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fs/ntfs3: Restyle comments to better align with kernel-doc

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Capitalize comments and end with period for better reading.

Also function comments are now little more kernel-doc style. This way we
can easily convert them to kernel-doc style if we want. Note that these
are not yet complete with this style. Example function comments start
with /* and in kernel-doc style they start /**.

Use imperative mood in function descriptions.

Change words like ntfs -> NTFS, linux -> Linux.

Use "we" not "I" when commenting code.

Signed-off-by: Kari Argillander <kari.argillander@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
This commit is contained in:
Kari Argillander
2021-08-03 14:57:09 +03:00
committed by Konstantin Komarov
parent b8155e95de
commit e8b8e97f91
21 changed files with 1987 additions and 2070 deletions
Download Patch File Download Diff File Expand all files Collapse all files

201
fs/ntfs3/bitmap.c
View File

@@ -6,7 +6,7 @@
* This code builds two trees of free clusters extents.
* Trees are sorted by start of extent and by length of extent.
* NTFS_MAX_WND_EXTENTS defines the maximum number of elements in trees.
* In extreme case code reads on-disk bitmap to find free clusters
* In extreme case code reads on-disk bitmap to find free clusters.
*
*/
@@ -29,12 +29,10 @@ struct rb_node_key {
size_t key;
};
/*
* Tree is sorted by start (key)
*/
/* Tree is sorted by start (key). */
struct e_node {
struct rb_node_key start; /* Tree sorted by start */
struct rb_node_key count; /* Tree sorted by len*/
struct rb_node_key start; /* Tree sorted by start. */
struct rb_node_key count; /* Tree sorted by len. */
};
static int wnd_rescan(struct wnd_bitmap *wnd);
@@ -62,9 +60,12 @@ static inline u32 wnd_bits(const struct wnd_bitmap *wnd, size_t i)
}
/*
* b_pos + b_len - biggest fragment
* Scan range [wpos wbits) window 'buf'
* Returns -1 if not found
* wnd_scan
*
* b_pos + b_len - biggest fragment.
* Scan range [wpos wbits) window @buf.
*
* Return: -1 if not found.
*/
static size_t wnd_scan(const ulong *buf, size_t wbit, u32 wpos, u32 wend,
size_t to_alloc, size_t *prev_tail, size_t *b_pos,
@@ -96,7 +97,7 @@ static size_t wnd_scan(const ulong *buf, size_t wbit, u32 wpos, u32 wend,
}
/*
* Now we have a fragment [wpos, wend) staring with 0
* Now we have a fragment [wpos, wend) staring with 0.
*/
end = wpos + to_alloc - *prev_tail;
free_bits = find_next_bit(buf, min(end, wend), wpos);
@@ -125,9 +126,7 @@ static size_t wnd_scan(const ulong *buf, size_t wbit, u32 wpos, u32 wend,
}
/*
* wnd_close
*
* Frees all resources
* wnd_close - Frees all resources.
*/
void wnd_close(struct wnd_bitmap *wnd)
{
@@ -170,9 +169,7 @@ static struct rb_node *rb_lookup(struct rb_root *root, size_t v)
}
/*
* rb_insert_count
*
* Helper function to insert special kind of 'count' tree
* rb_insert_count - Helper function to insert special kind of 'count' tree.
*/
static inline bool rb_insert_count(struct rb_root *root, struct e_node *e)
{
@@ -205,9 +202,7 @@ static inline bool rb_insert_count(struct rb_root *root, struct e_node *e)
}
/*
* inline bool rb_insert_start
*
* Helper function to insert special kind of 'start' tree
* rb_insert_start - Helper function to insert special kind of 'count' tree.
*/
static inline bool rb_insert_start(struct rb_root *root, struct e_node *e)
{
@@ -237,10 +232,8 @@ static inline bool rb_insert_start(struct rb_root *root, struct e_node *e)
}
/*
* wnd_add_free_ext
*
* adds a new extent of free space
* build = 1 when building tree
* wnd_add_free_ext - Adds a new extent of free space.
