Commit graph

163 commits

Author SHA1 Message Date
Heinrich Schuchardt
f105fe7bc5 fs: fat: fix set_cluster()
Avoid CoverityScan warning SIGN_EXTENSION by changing the type of
parameter size of set_cluster().

Avoid leaking stack content when writing an incomplete last sector.

Reported-by: Coverity (CID: 184096)
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2018-10-06 14:09:41 -04:00
Heinrich Schuchardt
0d532e911c fs: fat: memory leak in fat_unlink()
Do not leak filename_copy in case of error.
Catch out of memory when calling strdup.

Reported-by: Coverity (CID: 184086)
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2018-10-06 14:09:41 -04:00
Heinrich Schuchardt
1c381cebb7 fs: fat: unaligned buffers are not an error
The FAT driver supports unaligned reads and writes and EFI applications
will make use of these. So a misaligned buffer is only worth a debug
message.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-09-23 21:55:30 +02:00
AKASHI Takahiro
f8240ce95d fs: fat: support unlink
In this patch, unlink support is added to FAT file system.
A directory can be deleted only if it is empty.

In this implementation, only a directory entry for a short file name
will be removed. So entries for a long file name can and should be
reclaimed with fsck.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-09-23 21:55:30 +02:00
AKASHI Takahiro
31a18d570d fs: fat: support mkdir
In this patch, mkdir support is added to FAT file system.
A newly created directory contains only "." and ".." entries.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-09-23 21:55:30 +02:00
AKASHI Takahiro
3a10e07234 fs: fat: remember the starting cluster number of directory
The starting cluster number of directory is needed to initialize ".."
(parent directory) entry when creating a new directory.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-09-23 21:55:29 +02:00
AKASHI Takahiro
cb8af8af5b fs: fat: support write with non-zero offset
In this patch, all the necessary code for allowing for a file offset
at write is implemented. What plays a major roll here is get_set_cluster(),
which, in contrast to its counterpart, set_cluster(), only operates on
already-allocated clusters, overwriting with data.

So, with a file offset specified, set_contents() seeks and writes data
with set_get_cluster() until the end of a file, and, once it reaches
there, continues writing with set_cluster() for the rest.

Please note that a file will be trimmed as a result of write operation if
write ends before reaching file's end. This is an intended behavior
in order to maintain compatibility with the current interface.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-09-23 21:55:29 +02:00
AKASHI Takahiro
704df6aa0a fs: fat: refactor write interface for a file offset
The current write implementation is quite simple: remove existing clusters
and then allocating new ones and filling them with data. This, inevitably,
enforces always writing from the beginning of a file.

As the first step to lift this restriction, fat_file_write() and
set_contents() are modified to accept an additional parameter, file offset
and further re-factored so that, in the next patch, all the necessary code
will be put into set_contents().

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-09-23 21:55:29 +02:00
AKASHI Takahiro
4ced2039dc fs: fat: support write with sub-directory path
In this patch, write implementation is overhauled and rewritten by
making full use of directory iterator. The obvious bonus is that we are
now able to write to a file with a directory path, like /A/B/C/FILE.

Please note that, as there is no notion of "current directory" on u-boot,
a file name specified must contain an absolute directory path. Otherwise,
"/" (root directory) is assumed.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-09-23 21:55:29 +02:00
AKASHI Takahiro
f1149cea16 fs: fat: write returns error code instead of -1
It would be good that FAT write function return error code instead of
just returning -1 as fat_read_file() does.
This patch attempts to address this issue although it is 'best effort
(or estimate)' for now.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-09-23 21:55:29 +02:00
AKASHI Takahiro
25bb9dab14 fs: fat: check and normalize file name
FAT file system's long file name support is a bit complicated and has some
restrictions on its naming. We should be careful about it especially for
write as it may easily end up with wrong file system.

