ext2_find_first_zero_bit
715#define ext4_find_next_zero_bit ext2_find_next_zero_bit
716#define ext4_find_next_bit ext2_find_next_bit
717
718/*
719 * Maximal mount counts between two filesystem checks
720 */
721#define EXT4_DFL_MAX_MNT_COUNT 20 /* Allow 20 mounts */
722#define EXT4_DFL_CHECKINTERVAL 0 /* Don't use interval check */
723
724/*
725 * Behaviour when detecting errors
726 */
727#define EXT4_ERRORS_CONTINUE 1 /* Continue execution */
728#define EXT4_ERRORS_RO 2 /* Remount fs read-only */
729#define EXT4_ERRORS_PANIC 3 /* Panic */
730#define EXT4_ERRORS_DEFAULT EXT4_ERRORS_CONTINUE
731
732/*
733 * Structure of the super block
734 */
735struct ext4_super_block {
736/*00*/ __le32 s_inodes_count; /* Inodes count */
737    __le32 s_blocks_count_lo; /* Blocks count */
738    __le32 s_r_blocks_count_lo; /* Reserved blocks count */
739    __le32 s_free_blocks_count_lo; /* Free blocks count */
740/*10*/ __le32 s_free_inodes_count; /* Free inodes count */
741    __le32 s_first_data_block; /* First Data Block */
742    __le32 s_log_block_size; /* Block size */
743    __le32 s_obso_log_frag_size; /* Obsoleted fragment size */
744/*20*/ __le32 s_blocks_per_group; /* # Blocks per group */
745    __le32 s_obso_frags_per_group; /* Obsoleted fragments per group */
746    __le32 s_inodes_per_group; /* # Inodes per group */
747    __le32 s_mtime; /* Mount time */
748/*30*/ __le32 s_wtime; /* Write time */
749    __le16 s_mnt_count; /* Mount count */
750    __le16 s_max_mnt_count; /* Maximal mount count */
751    __le16 s_magic; /* Magic signature */
752    __le16 s_state; /* File system state */
753    __le16 s_errors; /* Behaviour when detecting errors */
754    __le16 s_minor_rev_level; /* minor revision level */
755/*40*/ __le32 s_lastcheck; /* time of last check */
756    __le32 s_checkinterval; /* max. time between checks */
757    __le32 s_creator_os; /* OS */
758    __le32 s_rev_level; /* Revision level */
759/*50*/ __le16 s_def_resuid; /* Default uid for reserved blocks */
760    __le16 s_def_resgid; /* Default gid for reserved blocks */
761    /*
762     * These fields are for EXT4_DYNAMIC_REV superblocks only.
763     *
764     * Note: the difference between the compatible feature set and
765     * the incompatible feature set is that if there is a bit set
766     * in the incompatible feature set that the kernel doesn't
767     * know about, it should refuse to mount the filesystem.
768     *
769     * e2fsck's requirements are more strict; if it doesn't know
770     * about a feature in either the compatible or incompatible
771     * feature set, it must abort and not try to meddle with
772     * things it doesn't understand...
773     */
774    __le32 s_first_ino; /* First non-reserved inode */
775    __le16 s_inode_size; /* size of inode structure */
776    __le16 s_block_group_nr; /* block group # of this superblock */
777    __le32 s_feature_compat; /* compatible feature set */
778/*60*/ __le32 s_feature_incompat; /* incompatible feature set */
779    __le32 s_feature_ro_compat; /* readonly-compatible feature set */
780/*68*/ __u8 s_uuid[16]; /* 128-bit uuid for volume */
781/*78*/ char s_volume_name[16]; /* volume name */
782/*88*/ char s_last_mounted[64]; /* directory where last mounted */
783/*C8*/ __le32 s_algorithm_usage_bitmap; /* For compression */
784    /*
785     * Performance hints. Directory preallocation should only
786     * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
787     */
788    __u8 s_prealloc_blocks; /* Nr of blocks to try to preallocate*/
789    __u8 s_prealloc_dir_blocks; /* Nr to preallocate for dirs */
790    __le16 s_reserved_gdt_blocks; /* Per group desc for online growth */
791    /*
792     * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
793     */
794/*D0*/ __u8 s_journal_uuid[16]; /* uuid of journal superblock */
795/*E0*/ __le32 s_journal_inum; /* inode number of journal file */
796    __le32 s_journal_dev; /* device number of journal file */
797    __le32 s_last_orphan; /* start of list of inodes to delete */
798    __le32 s_hash_seed[4]; /* HTREE hash seed */
799    __u8 s_def_hash_version; /* Default hash version to use */
800    __u8 s_reserved_char_pad;
801    __le16 s_desc_size; /* size of group descriptor */
802/*100*/ __le32 s_default_mount_opts;
803    __le32 s_first_meta_bg; /* First metablock block group */
804    __le32 s_mkfs_time; /* When the filesystem was created */