* @build: 1 when building tree.
*/
static void wnd_add_free_ext(struct wnd_bitmap *wnd, size_t bit, size_t len,
bool build)
@@ -250,14 +243,14 @@ static void wnd_add_free_ext(struct wnd_bitmap *wnd, size_t bit, size_t len,
struct rb_node *n;
if (build) {
/* Use extent_min to filter too short extents */
/* Use extent_min to filter too short extents. */
if (wnd->count >= NTFS_MAX_WND_EXTENTS &&
len <= wnd->extent_min) {
wnd->uptodated = -1;
return;
}
} else {
/* Try to find extent before 'bit' */
/* Try to find extent before 'bit'. */
n = rb_lookup(&wnd->start_tree, bit);
if (!n) {
@@ -266,7 +259,7 @@ static void wnd_add_free_ext(struct wnd_bitmap *wnd, size_t bit, size_t len,
e = rb_entry(n, struct e_node, start.node);
n = rb_next(n);
if (e->start.key + e->count.key == bit) {
/* Remove left */
/* Remove left. */
bit = e->start.key;
len += e->count.key;
rb_erase(&e->start.node, &wnd->start_tree);
@@ -284,7 +277,7 @@ static void wnd_add_free_ext(struct wnd_bitmap *wnd, size_t bit, size_t len,
if (e->start.key > end_in)
break;
/* Remove right */
/* Remove right. */
n = rb_next(n);
len += next_end - end_in;
end_in = next_end;
@@ -299,7 +292,7 @@ static void wnd_add_free_ext(struct wnd_bitmap *wnd, size_t bit, size_t len,
}
if (wnd->uptodated != 1) {
/* Check bits before 'bit' */
/* Check bits before 'bit'. */
ib = wnd->zone_bit == wnd->zone_end ||
bit < wnd->zone_end
? 0
@@ -310,7 +303,7 @@ static void wnd_add_free_ext(struct wnd_bitmap *wnd, size_t bit, size_t len,
len += 1;
}
/* Check bits after 'end_in' */
/* Check bits after 'end_in'. */
ib = wnd->zone_bit == wnd->zone_end ||
end_in > wnd->zone_bit
? wnd->nbits
@@ -322,29 +315,29 @@ static void wnd_add_free_ext(struct wnd_bitmap *wnd, size_t bit, size_t len,
}
}
}
/* Insert new fragment */
/* Insert new fragment. */
if (wnd->count >= NTFS_MAX_WND_EXTENTS) {
if (e0)
kmem_cache_free(ntfs_enode_cachep, e0);
wnd->uptodated = -1;
/* Compare with smallest fragment */
/* Compare with smallest fragment. */
n = rb_last(&wnd->count_tree);
e = rb_entry(n, struct e_node, count.node);
if (len <= e->count.key)
goto out; /* Do not insert small fragments */
goto out; /* Do not insert small fragments. */
if (build) {
struct e_node *e2;
n = rb_prev(n);
e2 = rb_entry(n, struct e_node, count.node);
/* smallest fragment will be 'e2->count.key' */
/* Smallest fragment will be 'e2->count.key'. */
wnd->extent_min = e2->count.key;
}
/* Replace smallest fragment by new one */
/* Replace smallest fragment by new one. */
rb_erase(&e->start.node, &wnd->start_tree);
rb_erase(&e->count.node, &wnd->count_tree);
wnd->count -= 1;
@@ -371,9 +364,7 @@ out:;
}
/*
* wnd_remove_free_ext
*
* removes a run from the cached free space
* wnd_remove_free_ext - Remove a run from the cached free space.