normalize_longname() check for the rules and normalize a file name
if necessary. Please note, however, that this function is yet to be
extended to fully comply with the standard.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-09-23 21:55:29 +02:00
AKASHI Takahiro
881042ef02 Revert "fs: fat: cannot write to subdirectories"
This reverts commit 0dc1bfb730.
The succeeding patch series will supersede it.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-09-23 21:55:29 +02:00
AKASHI Takahiro
f528c140c8 fs: fat: assure iterator's ->dent belongs to ->clust
In my attempt to re-work write operation, it was revealed that iterator's
"clust" does not always point to a cluster to which a current directory
entry ("dent") belongs.
This patch assures that it is always true by adding "next_clust" which is
used solely for dereferencing a cluster chain.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-09-23 21:55:29 +02:00
AKASHI Takahiro
b94b6be543 fs: fat: handle "." and ".." of root dir correctly with fat_itr_resolve()
FAT's root directory does not have "." nor ".."
So care must be taken when scanning root directory with fat_itr_resolve().
Without this patch, any file path starting with "." or ".." will not be
resolved at all.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-09-23 21:55:29 +02:00
AKASHI Takahiro
f23101f951 fs: fat: extend get_fs_info() for write use
get_fs_info() was introduced in major re-work of read operation by Rob.
We want to reuse this function in write operation by extending it with
additional members in fsdata structure.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-09-23 21:55:29 +02:00
Andreas Dannenberg
287c04e11a fs/fat: debug-print file read position during file_fat_read_at()
In order to make the debug print in file_fat_read_at() a tad more useful,
show the offset the file is being read at alongside the filename.

Suggested-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
2018-08-20 07:21:28 -04:00
Heinrich Schuchardt
0dc1bfb730 fs: fat: cannot write to subdirectories
fs_fat_write() is not able to write to subdirectories.

Currently if a filepath with a leading slash is passed, the slash is
treated as part of the filename to be created in the root directory.

Strip leading (back-)slashes.

Check that the remaining filename does not contain any illegal characters
(<>:"/\|?*). This way we will throw an error when trying to write to a
subdirectory.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
2018-07-25 14:59:44 +02:00
Tom Rini
83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00
Tuomas Tynkkynen
8bad6cb176 fs: fat: Drop CONFIG_SUPPORT_VFAT
fat.h unconditionally defines CONFIG_SUPPORT_VFAT (and has done since
2003), so as a result VFAT support is always enabled regardless of
whether a board config defines it or not. Drop this unnecessary option.

Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com>
2018-01-22 16:43:31 -05:00
Tuomas Tynkkynen
e8df14d216 fs: FAT: Fix typo in FS_FAT_MAX_CLUSTSIZE description
Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com>
2018-01-22 16:43:31 -05:00
Heinrich Schuchardt
d2f7158028 fs/fat: remove distractive message in file_fat_read_at()
The message "reading %s\n" may be interesting when
debugging but otherwise it is superfluous.

Only output the message when debugging.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
2018-01-19 15:49:28 -05:00
Jean-Jacques Hiblot
2c33b0c7d8 fat write: Fixed a problem with the case of file names when writing files
commit 21a24c3bf3 ("fs/fat: fix case for FAT shortnames") made it
possible that get_name() returns file names with some upper cases.
find_directory_entry() must be updated to take this account, and use
case-insensitive functions to compare file names.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
2018-01-10 08:05:51 -05:00
Neil Armstrong
34dd853ce5 fat: Use cache aligned buffers for fat_opendir
Before this patch one could receive following errors when executing "fatls"
command on machine with cache enabled (ex i.MX6Q) :

=> fatls mmc 0:1
CACHE: Misaligned operation at range [4f59dfc8, 4f59e7c8]
CACHE: Misaligned operation at range [4f59dfc8, 4f59e7c8]
ERROR: v7_outer_cache_inval_range - start address is not aligned - 0x4f59dfc8
ERROR: v7_outer_cache_inval_range - stop address is not aligned - 0x4f59e7c8
CACHE: Misaligned operation at range [4f59dfc8, 4f59e7c8]
CACHE: Misaligned operation at range [4f59dfc8, 4f59e7c8]
ERROR: v7_outer_cache_inval_range - start address is not aligned - 0x4f59dfc8
ERROR: v7_outer_cache_inval_range - stop address is not aligned - 0x4f59e7c8

To alleviate this problem - the calloc()s have been replaced with
malloc_cache_aligned() and memset().