805    __le32 s_jnl_blocks[17]; /* Backup of the journal inode */
806    /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
807/*150*/ __le32 s_blocks_count_hi; /* Blocks count */
808    __le32 s_r_blocks_count_hi; /* Reserved blocks count */
809    __le32 s_free_blocks_count_hi; /* Free blocks count */
810    __le16 s_min_extra_isize; /* All inodes have at least # bytes */
811    __le16 s_want_extra_isize; /* New inodes should reserve # bytes */
812    __le32 s_flags; /* Miscellaneous flags */
813    __le16 s_raid_stride; /* RAID stride */
814    __le16 s_mmp_interval; /* # seconds to wait in MMP checking */
815    __le64 s_mmp_block; /* Block for multi-mount protection */
816    __le32 s_raid_stripe_width; /* blocks on all data disks (N*stride)*/
817    __u8 s_log_groups_per_flex; /* FLEX_BG group size */
818    __u8 s_reserved_char_pad2;
819    __le16 s_reserved_pad;
820    __le64 s_kbytes_written; /* nr of lifetime kilobytes written */
821    __u32 s_reserved[160]; /* Padding to the end of the block */
822};
823
824#ifdef __KERNEL__
825
826/*
827 * run-time mount flags
828 */
829#define EXT4_MF_MNTDIR_SAMPLED 0x0001
830#define EXT4_MF_FS_ABORTED 0x0002 /* Fatal error detected */
831
832/*
833 * fourth extended-fs super-block data in memory
834 */
835struct ext4_sb_info {
836    unsigned long s_desc_size; /* Size of a group descriptor in bytes */
837    unsigned long s_inodes_per_block;/* Number of inodes per block */
838    unsigned long s_blocks_per_group;/* Number of blocks in a group */
839    unsigned long s_inodes_per_group;/* Number of inodes in a group */
840    unsigned long s_itb_per_group; /* Number of inode table blocks per group */
841    unsigned long s_gdb_count; /* Number of group descriptor blocks */
842    unsigned long s_desc_per_block; /* Number of group descriptors per block */
843    ext4_group_t s_groups_count; /* Number of groups in the fs */
844    unsigned long s_overhead_last; /* Last calculated overhead */
845    unsigned long s_blocks_last; /* Last seen block count */
846    loff_t s_bitmap_maxbytes; /* max bytes for bitmap files */
847    struct buffer_head * s_sbh; /* Buffer containing the super block */
848    struct ext4_super_block *s_es; /* Pointer to the super block in the buffer */
849    struct buffer_head **s_group_desc;
850    unsigned int s_mount_opt;
851    unsigned int s_mount_flags;
852    ext4_fsblk_t s_sb_block;
853    uid_t s_resuid;
854    gid_t s_resgid;
855    unsigned short s_mount_state;
856    unsigned short s_pad;
857    int s_addr_per_block_bits;
858    int s_desc_per_block_bits;
859    int s_inode_size;
860    int s_first_ino;
861    unsigned int s_inode_readahead_blks;
862    unsigned int s_inode_goal;
863    spinlock_t s_next_gen_lock;
864    u32 s_next_generation;
865    u32 s_hash_seed[4];
866    int s_def_hash_version;
867    int s_hash_unsigned; /* 3 if hash should be signed, 0 if not */
868    struct percpu_counter s_freeblocks_counter;
869    struct percpu_counter s_freeinodes_counter;
870    struct percpu_counter s_dirs_counter;
871    struct percpu_counter s_dirtyblocks_counter;
872    struct blockgroup_lock *s_blockgroup_lock;
873    struct proc_dir_entry *s_proc;
874    struct kobject s_kobj;
875    struct completion s_kobj_unregister;
876
877    /* Journaling */
878    struct inode *s_journal_inode;
879    struct journal_s *s_journal;
880    struct list_head s_orphan;
881    struct mutex s_orphan_lock;
882    struct mutex s_resize_lock;
883    unsigned long s_commit_interval;
884    u32 s_max_batch_time;
885    u32 s_min_batch_time;
886    struct block_device *journal_bdev;
887#ifdef CONFIG_JBD2_DEBUG
888    struct timer_list turn_ro_timer; /* For turning read-only (crash simulation) */
889    wait_queue_head_t ro_wait_queue; /* For people waiting for the fs to go read-only */
890#endif
891#ifdef CONFIG_QUOTA
892    char *s_qf_names[MAXQUOTAS]; /* Names of quota files with journalled quota */
893    int s_jquota_fmt; /* Format of quota to use */
894#endif
895    unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
896    struct rb_root system_blks;
897
898#ifdef EXTENTS_STATS
899    /* ext4 extents stats */
900    unsigned long s_ext_min;
901    unsigned long s_ext_max;
902    unsigned long s_depth_max;
903    spinlock_t s_ext_stats_lock;
904    unsigned long s_ext_blocks;
905    unsigned long s_ext_extents;
906#endif
907
908    /* for buddy allocator */