*/
static void wnd_remove_free_ext(struct wnd_bitmap *wnd, size_t bit, size_t len)
{
@@ -382,7 +373,7 @@ static void wnd_remove_free_ext(struct wnd_bitmap *wnd, size_t bit, size_t len)
size_t end_in = bit + len;
size_t end3, end, new_key, new_len, max_new_len;
/* Try to find extent before 'bit' */
/* Try to find extent before 'bit'. */
n = rb_lookup(&wnd->start_tree, bit);
if (!n)
@@ -394,11 +385,11 @@ static void wnd_remove_free_ext(struct wnd_bitmap *wnd, size_t bit, size_t len)
new_key = new_len = 0;
len = e->count.key;
/* Range [bit,end_in) must be inside 'e' or outside 'e' and 'n' */
/* Range [bit,end_in) must be inside 'e' or outside 'e' and 'n'. */
if (e->start.key > bit)
;
else if (end_in <= end) {
/* Range [bit,end_in) inside 'e' */
/* Range [bit,end_in) inside 'e'. */
new_key = end_in;
new_len = end - end_in;
len = bit - e->start.key;
@@ -478,13 +469,13 @@ static void wnd_remove_free_ext(struct wnd_bitmap *wnd, size_t bit, size_t len)
if (wnd->count >= NTFS_MAX_WND_EXTENTS) {
wnd->uptodated = -1;
/* Get minimal extent */
/* Get minimal extent. */
e = rb_entry(rb_last(&wnd->count_tree), struct e_node,
count.node);
if (e->count.key > new_len)
goto out;
/* Replace minimum */
/* Replace minimum. */
rb_erase(&e->start.node, &wnd->start_tree);
rb_erase(&e->count.node, &wnd->count_tree);
wnd->count -= 1;
@@ -508,9 +499,7 @@ out:
}
/*
* wnd_rescan
*
* Scan all bitmap. used while initialization.
* wnd_rescan - Scan all bitmap. Used while initialization.
*/
static int wnd_rescan(struct wnd_bitmap *wnd)
{
@@ -541,7 +530,7 @@ static int wnd_rescan(struct wnd_bitmap *wnd)
if (wnd->inited) {
if (!wnd->free_bits[iw]) {
/* all ones */
/* All ones. */
if (prev_tail) {
wnd_add_free_ext(wnd,
vbo * 8 - prev_tail,
@@ -551,7 +540,7 @@ static int wnd_rescan(struct wnd_bitmap *wnd)
goto next_wnd;
}
if (wbits == wnd->free_bits[iw]) {
/* all zeroes */
/* All zeroes. */
prev_tail += wbits;
wnd->total_zeroes += wbits;
goto next_wnd;
@@ -604,14 +593,14 @@ static int wnd_rescan(struct wnd_bitmap *wnd)
wpos = used;
if (wpos >= wbits) {
/* No free blocks */
/* No free blocks. */
prev_tail = 0;
break;
}
frb = find_next_bit(buf, wbits, wpos);
if (frb >= wbits) {
/* keep last free block */
/* Keep last free block. */
prev_tail += frb - wpos;
break;
}
@@ -619,9 +608,9 @@ static int wnd_rescan(struct wnd_bitmap *wnd)
wnd_add_free_ext(wnd, wbit + wpos - prev_tail,
frb + prev_tail - wpos, true);
/* Skip free block and first '1' */
/* Skip free block and first '1'. */
wpos = frb + 1;
/* Reset previous tail */
/* Reset previous tail. */
prev_tail = 0;
} while (wpos < wbits);
@@ -638,15 +627,15 @@ next_wnd:
}
}
/* Add last block */
/* Add last block. */
if (prev_tail)
wnd_add_free_ext(wnd, wnd->nbits - prev_tail, prev_tail, true);
/*
* Before init cycle wnd->uptodated was 0
* Before init cycle wnd->uptodated was 0.
* If any errors or limits occurs while initialization then
* wnd->uptodated will be -1
* If 'uptodated' is still 0 then Tree is really updated
* wnd->uptodated will be -1.
* If 'uptodated' is still 0 then Tree is really updated.
*/
if (!wnd->uptodated)
wnd->uptodated = 1;
@@ -662,9 +651,6 @@ out:
return err;
}
/*
* wnd_init
*/
int wnd_init(struct wnd_bitmap *wnd, struct super_block *sb, size_t nbits)
{
int err;
@@ -697,9 +683,7 @@ int wnd_init(struct wnd_bitmap *wnd, struct super_block *sb, size_t nbits)
}
/*
* wnd_map
*
* call sb_bread for requested window
* wnd_map - Call sb_bread for requested window.