After those changes the buffers are properly aligned (with both start
address and size) to SoC cache line.

Fixes: 09fa964bba ("fs/fat: Fix 'CACHE: Misaligned operation at range' warnings")
Suggested-by: Lukasz Majewski <lukma@denx.de>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
2017-11-29 22:36:59 -05:00
Tuomas Tynkkynen
af609e3764 fs/fat: Check malloc return values and fix memory leaks
Check malloc() return values and properly unwind on errors so
memory allocated for fat_itr structures get freed properly.

Also fixes a leak of fsdata.fatbuf in fat_size().

Fixes: 2460098cff ("fs/fat: Reduce stack usage")
Reported-by: Coverity (CID: 167225, 167233, 167234)
Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Reviewed-by: Tom Rini <trini@konsulko.com>
2017-10-08 16:19:56 -04:00
Tuomas Tynkkynen
09fa964bba fs/fat: Fix 'CACHE: Misaligned operation at range' warnings
The 'block' field of fat_itr needs to be properly aligned for DMA and
while it does have '__aligned(ARCH_DMA_MINALIGN)', the fat_itr structure
itself needs to be properly aligned as well.

While at it use malloc_cache_aligned() for the other aligned allocations
in the file as well.

Fixes: 2460098cff ("fs/fat: Reduce stack usage")
Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Reviewed-by: Tom Rini <trini@konsulko.com>
2017-10-08 16:19:56 -04:00
Tuomas Tynkkynen
8df8731474 fs/fat: Fix pathnames using '..' that lead to the root directory
If we end up back in the root directory via a '..' directory entry, set
itr->is_root accordingly. Failing to do that gives spews like
"Invalid FAT entry" and being unable to access directory entries located
past the first cluster of the root directory.

Fixes: 8eafae209c ("fat/fs: convert to directory iterators")
Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
2017-10-06 11:28:19 -04:00
Tom Rini
2460098cff fs/fat: Reduce stack usage
We have limited stack in SPL builds.  Drop itrblock and move to
malloc/free of itr to move this off of the stack.  As part of this fix a
double-free issue in fat_size().

Signed-off-by: Tom Rini <trini@konsulko.com>
---
Rework to use malloc/free as moving this to a global overflows some SH
targets.
2017-09-22 07:37:43 -04:00
Rob Clark
725ffdb5cb fs/fat: fix fatbuf leak
A new fatbuf was allocated by get_fs_info() (called by fat_itr_root()),
but not freed, resulting in eventually running out of memory.  Spotted
by running 'ls -r' in a large FAT filesystem from Shell.efi.

fatbuf is mainly used to cache FAT entry lookups (get_fatent())..
possibly once fat_write.c it can move into the iterator to simplify
this.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Łukasz Majewski <lukma@denx.de>
2017-09-15 09:03:15 -04:00
Rob Clark
265edc03d5 fs/fat: Clean up open-coded sector <-> cluster conversions
Use the clust_to_sect() helper that was introduced earlier, and add an
inverse sect_to_clust(), plus update the various spots that open-coded
this conversion previously.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-09-15 09:03:15 -04:00
Rob Clark
21a24c3bf3 fs/fat: fix case for FAT shortnames
Noticed when comparing our output to linux.  There are some lcase bits
which control whether filename and/or extension should be downcase'd.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Łukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-09-15 09:03:14 -04:00
Rob Clark
89191d6267 fat/fs: move ls to generic implementation
Add a generic implementation of 'ls' using opendir/readdir/closedir, and
replace fat's custom implementation.  Other filesystems should move to
the generic implementation after they add opendir/readdir/closedir
support.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Łukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-09-15 09:03:13 -04:00
Rob Clark
41fa83d1a6 fat/fs: remove a bunch of dead code
Spotted by chance, when trying to remove file_fat_ls(), I noticed there
were some dead users of the API.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Acked-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-09-15 09:03:12 -04:00
Rob Clark
1f40366b31 fs/fat: implement opendir/readdir/closedir
Implement the readdir interface using the directory iterators.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Łukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-09-15 09:03:12 -04:00
Rob Clark
8eafae209c fat/fs: convert to directory iterators
And drop a whole lot of ugly code!