909    struct ext4_group_info ***s_group_info;
910    struct inode *s_buddy_cache;
911    long s_blocks_reserved;
912    spinlock_t s_reserve_lock;
913    spinlock_t s_md_lock;
914    tid_t s_last_transaction;
915    unsigned short *s_mb_offsets;
916    unsigned int *s_mb_maxs;
917
918    /* tunables */
919    unsigned long s_stripe;
920    unsigned int s_mb_stream_request;
921    unsigned int s_mb_max_to_scan;
922    unsigned int s_mb_min_to_scan;
923    unsigned int s_mb_stats;
924    unsigned int s_mb_order2_reqs;
925    unsigned int s_mb_group_prealloc;
926    /* where last allocation was done - for stream allocation */
927    unsigned long s_mb_last_group;
928    unsigned long s_mb_last_start;
929
930    /* history to debug policy */
931    struct ext4_mb_history *s_mb_history;
932    int s_mb_history_cur;
933    int s_mb_history_max;
934    int s_mb_history_num;
935    spinlock_t s_mb_history_lock;
936    int s_mb_history_filter;
937
938    /* stats for buddy allocator */
939    spinlock_t s_mb_pa_lock;
940    atomic_t s_bal_reqs; /* number of reqs with len > 1 */
941    atomic_t s_bal_success; /* we found long enough chunks */
942    atomic_t s_bal_allocated; /* in blocks */
943    atomic_t s_bal_ex_scanned; /* total extents scanned */
944    atomic_t s_bal_goals; /* goal hits */
945    atomic_t s_bal_breaks; /* too long searches */
946    atomic_t s_bal_2orders; /* 2^order hits */
947    spinlock_t s_bal_lock;
948    unsigned long s_mb_buddies_generated;
949    unsigned long long s_mb_generation_time;
950    atomic_t s_mb_lost_chunks;
951    atomic_t s_mb_preallocated;
952    atomic_t s_mb_discarded;
953
954    /* locality groups */
955    struct ext4_locality_group *s_locality_groups;
956
957    /* for write statistics */
958    unsigned long s_sectors_written_start;
959    u64 s_kbytes_written;
960
961    unsigned int s_log_groups_per_flex;
962    struct flex_groups *s_flex_groups;
963};
964
965static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
966{
967    return sb->s_fs_info;
968}
969static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
970{
971    return container_of(inode, struct ext4_inode_info, vfs_inode);
972}
973
974static inline struct timespec ext4_current_time(struct inode *inode)
975{
976    return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
977        current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
978}
979
980static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
981{
982    return ino == EXT4_ROOT_INO ||
983        ino == EXT4_JOURNAL_INO ||
984        ino == EXT4_RESIZE_INO ||
985        (ino >= EXT4_FIRST_INO(sb) &&
986         ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
987}
988#else
989/* Assume that user mode programs are passing in an ext4fs superblock, not
990 * a kernel struct super_block. This will allow us to call the feature-test
991 * macros from user land. */
992#define EXT4_SB(sb) (sb)
993#endif
994
995#define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
996
997/*
998 * Codes for operating systems
999 */
1000#define EXT4_OS_LINUX 0
1001#define EXT4_OS_HURD 1
1002#define EXT4_OS_MASIX 2
1003#define EXT4_OS_FREEBSD 3
1004#define EXT4_OS_LITES 4
1005
1006/*
1007 * Revision levels
1008 */
1009#define EXT4_GOOD_OLD_REV 0 /* The good old (original) format */
1010#define EXT4_DYNAMIC_REV 1 /* V2 format w/ dynamic inode sizes */
1011
1012#define EXT4_CURRENT_REV EXT4_GOOD_OLD_REV
1013#define EXT4_MAX_SUPP_REV EXT4_DYNAMIC_REV
1014
1015#define EXT4_GOOD_OLD_INODE_SIZE 128
1016
1017/*
1018 * Feature set definitions
1019 */
1020
1021#define EXT4_HAS_COMPAT_FEATURE(sb,mask) \
1022    ((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1023#define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask) \
1024    ((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1025#define EXT4_HAS_INCOMPAT_FEATURE(sb,mask) \
1026    ((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1027#define EXT4_SET_COMPAT_FEATURE(sb,mask) \
1028    EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1029#define EXT4_SET_RO_COMPAT_FEATURE(sb,mask) \
1030    EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1031#define EXT4_SET_INCOMPAT_FEATURE(sb,mask) \
1032    EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1033#define EXT4_CLEAR_COMPAT_FEATURE(sb,mask) \
1034    EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1035#define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask) \