*/
static struct buffer_head *wnd_map(struct wnd_bitmap *wnd, size_t iw)
{
@@ -728,9 +712,7 @@ static struct buffer_head *wnd_map(struct wnd_bitmap *wnd, size_t iw)
}
/*
* wnd_set_free
*
* Marks the bits range from bit to bit + bits as free
* wnd_set_free - Mark the bits range from bit to bit + bits as free.
*/
int wnd_set_free(struct wnd_bitmap *wnd, size_t bit, size_t bits)
{
@@ -783,9 +765,7 @@ int wnd_set_free(struct wnd_bitmap *wnd, size_t bit, size_t bits)
}
/*
* wnd_set_used
*
* Marks the bits range from bit to bit + bits as used
* wnd_set_used - Mark the bits range from bit to bit + bits as used.
*/
int wnd_set_used(struct wnd_bitmap *wnd, size_t bit, size_t bits)
{
@@ -839,7 +819,7 @@ int wnd_set_used(struct wnd_bitmap *wnd, size_t bit, size_t bits)
/*
* wnd_is_free_hlp
*
* Returns true if all clusters [bit, bit+bits) are free (bitmap only)
* Return: True if all clusters [bit, bit+bits) are free (bitmap only).
*/
static bool wnd_is_free_hlp(struct wnd_bitmap *wnd, size_t bit, size_t bits)
{
@@ -882,7 +862,7 @@ static bool wnd_is_free_hlp(struct wnd_bitmap *wnd, size_t bit, size_t bits)
/*
* wnd_is_free
*
* Returns true if all clusters [bit, bit+bits) are free
* Return: True if all clusters [bit, bit+bits) are free.
*/
bool wnd_is_free(struct wnd_bitmap *wnd, size_t bit, size_t bits)
{
@@ -914,7 +894,7 @@ use_wnd:
/*
* wnd_is_used
*
* Returns true if all clusters [bit, bit+bits) are used
* Return: True if all clusters [bit, bit+bits) are used.
*/
bool wnd_is_used(struct wnd_bitmap *wnd, size_t bit, size_t bits)
{
@@ -973,11 +953,11 @@ out:
}
/*
* wnd_find
* wnd_find - Look for free space.
*
* - flags - BITMAP_FIND_XXX flags
*
* looks for free space
* Returns 0 if not found
* Return: 0 if not found.
*/
size_t wnd_find(struct wnd_bitmap *wnd, size_t to_alloc, size_t hint,
size_t flags, size_t *allocated)
@@ -994,7 +974,7 @@ size_t wnd_find(struct wnd_bitmap *wnd, size_t to_alloc, size_t hint,
bool fbits_valid;
struct buffer_head *bh;
/* fast checking for available free space */
/* Fast checking for available free space. */
if (flags & BITMAP_FIND_FULL) {
size_t zeroes = wnd_zeroes(wnd);
@@ -1020,7 +1000,7 @@ size_t wnd_find(struct wnd_bitmap *wnd, size_t to_alloc, size_t hint,
if (RB_EMPTY_ROOT(&wnd->start_tree)) {
if (wnd->uptodated == 1) {
/* extents tree is updated -> no free space */
/* Extents tree is updated -> No free space. */
goto no_space;
}
goto scan_bitmap;
@@ -1030,7 +1010,7 @@ size_t wnd_find(struct wnd_bitmap *wnd, size_t to_alloc, size_t hint,
if (!hint)
goto allocate_biggest;
/* Use hint: enumerate extents by start >= hint */
/* Use hint: Enumerate extents by start >= hint. */
pr = NULL;
cr = wnd->start_tree.rb_node;
@@ -1059,7 +1039,7 @@ size_t wnd_find(struct wnd_bitmap *wnd, size_t to_alloc, size_t hint,
goto allocate_biggest;
if (e->start.key + e->count.key > hint) {
/* We have found extension with 'hint' inside */
/* We have found extension with 'hint' inside. */
size_t len = e->start.key + e->count.key - hint;
if (len >= to_alloc && hint + to_alloc <= max_alloc) {
@@ -1080,7 +1060,7 @@ size_t wnd_find(struct wnd_bitmap *wnd, size_t to_alloc, size_t hint,
}
allocate_biggest:
/* Allocate from biggest free extent */
/* Allocate from biggest free extent. */
e = rb_entry(rb_first(&wnd->count_tree), struct e_node, count.node);