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Łukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-09-15 09:03:11 -04:00
Rob Clark
c6e3baa565 fs/fat: introduce new director iterators
Untangle directory traversal into a simple iterator, to replace the
existing multi-purpose do_fat_read_at() + get_dentfromdir().

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Łukasz Majewski <lukma@denx.de>
2017-09-15 09:03:10 -04:00
Rob Clark
45449980f8 fs/fat: split out helper to init fsdata
Want to re-use this in fat dirent iterator in next patch.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Łukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
2017-09-15 09:03:09 -04:00
Reno Farnesi
76216211f8 fs: fat: fix fatwrite overflow calculation
The overflow calculation was incorrect. Adding the start block of the
partition is not needed because the sectors are already relative to the
beginning of the partition. If you attempted to write a file smaller
than cur_part_info.start blocks on a full partition the old calculation
fails to catch the overflow. This would cause an infinite loop in the
determine_fatent function.

Old, incorrect calculation:

ending sector of new file = start sector + file size (in sectors)
last sector = partition start + total sectors on the partition

Adding the partition start block number is not needed because sectors
are already relative to the start of the partition.

New calculation:

ending sector of new file = start sector + file size (in sectors)
last sector = total sectors on the partition

Signed-off-by: Reno Farnesi <nfarnesi4@gmail.com>
2017-08-26 14:56:07 -04:00
Tom Rini
42a9f147d8 fs/fat: Correct blk_dread() return value check
The function blk_dread will return -ENOSYS on failure or on success the
number of blocks read, which must be the number asked to read (otherwise
it failed somewhere).  Correct this check.

Signed-off-by: Tom Rini <trini@konsulko.com>
2017-08-20 09:54:31 -04:00
Simon Glass
10e40d54b3 Kconfig: Add CONFIG_SATA to enable SATA
At present CONFIG_CMD_SATA enables the 'sata' command which also brings
in SATA support. Some boards may wish to enable SATA without the command.
Add a separate CONFIG to permit this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2017-07-11 10:08:19 -06:00
Sekhar Nori
eedfb89e61 fs: fat: add kbuild configuration support
Add Kconfig symbols for various configurations
supported by FAT filesystem support code.

CONFIG_SUPPORT_VFAT has been left out since its
force enabled in include/fat.h and probably
should get removed at some point.

Signed-off-by: Sekhar Nori <nsekhar@ti.com>
[trini: add select FS_FAT for CMD_FAT and SPL_FAT_SUPPORT]
Signed-off-by: Tom Rini <trini@konsulko.com>
2017-06-03 17:55:16 -04:00
Simon Glass
fc843a02ac Kconfig: Add a CONFIG_IDE option
At present IDE support is controlled by CONFIG_CMD_IDE. Add a separate
CONFIG_IDE option so that IDE support can be enabled without requiring
the 'ide' command.

Update existing users and move the ide driver into drivers/block since
it should not be in common/.