1036    EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1037#define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask) \
1038    EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1039
1040#define EXT4_FEATURE_COMPAT_DIR_PREALLOC 0x0001
1041#define EXT4_FEATURE_COMPAT_IMAGIC_INODES 0x0002
1042#define EXT4_FEATURE_COMPAT_HAS_JOURNAL 0x0004
1043#define EXT4_FEATURE_COMPAT_EXT_ATTR 0x0008
1044#define EXT4_FEATURE_COMPAT_RESIZE_INODE 0x0010
1045#define EXT4_FEATURE_COMPAT_DIR_INDEX 0x0020
1046
1047#define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
1048#define EXT4_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
1049#define EXT4_FEATURE_RO_COMPAT_BTREE_DIR 0x0004
1050#define EXT4_FEATURE_RO_COMPAT_HUGE_FILE 0x0008
1051#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010
1052#define EXT4_FEATURE_RO_COMPAT_DIR_NLINK 0x0020
1053#define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE 0x0040
1054
1055#define EXT4_FEATURE_INCOMPAT_COMPRESSION 0x0001
1056#define EXT4_FEATURE_INCOMPAT_FILETYPE 0x0002
1057#define EXT4_FEATURE_INCOMPAT_RECOVER 0x0004 /* Needs recovery */
1058#define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV 0x0008 /* Journal device */
1059#define EXT4_FEATURE_INCOMPAT_META_BG 0x0010
1060#define EXT4_FEATURE_INCOMPAT_EXTENTS 0x0040 /* extents support */
1061#define EXT4_FEATURE_INCOMPAT_64BIT 0x0080
1062#define EXT4_FEATURE_INCOMPAT_MMP 0x0100
1063#define EXT4_FEATURE_INCOMPAT_FLEX_BG 0x0200
1064
1065#define EXT4_FEATURE_COMPAT_SUPP EXT2_FEATURE_COMPAT_EXT_ATTR
1066#define EXT4_FEATURE_INCOMPAT_SUPP (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1067                     EXT4_FEATURE_INCOMPAT_RECOVER| \
1068                     EXT4_FEATURE_INCOMPAT_META_BG| \
1069                     EXT4_FEATURE_INCOMPAT_EXTENTS| \
1070                     EXT4_FEATURE_INCOMPAT_64BIT| \
1071                     EXT4_FEATURE_INCOMPAT_FLEX_BG)
1072#define EXT4_FEATURE_RO_COMPAT_SUPP (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1073                     EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1074                     EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1075                     EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1076                     EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1077                     EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1078                     EXT4_FEATURE_RO_COMPAT_HUGE_FILE)
1079
1080/*
1081 * Default values for user and/or group using reserved blocks
1082 */
1083#define EXT4_DEF_RESUID 0
1084#define EXT4_DEF_RESGID 0
1085
1086#define EXT4_DEF_INODE_READAHEAD_BLKS 32
1087
1088/*
1089 * Default mount options
1090 */
1091#define EXT4_DEFM_DEBUG 0x0001
1092#define EXT4_DEFM_BSDGROUPS 0x0002
1093#define EXT4_DEFM_XATTR_USER 0x0004
1094#define EXT4_DEFM_ACL 0x0008
1095#define EXT4_DEFM_UID16 0x0010
1096#define EXT4_DEFM_JMODE 0x0060
1097#define EXT4_DEFM_JMODE_DATA 0x0020
1098#define EXT4_DEFM_JMODE_ORDERED 0x0040
1099#define EXT4_DEFM_JMODE_WBACK 0x0060
1100
1101/*
1102 * Default journal batch times
1103 */
1104#define EXT4_DEF_MIN_BATCH_TIME 0
1105#define EXT4_DEF_MAX_BATCH_TIME 15000 /* 15ms */
1106
1107/*
1108 * Minimum number of groups in a flexgroup before we separate out
1109 * directories into the first block group of a flexgroup
1110 */
1111#define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME 4
1112
1113/*
1114 * Structure of a directory entry
1115 */
1116#define EXT4_NAME_LEN 255
1117
1118struct ext4_dir_entry {
1119    __le32 inode; /* Inode number */
1120    __le16 rec_len; /* Directory entry length */
1121    __le16 name_len; /* Name length */
1122    char name[EXT4_NAME_LEN]; /* File name */
1123};
1124
1125/*
1126 * The new version of the directory entry. Since EXT4 structures are
1127 * stored in intel byte order, and the name_len field could never be
1128 * bigger than 255 chars, it's safe to reclaim the extra byte for the
1129 * file_type field.
1130 */
1131struct ext4_dir_entry_2 {
1132    __le32 inode; /* Inode number */
1133    __le16 rec_len; /* Directory entry length */
1134    __u8 name_len; /* Name length */
1135    __u8 file_type;
1136    char name[EXT4_NAME_LEN]; /* File name */
1137};
1138
1139/*
1140 * Ext4 directory file types. Only the low 3 bits are used. The
1141 * other bits are reserved for now.