if (e->count.key != wnd->extent_max)
wnd->extent_max = e->count.key;
@@ -1090,14 +1070,14 @@ allocate_biggest:
;
} else if (flags & BITMAP_FIND_FULL) {
if (e->count.key < to_alloc0) {
/* Biggest free block is less then requested */
/* Biggest free block is less then requested. */
goto no_space;
}
to_alloc = e->count.key;
} else if (-1 != wnd->uptodated) {
to_alloc = e->count.key;
} else {
/* Check if we can use more bits */
/* Check if we can use more bits. */
size_t op, max_check;
struct rb_root start_tree;
@@ -1118,7 +1098,7 @@ allocate_biggest:
to_alloc = op - e->start.key;
}
/* Prepare to return */
/* Prepare to return. */
fnd = e->start.key;
if (e->start.key + to_alloc > max_alloc)
to_alloc = max_alloc - e->start.key;
@@ -1126,7 +1106,7 @@ allocate_biggest:
}
if (wnd->uptodated == 1) {
/* extents tree is updated -> no free space */
/* Extents tree is updated -> no free space. */
goto no_space;
}
@@ -1140,7 +1120,7 @@ scan_bitmap:
/* At most two ranges [hint, max_alloc) + [0, hint) */
Again:
/* TODO: optimize request for case nbits > wbits */
/* TODO: Optimize request for case nbits > wbits. */
iw = hint >> log2_bits;
wbits = sb->s_blocksize * 8;
wpos = hint & (wbits - 1);
@@ -1155,7 +1135,7 @@ Again:
nwnd = likely(t > max_alloc) ? (t >> log2_bits) : wnd->nwnd;
}
/* Enumerate all windows */
/* Enumerate all windows. */
for (; iw < nwnd; iw++) {
wbit = iw << log2_bits;
@@ -1165,7 +1145,7 @@ Again:
b_len = prev_tail;
}
/* Skip full used window */
/* Skip full used window. */
prev_tail = 0;
wpos = 0;
continue;
@@ -1189,25 +1169,25 @@ Again:
zbit = max(wnd->zone_bit, wbit);
zend = min(wnd->zone_end, ebit);
/* Here we have a window [wbit, ebit) and zone [zbit, zend) */
/* Here we have a window [wbit, ebit) and zone [zbit, zend). */
if (zend <= zbit) {
/* Zone does not overlap window */
/* Zone does not overlap window. */
} else {
wzbit = zbit - wbit;
wzend = zend - wbit;
/* Zone overlaps window */
/* Zone overlaps window. */
if (wnd->free_bits[iw] == wzend - wzbit) {
prev_tail = 0;
wpos = 0;
continue;
}
/* Scan two ranges window: [wbit, zbit) and [zend, ebit) */
/* Scan two ranges window: [wbit, zbit) and [zend, ebit). */
bh = wnd_map(wnd, iw);
if (IS_ERR(bh)) {
/* TODO: error */
/* TODO: Error */
prev_tail = 0;
wpos = 0;
continue;
@@ -1215,9 +1195,9 @@ Again:
buf = (ulong *)bh->b_data;
/* Scan range [wbit, zbit) */
/* Scan range [wbit, zbit). */
if (wpos < wzbit) {
/* Scan range [wpos, zbit) */
/* Scan range [wpos, zbit). */
fnd = wnd_scan(buf, wbit, wpos, wzbit,
to_alloc, &prev_tail,
&b_pos, &b_len);
@@ -1229,7 +1209,7 @@ Again:
prev_tail = 0;
/* Scan range [zend, ebit) */
/* Scan range [zend, ebit). */
if (wzend < wbits) {
fnd = wnd_scan(buf, wbit,
max(wzend, wpos), wbits,
@@ -1247,24 +1227,24 @@ Again:
}
}
/* Current window does not overlap zone */
/* Current window does not overlap zone. */
if (!wpos && fbits_valid && wnd->free_bits[iw] == wbits) {
/* window is empty */
/* Window is empty. */
if (prev_tail + wbits >= to_alloc) {
fnd = wbit + wpos - prev_tail;
goto found;
}
/* Increase 'prev_tail' and process next window */
/* Increase 'prev_tail' and process next window. */
prev_tail += wbits;
wpos = 0;
continue;
}
/* read window */
/* Read window */
bh = wnd_map(wnd, iw);
if (IS_ERR(bh)) {
// TODO: error
// TODO: Error.