Signed-off-by: Simon Glass <sjg@chromium.org>
2017-05-22 12:45:27 -04:00
Stefan Brüns
b352caea75 fs/fat: Fix unaligned __u16 reads for FAT12 access
Doing unaligned reads is not supported on all architectures, use
byte sized reads of the little endian buffer.
Rename off16 to off8, as it reflects the buffer offset in byte
granularity (offset is in entry, i.e. 12 bit, granularity).
Fix a regression introduced in 8d48c92b45

Reported-by: Oleksandr Tymoshenko <gonzo@bluezbox.com>
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Tested-by: Oleksandr Tymoshenko <gonzo@bluezbox.com>
2017-01-28 14:04:51 -05:00
Patrick Delaunay
b331cd6204 cmd, disk: convert CONFIG_PARTITION_UUIDS, CMD_PART and CMD_GPT
We convert CONFIG_PARTITION_UUIDS to Kconfig first.  But in order to cleanly
update all of the config files we must also update CMD_PART and CMD_GPT to also
be in Kconfig in order to avoid complex logic elsewhere to update all of the
config files.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay73@gmail.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
2017-01-28 08:48:03 -05:00
Stefan Brüns
8d48c92b45 fs/fat: simplify get_fatent for FAT12
Instead of shuffling bits from two adjacent 16 bit words, use one 16 bit
word with the appropriate byte offset in the buffer.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
2016-12-27 11:24:14 -05:00
Stefan Brüns
b8948d2aef fs/fat: merge readwrite get_fatent_value() with readonly get_fatent()
get_fatent_value(...) flushes changed FAT entries to disk when fetching
the next FAT blocks, in every other aspect it is identical to
get_fatent(...).

Provide a stub implementation for flush_dirty_fat_buffer if
CONFIG_FAT_WRITE is not set. Calling flush_dirty_fat_buffer during read
only operation is fine as it checks if any buffers needs flushing.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau.dev@gmail.com>
2016-12-27 11:24:14 -05:00
Stefan Brüns
6c1a808052 fs/fat: Avoid corruption of sectors following the FAT
The FAT is read/flushed in segments of 6 (FATBUFBLOCKS) disk sectors. The
last segment may be less than 6 sectors, cap the length.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau.dev@gmail.com>
2016-12-27 11:24:13 -05:00
Philipp Skadorov
49abbd9cc3 fat: fatwrite: fix the command for FAT12
The u-boot command fatwrite empties FAT clusters from the beginning
till the end of the file.
Specifically for FAT12 it fails to detect the end of the file and goes
beyond the file bounds thus corrupting the file system.

Additionally, FAT entry chaining-up into a file is not implemented
for FAT12.

The users normally workaround this by re-formatting the partition as
FAT16/FAT32, like here:
https://github.com/FEDEVEL/openrex-uboot-v2015.10/issues/1

The patch fixes the bounds of a file and FAT12 entries chaining into
a file, including EOF markup.

Signed-off-by: Philipp Skadorov <philipp.skadorov@savoirfairelinux.com>
2016-12-27 11:24:13 -05:00
Tien Fong Chee
7aa1a6b71c fs/fat/fatwrite: Local variable as buffer to store dir_slot entries
fill_dir_slot use get_contents_vfatname_block as a temporary buffer for
constructing a list of dir_slot entries. To save the memory and providing
correct type of memory for above usage, a local buffer with accurate size
declaration is introduced.

The local array size 640 is used because for long file name entry,
each entry use 32 bytes, one entry can store up to 13 characters.
The maximum number of entry possible is 20. So, total size is
32*20=640bytes.

Signed-off-by: Genevieve Chan <ccheauya@altera.com>
Signed-off-by: Tien Fong Chee <tfchee@altera.com>
2016-11-28 20:09:45 -05:00
Stefan Brüns
ae1755be37 fs/fat: Correct description of determine_fatent function
Current description does not match the function behaviour.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
2016-09-23 08:55:57 -04:00
Stefan Brüns
3c0ed9c3a5 fs/fat: Do not write unmodified fat entries to disk
The code caches 6 sectors of the FAT. On FAT traversal, the old contents
needs to be flushed to disk, but only if any FAT entries had been modified.
Explicitly flag the buffer on modification.

Currently, creating a new file traverses the whole FAT up to the first
free cluster and rewrites the on-disk blocks.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
2016-09-23 08:55:56 -04:00