1142 */
1143#define EXT4_FT_UNKNOWN 0
1144#define EXT4_FT_REG_FILE 1
1145#define EXT4_FT_DIR 2
1146#define EXT4_FT_CHRDEV 3
1147#define EXT4_FT_BLKDEV 4
1148#define EXT4_FT_FIFO 5
1149#define EXT4_FT_SOCK 6
1150#define EXT4_FT_SYMLINK 7
1151
1152#define EXT4_FT_MAX 8
1153
1154/*
1155 * EXT4_DIR_PAD defines the directory entries boundaries
1156 *
1157 * NOTE: It must be a multiple of 4
1158 */
1159#define EXT4_DIR_PAD 4
1160#define EXT4_DIR_ROUND (EXT4_DIR_PAD - 1)
1161#define EXT4_DIR_REC_LEN(name_len) (((name_len) + 8 + EXT4_DIR_ROUND) & \
1162                     ~EXT4_DIR_ROUND)
1163#define EXT4_MAX_REC_LEN ((1<<16)-1)
1164
1165/*
1166 * Hash Tree Directory indexing
1167 * (c) Daniel Phillips, 2001
1168 */
1169
1170#define is_dx(dir) (EXT4_HAS_COMPAT_FEATURE(dir->i_sb, \
1171                      EXT4_FEATURE_COMPAT_DIR_INDEX) && \
1172              (EXT4_I(dir)->i_flags & EXT4_INDEX_FL))
1173#define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1174#define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1175
1176/* Legal values for the dx_root hash_version field: */
1177
1178#define DX_HASH_LEGACY 0
1179#define DX_HASH_HALF_MD4 1
1180#define DX_HASH_TEA 2
1181#define DX_HASH_LEGACY_UNSIGNED 3
1182#define DX_HASH_HALF_MD4_UNSIGNED 4
1183#define DX_HASH_TEA_UNSIGNED 5
1184
1185#ifdef __KERNEL__
1186
1187/* hash info structure used by the directory hash */
1188struct dx_hash_info
1189{
1190    u32 hash;
1191    u32 minor_hash;
1192    int hash_version;
1193    u32 *seed;
1194};
1195
1196#define EXT4_HTREE_EOF 0x7fffffff
1197
1198/*
1199 * Control parameters used by ext4_htree_next_block
1200 */
1201#define HASH_NB_ALWAYS 1
1202
1203
1204/*
1205 * Describe an inode's exact location on disk and in memory
1206 */
1207struct ext4_iloc
1208{
1209    struct buffer_head *bh;
1210    unsigned long offset;
1211    ext4_group_t block_group;
1212};
1213
1214static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
1215{
1216    return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
1217}
1218
1219/*
1220 * This structure is stuffed into the struct file's private_data field
1221 * for directories. It is where we put information so that we can do
1222 * readdir operations in hash tree order.
1223 */
1224struct dir_private_info {
1225    struct rb_root root;
1226    struct rb_node *curr_node;
1227    struct fname *extra_fname;
1228    loff_t last_pos;
1229    __u32 curr_hash;
1230    __u32 curr_minor_hash;
1231    __u32 next_hash;
1232};
1233
1234/* calculate the first block number of the group */
1235static inline ext4_fsblk_t
1236ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
1237{
1238    return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
1239        le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1240}
1241
1242/*
1243 * Special error return code only used by dx_probe() and its callers.
1244 */
1245#define ERR_BAD_DX_DIR -75000
1246
1247void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
1248            ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp);
1249
1250extern struct proc_dir_entry *ext4_proc_root;
1251
1252/*
1253 * Function prototypes
1254 */
1255
1256/*
1257 * Ok, these declarations are also in <linux/kernel.h> but none of the
1258 * ext4 source programs needs to include it so they are duplicated here.
1259 */
1260# define NORET_TYPE /**/
1261# define ATTRIB_NORET __attribute__((noreturn))
1262# define NORET_AND noreturn,
1263
1264/* bitmap.c */
1265extern unsigned int ext4_count_free(struct buffer_head *, unsigned);
1266
1267/* balloc.c */
1268extern unsigned int ext4_block_group(struct super_block *sb,
1269            ext4_fsblk_t blocknr);
1270extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
1271            ext4_fsblk_t blocknr);
1272extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
1273extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
1274            ext4_group_t group);
1275extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
1276            ext4_fsblk_t goal, unsigned long *count, int *errp);
1277extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1278extern int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
1279extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
1280            ext4_fsblk_t block, unsigned long count, int metadata);
1281extern void ext4_add_groupblocks(handle_t *handle, struct super_block *sb,
1282                ext4_fsblk_t block, unsigned long count);
1283extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
1284extern void ext4_check_blocks_bitmap(struct super_block *);
1285extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
1286                            ext4_group_t block_group,
1287                            struct buffer_head ** bh);
1288extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
1289struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
1290                      ext4_group_t block_group);
1291extern unsigned ext4_init_block_bitmap(struct super_block *sb,
1292                       struct buffer_head *bh,
1293                       ext4_group_t group,
1294                       struct ext4_group_desc *desc);
1295#define ext4_free_blocks_after_init(sb, group, desc) \
1296        ext4_init_block_bitmap(sb, NULL, group, desc)
1297
1298/* dir.c */
1299extern int ext4_check_dir_entry(const char *, struct inode *,