prev_tail = 0;
wpos = 0;
continue;
@@ -1272,7 +1252,7 @@ Again:
buf = (ulong *)bh->b_data;
/* Scan range [wpos, eBits) */
/* Scan range [wpos, eBits). */
fnd = wnd_scan(buf, wbit, wpos, wbits, to_alloc, &prev_tail,
&b_pos, &b_len);
put_bh(bh);
@@ -1281,15 +1261,15 @@ Again:
}
if (b_len < prev_tail) {
/* The last fragment */
/* The last fragment. */
b_len = prev_tail;
b_pos = max_alloc - prev_tail;
}
if (hint) {
/*
* We have scanned range [hint max_alloc)
* Prepare to scan range [0 hint + to_alloc)
* We have scanned range [hint max_alloc).
* Prepare to scan range [0 hint + to_alloc).
*/
size_t nextmax = hint + to_alloc;
@@ -1312,7 +1292,7 @@ Again:
found:
if (flags & BITMAP_FIND_MARK_AS_USED) {
/* TODO optimize remove extent (pass 'e'?) */
/* TODO: Optimize remove extent (pass 'e'?). */
if (wnd_set_used(wnd, fnd, to_alloc))
goto no_space;
} else if (wnd->extent_max != MINUS_ONE_T &&
@@ -1328,9 +1308,7 @@ no_space:
}
/*
* wnd_extend
*
* Extend bitmap ($MFT bitmap)
* wnd_extend - Extend bitmap ($MFT bitmap).
*/
int wnd_extend(struct wnd_bitmap *wnd, size_t new_bits)
{
@@ -1347,7 +1325,7 @@ int wnd_extend(struct wnd_bitmap *wnd, size_t new_bits)
if (new_bits <= old_bits)
return -EINVAL;
/* align to 8 byte boundary */
/* Align to 8 byte boundary. */
new_wnd = bytes_to_block(sb, bitmap_size(new_bits));
new_last = new_bits & (wbits - 1);
if (!new_last)
@@ -1367,7 +1345,7 @@ int wnd_extend(struct wnd_bitmap *wnd, size_t new_bits)
wnd->free_bits = new_free;
}
/* Zero bits [old_bits,new_bits) */
/* Zero bits [old_bits,new_bits). */
bits = new_bits - old_bits;
b0 = old_bits & (wbits - 1);
@@ -1403,7 +1381,7 @@ int wnd_extend(struct wnd_bitmap *wnd, size_t new_bits)
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
unlock_buffer(bh);
/*err = sync_dirty_buffer(bh);*/
/* err = sync_dirty_buffer(bh); */
b0 = 0;
bits -= op;
@@ -1418,9 +1396,6 @@ int wnd_extend(struct wnd_bitmap *wnd, size_t new_bits)
return 0;
}
/*
* wnd_zone_set
*/
void wnd_zone_set(struct wnd_bitmap *wnd, size_t lcn, size_t len)
{
size_t zlen;
@@ -1502,7 +1477,7 @@ int ntfs_trim_fs(struct ntfs_sb_info *sbi, struct fstrim_range *range)
put_bh(bh);
}
/* Process the last fragment */
/* Process the last fragment. */
if (len >= minlen) {
err = ntfs_discard(sbi, lcn, len);
if (err)