1300                struct ext4_dir_entry_2 *,
1301                struct buffer_head *, unsigned int);
1302extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
1303                    __u32 minor_hash,
1304                    struct ext4_dir_entry_2 *dirent);
1305extern void ext4_htree_free_dir_info(struct dir_private_info *p);
1306
1307/* fsync.c */
1308extern int ext4_sync_file(struct file *, struct dentry *, int);
1309
1310/* hash.c */
1311extern int ext4fs_dirhash(const char *name, int len, struct
1312              dx_hash_info *hinfo);
1313
1314/* ialloc.c */
1315extern struct inode *ext4_new_inode(handle_t *, struct inode *, int,
1316                    const struct qstr *qstr, __u32 goal);
1317extern void ext4_free_inode(handle_t *, struct inode *);
1318extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
1319extern unsigned long ext4_count_free_inodes(struct super_block *);
1320extern unsigned long ext4_count_dirs(struct super_block *);
1321extern void ext4_check_inodes_bitmap(struct super_block *);
1322extern unsigned ext4_init_inode_bitmap(struct super_block *sb,
1323                       struct buffer_head *bh,
1324                       ext4_group_t group,
1325                       struct ext4_group_desc *desc);
1326extern void mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
1327
1328/* mballoc.c */
1329extern long ext4_mb_stats;
1330extern long ext4_mb_max_to_scan;
1331extern int ext4_mb_init(struct super_block *, int);
1332extern int ext4_mb_release(struct super_block *);
1333extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
1334                struct ext4_allocation_request *, int *);
1335extern int ext4_mb_reserve_blocks(struct super_block *, int);
1336extern void ext4_discard_preallocations(struct inode *);
1337extern int __init init_ext4_mballoc(void);
1338extern void exit_ext4_mballoc(void);
1339extern void ext4_mb_free_blocks(handle_t *, struct inode *,
1340        ext4_fsblk_t, unsigned long, int, unsigned long *);
1341extern int ext4_mb_add_groupinfo(struct super_block *sb,
1342        ext4_group_t i, struct ext4_group_desc *desc);
1343extern void ext4_mb_update_group_info(struct ext4_group_info *grp,
1344        ext4_grpblk_t add);
1345extern int ext4_mb_get_buddy_cache_lock(struct super_block *, ext4_group_t);
1346extern void ext4_mb_put_buddy_cache_lock(struct super_block *,
1347                        ext4_group_t, int);
1348/* inode.c */
1349int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
1350        struct buffer_head *bh, ext4_fsblk_t blocknr);
1351struct buffer_head *ext4_getblk(handle_t *, struct inode *,
1352                        ext4_lblk_t, int, int *);
1353struct buffer_head *ext4_bread(handle_t *, struct inode *,
1354                        ext4_lblk_t, int, int *);
1355int ext4_get_block(struct inode *inode, sector_t iblock,
1356                struct buffer_head *bh_result, int create);
1357
1358extern struct inode *ext4_iget(struct super_block *, unsigned long);
1359extern int ext4_write_inode(struct inode *, int);
1360extern int ext4_setattr(struct dentry *, struct iattr *);
1361extern int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
1362                struct kstat *stat);
1363extern void ext4_delete_inode(struct inode *);
1364extern int ext4_sync_inode(handle_t *, struct inode *);
1365extern void ext4_dirty_inode(struct inode *);
1366extern int ext4_change_inode_journal_flag(struct inode *, int);
1367extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
1368extern int ext4_can_truncate(struct inode *inode);
1369extern void ext4_truncate(struct inode *);
1370extern void ext4_set_inode_flags(struct inode *);
1371extern void ext4_get_inode_flags(struct ext4_inode_info *);
1372extern int ext4_alloc_da_blocks(struct inode *inode);
1373extern void ext4_set_aops(struct inode *inode);
1374extern int ext4_writepage_trans_blocks(struct inode *);
1375extern int ext4_meta_trans_blocks(struct inode *, int nrblocks, int idxblocks);
1376extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
1377extern int ext4_block_truncate_page(handle_t *handle,
1378        struct address_space *mapping, loff_t from);
1379extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
1380extern qsize_t ext4_get_reserved_space(struct inode *inode);
1381
1382/* ioctl.c */
1383extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
1384extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
1385
1386/* migrate.c */
1387extern int ext4_ext_migrate(struct inode *);
1388
1389/* namei.c */
1390extern unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize);
1391extern __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize);
1392extern int ext4_orphan_add(handle_t *, struct inode *);
1393extern int ext4_orphan_del(handle_t *, struct inode *);
1394extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
1395                __u32 start_minor_hash, __u32 *next_hash);
1396
1397/* resize.c */
1398extern int ext4_group_add(struct super_block *sb,
1399                struct ext4_new_group_data *input);
1400extern int ext4_group_extend(struct super_block *sb,
1401                struct ext4_super_block *es,
1402                ext4_fsblk_t n_blocks_count);
1403
1404/* super.c */
1405extern void ext4_error(struct super_block *, const char *, const char *, ...)
1406    __attribute__ ((format (printf, 3, 4)));
1407extern void __ext4_std_error(struct super_block *, const char *, int);
1408extern void ext4_abort(struct super_block *, const char *, const char *, ...)
1409    __attribute__ ((format (printf, 3, 4)));
1410extern void ext4_warning(struct super_block *, const char *, const char *, ...)
1411    __attribute__ ((format (printf, 3, 4)));
1412extern void ext4_msg(struct super_block *, const char *, const char *, ...)
1413    __attribute__ ((format (printf, 3, 4)));
1414extern void ext4_grp_locked_error(struct super_block *, ext4_group_t,
1415                const char *, const char *, ...)
1416    __attribute__ ((format (printf, 4, 5)));
1417extern void ext4_update_dynamic_rev(struct super_block *sb);
1418extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
1419                    __u32 compat);
1420extern int ext4_update_rocompat_feature(handle_t *handle,
1421                    struct super_block *sb, __u32 rocompat);
1422extern int ext4_update_incompat_feature(handle_t *handle,
1423                    struct super_block *sb, __u32 incompat);
1424extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
1425                      struct ext4_group_desc *bg);
1426extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
1427                      struct ext4_group_desc *bg);
1428extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
1429                     struct ext4_group_desc *bg);
1430extern __u32 ext4_free_blks_count(struct super_block *sb,
1431                struct ext4_group_desc *bg);
1432extern __u32 ext4_free_inodes_count(struct super_block *sb,
1433                 struct ext4_group_desc *bg);
1434extern __u32 ext4_used_dirs_count(struct super_block *sb,
1435                struct ext4_group_desc *bg);
1436extern __u32 ext4_itable_unused_count(struct super_block *sb,
1437                   struct ext4_group_desc *bg);
1438extern void ext4_block_bitmap_set(struct super_block *sb,
1439                  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1440extern void ext4_inode_bitmap_set(struct super_block *sb,
1441                  struct ext4_group_desc *bg, ext4_fsblk_t blk);
1442extern void ext4_inode_table_set(struct super_block *sb,
1443                 struct ext4_group_desc *bg, ext4_fsblk_t blk);
1444extern void ext4_free_blks_set(struct super_block *sb,
1445                   struct ext4_group_desc *bg, __u32 count);
1446extern void ext4_free_inodes_set(struct super_block *sb,
1447                struct ext4_group_desc *bg, __u32 count);
1448extern void ext4_used_dirs_set(struct super_block *sb,
1449                struct ext4_group_desc *bg, __u32 count);
1450extern void ext4_itable_unused_set(struct super_block *sb,
1451                   struct ext4_group_desc *bg, __u32 count);
1452extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
1453                   struct ext4_group_desc *gdp);
1454extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
1455                       struct ext4_group_desc *gdp);
1456
1457static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
1458{
1459    return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
1460        le32_to_cpu(es->s_blocks_count_lo);
1461}
1462
1463static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
1464{
1465    return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
1466        le32_to_cpu(es->s_r_blocks_count_lo);
1467}
1468
1469static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
1470{
1471    return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
1472        le32_to_cpu(es->s_free_blocks_count_lo);
1473}
1474
1475static inline void ext4_blocks_count_set(struct ext4_super_block *es,
1476                     ext4_fsblk_t blk)
1477{
1478    es->s_blocks_count_lo = cpu_to_le32((u32)blk);
1479    es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
1480}
1481
1482static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
1483                          ext4_fsblk_t blk)
1484{
1485    es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
1486    es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
1487}
1488
1489static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
1490                       ext4_fsblk_t blk)
1491{
1492    es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
1493    es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
1494}
1495
1496static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
1497{
1498    if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
1499        return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
1500            le32_to_cpu(raw_inode->i_size_lo);
1501    else
1502        return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
1503}
1504
1505static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
1506{
1507    raw_inode->i_size_lo = cpu_to_le32(i_size);
1508    raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
1509}
1510
1511static inline
1512struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
1513                        ext4_group_t group)
1514{
1515     struct ext4_group_info ***grp_info;
1516     long indexv, indexh;
1517     grp_info = EXT4_SB(sb)->s_group_info;
1518     indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
1519     indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
1520     return grp_info[indexv][indexh];
1521}
1522
1523/*
1524 * Reading s_groups_count requires using smp_rmb() afterwards. See
1525 * the locking protocol documented in the comments of ext4_group_add()
1526 * in resize.c
1527 */
1528static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
1529{
1530    ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
1531
1532    smp_rmb();
1533    return ngroups;
1534}
1535
1536static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
1537                         ext4_group_t block_group)
1538{
1539    return block_group >> sbi->s_log_groups_per_flex;
1540}
1541
1542static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
1543{
1544    return 1 << sbi->s_log_groups_per_flex;
1545}
1546
1547#define ext4_std_error(sb, errno) \
1548do { \
1549    if ((errno)) \
1550        __ext4_std_error((sb), __func__, (errno)); \
1551} while (0)
1552
1553#ifdef CONFIG_SMP
1554/* Each CPU can accumulate percpu_counter_batch blocks in their local
1555 * counters. So we need to make sure we have free blocks more
1556 * than percpu_counter_batch * nr_cpu_ids. Also add a window of 4 times.
1557 */
1558#define EXT4_FREEBLOCKS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
1559#else
1560#define EXT4_FREEBLOCKS_WATERMARK 0
1561#endif
1562
1563static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
1564{
1565    /*
1566     * XXX: replace with spinlock if seen contended -bzzz
1567     */
1568    down_write(&EXT4_I(inode)->i_data_sem);
1569    if (newsize > EXT4_I(inode)->i_disksize)
1570        EXT4_I(inode)->i_disksize = newsize;
1571    up_write(&EXT4_I(inode)->i_data_sem);
1572    return ;
1573}
1574
1575struct ext4_group_info {
1576    unsigned long bb_state;
1577    struct rb_root bb_free_root;
1578    unsigned short bb_first_free;
1579    unsigned short bb_free;
1580    unsigned short bb_fragments;
1581    struct list_head bb_prealloc_list;
1582#ifdef DOUBLE_CHECK
1583    void *bb_bitmap;
1584#endif
1585    struct rw_semaphore alloc_sem;
1586    unsigned short bb_counters[];
1587};
1588
1589#define EXT4_GROUP_INFO_NEED_INIT_BIT 0
1590
1591#define EXT4_MB_GRP_NEED_INIT(grp) \
1592    (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
1593
1594static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
1595                          ext4_group_t group)
1596{
1597    return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
1598}
1599
1600static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
1601{
1602    spin_lock(ext4_group_lock_ptr(sb, group));
1603}
1604
1605static inline void ext4_unlock_group(struct super_block *sb,
1606                    ext4_group_t group)
1607{
1608    spin_unlock(ext4_group_lock_ptr(sb, group));
1609}
1610
1611/*
1612 * Inodes and files operations
1613 */
1614
1615/* dir.c */
1616extern const struct file_operations ext4_dir_operations;
1617
1618/* file.c */
1619extern const struct inode_operations ext4_file_inode_operations;
1620extern const struct file_operations ext4_file_operations;
1621
1622/* namei.c */
1623extern const struct inode_operations ext4_dir_inode_operations;
1624extern const struct inode_operations ext4_special_inode_operations;
1625extern struct dentry *ext4_get_parent(struct dentry *child);
1626
1627/* symlink.c */
1628extern const struct inode_operations ext4_symlink_inode_operations;
1629extern const struct inode_operations ext4_fast_symlink_inode_operations;
1630
1631/* block_validity */
1632extern void ext4_release_system_zone(struct super_block *sb);
1633extern int ext4_setup_system_zone(struct super_block *sb);
1634extern int __init init_ext4_system_zone(void);
1635extern void exit_ext4_system_zone(void);
1636extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
1637                 ext4_fsblk_t start_blk,
1638                 unsigned int count);
1639
1640/* extents.c */
1641extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
1642extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
1643extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks,
1644                       int chunk);
1645extern int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
1646                   ext4_lblk_t iblock, unsigned int max_blocks,
1647                   struct buffer_head *bh_result, int flags);
1648extern void ext4_ext_truncate(struct inode *);
1649extern void ext4_ext_init(struct super_block *);
1650extern void ext4_ext_release(struct super_block *);
1651extern long ext4_fallocate(struct inode *inode, int mode, loff_t offset,
1652              loff_t len);
1653extern int ext4_get_blocks(handle_t *handle, struct inode *inode,
1654               sector_t block, unsigned int max_blocks,
1655               struct buffer_head *bh, int flags);
1656extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1657            __u64 start, __u64 len);
1658/* move_extent.c */
1659extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
1660                 __u64 start_orig, __u64 start_donor,
1661                 __u64 len, __u64 *moved_len);
1662
1663
1664/*
1665 * Add new method to test wether block and inode bitmaps are properly
1666 * initialized. With uninit_bg reading the block from disk is not enough
1667 * to mark the bitmap uptodate. We need to also zero-out the bitmap
1668 */
1669#define BH_BITMAP_UPTODATE BH_JBDPrivateStart
1670
1671static inline int bitmap_uptodate(struct buffer_head *bh)
1672{
1673    return (buffer_uptodate(bh) &&
1674            test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
1675}
1676static inline void set_bitmap_uptodate(struct buffer_head *bh)
1677{
1678    set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
1679}
1680
1681#endif /* __KERNEL__ */
1682
1683#endif /* _EXT4_H */
1684

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